Effects of posterior capsular opacification on the evaluation of retinal nerve fiber layer as measured by Stratus optical coherence tomography.

ABSTRACT

OBJECTIVE: To evaluate the effects of posterior capsular opacification (PCO) and NdYAG laser capsulotomy on the evaluation of peripapillary retinal nerve fibre layer (RNFL) as measured by Stratus (Carl Zeiss Meditec, Dublin, CA) optical coherence tomography (OCT). DESIGN: Prospective interventional case series. PARTICIPANTS: We studied 98 eyes of 89 patients experiencing PCO. METHODS: We performed a complete ophthalmologic examination and evaluation of RNFL as measured by Stratus OCT before and after NdYAG capsulotomy. The patients were classified on the basis of PCO score or signal strength (SS) obtained by prelaser OCT scans. RESULTS: The preoperative and postoperative peripapillary RNFL thicknesses were 90.24 ± 15.9 µm and 98.27 ± 14.1 µm, respectively (p < 0.001). The mean preoperative SSs were 5.4 ± 1.6, and they improved to 9.5 ± 0.5 postoperatively (p < 0.001). Prelaser and postlaser RNFL thicknesses differed significantly in eyes with preoperative SSs less than 7 (p < 0.05). Also, in patients with preoperative PCO grades higher than 2, there were significant increases in RNFL thickness after laser capsulotomy (p < 0.05). CONCLUSION: RNFL thickness measured by the Stratus OCT is affected by PCO. RFNL thickness may be underestimated in eyes with preoperative PCO grades higher than 2 and in eyes with preoperative SSs lower than 7.