ocular surface & dry eye
No simple story

A look at the current perspective on ocular surface disease

Conjunctival sub-epithelial fibrosis in a patient with severe dry eye condition
Source: Esen K. Akpek, M.D.

The significant increase in the visual expectations of patients following cataract and refractive surgery have led to a heightened concern among surgeons about optimizing the ocular surface, said Christopher Starr, M.D., Weill Cornell Eye Associates, New York.
A dry ocular surface or unoptimized surface can have a significant negative effect on vision and visual quality, he said.
Until fairly recently, efforts to treat problems of the ocular surface were often chartered in isolated fashion, said Terrence O’Brien, M.D., Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, “So someone would be impressed by the dry aspects [of the disease and] they would be treating for dry eye with things that mainly are for lubrication and that in and of themselves were ok but it neglected that part of the dryness may be coming from the lid margin or from the meibomian gland dysfunction that was leading to evaporation of tears and increased tear break-up time.”
In the last few years, however, physicians have become increasingly aware of how interrelated the lid margin, the tear film, the cornea and the conjunctiva are, Dr. O’Brien said. They are now thinking of the ocular surface as a functional unit and also an anatomic unit that is contiguous and integrally related to the performance of the eye, he said.
A clear illustration of this change in perception is in the DEWS (Dry Eye Workshop) Report that expanded the characterization of dry eye disease and placed it within the perspective of ocular surface disease. Published in the April 2007 issue of The Ocular Surface Magazine, the definition of dry eye disease originally adopted by the 1995 National Eye Institute (NEI)/Industry Dry Eye Workshop, was updated by members of the Dry Eye Workshop (DEWS) Definition and Classification Subcommittee.
According to the previous definition, dry eye is “a disorder of the tear film due to tear deficiency or excessive evaporation, which causes damage to the interpalpebral ocular surface and is associated with symptoms of ocular discomfort.”
The new definition quantified dry eye as “a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. It is accompanied by increased osmolarity of the tear film and inflammation of the ocular surface.”
Changes in treatment approaches to the ocular surface and outcomes
This shift in defining dry eye has certainly improved outcomes, according to Dr. Starr, with its accompanied aggressive diagnosis and treatment of patients preoperatively and postoperatively.
Recognition of the ocular surface as an interrelated functional unit means that often, the treatment approach will be multifaceted to include different treatments aimed at different aspects of the problem, all of which affect the ocular surface, Dr. O’Brien said.
Treatment options include some or all of the following: anti-inflammatory drops, antibiotic drops, immunomodulatory drops like cyclosporine, oral medication, nutritional changes such as an inclusion of more omega-3 essential fatty acid, he explained.
There are a myriad of different potential causes of dry eye, Dr. Starr said, but he offered that a generic treatment modality would include a combination of a high quality and high retention lubricating drop as often as needed.
Restasis (ophthalmic cyclosporin A, Allergan, Irvine, Calif.) is a big part of his treatment regimen as well, he said, and he starts that on all his refractive and cataract patients pre-op and continues it post-op. He is also a proponent of using a mild steroid around the time that he starts cyclosporine A and usually starts them concurrently. He uses Lotemax (loteprednol etabonate ophthalmic suspension 0.5%, Bausch & Lomb, Rochester, N.Y.), drops frequently in conjunction with Restasis: Restasis twice a day, Lotemax four times a day for a month.
Dr. Starr also recently started using Azasite (azithromycin ophthalmic solution, Inspire Pharmaceuticals, Durham, N.C.) more often in patients who have blepharitis and dry eye, “I find that Azasite pre-op helps to control the blepharitis and meibomian gland dysfunction,” he explained.
In patients who have severe rosacea and severe blepharitis, Dr. Starr adds oral doxycycline as well or Alodox (20 mg doxycycline hyclate, OCuSOFT, Richmond, Texas). Warm compresses and aggressive scrubbing of the eyelids when people have blepharitis, is a must as well. Finally, he has his patients use Oxysoft plus with scrubs pre-op as its cleansing reduces MRSA on the eyelids pre-op, he explained.
“That’s pretty much my go-to regimen and I’ll use either all of that in severe cases or a fraction of that in more mild cases,” he said.
Dr. Starr underlined the importance of treating the surface prior to surgery before taking final pre-op measurements. For refractive surgery that includes the wavescan, topography and refraction and for cataract surgery includes topography, keratometry and the A-scan axial length measurements, he said.
Ocular surface disease requires treating with multiple agents in a coordinated fashion but its not one set treatment, Dr. O’Brien said. “We now have more treatments that often have to be combined to bring the conditions under control and to support the ocular surface,” he explained.
It is vital that physicians look at all areas that impact the ocular surface to determine which components may be uncontrolled or contributing the greatest amount of instability to the ocular surface, Dr. O’Brien stressed. An accordingly balanced treatment plan should then follow.
Dr. O’Brien also warned that clinicians should not overlook the high correlation between lid margin disease and dry eye. The two are interrelated in a high percentage of patients, he said,
“That doesn’t mean that every single dry eye patient has lid margin disease but I think we’re recognizing now that a high percentage, anywhere from 30-50% will have some aspect of lid margin disease contributing to their dry eye condition and therefore efforts to treat both the lid margin as well as the aqueous tear layer in sufficiency are necessary.”

Not the end of it

Still, the treatment of ocular surface disease has proven not as simple as was previously thought. Dr. O’Brien pointed out the controversy of parasite colonization or infestations of the eyelids or lashes in older people. Demodex parasites in particular, are found as we get older in more and more people and what is uncertain at the moment is does their mere presence indicate disease since so many people have them and if so is treatment required, Dr. O’Brien said.
This is just another example of the different components involved in ocular surface disease, he added.

Editors’ note: Dr. Starr has financial interests with Abbott Medical Optics (Santa Ana, Calif.) and Allergan (Irvine, Calif.). Dr. O’Brien did not indicate any financial interests related to his comments.

Contact information

O’Brien: 561-515-1544, tobrien@med.miami.edu
Starr: 646-962-2020, drstarr@gmail.com

Additional source: The Ocular Surface April 2007 DEWS Report