How much astigmatism to treat in cataract surgery

Astigmatism correction in cataract surgery is a common surgical challenge. Although there are numerous approaches to its treatment during cataract surgery, there remains a lack of consensus on what level of postoperative astigmatism to target. We examine the literature to determine the effect of astigmatism on visual function and provide a recommendation on how much to treat in cataract surgery.

Distance visual acuity decreases as myopic, hyperopic, or mixed astigmatism increases. Near visual acuity decreases with hyperopic astigmatism but improves with myopic astigmatism. The effect of astigmatism is generally independent of axis; however, against-the-rule (ATR) astigmatism with mild myopia may benefit reading. A progressive ATR shift occurs with age whether or not an individual undergoes cataract surgery. In the presence of higher order aberrations, correction of astigmatism below 0.5 D shows minimal practical benefit. Presbyopia-correcting intraocular lenses (IOLs) are sensitive to astigmatism but achieve distance visual acuities similar to monofocal IOLs and reach their full near and/or intermediate potential when residual astigmatism 0.5 D or less.

In cataract surgery, we recommend correction to 0.5 D or less of postoperative residual astigmatism to achieve optimum visual function and patient satisfaction following cataract surgery.