Keeping Tabs on Keratoconus

The 2025 MOD Live meeting, held November 7-9, in Austin, provided many interactive and insightful discussions for attendees to apply in their own clinics. As this issue of Modern Optometry focuses on the anterior segment, here is a look at the information provided during the session, “Where Are the Cones,” moderated by Walter O. Whitley, OD, MBA, FAAO, one of Modern Optometry’s chief medical editors.

A CASE OF TISSUE ADDITION

Selina McGee, OD, FAAO, also a chief medical editor of Modern Optometry, kicked off the session by discussing a keratoconus (KC) patient who had corneal tissue addition keratoplasty (CTAK) to improve visual acuity and allow for spectacle wear (Figure 1). 

CTAK, first performed in 2016, aims to improve the shape of an eye that has KC by using corneal tissue addition. The procedure offers biocompatibility, customization, accuracy, and precision, Dr. McGee said. Through the corneal tissue preservation process, gamma irradiation depletes antigen-presenting cells to increase tissue viability for multiple recipients.

Dr. McGee discussed the steps of the procedure, noting that the intrastromal channel is cut by femtosecond laser and dissected. The tissue is then inserted and smoothed into its final position. She warned attendees that careful patient selection is necessary, as not everyone, such as those who have corneal thinning, is an ideal candidate for CTAK.

CROSSLINKING IN KC

Next, Dr. Whitley set the stage for a panel-guided conversation on corneal crosslinking (CXL) for KC. During his talk, he noted that, despite advances in diagnostics, KC is often diagnosed at a late stage. Further, he explained that complications, such as higher-order aberrations, come with KC progression, highlighting the importance of closing this diagnostic gap to avoid increased visual decline. He noted that high keratometry values and worse tomography and topography indices at baseline are telltale signs of fast KC progression.

This is where CXL comes in, as it halts or slows KC progression, Dr. Whitley pointed out (Figure 2). Candidacy requirements for epithelium-off CXL include central corneal thickness greater than 400 µm and keratometry values less than 60 D.

The procedure involves corneal epithelium debridement, riboflavin drop application to the cornea every 2 minutes, UVA light exposure to the eye for 30 minutes, and bandage contact lens (CL) placement. Patient education is needed on the importance of postoperative side effect management and visual correction evaluation.

With its approval in October, epithelium-on CXL (Epioxa, Glaukos) is now part of the CXL conversation. The procedure leaves the epithelium intact for a fast recovery period, does not require KC progression for patient qualification, and can be performed on eyes that have central corneal thicknesses as thin as 325 µm. As optometrists navigate initial adoption hurdles, such as insurance, time will tell what epithelium-on CXL’s role will look like in treatment of the KC patient.

INFECTIOUS KERATITIS

Marie Huegel, OD, FAAO, then discussed infectious keratitis, which those who have KC are at an elevated risk of developing. Infectious keratitis (microbial or viral) is the fifth leading cause of blindness and visual impairment globally, with side effects ranging from corneal scarring to vision loss. Dr. Huegel noted CL wearers have a 10-times higher risk of developing infectious keratitis versus non-wearers. She presented several cases, one involving an extended CL wearer who developed fungal keratitis from gardening (Figure 3).

In addition to stressing the importance of intervening early, taking a case history, confirming the etiology, and exercising caution with steroid use, she highlighted these CL pearls:

Avoid water exposure, lens rubbing, and wear during eye irritation.

Use a hydrogen peroxide solution.

Replace the lens case every 3 months, or sooner if needed.

CORNEAL NERVE VOCALITY

Nabila Gomez, OD, FAAO, finished the session with case examples of ocular neuropathy to clarify action steps when corneal nerves are “silent” versus “vocal.” Specifically, she discussed neurotrophic keratitis, which can lead to epithelial cell damage. Dr. Gomez noted that ODs can differentiate neurotrophic keratitis from dry eye disease (DED) when DED treatment ultimately fails, there is a history of autoimmune disease, or nerve dysfunction is present.

Next, Dr. Gomez discussed neurotrophic corneal pain, the result of a hypersensitivity response after an injury that lasts longer than anticipated. Sensitization may be peripheral (pain with minimal or no stimulus) or central (amplification of pain signals with minimal or no stimulus). Understanding the difference between neurotrophic keratitis and neurotrophic corneal pain, Dr. Gomez said, guides management, which should include ocular surface optimization, nerve soothing, comorbidity management, and patient expectation setting. n

Stay tuned for information on attending the next MOD Live meeting!