Microcyst-Like Epithelial Changes Associated With Antibody-Drug Conjugates

Patients treated with antibody-drug conjugates (ADCs) presented with microcyst-like epithelial changes (MECs), according to a study published in Cornea.

Participants included 29 patients (median age 60 years [range,42-86], 44% were men) who all showed evidence of corneal toxicity and were treated with ADCs between 2017 and 2020. The median number of ADC cycles prior to the onset of blurred vision was 2 (range, 1-12), and time on ADC before corneal effects were realized was 39 days (range, 20-251). 

Visual acuity was affected in 89% of participants. Both hyperopic and myopic refractive errors were observed in 29% of eyes. In the 97 total time intervals between visits while on ADC, 48% of eyes experienced a myopic refractive shift, 36% a hyperopic shift, and 16% no shift. In the 22 time intervals off ADC, 36% had a myopic shift, 59% a hyperopic shift, and 5% no shift. The greatest changes in spherical equivalent from baseline were myopic (68%, as high as -4.75 D) and hyperopic (32%, as much as +3.75 D).

Return to normal vision occurred at 71.5 days (range, 12-148) after discontinuation of ADCs. Participants followed after ADC cessation (n=19 eyes) showed an 84% return to baseline vision.

Researchers noted the location of ADC-related MECs had a significant effect on refractive error. An analysis of a subset of 20 eyes revealed that MECs were peripheral in 85% of cases, and 80% of those cases presented with hyperopic shift (P <.001). Eyes with paracentral or central MECs tended to present with myopia (63%; P <.001).

Study limitations include its retrospective nature, a single-center design, and keratometry readings that only measured a 7.7 mm diameter of the central cornea. 

Reference

Canestraro J, Hultcrantz M, Modi S, et al. Refractive shifts and changes in corneal curvature associated with antibody-drug conjugates. Cornea. Published online November 24, 2021. doi:10.1097/ICO.0000000000002934