Baseline ophthalmic findings and complications in pediatric patients treated with MEK inhibitors

MEK inhibitors are an increasingly used class of medications associated with ocular complications, including serous retinal detachments, vein occlusions, uveitis, and dry eye syndrome in adults. However, baseline ophthalmic findings and MEK inhibitor-related complications in children are underreported.

The medical records of patients <21 years of age who underwent MEK inhibitor treatment at our institution between 2016 and 2023 were reviewed retrospectively. Patients with baseline examination and at least one follow-up eye examination were included. Systemic and ophthalmic diagnoses, MEK inhibitor treatment course, and ocular findings were extracted from the record.

A total of 45 patients (23 males) were treated with a MEK inhibitor for tumor with neurofibromatosis type 1 (NF1, n = 20), tumor without NF1 (n = 22), or non-tumor (n = 3) at a mean age of 9.4 ± 4.8 years. Nineteen patients were treated with trametinib, 20 with selumetinib, and 6 with combined trametinib and dabrafenib. Thirty-three patients (73%), all with neurological tumors, had abnormal baseline eye examinations, including optic nerve abnormalities (n = 20), visual acuity impairment (n = 17), visual field defect (n = 8), strabismus (n = 10), or anterior segment abnormalities (n = 14). Average time on MEK inhibitors was 445.5 ± 377.8 days. Three patients with neurologic tumors without NF1 developed ophthalmic side effects of dry eye syndrome (n = 1) or symptomatic anterior uveitis (n = 2) at 6-7 months after initiation of MEK inhibitor. All 3 patients responded to topical medications.

The majority of children started on MEK inhibitors had baseline eye abnormalities due to ocular or visual pathway involvement of neurological tumors. Ophthalmic side effects of MEK inhibitors occurred in 7% of children. Additional studies are required to formulate screening guidelines for the pediatric population.