Need for second cataract surgery depends on vision in fellow eye
MedWire News: Performing second eye cataract surgery may only improve patients' visual functioning if their fellow eye has minimal cataract or good visual acuity, show study results from a Singaporean cohort.
Indeed, the data indicate that bilateral cataract surgery only has a significantly greater benefit to visual functioning compared with unilateral surgery when the fellow eye has poor visual acuity or significant cataract.
"These findings support the benefits of second eye surgery in eyes with bilateral significant cataract, as demonstrated previously," say Anna Tan (Singapore National Eye Centre) and colleagues.
The team believes their results may be useful in determining resource allocation and public funding levels for cataract surgery, and that second eye surgery should only be considered based on the health and vision of the fellow eye.
The researchers assessed visual functioning in a cohort of 3225 people, defined as the level of difficulty in performing activities of daily living. A score of 0 denoted no difficulty, and 4 denoted being unable to perform that activity.
In all, 151 participants had bilateral cataract surgery, the majority (n=98) of whom had no or mild visual impairment in both eyes. Similarly, among 130 participants who had unilateral surgery, 41.9% had no or mild visual impairment in both eyes.
Tan and co-authors compared visual functioning among participants who underwent bilateral and unilateral surgery, and found similar results for both groups in terms of visual function, at 3.22 versus 3.25.
Furthermore, they write in the British Journal of Ophthalmology, when the fellow eyes of unilateral cataract surgery patients presented with a visual acuity better than 6/12 (measured using a logarithm of the minimum angle of resolution [LogMar]), there was no significant difference in visual function scores from their bilateral surgery counterparts, at 3.38 versus 3.25.
By contrast, when unilateral surgery participants' fellow eye had a significant cataract, visual function was significantly worse than that of their peers who underwent bilateral surgery, at 2.81 versus 3.25. Tan et al also noted the same trend when the fellow eye had a LogMar score of less than 6/12, with visual functioning scores of 2.78 for unilateral surgery and 3.25 for bilateral surgery.
The findings support use of a visual acuity cutoff of approximately 6/12 or worse as an indication for cataract surgery, suggest Tan and co-workers.
By Sarah Guy