Optical Coherence Tomography Assessment of Risk Factors for Visual Acuity Decline after Trabeculectomy in Patients with Advanced Open-Angle Glaucoma

Précis:Thinning of the macular retinal nerve fiber layer (mRNFL) and ganglion cell complex in the papillomacular bundle area contributed significantly to visual acuity (VA) decline in advanced glaucoma patients after trabeculectomy.Purpose:To identify structural parameters that could predict VA decline after trabeculectomy in patients with advanced open-Angle glaucoma.Patients and Methods:Retrospective review of 74 eyes of 74 patients with advanced glaucoma (defined as mean deviation-12 dB or worse) and best-corrected VA (BCVA) of ≥40/200. All patients underwent trabeculectomy between 2013 and 2016. Measurements included intraocular pressure, BCVA, visual field parameters, and optical coherence tomography-derived parameters [(in both the overall macula and within the papillomacular bundle (PMB)], including mRNFL thickness (mRNFLT), ganglion cell layer/inner plexiform layer thickness, and ganglion cell complex thickness. Measurements were obtained before and after surgery, and follow-up was at least 6 months. We grouped the patients according to whether they underwent VA decline of >3 lines of BCVA after 6 months. We then compared the VA-decline group and the stable-VA group and performed a receiver operating characteristic analysis to determine optimal cut-off values for predicting VA decline.Results:The VA-decline group comprised 7 eyes (9.5%) and had lower preoperative mean deviation (P=0.021) and thinner mRNFL, ganglion cell layer/inner plexiform layer, and ganglion cell complex in the PMB (P=0.003, 0.135, and 0.023, respectively) than the stable-VA group. The cut-off values for predicting VA decline were 9.5 μm for mRNFLT in the PMB.Conclusions:This study found that thin mRNFLT in the PMB were risk factors for VA decline after trabeculectomy.