Reducing the burden of spectacles after cataract surgery in outreach camps in Uttar Pradesh (India)

Session Details

Session Title: Orbis Treatment and Prevention of Blindness in the Developing World

Session Date/Time: Monday 24/09/2018 | 12:15-12:45

Paper Time: 12:27

Venue: Stolz 1

First Author: : R.Malik INDIA

Co Author(s): :    V. Malik   K. Malik                 

Abstract Details

Purpose:

1.To find out the residual spherical refractive error after phacoemulsification surgery. 2.To optimize the A constant of SRK II formula, using the residual spherical refractive error. 3.To use the optimised A constant to calculate PCIOL power to eliminate/reduce residual spherical refractive error - Hence reduce the need for Post-op spectacles.

Setting:

Subharti Medical College, Meerut, UP, India

Methods:

The study includes 150 eyes of 150 cataractous patients. Phacoemulsification carried out by a single surgeon. Using the post-operative RSRE and the Pre-operative keratometry and Axial lengths, a ‘Surgeon specific A-constant’ is deduced to be used in the SRK-II formula, using “Initial IOL constant calculation sheet”, developed by Warren E. Hill. Patients divided as: Group-A(75 patients) Patients will undergo phacoemulsification, and post-op RSRE calculated at 6 weeks. Using RSRE, a new A-Constant will be calculated. Group-B(75 patients) The new A-constant will be used to calculate the IOL power. The RSRE will be observed at 6 weeks, compared with Group A.

Results:

The mean RSRE at the end of 6-weeks for Group-A was -0.2733±0.6879 DS. 53.33% cases were Myopic (RSRE <0DS), 25.33% emmetropic (RSRE 0DS) and 21.33% Hypermetropic (RSRE >0DS). Using RSRE, the new A-Constant derived was 117.35±1.89. For group-B, IOL power was calculated using new A-Constant. The mean RSRE at the end of 6 weeks for group-B was 0.0833±0.2674 DS. 12% cases were myopic, 57.33% emmetropic and 30.67% hypermetropic. The RSRE at the end of 6 weeks for group-A and group-B were compared using the Unpaired t-test. The p-value was found to be < 0.0001, and hence extremely statistically significant (p-value<0.05).

Conclusions:

In our setup, majority patients were left myopic after phacoemulsification. Using the new ‘Surgeon specific’ A-Constant, this myopic trend changed towards Emmetropia. Optimising the A-Constant for SRK-II formula to get a surgeon specific A-Constant is an effective method of reducing the RSRE, and hence need for spectacles. Discrepancy regarding the accuracy of the preoperative measurement of the ocular axis length is suggested to be the main cause of unpredicted postoperative refractive errors. Hence, a Surgeon specific A-Constant can be used in setups still relying on Indentation techniques of Axial length measurement.

Financial Disclosure:

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