Efficacy And Safty Of The Soft-shell Technique During Cataract Surgery In Difficult Cases.

Purpose:To compare the ability of the soft-shell technique using DuoVisc (Viscoat: sodiumhyaluronate 3% -chondroitin sulfate 4% and Provisc:sodium hyaluronate 1%) andQishen (sodium hyaluronate 1.5%) to protect the corneal endothelium followingin-the-bag phacoemulsification with implantation of a foldable posterior chamberintraocular lens (IOL) in difficult cases..Methods:PartⅠ: In a prospective single-masked randomized study, 60 eyes of 60 cataractpatients with a hard lens nucleus (Emery-Little classification grade 4 or higher) hadphacoemulsification using the soft-shell technique with Provisc (sodium hyaluronate1%) and Viscoat(?) (sodium hyaluronate 3.0%-chondroitin sulfate 4.0%) (soft-shellgroup) or with Qishen (sodium hyaluronate 1.5%) alone (control group). The cornealresponse to surgery was evaluated by measuring the endothelial cell loss, the variationin mean cell area of the endothelial cells (CV), the frequency of hexagonal cells, andthe central corneal thickness. Data were recorded preoperatively and 12 weekspostoperatively.PartⅡ: In a prospective single-masked randomized study, 40 eyes of 40 cataractpatients complicating closure glaucoma had phacoemulsification using the soft-shelltechnique with Healon(?) (sodium hyaluronate 1%) and Viscoat(?) (sodium hyaluronate3.0% -chondroitin sulfate 4.0%) (soft-shell group) or with Qishen alone (controlgroup). Postoperative visual acuity, IOP, the endothelial cell loss, the variation inmean cell area of the endothelial cells (CV), the frequency of hexagonal cells, and thecentral corneal thickness were evaluated postoperatively. Data were recordedpreoperatively and 12 weeks postoperatively.Results:PartⅠ: Preoperatively, no significant difference was observed in cell count, CV,hexagonal pattern or pachymetry among groups. Postoperatively, both two groups hada significant decrease in cell count, but the decrease was significantly less in the soft-shell group (6.6%) than in the control groups (15.5%). No changes in CV,hexagonality or corneal thickness were observed within any of the two groups oramong the groups. There was an equal and significant increase in visual acuity.Intraoperative and postoperative complications were few and manageable.PartⅡ:Preoperatively, no significant difference was observed in cell count, CV, hexagonalpattern or pachymetry among groups. Postoperatively, both two groups had asignificant decrease in cell count, but the decrease was significantly less in thesoft-shell group (6.5%) than in the control groups (16.8%). No changes in CV,hexagonality or corneal thickness were observed within any of the two groups oramong the groups. Glaucoma control was achieved in 40 eyes (100%) in the twogroups. Mean IOP on admission was 45.6±3.5 mmHg (standard deviation) and 46.3±3.8mmHg, respectively (P=0.55). Mean postoperative IOP was 13.6±3.0 mmHg(the soft-shell group) and 13.9±2.8 mmHg (control group) after a mean follow-up of84±10 days (P=0.75). There was an equal and significant increase in visual acuity.Intraoperative and postoperative complications were few and manageable.Conclusions:Phacoemulsification with implantation of a posterior chamber lens is known to affectthe density and morphology of comeal endothelial cells. Viscoelastics facilitatecataract surgery and protect the corneal endothelium during the procedure. Choosingthe soft-shell technique OVD during the phaco procedure may allow for protection ofthe endothelial cells.