Abstract
Purpose: :
The presence of cystic-appearing lesions in the macula, presumed to represent cystoid macular edema, has been previously observed to occur in all genetic types of patients with retinitis pigmentosa (RP). These lesions may not always be detected by direct ophthalmoscopy or contact lens biomicroscopy. In this study, we determined the prevalence of cystoid macular edema by optical coherence tomography (OCT) in retinitis pigmentosa patients who showed no evidence of cystic lesions on retinal exam.
Methods: :
We included 63 RP patients with no evidence of cysic appearing macular lesions on clinical fundus exam. All patients underwent a complete ocular examination, including best corrected visual acuity using an ETDRS chart, intraocular pressure measurement, anterior segment exam, and a detailed fundus exam. On 50 of the 63 patients who were examined, Fourier Domain OCT was performed using the radial slicer protocol. The additional 13 of the 63 RP patients were scanned with a Time-Domain OCT, OCT3 unit, using the macular thickness protocol. The diagnosis of CME was defined by the presence of small round hypo-reflective lacunae with well-defined boundaries on at least 2 of the scans.
Results: :
The mean age of patients included in the study was 36 years (range 9-71 years). Out of the 63 patients examined, 20 patients showed CME in at least one eye (32%), while 11 patients showed CME in both eyes (18%).
Conclusions: :
Our findings demonstrated that a substantial number of RP patients with cystoid macular edema, as determined by OCT, may not show evident cystic changes by direct ophthalmoscopy or contact lens biomicroscopy. This observation may have implication for future therapeutic trials where visual acuity is used as an outcome measure. Knowledge of the high frequency for macular edema in such patients can also serve to identify those who may be amenable to treatment of their macular edema with either current or future strategies.
Keywords: retinal degenerations: hereditary • macula/fovea • edema