Clinical characteristics of neovascular glaucoma secondary to central retinal vein occlusion and diabetic retinopathy

Abstract

Background Neovascular glaucoma (NVG) is a serious ocular disease which may cause blindness.The primary pathogenesis of NVG is ischemic retinopathy derived by central retinal vein occlusion (CRVO) and diabetic retinopathy (DR).Clinical characteristics of NVG are variable based on the difference of primary diseases,such as CRVO and DR.However,there is a few studies regarding the diffcrcnces of NVG initiated by CRVO and DR.Objective This study was to compare the clinical characteristics in NVG patients secondary to CRVO and DR.Methods A series case observational study was carried out in Hiserve Hospital of Qingdao University from January 2009 to June 2012.Twenty-nine eyes of 27 patients with NVG caused by CRVO (10 eyes of 10 patients) and DR (19 eyes of 17 patients) were included.The history of underlying diseases,course of NVG,intraocular pressure(IOP),fundus findings and complications after treatment were analyzed and compared between the CRVO-derived NVG and DR-derived NVG.All patients underwent panretinal photocoagulation,improving microcirculation therapy,anti-glaucoma (drug or surgery) and causative disease treatment,and some of them received vitrectomy or/and cataract surgery.Two eyes from each group received intravitreal injection of ranibizumab.The follow-up time in both groups was (14.00±10.13) months and (17.89±12.52) months,respectively.Results The median time of underlying disease was 3.3 months (2 weeks to 6 months) in the CRVO patients and 11.1 months (4 to 36 mouths) in the DR patients,with a significant difference between them (Z =-2.40,P＜0.05).CRVO-derived NVG progress was much faster than that of DR-derived NVG.The number of the eyes with visual acuity improvement after treatment was 2 in the CRVO-derived NVG and 15 in the DR-derived NVG;while the number of the eyes with unchanged or worse visual acuity was 8 and 4 in the CRVO-derived NVG eyes and the DR-derived NVG eyes (x2 =9.38,P＜0.01).The difference of IOP in pre-and post-treatment was (37.00±9.91)mmHg in the CRVOderived NVG eyes and (8.92±12.05)mmHg in the DR-derived NVG eyes,showing a significant difference between them (t =6.30,P＜0.01).In the CRVO-derived NVG eyes,optic disc edema,retinal hemorrhage,and vein dilatation were seen in 6 eyes,and mild optic disc edema and retinal hemorrhage were observed in 4 eyes.After treatment,fundus could not be seen in 4 eyes,in other 2 eyes optic disc and retinal laser spots were unclearly observed.In addition,pale optic disc and retinal vessel occlusion appeared in 2 eyes,and silver wire-like arteries exhibited in 2 eyes.In pre-treated DR-derived NVG eyes,fundus could not be seen in 8 eyes and Ⅲ-Ⅳv stages of DR findings appeared in 11 eyes.After treatment,retinopathy was stabilized in 16 eyes of 15 cases.Advanced retinopathy(V-Ⅵ stages of DR findings) was revealed in 3 eyes of 3 cases.The incidence of the complication after treatment was 100.0％ in the CRVO-derived NVG eyes and 21.1％ in the DR-derived NVG eyes (x2=5.18,P＜0.05).Conclusions The clinical characteristics of NVG secondary to CRVO and DR are variable,an appropriate treatment option should be selected according to different features of NVG. Key words: Glaucoma/neovascular, refractory; Central retinal vein occlusion; Diabetic mellitus/complication, retinopathy; Clinical characteristic; Prognosis