Abstract
Purpose: :
To compare differences in corneal endothelial cell loss (ECL) and surgically induced astigmatism (SIA) between wound-assisted (WA) and wound-directed (WD) IOL insertion after phaco.
Methods: :
72 consecutive eyes of 62 patients undergoing cataract surgery were randomized to a WD or WA technique of IOL insertion. Preoperative evaluation included specular microscopy, corneal topography, and cataract grading using the LOCS III classification system. All surgeries were performed by the same surgeon (KLC) using a bimanual micro-incision technique through 1.2x1.4 mm clear corneal incisions placed supratemporally and infratemporally, enlarging the inferior incision in the OD and the superior incision in the OS to 2.2 mm for WA or 2.4 mm for WD insertion of IOLs (Tecnis 1-piece IOL model ZCB00, AMO using an Alcon D-cartridge). Wound sizes were measured before and after IOL insertion, and were left sutureless. Phaco parameters (total phaco time, time in foot position 3, and average phaco power) were recorded. Specular microscopy and topography were repeated at the 1 month post-operative visit. Preoperative LOCS III, phaco parameters, ECL, and SIA (Alpins vector analysis method) were compared between groups and a non-surgical control group composed of 32 fellow eyes.
Results: :
A total of 62 eyes completed the study (WA, n=30), (WD, n=32). 10 eyes were lost to follow-up or had incomplete data. There were no statistical differences in LOCS III grades or phaco parameters between the two groups. Mean topographic SIA was 0.51 +/- 0.39 D in the WD group, 0.51 +/- 0.30 D in the WA group and 0.36 +/- 0.26 D in the non-surgical control group (p=0.09). Mean wound enlargement was 0.22mm in each group with a final mean wound size of 2.58mm in the WD and 2.44mm in the WA groups (p<0.01). Mean ECL was 7.1% in the WD and 9.8% in the WA group (p=0.25). Mean ECL was 1.6% in the non-surgical controls.
Conclusions: :
Using bimanual micro-incision phaco, WA and WD IOL insertions are comparable techniques with no differences in SIA and ECL. Wound enlargement occurs using both techniques, although a smaller final wound size was possible using the WA technique. Bimanual micro-incision phaco with either WA or WD IOL insertion is astigmatically neutral. ECL and SIA through enlarged bimanual micro-incisions are similar to studies which evaluated ECL (10% - 23%) and SIA (0.5 D) in microcoaxial phaco through 1.8 mm to 2.2 mm incisions and also studies which evaluated ECL (9%) and SIA (0.56 D) in bimanual micro-incision phaco when a third, 2.75 mm incision was used for IOL insertion.
Clinical Trial: :
http://www.clinicaltrials.gov NCT01250964
Keywords: cataract • astigmatism • cornea: endothelium