Dovepress • Pre-existing holes predating the surgery. These were classified as such if seen preoperatively or had signs of chronicity including a pigment ring. • Posterior retinal breaks, created during membrane dissection or traction from membrane dissection. Phacovitrectomy was carried out in cases with visu- ally signif icant cataract obscuring the operative view. Patients were followed up at one day, two weeks, and one, two, four, and six months postoperatively, and then at intervals of 2 to 6 months as needed according to clinical circumstances. A variety of preoperative and intraoperative characteristics for the patients were recorded, including age, gender, and type and duration of diabetes. The amount of preoperative Table 1 Demographics and other characteristics of groups retinal breaks in transconjunctival vitrectomy panretinal photocoagulation administered was graded as equal or more than Early Treatment Diabetic Retinopathy Study (ETDRS) full scatter, less than standard ETDRS full scatter, or no scatter.8 statistical analysis The two groups were compared using nonpaired Student t-tests for normal continuous variables, and Fisher’s Exact test and Chi-squared test as appropriate for categorical data. Results Eighty-five eyes were included in the 20 gauge group and 85 eyes in the 23 gauge group. The groups were well matched in terms of basic demographic variables (Table 1). There numbers Age (mean, range, sD) gender Type of diabetes Duration of diabetes (mean, range, sD) % hbA 1c on admission for surgery (mean, range, sD) random glucose on admission for surgery (mean, range, sD) Indication for surgery Amount of preoperative PrP Lens status at time of surgery Combined phacoemulsification and IOL Extent of fibrovascular membrane at vitrectomy Categorisation of Vr attachments gas tamponade used Use of scissors required Postoperative rhegmatogenous detachment 20 gauge control group 85 eyes (69 patients) 51 (21–81) years sD = 15 38 (55%) male 31 (45%) female 32 (46%) type I 37 (54%) type II 17 (1–42) years sD = 9 8.6 (5.5%–12.3%) sD = 1.5% 9.8 (2.3–29.6) mmol/L sD = 5.8 46 (54%) eyes vitreous hemorrhage 9 (10.5%) macular traction 30 (35%) both 51 (60%) eyes $ eTDrs full scatter 23 (27%) eyes , eTDrs full scatter 11 (13%) eyes “none” 63 (74%) eyes phakic 22 (26%) eyes pseudophakic 12 (14%) eyes 17 (20%) eyes . 10 DA 35 (41%) eyes 2–10 DA 22 (26%) eyes , 2 DA 11 (13%) eyes none PVD: 11 (13%) disc attachment only: 12 (14%) posterior pole only: 47 (55%) anterior one quadrant: 9 (11%) two quad: 3 (4%) three quad: 2 (2%) four quad: 1 (1%) 27 (32%) eyes 30 (35%) eyes 1 eye 23 gauge group 85 eyes (67 patients) 50 (19–90) years sD = 16 35 (52%) male 32 (48%) female 27 (40%) type I 40 (60%) type II 18 (0.5–40) years sD = 8 8.2 (5.6%–11.7%) sD = 1.8% 10.6 (2.8–29) mmol/L sD = 6.0 44 (52%) eyes vitreous hemorrhage 13 (15%) macular traction 28 (33%) both 54 (64%) eyes $ eTDrs full scatter 25 (29%) eyes , eTDrs full scatter 6 (7%) eyes “none” 66 (78%) eyes phakic 19 (22%) pseudophakic 14 (16%) eyes 20 (24%) eyes . 10 DA 37 (44%) eyes 2–10 DA 20 (24%) eyes , 2 DA 8 (9%) eyes none PVD: 8 (9%) disc attachment only: 10 (12%) posterior pole only: 48 (56%) anterior one quadrant: 10 (12%) two quad: 4 (5%) three quad: 2 (2%) four quad: 2 (2%) 10 (12%) eyes 5 (6%) eyes 1 eye P value 0.89 0.27 0.49 0.44 0.39 0.24 0.48 0.11 0.43 0.83 0.59 0.84 0.002 0.000002 1 Note: Suspicious lesions: possible breaks that were suspicious for, but not definite, retinal breaks. Abbreviations: eTDrs, early Treatment Diabetic retinopathy study; IOL, intraocular lens; sD, standard deviation; PVD, posterior vitreous detachment; Vr, vitreoretinal; DA, disc areas; PrP, panretinal photocoagulation. Clinical Ophthalmology 2011:5 submit your manuscript | www.dovepress.com Dovepress 111