Posters

Effect of cataract surgery incision site on total keratometry measured by a swept source optical coherence tomography biometer

Poster Details

First Author: A.Carreira PORTUGAL

Co Author(s):    F. Moraes   T. Loureiro   D. Lopes   G. Alves   J. Cardoso   N. Campos     

Abstract Details

Purpose:

To assess the effect of cataract surgery incision site on total keratometry, measured by a Swept Source Optical Coherence Tomography (SS-OCT) biometer.

Setting:

Ophthalmology Department of Garcia de Orta Hospital, Almada, Portugal.

Methods:

This prospective study enrolled patients undergoing phacoemulsification surgery with a 2.4mm clear corneal incision (CCI) and monofocal intraocular lens implantation. Anterior segment parameters, steep K (K2) and flat K (K1) of anterior and total corneal surface and anterior astigmatism (AA) and total astigmatism (TA) were assessed by Zeiss IOLMaster 700 preoperatively and one month after surgery. Patients were divided according to incision site: temporal steep-axis CCI (group 1), nasal steep-axis CCI (group 2), temporal CCI 20º-45º from steep-axis (group 3) and nasal CCI 20º-45º from steep-axis (group 4). CCI was created under the guidance of Alcon VERION.

Results:

Nineteen patients were included in group 1, 19 in group 2, 15 in group 3 and 25 in group 4. AA and TA decreased in group 1 (average 0,32D, p=0.002; 0,37D, p=0.002, respectively) and group 2 (average 0.15D,p < 0.001; 0.07D, p=0.04, respectively). AA and TA increased in group 3 (average 0.20D, p=0.08; 0.54D, p=0.02, respectively) and group 4 (average 0.36D, p < 0.001; 0.53D, p < 0.001). Surgically induced astigmatism (SIA) measurements were similar to total SIA values in all groups (p > 0.05).

Conclusions:

Our study confirmed that steep-axis CCIs are associated with a decrease in both AA and TA and tend to be more effective in reducing corneal astigmatism when done in the temporal quadrant compared to the nasal quadrant. In cases of off-axis CCIs, there was an increase in corneal astigmatism regardless of incision site, especially in TA compared to AA. In our study, there were not significant differences between SIA and total SIA values, which suggests that both measurements are equivalent in clinical practice.

Financial Disclosure:

None