|Posted by australiandryeye on November 20, 2017 at 8:15 PM||comments (0)|
Cannabinoids could have potential in a novel topical drug delivery vehicle to treat neuropathic dry eye pain.
The disconnect between signs and symptoms in dry eye disease is an intriguing clinical problem. Although we know quite a lot about the etiology of dry eye, the ideal structure of the tear film and how to diagnose and treat dry eye disease, there are still some patients who do not respond to treatment or who present complaining of severe symptoms that seem to be poorly correlated with clinical signs. Complaints may include a burning or stabbing sensation or a feeling of pressure in the eyes.
Many clinicians find these patients—and the chair time they consume—frustrating. But before dismissing them as “crazy,” it may help to consider whether they could be suffering from a different form of dry eye that is difficult to detect by traditional methods.
In 2009, Perry Rosenthal and colleagues observed what they presumed to be corneal neuralgia, which they termed “pain without stain” because of the paucity of corneal staining or other clinical signs.1 They speculated that the pain symptoms could be related to a neuropathic disorder, rather than to qualitative or quantitative tear film factors.
Later work by Rosenthal further elucidated how the nociceptive system—critical to vision when functioning properly, because it monitors and restores the optical tear film—could become dysfunctional.2 When this happens, the corneal nerves, the central trigeminal sensory network, and/or the pain organising centres in the brain escalate the eye’s natural ‘alarm system’, sending pain signals that are out of proportion to the physical insult (if indeed there is any injury at all).
Neuropathic dry eye pain may be triggered or exacerbated by ocular surgery, systemic conditions or even psychological distress.
The dry eye community has been increasingly interested in neuropathic dry eye. In fact, the new DEWS II definition of dry eye explicitly includes “neurosensory abnormalities” in the list of etiological factors in dry eye.3
A DEWS II subcommittee report on pain and sensation notes that long-term inflammation can alter neuron excitability, connectivity and impulse firing and that disturbances in ocular sensory pathways may ultimately lead to neuropathic pain.4 However, as yet, there are no dry eye therapies that specifically target neuropathic pain.
The role of cannabis
Cannabinoids and, in particular, tetrahydrocannabinol (THC, the main active ingredient in recreational marijuana) is of great interest in the treatment of neuropathic pain. Cannabinoid receptors are known to modulate pain and inflammation and are located throughout the eye, including the corneal epithelium and the retina; they are present on immune cells and may be involved in wound healing, as well.5 So, from a theoretical perspective there are a number of reasons to pursue the use of cannabinoids to treat dry eye.
And the time may be right to conduct such research now. Regulatory restrictions around the use of cannabinoids are being loosened, with more than half of U.S. states and several European countries now permitting the use of THC for medical purposes.
In Germany, where I practice, a special permit is required and the drug must be used in a controlled research setting as part of a clinical trial, which seems to be a reasonable way to open the doors to research on cannabinoid compounds while still limiting the potential for abuse.
In my laboratory, we have been actively investigating what the best targets for treating neuropathic pain might be and how THC could be safely and effectively delivered to those targets.
There are a number of challenges in using THC therapeutically. Smoking marijuana or consuming THC in edible form is impractical for the treatment of ocular disease; these systemic applications deliver an unpredictable dose with unwanted systemic side effects.
Sublingual and dermal administration have similar effects and are probably not appropriate for ocular conditions. For these reasons, and due to a lack of evidence of predictable, long-lasting therapeutic effect, a number of professional organisations, including the Canadian Ophthalmological Society and the American Academy of Ophthalmology, have taken positions against the use of systemic THC treatment for ocular conditions.
Local application of THC is considerably more compelling. Cannabinoid eye drops have been investigated and are available for glaucoma from at least one small manufacturer. But noone yet has been particularly successful with this approach due to the challenges of formulating the drops appropriately.
THC and most other pain-relieving or anaesthetic compounds are quite lipophilic. Like oil with water, they do not mix well with the aqueous solutions in most eye drops, making it difficult to get THC into the target ocular tissues.
Enhanced topical drug delivery
Recently, we have been investigating the use of a novel semi-fluorinated alkane (SFA) drug delivery technology (EyeSol, Novaliq) as a vehicle to deliver cannabinoids to the ocular surface. This class of molecules has a number of advantages as an eye drop.
EyeSol-based drops contain no water, so they mix well with lipophilic substances, including cyclosporine and THC, and allow them to remain solubilised instead of separating out in the bottle. They have a very low surface tension so a drop on the eye rapidly forms a very thin layer, giving it spreading properties that are far superior to an aqueous eye drop (Figure 1).
These properties should help to distribute a drug across the uneven ocular surface without the drug being immediately drained or spilling out of the eye as excess aqueous. SFA molecules are metabolically inert and do not interact with the immune system. Finally, they have a refractive index similar to water, so they do not disturb vision the way oil emulsions of lipophilic ingredients can.
In several observational trials we conducted, q.i.d. treatment with an EyeSol delivery vehicle alone resulted in a highly significant reduction in corneal staining and a 20-point improvement in OSDI scores after just six weeks.6 We thought that if this vehicle could be combined with a compound like THC for pain and inflammation, it could be very beneficial in dry eye treatment.
We began to conduct experiments using an established mouse model for dry eye disease that relies on behavioural testing methods to determine pain levels, as well as other testing methods (Figure 2). We compared a group treated with EyeSol THC eye drops to a control group treated with topical cyclosporine.
One-year results of these preclinical studies suggest that the drop is at least as effective as cyclosporine and may have dual or even triple mechanisms of action, including lubrication, anti-inflammation and pain reduction. Although we continue to evaluate various parameters, the pharmacodynamics thus far are very promising.
We are fairly confident that topical application of THC dissolved in EyeSol will not result in any measurable systemic effects. The first human clinical trials in dry eye disorder are expected to begin in the second half of 2018.
Understanding neuropathic pain
Even as research into THC delivery to the ocular surface continues, we have also been seeking to gain a better understanding of neuropathic pain and the characteristics of patients who may suffer from this form of dry eye. To do this, we in the dry eye clinic have been working closely with experts from the University of Cologne’s pain clinic.
We retrospectively evaluated 52 patients seen in our dry eye clinic who fell into the ‘pain without stain’ category. These subjects had normal Schirmer’s, no corneal staining and no signs of blepharitis, but they had OSDI scores >40, in the ‘severe’ symptom range (median score 77).
In addition to a very thorough history and examination in our clinic, many of the patients also underwent a full pain inventory and Hospital Anxiety and Depression Score (HADS) questionnaire. Comorbidities included depression (n=9), chronic pain syndrome (9), anxiety disorders (4), and prior eye surgery (17).7 Other researchers have also recently shown that severe dry eye pain is correlated with antidepressant use but not with corneal staining.8
For ophthalmologists, these are exactly the sort of patients who are mystifying at best, and often get dismissed as people whose symptoms are “just” psychological. To the pain experts we consulted, however, it was very clear that these were typical pain patients, with the same types of concomitant psychosomatic conditions they often see among patients who suffer from chronic headache or back pain.
A typical patient in our study, for example, might have fibromyalgia and rheumatoid arthritis, with an OSDI score of 65 but no clinical signs of dry eye. Upon questioning, she might have first noticed the dry eye pain following LASIK or around the time of a particularly stressful life event, such as the death of a close family member.
In some cases, the patients had no response to topical anaesthesia or to systemic pain medications, which was quite interesting, since it indicates there is something very unusual going on with regards to their pain response. It seems that these individuals may be predisposed to systemic neuropathic pain, of which ocular pain is but one manifestation.
These insights have changed the way I practice in a number of ways. For example, I have started using the HADS questionnaire more frequently for patients with severe symptoms. I ask broader questions about fatigue, anxiety and depression as part of my history taking.
Recognising that ocular surgery can trigger an underlying pain syndrome, I am more thoughtful about evaluating postoperative patients with unexplained symptoms to determine whether they might be most appropriately managed as a pain patient. As medical doctors, it is our responsibility to see the whole patient and, when appropriate, help them to seek treatment for systemic autoimmune disorders, psychosomatic illnesses and other pain syndromes.
‘Pain without stain’ patients provide us with a model to understand the process of neuropathic dry eye. Because they do not have significant meibomian gland dysfunction or aqueous deficiency, we are able to isolate the neuropathic disease and hopefully identify new therapies to relieve their symptoms.
While these patients represent what is probably a very rare subtype of dry eye, it is likely that many more dry eye patients who do have clinical signs also have neuropathic pain as a component of their dry eye. In fact, I believe that most of the patients who fail, even partially, to respond to stepwise, appropriate dry eye therapy or for whom resolution of signs does not lead to significant improvement in symptoms, might also have an additional neuropathic disorder.
What we learn from treating the extreme form, therefore, has the potential to benefit a much broader range of patients whose pain is inadequately addressed with current therapy.
It has become clear to me that there is a strong unmet need for treatments that specifically address ocular surface pain. Although much research remains to be undertaken, I am optimistic about the potential for cannabinoid therapies, particularly if we are able to confirm that use of an SFA drug delivery technology is effective in reaching the target tissues without systemic side effects.
Rosenthal P, Baran I, Jacobs DS. Corneal pain without stain: Is it real? Ocul Surf. 2009;7(1):28-40.
Rosenthal P, Borsook D. Ocular neuropathic pain. Br J Ophthalmol. 2016;100(1):128-134.
Nelson JD, Craig JP, Akpek EK, et al. TFOS DEWS II introduction. Ocul Surf. 2017;15:269-275.
Belmonte C, Nichols JJ, Cox SM, et al. TFOS DEWS II pain and sensation report. Ocul Surf. 2017;15(3):404-437.
Toguri JT, Caldwell M, Kelly MEM. Turning down the thermostat: modulating the endocannabinoid system in ocular inflammation and pain. Front Pharmacol. 2016;7:304.
Steven P, Scherer D, Krösser S, et al. Semifluorinated alkane eye drops for treatment of dry eye disease—a prospective, multicenter noninterventional study. J Ocul Pharmacol. Ther 2015;31(8):498-503.
Steven P, Schneider T, Ramesh I, et al. Pain in dry eye patients without corresponding clinical signs—a retrospective analysis. Association for Research in Vision and Ophthalmology. 2016, Abstract 2848-A0057.
Satitpitakul V, Kheirkhah A, Cmej A, et al. Determinants of ocular pain severity in patients with dry eye disease. Am J Ophthalmol. 2017;179:198-204.
Professor Philipp Steven, MD
Prof. Steven is principle investigator for the Ocular Surface Group in the Department of Ophthalmology at the University of Cologne, in Germany. He consults for and receives research funding from Novaliq and has a patent pending related to the work described within this article.
|Posted by australiandryeye on March 2, 2017 at 4:05 AM||comments (0)|
Research shows we read emotions in each other’s eyes – that’s the power of eye language. But common symptoms of Chronic Dry Eye disease like red, itchy, burning eyes may be sending the wrong message, one you don’t intend.
Chronic Dry Eye (CDE) is a medical disease that, over time, can decrease the eye’s ability to make and/or maintain sufficient quality and quantity of tears for a healthy tear film. Up to 33 million people in the United States suffer from symptoms of CDE.
Visit www.eyepowerment.com for more information.
|Posted by No More Tears on July 6, 2016 at 9:20 PM||comments (0)|
Oculocin Propo Testimonial
Oculocin Propo provides a natural, preservative free option for supporting and treating the ocular surface. I have achieved outstanding results with patients suffering from chronic dry eye, where they feel their eyes are more comfortable, lubricated and ‘relieved’. Furthermore, I have also been able to correlate these results with improved tear film quality and surface staining during examination. This is another effective tool that should be considered in the complex battle against ocular surface disease.
– Shonit Jagmohan, Optometrist BOptom (Hons), Ophthalmic Medicines Prescriber, Orthokeratologist
Member of the Public
My children are constantly getting conjunctivitis &my doctor has prescribed various antibiotics which seem to work for a short while, then the conjunctivitis reoccurs.
Finally I discovered a natural eye drop that treats conjunctivitis and I am pleased to say, this has worked on my children and ever since I have used, it has cleared up the conjunctivitis
Thanks goodness I discovered Oculocin Propo.
I recommend you try it if either you or a family member suffers from conjunctivitis
Kim Sbisa-Victoria Australia
|Posted by No More Tears on September 5, 2015 at 11:45 PM||comments (2)|
BARCELONA — A novel eyelid massaging device improved symptoms of dry eye by enhancing stability and uniformity of the tear lipid layer, according a speaker.
“Eyepeace is designed to express the meibomian glands by a massaging, vertical motion, as a treatment for meibomian gland dysfunction (MGD). It is meant to be used by the patients at home twice a day,” Johnny Moore, MA, FRCOphth, PhD, said at the EuCornea meeting preceding the European Society of Cataract and Refractive Surgeons meeting.
|Posted by No More Tears on September 5, 2015 at 11:40 PM||comments (0)|
Lµbris BioPharma is a biopharmaceutical company developing recombinant human lubricin for the treatment of dry eye, osteoarthritis and other age & inflammation-related conditions.
Lubricin functions like biologic Teflon® – it is naturally produced throughout the human body protecting tissues and other surfaces from friction-related damage and wear.
Supplementation with recombinant human lubricin is an innovative and exciting new approach to disease management.
Lubricin may be an extremely important barrier to the development of ocular surface damage, such as occurs in dry eye disease (eg.,aging, Sjögren’s syndrome, refractive surgery & contact lens wear). Topical administration of recombinant human lubricin may alleviate the shear stress (friction) that occurs in dry eye disease preventing the onset of inflammation and greatly improving patient quality of life.
David Sullivan, PhD - Associate Professor Harvard Medical School, Department of Ophthalmology
According to Market Scope, approximately 19 million people in the United States are affected by dry eye disease. Symptoms related to dry eye are the most frequent cause of patient visits to eye care practitioners. Traditional therapies provide only limited symptomatic relief and dry eye sufferers are desperately seeking new and more effective treatments.
The human eye blinks almost 20,000 times daily!
Blinking cleans the eye and replenishes eye moisture by spreading a thin film of tears across the front surface of the eye. If the tear film is compromised, it may result in increased friction on the ocular surface, inflammation, increased osmolarity, significant pain and ultimately dry eye disease.
Lubricin, which is naturally found on the ocular surface, may play an important role in eye health and comfort by preventing friction between the cornea and conjunctiva which reduces shear stress (such as during eye blinking) to prevent eye injury at the corneal and ocular surface. In patients suffering from moderate to severe dry eye, lubricin is diminished and the act of blinking causes significant discomfort.
Topical administration of recombinant human lubricin may provide superior reduction in the signs and symptoms of dry eye disease compared to existing treatments by preventing friction and wear on the ocular surface and restoring homeostasis to the tear film. Additionally, a Lubricin-coated contact lens may help improve biocompatibility and extend wear time.
|Posted by No More Tears on March 10, 2015 at 2:05 AM||comments (6)|
The ocular (eye) surface includes two major territories, i.e. the cornea and the conjunctiva, bordered by upper and lower lids. It is imperative that this ocular surface remains healthy to ensure clear vision, maintain comfort and guard against infections. Tear formation plays an essential role in the maintenance of a healthy cornea and conjunctiva. It is comprised of epidermal growth factors (EGF) and Vitamin A which have an important effect on the proliferation, differentiation and maturation of the ocular surface epithelium.
Dysfunction in the formation of an adequate tear film or a delay in epithelial healing will result in ocular surface diseases. Patients with ocular surface diseases suffer from loss of vision, discomfort and pain, infection, erosion, ulceration, and destruction with scarring of the eye surface.
Umbilical cord blood serum has been found to contain similar growth factors, proteins and Vitamin A to tears. Therefore, umbilical cord blood serum can be used successfully in treatment for ocular surface diseases. Netcells packages cord blood serum as OptiSerum [cb] ™ for your convenient use.
For more information click https://www.netcells.co.za" target="_blank">here.
|Posted by No More Tears on October 4, 2013 at 5:35 AM||comments (0)|
Researchers in the United States have discovered a new therapy for people with dry eye they claim can restore natural tear film chemistry in a lasting manner.
The therapy is called Lacripep, and it has been founded by Gordon W. Laurie, an Associate Professor in Cell Biology and Ophthalmology at the University of Virginia. A/Prof. Laurie has been researching dry eye for over 25 years.
Lacripep is a proprietary synthetic fragment of lacritin, the secreted protein found in tears and saliva. While most lacritin is produced by the lacrimal gland, some is secreted by the meibomian gland and the epithelial cells of the conjunctiva and cornea. Together these epithelia comprise much of the lacrimal functional unit (LFU). Lacritin is deficient in dry eye, the most common disease of the LFU.
According to A/Prof. Laurie, although a tear protein, lacritin helps stimulate creation of the protective three-layer tear film as it flows through tear ducts onto the surface of the eye. It also acts as a shield against inflammation-associated cell death by promoting the health of the ocular surface.
A/Prof. Laurie intends to commence preclinical through to phase three trials as soon as possible and hopes to commercialise Lacripep within five to six years.
Continue reading at MiVision: http://www.mivision.com.au/natural-dry-eye-therapy-promises-lasting-effect/
For further information visit: TearSolutionsLLC
|Posted by No More Tears on September 30, 2013 at 12:30 AM||comments (0)|
Assessments including but not limited to determining if causes for dry eye:
- Meibomian gland dysfunction asssessment (gentle expression for diagnostic reasons to determine MGD involvement)
- Blepharitis assessment
- Evaporative/Aqueous deficient dry eye assessment
- Lid wiper epitheliopathy involvement assessment
- TBUT assessments
- Tear film and tear quality and quantity assessment
- Assess if there are other conditions that may also be contributing to the condition
- Prescribing of counselling, guidelines or management to reduce patients dry eye symptoms
If indicated, this includes management with possible outcomes of:
- Counselling on appropriate eye lubricants to reduce symptoms
- Blephasteam in-practice treatment
- Followed by meibomian gland expression
- Or in more severe dry eye cases, this may include prescribing bandage miniscleral contact lenses for symptomatic relief
- Or prescribing potential antibiotic or steroidal or cyclosporine therapy on indication when cases may benefit from this.
Click here to book an appointment.
|Posted by No More Tears on August 18, 2013 at 8:20 AM||comments (0)|
The importance of the mucin layer of the tear film is often neglected in treaing Dry Eye.
"It forms the first layer that is adjacent to the eye and on it the water and then the oily layer sit on top to complete the lubricating system of the eye. One way to think of the mucin layer is like the foundation of a building. If the foundation is not ample and stable the whole building becomes unstable"
For further information Dry Eye, please visit his website:
|Posted by No More Tears on August 15, 2013 at 8:20 AM||comments (0)|
Scleral lenses were the very first type of contact lens made. First created in the 1800s, early designs proved primitive. Made with blown glass, they were hard on the eyes and, ultimately, too uncomfortable for wearers. The design of scleral lenses evolved over the course of the next century, pioneered by the likes of Australian optometrist Don Ezekiel, OD, the first to report the use of the gas-permeable scleral lens, which was welcome news to patients with irregular corneas and, particularly, sufferers of Dry Eye.
Scleral lenses from the 1800's
Scleral lenses are larger than conventional lenses, and rest on the sclera (the white part of the eye) as opposed to the cornea, which is where conventional contact lenses rest. This alternative positioning is used in patients whose corneas cannot support the lens directly. Scleral lenses are large and create a saline-filled chamber over the cornea to avoid direct contact. This layer is commonly known as a liquid band-aid. They are specifically designed to treat a variety of ocular conditions, many of which do not respond to other forms of treatment. Evaporative Dry Eye, a condition that can arise when the gland responsible for lubricating the eyes with lipids, the meibomian gland, becomes blocked or dysfunctional. It results in irritations, dyness, grittiness and general discomfort for the patient.
Scleral lenses are often used for relief for Dry Eye, but bulge outward considerably more than other lenses because the space between the cornea and the lens is filled with a saline solution or artificial tears. But because the liquid allows vision to be comfortably restored, it is crucial.
Modern Scleral lens on an ocular surface
Scleral lenses can be successful in reducing pain and light sensitivity for people suffering from Dry Eye. However, they are not, and should never be, hailed as a cure for Dry Eye. Although the lenses undoubtedly ease the condition, sufferers would be best served by investigating the cause of their Dry Eye rather than just treating its symptoms with scleral lenses. It is important to understand that the lenses allow for the management of the condition, and not a cure.
Scleral lenses for sufferers of Dry Eye
The cornea, unlike any other surface tissue of the human body breathes by extracting oxygen from the surrounding air rather than from blood circulation. Because patients suffering from Dry Eye need to wear lenses, the Scleral Lens was created with a highly oxygen-porous plastic, which allows the cornea to breathe through the lens. And because Scleral lenses are protected with a fluid layer, referred to as a liquid band-aid, the dryness is eased.
Fenestrated and non-fenestrated scleral lenses
Fenestrated sclerals are large and have holes drilled in the front to allow for tear and oxygen exchange. Non fenestrated scleral lenses are preferred by certain optometrists because they do not have any holes drilled in the front. Instead, they are made from oxygen permeable material, with some designs even allowing oxygen in from the sides.
Leading brands in Scleral Lens Design
Scleral lenses are available in different design dimensions and brands. Below is a short run-down of popular designs:
• PROSE lens from Boston Foundation for Sight: This design is widely reputed. PROSE, which stands for “prosthetic replacement of the ocular surface ecosystem,” protects and enables vision by replacing or supporting damaged ocular surface system functions. Optometrist custom design and fit these prosthetic devices to meet the needs of individual patients. The lenses are available at top-ranking clinics around the world.
• Jupiter lens – hailed as the ultimate lens for corneal irregularity, The Jupiter Scleral falls into two main design categories—the 15 mm diameter (mini-scleral) series and the 18 mm diameter series. Both series are true scleral lenses which 1) bear on the sclera and 2) vault the cornea. A lens that bears on the cornea in any way is not a scleral lens (although it may be a corneo-scleral or semi-scleral lens). It can address the most irregular and asymmetric corneas as well as provide a large tear volume for severe dry eye cases.
• Acculens Maxim Scleral Lens - this is a semi-sclera design. It is reputed to perform well on dry eyes and irregular corneas including keratoconus, corneal trauma, pellucid marginal degeneration, penetrating keratoplasties, post LASIK and RK patients. It incorporates a technology that is designed to obtain corneal alignment. The lenses are available in both 16.0mm and 17.5mm diameters in non-fenestrated clear material.
When Scleral Lenses are not enough. Did you know that Dry Eye is strongly linked to Meibomian Gland Dysfunction/Blephaharitis?
Sclerals are not a solution for Dry Eye in and of themselves. It is crucial to understand that up to 65 per cent of Dry Eye sufferers have what is known as Meibomian Gland Dysfunction (MGD) or Blepharitis. MGD is a condition wear the meibomian glands along the eyelids become blocked and cease to function. The glands release an oily secretion called meibum which keeps tears in tact. With MGD the meibum becomes solidified, rather than liquid and cannot be secreted. It is much like having acne of the eye lids. Thus, the tear/Aqueous layer quickly evaporates without meibum covering it. This results in severe dryness and discomfort and causes the eyelids to become inflamed. The resulting symptoms of the dryness are pesky sensations for the sufferer, such as feelings of grittiness, irritation and redness in and around the eyes. Over time, without adequate treatment, the condition worsens, resulting in unbearable pain, extreme sensitivity to light, making reading or using a computer impossible.
To understand MGD, it is important to be aware of the 3 layers of the tear film:
• The mucin Layer responsible for adhering tears to the eye
• The middle layer, which is called the Aqueous Layer, nourishes and protects the cornea
• The top layer is the Lipid (meibum) Layer, which prevents evaporation of the aqueous and mucin layers.
As can be seen from the above picture, the lipid layer is rather thick. The thickness is due to the large quantities required to keep the very Aqueous layer from evaporating. It’s the shine seen in healthy eyes. This healthy glow is missing in people with MGD, and can often be noticed.
Because scleral lenses do not cover the eyelids, they may-be unsuitable for the management of Dry Eye caused by MGD. Whilst they may offer a degree of comfort for a patient with both tear deficiency and MGD combined. The oil secreted by the Meibomian glands fail to lubricate and keep any tears intact to those areas not covered by the Scleral lens. For example: sides of the sclera (white parts of the eye) where the Scleral lens do not cover and the eyelids. Walking with Scleral lenses against the wind can still prove painful for an MGD/Blepharitis patient, and they often resort to wearing moisture chamber glasses over the top of the sclerals (many use moisture chamber glasses to manage the pain).
So unless the MGD/blepharitis is resolved and managed, Scleral lenses may only offer minimal benefit. In fact, many Dry Eye Scleral lens wearers continue to apply drops over the scleral lenses, since the dryness makes wearing them uncomfortable. Afterall, you are placing a large piece of plastic over the eye with Sclerals. Normal contact lenses that touch the cornea are contraindicated in people with dry eyes.
If you suffer from Dry Eye it would be wise to explore the cause. You should not rely on your doctor to push you into doing this, as oftentimes their focus is on prescribing medication rather than treating the cause.
Doctor James Rynerson from the Kentucky Eye Centre performs BlephEx treatment on his patients. BlephEx, which is described in greater detail below, is arguably one of the world’s top treatment for MGD along with meibomian gland probing. He had this to say to fellow eye care professionals:
"Don't throw the latest anti-allergy steroid at them or send them away with artificial tears if they're complaining of Blepharitis sypmptoms. Take the responsibility, do what you're paid to do. Clean the lid margins, and help them with eyelid health."
The very fact that he was moved to make such an impassioned plea indicates a general lack of willingness within the profession to comprehensively and diligently treat patients. Take your power back and insist on finding out if your Dry Eye is caused by MGD and, if it is, be aware that it can be treated. Please read below for information about how this can be done.
Treatment for MGD
If you have Dry Eye caused by MGD you should combine the use of scleral lenses with the following treatments:
• BlephEx™ is a relatively new treatment and is not yet available in Australia. It is a painless in-office procedure that can be performed by an eye care professional. A handpiece is used to precisely and carefully spin a medical grade micro-sponge along the edge of your eyelids and lashes, removing scurf and debris and exfoliating your eyelids. The micro-sponge is disposable and a clean one is used for each individual eyelid so bacteria are not spread between the lids. The eyes are rinsed well afterwards. The procedure lasts about 6 -8 minutes and is well tolerated. Most patients simply report a tickling sensation. A numbing drop is usually placed in each eye prior to treatment for increased comfort. After the procedure, the patient is instructed on how to maintain their clean eyelids with regular nightly lid hygiene. The procedure is typically repeated at 4-6 month intervals.
• Meibomian Gland Expression - Surgical meibomian gland expression can be performed in the office. Using the mastrota probes, the examiner can apply pressure to the glands of the lower lid, expressing opaque, gooey material. The upper lids can also be expressed but it leads to greater patient discomfort. Most patients experience some soreness for about 24 hours afterwards, with extensive pus production and stinging of the lids. This can be treated by the patient regularly irrigating the lids with eye wash for the first day and applying a topical antibiotic or steroid for 72 hours.
While scleral lenses are certainly important for the treatment of Dry Eye, they are not an exclusive treatment. MGD cannot be treated by the use of these lenses alone and requires specialist treatment such as those mentioned above. Be vigilant with your eye health and demand more of your practitioner.
|Posted by No More Tears on July 16, 2013 at 4:40 AM||comments (0)|
The latest treatment for Dry Eye is now available!
Optimel™ Antibacterial Manuka Eye Drops have two complimentary properties, low pH and high sugar content making it both antibacterial and hyperosmotic (draws fluid). The low pH creates an antibacterial environment much like the low pH of the acid mantel that protects our skin. Bacteria that can colonise on the eye surface of a patient are inhibited in the low pH environment. These bacteria are problematic in that if they are allowed to proliferate, they can cause an undesirable inflammatory response which exacerbates the symptoms of eye disease. After applying Optimel™ to the eye, it can be observed around the Meibomian glands. In patients with dry eye disease these glands become blocked and inflamed, in part due to colonisation by bacteria. The low pH of the honey used in Optimel™ creates an antibacterial environment while it is presumed that the high osmotic pressure due to the honey sugars plays a role to help to clear the ducts of the Meibomian glands.
The difference in antimicrobial activity among different honeys depends on their geographical, seasonal and botanical source as well as on processing and storage conditions. It has been demonstrated that various honeys of different geographical and botanical origin are effective against antibiotic-resistant bacterial strains. Honey from Australian and New Zealand Leptospermum species (commonly known as Manuka or tea tree or jelly bush) is the most documented honey in clinical studies because it has been found to have the highest and most consistent level of antibacterial activity.
There are numerous reports by clinicians and eye researchers that topical ophthalmic use of antibacterial honey is suitable and effective in treating a wide range of ocular surface conditions. These include dry eye, meibomian gland disease, conjunctivitis, corneal edema, keratitis, alkali burns, corneal abrasion and blepharitis. Moreover, investigators have determined that antibacterial honeys applied topically to the lid margins and conjunctival sac have efficacy in significantly reducing bacterial colony forming unit counts on the ocular surface in chronic dry eye and eye lid margin disease and in pre-surgical patients. Optimel™ Antibacterial Manuka Eye Drops create an antibacterial environment that reduces the risk of colonisation by bacteria. It should not be considered as an alternate therapy for acute ocular infection where more appropriate interventions should be considered.
- Aqueous tear deficiency
- Meibomian disease
- Corneal erosion
- Colonised ocular surface
Consult you eyecare practitioner first for a proper diagnosis and a management plan before commencing Optimel.™
Optimel is backed by a deep body of science.
To download an archive of all the documents please click here.
|Posted by No More Tears on July 3, 2013 at 12:50 AM||comments (5)|
The severity and pain of dry eyes is very underestimated. It’s not just a disease of the ageing but many younger people are diagnosed with dry eyes. Take for a 21 year old male intern studying to be a doctor struck down with dry eyes. As he studies research papers, glares into computer screens, he constantly applies eyedrops – all to no avail. The pain continues within minutes. The more he studies, the worse the pain gets. The pain begins to affect his mental health, and anxiety sets in as he doubts his condition will ever allow him to get through. With no effective treatment or relief available he decides on another career path, most likely only a part time one, that will take the strain off his eyes.
The middle aged man, perhaps a truckie with 5 children to support is struck down with dry eyes. He soon realizes he must wear moisture chamber glasses since no drop or ECP has been able to ease the pain. He soon realizes even the moisture chambers glasses are not working and ‘air’ is sneaking in, just the slightest air and he’s in pain. All vents in his cabin are pointed away from him, even in summer. He trains himself to put eyedrops on whilst he’s driving, risking an accident. Soon enough, he is late for deliveries and gets the sack.
A secretary with severe dry eyes working in an air-conditioned room. All her eye drops lined up in front of her and she is wearing her moisture chamber glasses. Her staff members said they wished they could see her real eyes, and assume, “Surely dry eyes are not that bad to need those glasses”. She feels embarrassed and demoralized. The constant application of tears affects her productivity and puts her behind schedule. She is considering quitting due to the pain.
Turning our attention to Corneal Pain
Corneal pain is one of the worst pain a human could possibly imagine. Have you ever had a tooth pulled out after enduring the dreaded anesthetic needles before it’s completely numb? What if your tooth was pulled out without anesthetic? It’d be a form of torture – correct? Indeed. Now imagine amplifying the pain 10 times more, then 40 times more. It would be so unbearable that one could not possibly imagine such pain could exist. Now imagine if that pain was continuous and there was nothing that could be done to stop it. Well, such pain does exist and it’s called corneal neuropathy. It’s so excruciating because the nerve fibers in the cornea are 40 times more abundant than in dental pulp.
Becoming a Ping Pong ball
One such woman whom suffered from the agonizing pain of corneal neuropathy (including photophobia), had seen a handful of physicians and ophthalmologists and was constantly fobbed off. No physical optical signs (using diagnostics) showed any proof of pain, thus she was sent to a ‘psychiatrist’. This is the worst kind of medical malpractice one could imagine! If you don’t know ‘how’ to treat someone, you send them to a psychiatrist? It’s more common than you may think!
By this stage, this woman was feeling like a ping pong ball, bouncing from one doctor to the next. But, luckily, this time the psychiatrist was sharp witted and recognized the difference between ‘stress’ induced pain, and real organic physiological pain. So she was referred to a pain specialist. Finally! She was getting warmer. Although, it required yet ‘another’ referral, the pain specialist referred her to Dr. Rosenthal, who is an assistant professor of ophthalmology at Harvard Medical School and scientific director of the Boston Foundation for Sight. Meeting Dr. Rosenthal is where she really lands on her feet, but more on this later.
Please take my eyes out!
The intensity and constancy of corneal neuralgia can be incapacitating and even induce suicidal thoughts, said Stephen C. Pflugfelder, MD. Dr. Plugfelder, who is professor of ophthalmology and director of the Ocular Surface Center at the Baylor College of Medicine in Houston, had a patient with so much corneal neuropathy following LASIK that he begged to have his eyes enucleated.
Dr. Rosenthal (mentioned above) is on a mission to teach fellow ophthalmologists that such patients may suffer from corneal neuropathic disease. Their pain is real, he said, and it can be excruciating. We would like to see such awareness of this type of pain in Australia rather than the large dismissal approach, especially when the patient doesn’t respond to ‘dry eye treatment’. We don’t necessarily blame the ophthalmologists, because in part they haven’t been trained to think beyond objective findings noted on slit-lamp examination.
The above three scenarios are life destroying, and it’s important to declare what is causing the pain and what classification it belongs too. In other words, an accurate diagnosis. Which isn’t as easy as one might think. I bet many of you having read the above thought “dry eye”, but what if it’s “corneal neuropathy". It’s tricky, because the symptoms for dry eye and corneal neuropathy can be identical. Tear evaporation, wind or dry environments that exacerbates classic dry eye also increases the neuralgia. Patients report severe, unremitting, burning pain and photophobia and some can’t stare at a computer screen without pain.
Many patients who do not have dry eyes, still have severe eye pain and ophthalmologists cannot explain this anomaly. If corneal neuralgia resembles the same pain as dry eye (but diagnostically normal), then perhaps our focus has been led astray. Perhaps the path we need to explore are what other conditions cause symptoms of dry eye? Neuropathy comes very close. So let’s take a closer look at corneal neuropathy...
Is what you see what you get?
No absolutely not. “Ophthalmologists may not easily diagnose corneal neuralgia patients because there is no clinical correlation on exam,” said Pedram Hamrah, MD. “I have seen many patients whose symptoms have been dismissed by physicians. But their symptoms are real. Dr. Hamrah, became interested in corneal neuropathy when he started seeing exactly those patients who had been dismissed by other doctors. “We began studying corneal nerves in these patients with the in vivo confocal microscope, which has a resolution up to 1 µm, and saw nerve abnormalities. In ophthalmology, we are mainly trained to treat what we see. But you can’t see the nerves with a slit lamp.”
The following is a list of pain medication categories are used to treat ‘nerve pain’, thus do they have a role to play in corneal neuropathy? Generally the cornea is not very rich in blood supply, thus oral drugs do not reach corneal tissue effectively.
Ever try popping Paracetamol for eye pain and find it doesn’t work? That’s because analgesics are ineffective against neuropathic pain. However, dry eyes often cause headaches and so it’s a good idea to keep a few analgesics with you.
Endep (Amitriptyline), a Tricyclic antidepressant is used widely for neuropathic body pain. However, it will cause dry mouth and eyes at certain doses.
Cymbalta (Duloxetine), an SNRI antidepressant used for peripheral neuropathy, particularly diabetic neuropathy. Side effects can cause dry mouth and eyes.
Neurontin (gabapentin) and Lyrica (Pregabalin) are both anti-convulsant drugs extensively studied for their use in diabetic neuropathy and post-herpetic neuralgia. Neurontin has been in use longer than Lyrica, thus experience with Lyrica is limited. However, it’s use is increasing and is a very popular drug for nerve pain.
Codeine, Oxycodone and other Morphine derivatives are Opioid drugs and generally used when other pain medications have failed. Whilst these medications may help dry eye pain in the ‘short term’ with higher doses, in the long term, they can cause ‘dry eyes’. A side effect is dry mouth, and anything that dries the mouth can dry the eyes. Furthermore, Opoids are seriously addictive and dry eyes my pale into insignificance compared to withdrawal side effects. Most of these medications are effective for bodily pains, but relatively ineffective for dry eyes. In fact, dry eyes can be aggravated by a number of these medications. It’s hit and miss, for example, various forms from patients taking Lyrica (for example), may indicate it assists there eyes, whilst others say it makes their eyes worse. Thus, one could experiment and always stop if it doesn’t work.
Beyond Oral Medication
This is probably what you started with. Treatment for dry eyes! And it’s recommended to begin treating a new case of corneal neuropathy with basic dry eye treatments. Thus “artificial tears” and the like. If the standard dry eye treatment doesn’t provide relief, generally, the patient is referred to a corneal specialist whom is able to treat corneal neuropathy at the underlying cause. Such a close perspective diagnosis is done using a scanning laser confocal microscopy (one of two new noninvasive corneal markers used for diabetic neuropathy. However, it’s applications expand to other areas of the body). The two new scanning devices outweigh old fashioned biopsies in that they are faster to perform, painless and ideal for clinical settings.
The problem is, how many corneal specialists would have a ‘scanning laser confocal microscopy’? How many who’d be ‘willing’ to investigate corneal neuropathy and dry eye? It’s all too often we hear of patients seeing several ECP’s before obtaining the effective treatment they really need. Once the cause of the pain is identified (dry eye or corneal neuropathy). Dr. Hamrah, who is assistant professor of ophthalmology at Harvard Medical School and on staff in the corneal and refractive surgery service at the Massachusetts Eye and Ear Infirmary in Boston recommends the use of a Scleral Lens. A Non-Fenestrated Scleral Lens can insulate the corneal surface from the stimuli of a hostile environment, Dr. Rosenthal said. The Boston Ocular Surface Prosthesis (formerly the Boston Scleral Lens), developed by Dr. Rosenthal, is a fluid-ventilated gas-permeable contact lens that rests entirely on the sclera, creating a fluid-filled space over the diseased cornea. The lens covers the entire corneal surface, bathing it in fluid, and may provide relief for the neuropathy.
Indeed, Scleral Lens practices are growing and becoming more recognized as a viable treatment for dry eye. However, the fitting process can be very tedious and lengthy.
If dry eye pain continues after the tear film has been stabilized, then these patients most likely have corneal neuropathy. These patients, whilst having a liquid bandaid (scleral lens) bathe their corneas in liquid still have pain means that certain nerves are damaged, firing incoherently, patches of nerve networks are flickering into each other. No amount of moisture will stop this sort of pain, perhaps slightly relieve at best. In the past, Dr. Rosenthal had success treating these patients with dilute, sub-hypoesthetic concentrations of local anaesthetics in the fluid reservoir of the scleral lens. Again, which ophthalmologist in Australia would have the courage to attempt such a treatment? Rather, they are too used to fobbing them off to someone else to deal with.
Yet, another, more recent innovation from Dr. Rosenthal shows him using the more newer antiepileptic drug Lacosamide. Dr. Rosenthal said it can ‘modulate’ the firing of over active pain firing sites. He has the Lacosamide compounded as an eye drop (as we’ve seen antiepileptic drugs are not so effective delivered via the oral route for corneal pain). Dr. Rosenthal uses 1% Lacrosamide drops in the fluid filled Scleral Lens. Remarkably, the patients once unrelentless, agonizing corneal pain subsides and can last as long as the patients’ waking hours. But not for everyone! Some people are resistant to Lacosamide and Dr. Rosenthal suggest those patients may require other antiepileptics such as gabapentin, pregabalin or carbamazepine. But their effectiveness can be sporadic.
Dr. Pflugfelder, who is professor of ophthalmology and director of the Ocular Surface Center at the Baylor College of Medicine in Houston agreed. Gabapentin and similar drugs may be used to blunt sensory nerve stimulation or the perception of nerve stimulation, but it doesn’t always work and it has side effects. “Unfortunately, I don’t think any of us have a good treatment,” he said.
Dr. Rosenthal persists and is currently working to reverse maladaptive brain plasticity with Scrambler Therapy (Delta). This uses transdermal transmission of encoded electrical signals that are interpreted in the brain as “no pain.” The treatment works dramatically in some patients; in others not at all, he said. Lastly on Dr. Rosenthal, he has a new foundation: http://www.bostoneyepain.org/. This story of young 21 year old patient Alicia will bring perspective to the reality of this disease and why is must not be trivialised. Many other stories of similar pain can be found here.