Neovascular Glaucoma After Vitrectomy
Neovascular Glaucoma After Vitrectomy
Purpose: To investigate the rate and risk factors for neovascular glaucoma (NVG) after vitrectomy in proliferative diabetic retinopathy (PDR).
Methods: Five hundred and twelve patients (512 eyes) with PDR who underwent vitrectomy between January 1, 2003 and June 30, 2009 at Kumamoto University Hospital, Japan, were retrospectively evaluated. Postoperative NVG was defined as neovascularization in the anterior segment and intraocular pressure (IOP) ≥ 22 mm Hg after vitrectomy. Kaplan-Meier survival analysis was applied to calculate the rate of NVG after vitrectomy. Risk factors for NVG after vitrectomy were identified by multivariable analysis using the Cox proportional hazards model.
Results: The mean follow-up period was 422 days. Twenty-seven of 512 patients (5.3%) developed postoperative NVG after vitrectomy. The probability of NVG occurrence at 6 and 12 months after vitrectomy was 6.0% and 7.1%, respectively. Male sex [relative risk (RR)=4.247; P = 0.0032), younger age (RR=0.956/y; P = 0.0237), higher baseline IOP (RR=1.203/mm Hg; P = 0.0335), preoperative neovascularization in the anterior chamber angle (RR=8.899; P < 0.0001), and presence of NVG in the fellow eye (RR=5.355; P = 0.0013) were significant risk factors for postoperative NVG.
Conclusions: The frequency of NVG in PDR eyes within 1 year after vitrectomy was estimated as 7.1%. The risk is independently associated with male sex, younger age, higher baseline IOP, preoperative neovascularization in the angle, and NVG in the fellow eye.
Vitrectomy has long been the mainstay of surgical treatment for the blinding complications of advanced proliferative diabetic retinopathy (PDR) such as persistent vitreous hemorrhage, tractional retinal detachment, and fibrovascular proliferation involving the macula. However, vitrectomized eyes often show postoperative progression of neovascularization in the anterior segment, which results in neovascular glaucoma (NVG).
The incidence of postoperative NVG has been reported to range from 2% to 18%. Clinical studies performed in the 1980s revealed that NVG occurrence in PDR patients after vitrectomy was significantly associated with combined pars plana lensectomy or preoperative aphakia 7,11–13 and residual retinal detachment after vitrectomy. However, sparing lenses during vitrectomy often cause postoperative cataract progression and may result in the need for more frequent additional vitreoretinal surgeries due to inadequate initial vitrectomy.
Recent combined lens extraction with vitrectomy has been performed by phacoemulsification with an intraocular lens implantation. The completion of retinal photocoagulation using an argon endolaser probe during vitrectomy presumably reduces the risk of anterior segment neovascularization compared with earlier methods. In addition to intraoperative panretinal photocoagulation, the technological development of vitreous cutter devices rarely leads to postoperative retinal detachment in vitrectomized PDR eyes. For these reasons, few PDR eyes are now associated with postoperative phakic lens or residual retinal detachment after vitrectomy, and we have insufficient evidence about the frequency of postoperative NVG or patient characteristics associated with PDR eyes after the use of modern vitrectomy techniques. The present retrospective study therefore analyzed the frequency and risk factors for NVG after vitrectomy in PDR eyes.
Abstract and Introduction
Abstract
Purpose: To investigate the rate and risk factors for neovascular glaucoma (NVG) after vitrectomy in proliferative diabetic retinopathy (PDR).
Methods: Five hundred and twelve patients (512 eyes) with PDR who underwent vitrectomy between January 1, 2003 and June 30, 2009 at Kumamoto University Hospital, Japan, were retrospectively evaluated. Postoperative NVG was defined as neovascularization in the anterior segment and intraocular pressure (IOP) ≥ 22 mm Hg after vitrectomy. Kaplan-Meier survival analysis was applied to calculate the rate of NVG after vitrectomy. Risk factors for NVG after vitrectomy were identified by multivariable analysis using the Cox proportional hazards model.
Results: The mean follow-up period was 422 days. Twenty-seven of 512 patients (5.3%) developed postoperative NVG after vitrectomy. The probability of NVG occurrence at 6 and 12 months after vitrectomy was 6.0% and 7.1%, respectively. Male sex [relative risk (RR)=4.247; P = 0.0032), younger age (RR=0.956/y; P = 0.0237), higher baseline IOP (RR=1.203/mm Hg; P = 0.0335), preoperative neovascularization in the anterior chamber angle (RR=8.899; P < 0.0001), and presence of NVG in the fellow eye (RR=5.355; P = 0.0013) were significant risk factors for postoperative NVG.
Conclusions: The frequency of NVG in PDR eyes within 1 year after vitrectomy was estimated as 7.1%. The risk is independently associated with male sex, younger age, higher baseline IOP, preoperative neovascularization in the angle, and NVG in the fellow eye.
Introduction
Vitrectomy has long been the mainstay of surgical treatment for the blinding complications of advanced proliferative diabetic retinopathy (PDR) such as persistent vitreous hemorrhage, tractional retinal detachment, and fibrovascular proliferation involving the macula. However, vitrectomized eyes often show postoperative progression of neovascularization in the anterior segment, which results in neovascular glaucoma (NVG).
The incidence of postoperative NVG has been reported to range from 2% to 18%. Clinical studies performed in the 1980s revealed that NVG occurrence in PDR patients after vitrectomy was significantly associated with combined pars plana lensectomy or preoperative aphakia 7,11–13 and residual retinal detachment after vitrectomy. However, sparing lenses during vitrectomy often cause postoperative cataract progression and may result in the need for more frequent additional vitreoretinal surgeries due to inadequate initial vitrectomy.
Recent combined lens extraction with vitrectomy has been performed by phacoemulsification with an intraocular lens implantation. The completion of retinal photocoagulation using an argon endolaser probe during vitrectomy presumably reduces the risk of anterior segment neovascularization compared with earlier methods. In addition to intraoperative panretinal photocoagulation, the technological development of vitreous cutter devices rarely leads to postoperative retinal detachment in vitrectomized PDR eyes. For these reasons, few PDR eyes are now associated with postoperative phakic lens or residual retinal detachment after vitrectomy, and we have insufficient evidence about the frequency of postoperative NVG or patient characteristics associated with PDR eyes after the use of modern vitrectomy techniques. The present retrospective study therefore analyzed the frequency and risk factors for NVG after vitrectomy in PDR eyes.
Source...