Optical Coherence Tomography and Fundus-Related Perimetry Changes in Solar Retinopathy

Abstract

Purpose:: Solar retinopathy is caused by macular exposure to solar radiation and is mediated by photochemical and thermal mechanisms. Ultrastructural examination shows the RPE and the outer segments of the photoreceptors as the most susceptible to solar insult. Our purpose is to describe the optical coherence tomography (OCT-3 Stratus) and the fundus-related perimetry (MP-1 microperimeter) findings of the disease.

Methods:: We performed a complete ophthalmological examination in 5 patients affected by solar retinopathy, including two new, highly sensitive diagnostic tools, the OCT-3 and the MP-1, soon after solar exposure and again up to 24 months after diagnosis.

Results:: Symptoms and macular changes were similar in these 5 patients despite different exposures to solar radiation. On initial visit, the OCT scans revealed in all 5 patients an irregular inner high-reflective layer (I-HRL) that appeared fragmented and interrupted. In addition, the OCT images showed a hyperreflective lesion, which, in 2 patients, involved the full foveal thickness, and in 3 patients was confined to the outer half of the foveal layers. In 4 patients there was an associated reduced reflectivness of the outer high-reflective layer (O-HRL). These OCT signs disappeared as early as one month follow-up. Fundus-related perimetry demonstrated, at the first visit, a significant reduction of retinal sensitivity in all patients, which was no longer evident at one-month follow-up.

Conclusions:: OCT may be an effective tool in diagnosing the acute phase of solar retinopathy and in differentiating it from other maculopathies. Fundus-related perimetry would seem to be a useful adjunctive method to better characterize the functional aspect of the disease.

Keywords: radiation damage: light/UV • macula/fovea • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)