Abstract
Purpose: :
To investigate the characteristics of patients that encountered secondary glaucoma after vitrectomy for proliferative diabetic retinopathy.
Methods: :
We retrospectively reviewed the medical records of patients who were treated with vitrectomy for proliferative retinopathy between January 2004 and December 2008. If both eyes underwent vitrectomy, only the eye that was treated first was included. Exclusion criteria were eyes with preoperative IOP of 22 mmHg or higher; eyes treated with silicone oil injection during vitrectomy; eyes with previous vitrectomy or previous glaucoma surgeries. Secondary glaucoma after vitrectomy was defined as a postoperative IOP ≥ 22 mm Hg verified at the next visit, or additional glaucoma surgeries. IOP levels after vitrectomy were derived from the medical records at 2 months or more after vitrectomy because of early postoperative IOP fluctuations. The frequency of eyes without secondary glaucoma after vitrectomy was determined with Kaplan-Meier survival curve analysis. Preoperative data including age, gender, systemic diseases (hypertension, anemia, decreased kidney function, heart disease, brain stroke), smoking, preoperative IOP, history of secondary glaucoma in the fellow eye, neovascularization in iris, neovascularization in angle (NVA), peripheral anterior synechia, vitreous hemorrhage, tractional retinal detachment, proliferative membrane and pan-retinal photocoagulation, and intraoperative data including combined cataract surgeries, the number of endolaser photocoagulation and gas injection were analyzed as potential risk factors for secondary glaucoma with Cox proportional hazard model.
Results: :
Four hundred twenty-seven eyes (427 patients) satisfied the study criteria. The means follow-up period was 525 +501 days. Thirty-eight eyes were defined as secondary glaucoma after vitrectomy. Kaplan-Meier analysis showed that the probability of no progression to secondary glaucoma was 89.6% after 1 year, 87.2% after 2 years and 83.6% after 3 years. Male (relative risk [RR] = 5.09, p = 0.0004), no smoking (RR =2.23, p = 0.0483), NVA (RR =5.18, p = 0.0002), the number of endolaser photocoagulation (RR = 1.00086 per spot, p = 0.0146) and no vitreous hemorrhage (RR = 2.32, p = 0.0485) were risk factors for secondary glaucoma.
Conclusions: :
Male and neovascularization in angle are risk factors for secondary glaucoma after vitrectomy for PDR patients. More number of endolaser photocoagulation, no vitreous hemorrhage and no smoking are also associated with the higher risk of secondary glaucoma.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • vitreoretinal surgery