In a treatment cohort with diverse baseline demographic and clinical characteristics, NGF treatment demonstrated both visual and non-visual benefits, highlighting its therapeutic value for this challenging condition, the researchers concluded in their study. Photo: Christine Sindt, OD. Click image to enlarge.

Neurotrophic keratopathy (NK) is a rare but degenerative corneal disease that can cause the breakdown of the corneal epithelium. Because of its rarity, there are some challenges in evaluating treatment efficacy, and previous studies have demonstrated discrepancies among nerve growth factor (NGF) therapy’s impact on visual acuity (VA). So, in a recent study, authors sought to get a comprehensive understanding of NGF treatment. The team’s paper on the work was recently published in Ophthalmology.

A total of 31,316 NK patients were retained from the IRIS Registry, among which 1,476 received NGF. The primary outcome was VA within one year of treatment. Secondary outcomes included changes in corneal comorbidities and procedures/surgeries performed.

NGF treatment significantly improved VA and non-visual outcomes and reversed the trend of visual decline in every patient who took it. There was a significantly higher percentage of Asian and white patients, possibly reflecting potential disparities in healthcare access or disease prevalence among demographics.

NGF-treated patients had significantly worse baseline VA compared to those not receiving the treatment. They also had more pre-existing corneal comorbidities, including corneal ulcer, herpetic keratitis and corneal dystrophy. On the other hand, corneal melting was more prevalent in the NGF-treated group, and similarly, a higher portion of NGF-treated patients had undergone procedures and surgeries (42.2%) compared to non-NGF treated patients (18.9%), most commonly amniotic membrane transplantation (25.1% vs 9.9%), therapeutic contact lenses (14.1% vs 4.5%) and punctal plug placement (12.0% vs 6.5%). This suggests that the NGF-treated cohort had more severe disease and that NGF therapy may have been preferentially administered to patients with more advanced disease and/or those who have failed conventional treatments.

Older age was associated with worse VA, as well as corneal melting, transplantation, opacity, recurrent erosions and ulcers. “Nevertheless, we found that these covariates had no significant effects on visual outcomes of NGF treatment, suggesting that NGF treatment resulted in vision improvement regardless of age, associated corneal comorbidities and the time from diagnosis to treatment,” the authors wrote in their paper. “However, further analysis is needed to clarify the precise impact of treatment on the resolution of these comorbidities and its subsequent effect on vision.”

The authors compared the incidence rates of associated corneal comorbidities, procedures and surgeries during the post-NGF treatment period to pre-treatment period and noted decreases in corneal ulcer (6.8% vs. 55.3%), corneal opacity (11.7% vs. 39.5%), corneal melting (1.5% vs. 92 7.3%) and recurrent corneal erosions (1.4% vs. 6.8%). They also found a decrease in amniotic membrane transplantation (5.6% vs. 41.9%), therapeutic contact lens use and punctal plugs after treatment. “It is worth noting that there was an increase in procedures performed immediately prior to NGF treatment, likely due to the advanced disease stage,” the authors added.