The Comparative Study Between The Modified Removal Ofsilicone Oil With 23-gauge And Traditional 23-gauge Transconjunctival Vitrectomy System

The research status:Silicone oil filling is an important method of vitrectomy to cure the complex hyperplastic vitreous retinopathy,being widely applied in the clinic because of its relatively stable physicochemical property,good transparency and exact retina restoration effect.Since it may cause various kinds of complications after operation with silicone oil,such as complicated cataract,secondary glaucoma,silicone oil emulsification and cornea degeneration,it need extract silicone oil to treat in good time.However,it is usually along with low intraocular tension,choroidal detachment,recurrent retinal detachment and other complications during or after extracting silicone oil.Therefore,it is a difficult problem for doctors in charge of vitrectomy that how do they extract silicone oil safely and effectively.At present,it uses 23 G minimally invasive vitreous cutting system to extract silicone oil without suturing scleral incision in the clinic but it is highly to appear low intraocular tension after operation.This study improves traditional 23 G silicone oil removal by presetting incision suture and increasing fluid-air exchanging times.Then it compares clinical effects of the two methods after operation to discuss the advantages of modified 23 G silicone oil removal with incision suture.Objective:To investigate and compare the safety and efficacy of a modified technique for silicone oil removal with a traditional 23-gauge(23G) transconjunctival vitrectomy system.To compare the mean operating time of modified technique for silicone oil removal with traditional 23-gauge(23G) transconjunctival vitrectomy system.To compare the postoperative visual acuity of modified technique for silicone oil removal with traditional 23-gauge(23G) transconjunctival vitrectomy system.To compare the postoperative IOP of modified technique for silicone oil removal with traditional 23-gauge(23G) transconjunctival vitrectomy system.To compare the complication of modified technique for silicone oil removal with traditional 23-gauge(23G) transconjunctival vitrectomy system.Method:A randomized controlled clinical prospective study was performed for 180 eyes, who once had pars plana vitrectomy combined with silicone oil tamponade underwent silicon oil removal. Patients were randomly separated into two groups: a traditional 23-gauge(23G) transconjunctival sutureless vitrectomy system group(A group,88 eyes) and a modified technique 23 G transconjunctival vitrectomy system with incision sutured group(B group, 92 eyes). The mean operation time and preoperative and postoperative intraocular pressure(IOP) levels and visual acuity with the two groups were recorded and compared. Rate of the complications were also compared during follow-up.Results:The mean operation time was 25.92±6.74 min in group A, and 27.87±6.68 min in group B(t = 1.95,P = 0.05).The postoperative corrected visual acuity compare between the two groups,52 eyes postoperative corrected visual acuity improved in group A(59.1%),60 eyes postoperative visual acuity improved in group A(59.1%)。The results of two groups of the preoperative and postoperative visual acuity between 1 day 1 week and 3 months were no statistical difference。(t =0.78,P =0.43;t =0.87,P =0.38;t =1.12,P =0.27;t =0.14,P =0.89)The results of two groups of the postoperative IOP between 1 day 1 week and 3 months: group A 18.07±4.23,12.23±4.42,14.69±3.21,15.14±3.0mm Hg;group B 17.86±3.73,13.78±3.72,15.37±3.09,15.61±2.91 mm Hg. Compared with the mean preoperative IOP, IOP on postoperative 1 day were lower in both groups. There were a statistically significant difference in postoperative 1 day IOP between the two groups(t = 2.55, P = 0.01). No statistical difference of IOP was found on preoperative and postoperative 1wk, 3mo. During 3 months follow-up.postoperative hypotony( < 6mm Hg) 25 eyes(28.4 %), choroidal detachment 8 eyes(9.1 %), vitreous hemorrhage 5 eyes(5.7 %), retinal reattachment 9 eyes(10.2 %),silicon oil remained in 7 eyes(8.0 %)in group A; postoperative hypotony 5 eyes(5.4 %), choroidal detachment 2 eyes(2.2 %), vitreous hemorrhage 2 eyes(2.2 %), retinal reattachment 8 eyes(8.7 %),silicon oil remained in 1 eye(1.0 %)in group B. There were statistically significant difference of postoperative hypotony, choroidal detachment and silicon oil remains between two groups(P<0.01、P = 0.04、P = 0.03).Conclusions:1. The modified technique using 23 G transconjunctival vitrectomy system with incision sutured could obviously avoid silicon oil remained.2. The IOP of modified technique using 23 G transconjunctival vitrectomy system with incision sutured was more stable that could reduce complications for silicon oil removal operation.