Pediatric MEK inhibitor-associated retinopathy: 8-year experience at a tertiary academic center and report of 2 cases.

Background: An adverse effect of mitogen-activated protein kinase (MEK) inhibitors is MEK inhibitor-associated retinopathy (MEKAR), a fluid collection between the retinal pigment epithelium (RPE) and interdigitation zone (IZ) seen in up to 90% of adults taking these medications. MEKAR is not well described in children. The purpose of this study was to characterize MEKAR screening practices, identify cases of MEKAR, and describe their clinical presentations in children.

Methods: We conducted a retrospective study at our tertiary care pediatric hospital, examining pediatric patients who underwent MEK inhibitor (MEK-i) therapy between 2015 and 2023. We describe 2 cases of pediatric MEKAR that arose during the study period.

Results: Of 152 patients identified, 104 met inclusion criteria. Trametinib was the most used MEK-i, with plexiform neurofibroma being the predominant indication for therapy. Optical coherence tomography macula screenings were predominantly performed in clinic, with varying screening intervals (mean, 9.85 months; median, 6.5 months). We identified 2 cases of pediatric MEKAR, both of which improved or resolved without altering MEK-i dosage. Our study suggests a lower rate of MEKAR in pediatric patients compared with adults, although limitations in screening frequency and duration may influence this observation.

Conclusions: Our findings underscore the importance of systematic MEKAR screening protocols in pediatric patients receiving MEK-i therapy, facilitating early detection and monitoring of ocular toxicity. When MEKAR develops, the risks of stopping treatment must be weighed against the risks of retinopathy, although in our patients, MEKAR resolved without alterations to their medication regimen.