A study has revealed that eye muscle surgery, which is performed to correct the position of the eyes in patients suffering from “crossed eyes”, also improves binocular vision.
The study titled “Binocular summation in comitant exotropia: Change after surgery” conducted by ophthalmologists of King George’s Medical University (KGMU) has found that on 20 children aged between four and eight years who had “crossed eyes”, a change was seen.
Prof Siddhartha Agrawal, faculty at ophthalmology department, KGMU, who led the study, was felicitated with “Best Clinical Paper” at KGMU research showcase 2022.
The study was conducted to assess change in binocular summation (BiS) in children whose one eye had been deviating outward to the other eye. They underwent eye-muscle surgery in 2021 and were under observation for three months after the operation.
“BiS score that shows the change in vision observed when both eyes are used (binocular) in comparison to one eye was calculated for the purpose. It was found that BiS had improved post-surgery earlier; it was not considered as a benefit of eye muscle surgery,” he added.
“For BiS, we recorded vision and contrast sensitivity of both eyes separately and together (binocularly). Later, before and after the surgery results were compared,” said Prof Siddhartha.
For measuring vision, a method of visual acuity (VA) examination was used in which a series of tests were performed to assess vision and ability to focus on and discern objects.
A Pelli Robson test was done to measure a patient’s contrast sensitivity (CS) by finding the lowest contrast letters.
“All patients had a successful motor outcome after surgery. It was found that post surgery VA score improved from average 2. 9 to 4. 5 and SC improved from 2. 7 to 4. 5,” he added.
“Though the sample size was less and further studies are needed to establish it, we recommend its inclusion in evaluation of functional outcome of eye muscle surgery,” said Prof Siddhartha.