Correlation and Comparison of Anterior and Posterior Corneal Surface Parameters in Healthy Eyes

Doi: 10.36351/pjo.v38i3.1380

Abstract

Purpose: To correlate and compare anterior and posterior corneal surface parameters like K_flat, K_steep, K_avg, R₁, R₂, R_avg and astigmatism in healthy eyes.

Study Design: Descriptive correlational study

Place and Duration of Study: This study was conducted at Mayo Hospital, Lahore from June 2020 to Dec 2020..

Methods: This study included 176 subjects (86 males and 90 females) with mean age of 28.06±9.68 and 28.13±8.24 respectively. The data was collected through non-random convenient sampling technique by self-made proforma after taking patients’ consent. Anterior and posterior corneal parameters (K_flat, K_steep, K_avg, R₁, R₂, R_avg and astigmatism) were measured with GALILEI G4. Pearson correlation test was used for correlation and independent sample t-test / Mann-Whitney U test was used for comparing means of anterior and posterior corneal parameters. Data was entered and analyzed in SPSS-21.

Results: Mean of anterior and posterior corneal curvatures was 44.21±1.01 D and -6.22±0.19 D[p<0.001], K_flat was 43.76±0.99 D and -6.08±0.19 D [p<0.001] and K_steep was 44.66±1.08 D, -6.34±0.21 D, respectively [p<0.001]. The anterior and posterior corneal curvature R_avg was 7.63±0.17 mm, 6.44±0.200 mm [p<0.001], mean R1 was 7.71±0.17 mm, 6.58±0.21 mm, [p<0.001] and mean R2 was 7.56±0.18 mm, 6.31±0.21 mm, respectively [p<0.001]. Anterior posterior corneal astigmatism was 0.90±0.55 D and -0.25±0.11 D, respectively [p<0.001].Anterior corneal parameters also show strong correlation with posterior corneal parameters.

Conclusion: There are significant difference between corneal parameters of anterior and posterior surface. Strong correlation was also found in anterior and posterior corneal parameters except corneal astigmatism.