Descriptive Analysis Of Biometric Parameters Obtained Through Optical Biometry In Cataract Surgery Candidates Based On Flat And Curved Keratometry Values At A Tertiary Hospital In Spain Between 2022 And 2025

The aim of this study is to describe the anterior segment biometric data obtained through optical biometry in patients diagnosed with cataract surgery. We categorize the patients based on flat keratometry (K1) and curved keratometry (K2) values in 3 groups and compare anterior segment measurements among them.

The study was conducted in the Ophthalmology Department at the tertiary Hospital Clínico Universitario in Valladolid, Spain. Data were collected via optical biometry (IOL Master 700, Zeiss) for patients diagnosed with cataract surgery between october 2022 and february 2025. Measurements that did not pass the quality control parameters of the biometer were excluded.

A database was created using Microsoft Excel. Patients were categorized based on K1 and K2 values into three groups: K1 and/or K2<41 diopters (D) (G1), K1 and/or K2 between 42.5-43.5D (G2), and K1 and/or K2>47D (G3). Patients with previous ophthalmic surgery or corneal disease were excluded. A descriptive analysis was conducted on the variables of interest, including axial length (AL), white-to-white (W2W) diameter, aquous depth (AQD), lens thickness (LT), in mm; central corneal thickness (CCT) in µm; K1, K2, posterior flat keratometry (KP1), posterior curved keratometry (KP2), simulated keratometry (SimK), and simulated posterior keratometry (SimKP); in D. The groups were compared using ANOVA and post hoc test Games-Howell.

From 10027 biometries 498 eyes were classified regarding K. G1 81 eyes, G2 335 and G3 82.The means were AL G1 25.65±1.47 G2 24.08±1.47 G3 22.43±1.27; K1 G1 39.54±1.09 G2 42.82±0.22 G3 47.52±0.44; K2 G1 40.25±0.83 G2 42.82±0.19 G3 48.31±0.72; SimK G1 39.89±0.94 G2 43.01±0.17 G3 47.91±0.51; KP1 G1 44.68±1.85 G2 47.39±0.89 G3 52.85±0.51; KP2 G1 46.76±1.92 G2 49.33±1.12 G3 54.96±1.46; SimKP G1 45.72±1.81 G2 48.36±0.91 G3 53.90±1.13; AQD G1 2.79±0.42 G2 2.64±0.41 G3 2.57±0.50; LT G1 4.24±0.52 G2 4.52±0.64 G3 4.60±0.89; CCT G1 552.04±30.51 G2 557.35±29.52 G3 540.79±25.81; W2W G1 12.37±0.47 G2 12.03±0.34 G3 11.36±0.31. In ANOVA, all comparisons were p<0.05; however, in post hoc test AQD G2vsG3 (p=0.66), LT G2vsG3 (p=0.83), and CCT G2vsG1 (p=0.47).

Our findings show significant differences in axial length, keratometry, and other anterior segment parameters across the three groups, which may influence surgical planning and intraocular lens (IOL) calculation. In particular Flat corneas (K<41) are associated with longer axial length and higher W2W, whereas very steep corneas (K>47) are linked to shorter axial length, smaller W2W, and thicker crystalline lenses. These differences are statistically significant in most parameters analyzed, except for AQD and LT (between G2 and G3) and CCT (between G2 and G1).