Author :
Amogha Uday Mahale, Deepa Vishwesh Muzumdar, Varsha Nitin Kulkarni, Jayshri Baswaraj Pandhre, Sanjiv Agrawal, Shivali Madhusudan Gadewar, Bhavana Bhanudas Survase
Volume :
11
Issue :
3
Abstract :
Background: In an era of premium IOLs and increase in patients’ visual demands after cataract surgery, it is important to ensure accurate IOL power calculation. The rising incidence of dry eyes poses a challenge to record accurate keratometric readings required for IOL power calculation. This study was conducted to assess the effect of tear substitutes on keratometry at different time intervals in cataract patients with and without dry eyes.Materials and Methods: This cross-sectional study was conducted in 260 patients diagnosed to have cataract. They were classified into 2 groups based on TBUT test- 1) Dry eyes 2) Non-dry eyes. Baseline keratometry was performed using optical biometer. Keratometric readings were again obtained at 30 seconds and 5 minutes after instillation of 1 drop of 0.1% Hydroxypropyl methylcellulose. IOL power was calculated with SRK-T formula using keratometric readings at different time intervals. Data was analysed using SPSS software.Results: At 30 seconds post instillation, in patients with dry eyes, a statistically significant change in keratometry and a subsequent change in IOL power was observed (P < .001), but in patients without dry eyes, this change was not statistically significant (P=0.454 and P=0.47 respectively). There was no statistically significant difference in keratometry and IOL power at 5 minutes in both the groups. Variability of keratometry was observed to be higher in the dry eyes group as compared to the non-dry eyes group.Conclusion: Instillation of tear substitutes is likely to affect keratometry readings. In cases where they have to be invariably used to stabilize the tear film, keratometry should be done at least 5 minutes after instillation of tear substitutes.
Keyword :
IOL power calculation, Keratometry, Tear substitutes, Dry eyes.