March 2021

CORNEA

A variety of cornea topics explored


by Clara Chan, MD Cornea Editor

In this issue, the Cornea section explores a variety of topics including vernal conjunctivitis, Demodex, herpes zoster ophthalmicus manifestations and management, and keratoconus screening.
I always remember the young patients I have met who have been afflicted with vernal keratoconjunctivitis. Mostly teenagers, they come into the office wearing sunglasses and a hat with the worst photophobia imaginable. In Canada, we recently had Verkazia (cyclosporine, Santen) approved for the treatment of severe vernal keratoconjunctivitis in children from 4 years of age through adolescence. To have a steroid-sparing agent available has been an exciting development in this population since checking for intraocular pressures can be impossible. Furthermore, the drug can be used off label for dry eye patients.
With regard to Demodex, I have found it to be so interesting to observe the characteristics of the patients I have seen who are bitterly symptomatic. Young females with inflamed lid margins and classic cylindrical sleeves at the base of their lashes complain that their eyelashes are falling out. Young males with extensive facial hair to hide their adult acne complain that their face and eyebrows are frequently itchy. Then there are the older septuagenarians and octogenarians whose eyelashes are littered with mites yet are minimally symptomatic. A few months ago as I was clearing out my late father’s office desk, I found a newspaper clipping dated December 4, 2001 with the title “It eats your face,” describing how Demodex mites gorge on oily secretions from sweat glands, as well as dead skin cells; have a life cycle of 14.5 days; and migrate across the face at night moving 1 cm per hour.
The excitement around COVID-19 vaccines has elevated the awareness of available viral vaccinations. The Shingrix vaccine that contains no live virus material is indicated for individuals over 50 years for herpes zoster. I want to highlight the Zoster Eye Disease Study (ZEDS) spearheaded by Elisabeth Cohen, MD, and Bennie Jeng, MD, which is a large NIH/NEI-supported randomized clinical trial aimed at evaluating the efficacy of prolonged low-dose oral anti-viral treatment to reduce chronic and recurrent eye disease. If you have patients with acute HZO or recent HZO-related inflammatory stromal disease or iritis, consider reaching out to find out if there is a trial investigator nearby to whom you can refer your patients to enroll in the study.
Lastly, I have some thoughts on keratoconus screening. This is such an important disease to diagnose as we now have corneal crosslinking as a treatment that can halt the progression. Advising patients to stop eye rubbing is also key. To save patients the need for a cornea transplant down the road is such a crucial responsibility. While there are low-tech methods to diagnose keratoconus, such as following refractions for increasing myopia and astigmatism, examining for the scissoring reflex, looking for an iron ring or the more obvious Munson’s sign, there are exciting high-tech diagnostic tools available. A recent paper identified that the corneal higher order aberration excimer ablation map identified a reproducible pattern in keratoconus eyes.1 It is an exciting time as we come to understand the combined impact of corneal OCT epithelial mapping, tomography, topography, biomechanical metrics, and analysis of HOAs in the diagnosis of keratoconus. Stay tuned!

Reference

1. Wallerstein A, et al. Keratoconus features on corneal higher-order aberration ablation maps: proof-of-concept of a new diagnostic modality. Clin Ophthalmol. 2021;15:623–633.

A variety of cornea topics explored A variety of cornea topics explored
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