CHANGES OF PARAFOVEAL RETINAL NERVE FIBER LAYER THICKNESS ANALYZED BY SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY AFTER PARS PLANA VITRECTOMY

Abstract

In Brief Purpose: To use spectral-domain optical coherence tomography to evaluate the postoperative retinal nerve fiber layer (RNFL) thickness changes in eyes undergoing vitrectomy. Methods: This is a retrospective study of 44 patients (44 eyes) who underwent monocular vitrectomy for an epiretinal membrane (19 eyes), macular hole (12 eyes), or vitreous hemorrhage (13 eyes). Quantitative analysis of the peripapillary RNFL by spectral-domain optical coherence tomography was performed before surgery and for 6 months postoperatively on both eyes. Results: Mean patient age was 62.72 ± 9.11 years. Mean preoperative RNFL thickness did not differ significantly between vitrectomized eyes (88.33 ± 13.23 μm) and nonvitrectomized fellow eyes (87.49 ± 13.18 μm; P > 0.05). In vitrectomized eyes, the preoperative mean RNFL thickness in the superior quadrant was significantly different from that at 6 months after surgery (P = 0.02). Vitrectomized eyes with a macular hole showed significant changes in the mean RNFL thickness in the inferior quadrant (P = 0.04). Conclusion: Retinal nerve fiber layer thickness was reduced in some of the quadrants of the vitrectomized eye during the 6-month postoperative follow-up period. Spectral-domain optical coherence tomography can be clinically useful for detection of localized RNFL defects in patients who underwent vitrectomy. Future prospective studies with more patients and longer follow-up duration are required. Clinical findings during the postoperative follow-up for vitrectomy often include optic disk pallor or optic nerve atrophy and sometimes related visual field defects. Previous report assessed the retinal nerve fiber layer (RNFL) by time-domain optical coherence tomography after vitrectomy for macular hole. These authors reported a significant reduction in the RNFL postoperatively. The purpose of the present study was to use spectral-domain optical coherence tomography (SD-OCT) to analyze and evaluate the postoperative RNFL thickness changes after pars plana vitrectomy. This is the first report to use SD-OCT to analyze the postoperative RNFL thickness changes after vitrectomy.