Purpose: To evaluate whether cystoid macular lesions respond to treatment with dorzolamide 2% drops in the enhanced S-cone syndrome (ESCS) child, as several case reports document favorable efficacy in adults.
Methods: Seven-year-old boy with ESCS and cystoid macular lesions was treated with dorzolamide 2% in both eyes three times a day for a period of 7 months. The efficacy of treatment was analyzed by visual acuity assessment (ETDRS), multifocal electroretinography and SD-OCT central foveal thickness (CFT) measurement.
Results: Baseline RE CFT was 540 and 453 µm in the LE, with amplitude of P1-wave density 39.8 and 50.4 nV/deg(2), respectively. Best corrected visual acuity (BCVA) was 0.3 logMAR RE and 0.3 logMAR LE at distance. At 7-month follow-up examination, CFT showed no reduction in thickness (RE 599 µm, LE 521 µm). P1-wave density increased (RE 49.1 nV/deg(2), LE 84.9 nV/deg(2)), with BCVA 0.3 logMAR RE and 0.2 logMAR LE.
Conclusions: To the best of our knowledge, this is the youngest ESCS patient treated with dorzolamide drops and the first report recording that cystoid macular lesions are resistant to topical dorzolamide treatment. Furthermore, these data are in favor of the hypothesis that microcystoid changes in ESCS appear due to defects in cell-to-cell adhesion rather than the disintegration of the retinal barrier. The marked differences in treatment response to carbonic anhydrase inhibitors between the adults and the child here presented suggest that the breakdown of the blood-retinal barrier may play a more important role later in life.
Keywords: Amblyopia; Carbonic anhydrase inhibitors; Enhanced S-cone syndrome; Multifocal electroretinography; Optical coherence tomography.