Comparative evaluation of intra-operative aberrometry and barrett’s toric calculator in toric intraocular lens implantation
Free Paper Details
First Author: R.Mukhija INDIA
Co Author(s): M. Vanathi M. Verma N. Gupta R. Tandon
To evaluate the accuracy of intra-operative aberrometry (Optiwave Refractive Analysis, ORA, Alcon) and Barrett’s toric calculator in predicting post-operative residual astigmatism in cases of toric intra-ocular lens implantation.
Prospective, observational, non-randomized study in a tertiary eye-care hospital
Inclusion Criteria: Age > 18 years; Visually significant cataract with significant corneal astigmatism; Written informed consent Exclusion Criteria: Any co-existent ocular co-morbidity, previous intra-ocular surgery Procedure: All patients fulfilling the selection criteria would undergo MICS phaco-emulsification with toric IOL implantation with IOL power and axis placement aided by intra-operative aberrometry. Outcome Measures: 1. Uncorrected distance visual acuity (UDVA) & post-operative residual astigmatism at 1 month 2. Correlation between residual clinical refractive error, residual error prediction by ORA, and Barrett’s toric calculator.
A total of 30 patients with mean age of 59.13+11.64 were included; mean pre-op UDVA, axial length, average keratometry and keratometric astigmatism were logMAR 1.120.58, 23.480.79mm, 44.011.85D & 1.720.66D respectively. At one month post-op, mean UDVA, mean residual astigmatism and mean residual spherical equivalent was logMAR 0.090.10, 0.600.34 D and -0.190.26 D respectively. The mean residual astigmatism was calculated as 0.170.02D on ORA and as 0.200.03D using Barretts toric calculator (P=0.35). The mean difference between residual astigmatism at one month and that calculated by Barretts was 0.390.07D (P<0.05) and 0.350.05D (P<0.05) when compared to calculations by ORA.
Both intra-operative aberrometry & Barrett’s toric calculator give reliable & comparable results in prediction of post-operative residual astigmatism for toric IOL implantation. Although the difference compared to clinical residual astigmatism using both techniques was statistically significant, it may not be clinically significant.