Estimation of mean keratometry from biometric data and postoperative refraction of children's eyes submitted to congenital and developmental cataract facectomy

Session Details

Session Title: Paediatric Cataract Surgery

Session Date/Time: Sunday 15/09/2019 | 16:30-18:00

Paper Time: 16:36

Venue: Free Paper Forum: Podium 2

First Author: : J.Prado Marques BRAZIL

Co Author(s): :    R. Fachinelli   A. Rodrigues                          

Abstract Details

Purpose:

To check possible observational errors of mean keratometry measured (KA) due to anesthesia by comparing KA in children examined under anesthesia preoperatively for congenital or developmental cataract surgery to mean keratometry obtained from a theoretical formula (KC) that uses the implanted intraocular lens (IOL) power value in addition to postoperative refractional and biometric data.

Setting:

A retrospective study of patients’ records with congenital or developmental bilateral cataract who underwent surgical treatment at HC-FMB.

Methods:

Seventy-three eyes in children that had at least one full postoperative exam were analyzed. Each individual eye assessment was considered one data point in the sample group, totaling 165 ophthalmic assessments. KC was determined by a theoretical formula for calculating IOL power by using postoperative biometric data (AL and ACD), postoperative automatic refractometry, and refractive power of the implanted IOL. Observational error value was obtained by subtracting KA from KC (Error = KA – KC). Statistical analysis of the observed errors and the comparison between KA and KC were made by Goodman’s association test and Kruskal-Wallis’ non-parametric test.

Results:

The mean patient age at first surgery was 954.62 days, standard deviation was 794.14 days, median was 953 days. Minimum age for the patient population was 44 days and maximum was 2659 days. Twenty-three (62.16%) patients were male and 14 (37.84%) female. KA ranged from 40.62D to 51.50D, median was 45.25D, mean was 45.32D, and standard deviation was 2.37D. KC ranged from 39.40D to 52.26D, median was 44.49D, mean was 44.54D, and standard deviation was 2.41D. Observational errors ranged from -2.28D to 3.81D, median was 0.83D, mean was 0.79D, and standard deviation was 1.18D. KA=1.0172KC.

Conclusions:

The comparison between KA and KC in children under general anesthesia showed that there is an overestimation of the value measured by KA when compared to KC. The analysis of the observational errors showed that the higher the KA, the greater is the overestimation, with significant difference (p<0.05) in the measurements over 44.00D.

Financial Disclosure:

None