Abstract
Purpose:
The prospective retinal and optic nerve vitrectomy evaluation (PROVE) study is an ongoing prospective, controlled clinical trial designed to assess long-term structural and functional outcomes following pars plana vitrectomy(PPV). Eyes with visual field changes following surgery were analyzed to determine the incidence of and risk factors for optic neuropathy.
Methods:
The PROVE Study enrolled 80 eyes of 40 patients that underwent unilateral PPV. Both the surgical (study) eye and the fellow (control) eye were examined by a retina and glaucoma specialist preoperatively and at 3 months postoperatively. Visual acuity, intraocular pressure, central corneal thickness, gonioscopy, Humphrey visual field (HVF), fundus photography and autofluorescence and spectral domain optical coherence tomography of the macula and optic nerve were recorded at each visit. Eyes that had 3-month visual field changes were analyzed for corresponding retinal nerve fiber layer alterations and optic nerve changes.
Results:
Eighty eyes of 40 patients completed 3-month follow-up. Surgical indications were epiretinal membrane (21 eyes), macular hole (14 eyes) and vitreous opacities (5 eyes). Four study eyes (10%) demonstrated new visual field defects after PPV with 2 of these eyes demonstrating optic disc pallor. At 3 months, mean deviation (MD) and pattern standard deviation (PSD) of these 4 study eyes was -5.0 ± 2.1 and 5.4 ± 3.3 respectively compared to -0.5 ± 1.3 (P=0.01) and 2.1 ± 1.3 (P=0.1) respectively for corresponding fellow eyes. MD -1.4 ± 1.8 (P<0.001) and PSD 2.2 ± 1.4 (P=0.001) of the remaining 36 study eyes was also significantly different. Inferior retinal nerve fiber layer thickness for the 4 study eyes with optic neuropathy was 107.3 ± 18 microns versus 122 ± 16 microns (P =0.08) for fellow eyes. One of the 4 study eyes with optic neuropathy suffered direct intraoperative mechanical trauma. The remaining 3 study eyes all underwent vitrectomy for macular hole repair (Odds ratio 15.5; 95% CI 0.7 to 326) with use of indocyanine green, removal of internal limiting membrane, and gas tamponade (P=0.04).
Conclusions:
In this cohort, 10% of eyes developed optic neuropathy after PPV. Risk of optic neuropathy was greater in eyes undergoing vitrectomy for macular hole repair.
Keywords: 762 vitreoretinal surgery •
629 optic nerve