The influence of corneal tunnel length on corneal thickness and surgically induced astigmatism after standard phacoemulsification through 2.75mm incision

Poster Details

First Author: E.Supady POLAND

Co Author(s):    M. Wilczynski   T. Wierzchowski   M. Zdzieszynski   A. Synder   W. Omulecki  

Abstract Details

Purpose:

The purpose of the study was to evaluate the influence of the corneal tunnel created during standard phacoemulsification through a 2.75mm clear corneal incision on the central corneal thickness, surgically induced astigmatism and corneal endothelial cell loss.

Setting:

Department of Ophthalmology, Medical University of Lodz, Poland.

Methods:

The study consisted of 27 eyes of 27 patients: 21 women (77.8%) and 6 men (22.2%), aged from 55 to 88 years old (mean age=78, SD=±7 years) All patients underwent uneventful phacoemulsification through a 2.75mm temporal clear corneal incision. Patients were examined preoperatively, 1 day, 7 days and 1 month after the surgery. We evaluated: best corrected visual acuity, keratometry, tonometry, anterior and posterior segment of the eye and corneal endothelial cell density. Surgically induced astigmetism was calculated using vector method. Corneal thickness and corneal tunnel length were measured using the anterior segment OCT. Statistical analysis was done using nonparametric tests: Wilcoxon test, Mann-Whitney U test and Spearmann correlation coefficient. Calculations were done using Addinsoft XLSTAT 2008 software for the significance level ? = 0,05.

Results:

Mean preoperative best corrected visual acuity (BCVA) was 0,30±0,24 and it improved to 0,94±0,18 one month after the surgery. The difference was significant (p<0,05). Mean length of corneal incision measured 1 day after the surgery was 1,84±0,36mm. SIA calculated with vector method amounted to 0,73±0,58 one day after the surgery and 0,51±0,41 one month postoperatively. The difference was significant (p<0,05). There was a correlation between the length of corneal incision and SIA calculated 30 days after the surgery (Spearman coefficient =0,4). Mean central corneal thickness was 0,51±0,05mm preoperatively, 0,56±0,09mm one day after the surgery and 0,51±0,05mm one month postoperatively. The difference in thickness 1 day postoperatively was significant (p<0,05). No correlation was found between the length of the tunnel and central corneal thickness 30 days after the surgery (Spearmann coefficient was 0,21, p=0,27).. Mean corneal endothelial cell density was 2483±417 cells/mm2 preoperatively and 2325±410 cells/mm2one month after the surgery. Mean corneal endothelial cell loss measured 30 days postoperatively amounted to 5,77%. No correlation was found between the length of the tunnel and corneal endothelial cell loss (Spearman coefficient=0,06).

Conclusions:

After uneventful standard phacoemulsification, the length of corneal tunnel influences the final surgically induced astigmatism, however it doesn’t influence central corneal thickness and corneal endothelial loss. FINANCIAL DISCLOSURE?: No