The keratometry changes pre and post-applanation tonometry

Purpose: The purpose of this study is to investigate the effect of applanation tonometry on keratometry measurements. Study Design: Prospective observational study Methods: 100 patients presenting to the outpatient department of a tertiary care hospital for cataract surgery were enrolled in the study. Keratometry measurements were performed on 200 eyes from 100 patients with IOLMaster 700 before and after performing Goldman applanation tonometry. Paired t-test analyses were used to compare measurements taken prior to and following applanation tonometry. P-values less than 0.05 are considered as statistically significant. Results: After applanation tonometry, ACD increased to 0.029 (P < 0.292). No other statistically significant and no clinically meaningful differences were observed in keratometry and other parameter measurements before versus after applanation tonometry. Age and time gaps do not significantly affect changes, except multivariate analysis shows ACD significantly changes post-tonometry. ACD change is influenced by pre-tonometry ACD (p<0.001) and the time gap between measurements (p=0.001). Conclusion: Goldman applanation tonometry did not affect the keratometry or other parameters measured by the IOL Master 700, with the exception of ACD measurements. Further studies are needed to explore the underlying mechanisms behind these changes. These findings highlight the importance of considering baseline ACD and timing when interpreting post-tonometry biometry changes