Macular phototoxicity after corneal crosslinking

Introduction: Keratoconus is a progressive degenerative corneal disease of variable severity. Its management includes medical and surgical treatment. Corneal crosslinking (CXL) is being increasingly used to stabilize the condition. Macular phototoxicity is a well-known side effect of light exposure; however, its incidence after treatment with riboflavin and UV light is unknown. This study reported the clinical features of a patient with macular phototoxicity after UV-A exposure and described the structural and angiographic retinal changes observed in the patient. Patient, Clinical Findings, and Diagnosis: A 37-year-old man with keratoconus underwent corneal refractive surgery (topography-guided custom ablation with accelerated and high-fluence CXL). Postoperatively, he had decreased vision in the operated eye. Ophthalmoscopy, spectral-domain optical coherence tomography, and fluorescein angiography revealed retinal pigment epithelial changes, ellipsoid zone disruption, and window defects, respectively. The patient was diagnosed with macular phototoxicity. The corrected distance visual acuity stabilized at 20/100 after 6 months. Conclusions: Macular phototoxicity may occur after UV-A exposure during CXL. The use of accelerated and high-fluence protocols might have contributed to its occurrence in this patient.