Abstract
Purpose: :
Long-term complications of pars plana vitrectomy (PPV), including open-angle glaucoma and macular damage from phototoxicity or vital dyes, remain unknown. The PROVE study is an ongoing prospective, controlled clinical trial designed to assess long-term structural and functional changes of the macula and optic nerve following PPV. Three month data of the study cohort are presented.
Methods: :
Patients without glaucoma or prior PPV undergoing unilateral PPV were eligible. The fellow eye served as a control. Enrollment goal is 80 eyes of 40 patients. Both eyes were examined by a retina and glaucoma specialist preoperatively, at three months postoperatively, and then yearly for five years. Data recorded include visual acuity (measured as logarithm of the minimal angle of resolution (logMAR)), intraocular pressure (IOP; by Goldmann applanation and tonopen), central corneal thickness (CCT), gonioscopy (GON), Humphrey 24 degree visual field (HVF), fundus photography and spectral domain optical coherence tomography of the macula and optic nerve. Three month primary outcomes include logMAR, IOP, CCT, GON, HVF mean deviation (MD) and pattern standard deviation (PSD), cup-to-disc ratio (CDR), peripapillary retinal nerve fiber layer (RFNL) and macular central subfield thickness (CST).
Results: :
66 eyes of 33 patients have completed the three month follow-up. Surgical indications were epiretinal membrane (ERM; 18 eyes), macular hole (MH; 10 eyes) and vitreous opacities (5 eyes). Among surgical eyes, no change was noted at three months compared to baseline for CCT, MD, PSD, CDR and GON. Mean IOP increased at three months by 0.35 mmHg, but this did not reach statistical significance. Among surgical eyes, mean RNFL thickness decreased by 4.2 µm at three months in contrast to an increase of 1.1 µm in fellow eyes (p = 0.002). Mean baseline CST among patients with an ERM was 418 µm, which decreased to 337 µm at three months (p=0.004), but remained 65 µm more thickened than fellow eyes (272 µm, p < 0.001). Among ERM and MH eyes, logMAR improved from 0.426 at baseline to 0.246 at three months (p=0.024).
Conclusions: :
In this current ongoing prospective study, three month analysis suggests no significant change in IOP, CCT, GON, MD, PSD, or CDR following PPV. A significant decrease in RNFL thickness was observed among surgical eyes and CST remained significantly higher in eyes with ERM. Continued follow-up of this study cohort should provide further insight into long-term changes after PPV.
Clinical Trial: :
http://www.clinicaltrials.gov NCT01162356
Keywords: vitreoretinal surgery • retina • optic disc