The estimated prevalence of astigmatism in the United States is 36.2% of the population (Vitale et al, 2008). Frequent replacement soft contact lenses are routinely fit to correct astigmatism, and a few designs also have multifocal power for the correction of presbyopia. Surprisingly, astigmatism can change after oculoplastic surgery, requiring a necessary refit.

A 63-year-old female patient had moderate astigmatism and a stable refraction of OD –3.75 –1.50 x 075, 20/20 and OS –4.75 –1.50 x 114, 20/20. Over the past seven years, she had been successfully wearing monthly replacement soft toric multifocal lenses with distance correction of OD –3.50 –1.75 x 070, 20/25 and OS –4.25 –1.75 x 120, 20/25. The near add power in each lens was +2.00D. The right lens had a center-near design, and the left had a center-distance design; this allowed her to see J1 vision at 40cm.

The patient slowly started to develop a bilateral ptosis (OS > OD) without neurological findings. She was referred to an oculoplastic specialist in 2016 who assessed her functional visual field. At that assessment, her Goldman visual fields were OD 51% superior field impairment to within 22º of fixation and OS 71% of superior visual field impairment within 12º of fixation. The patient opted for no surgical intervention. I followed the patient for the next three years, and there was no significant change in refraction and no change in her contact lens prescription.

In 2019, her ptosis had worsened and her Goldman visual field assessment measured OD 65% of superior field impairment to within 15º of fixation and OS 71% of superior field impairment to within 12º of fixation. She opted for functional ptosis surgery and had a bilateral external levator advancement (ELA) for both eyes. She was initially very satisfied with the surgery and subjectively noticed her improved functional visual field.

However, two months postoperatively, she complained of worse visual acuity with her left eye. The patient’s OS distance visual acuity with her toric soft lens was now 20/60, and she had a manifest refraction OS of –6.25D sphere, 20/20. Corneal topography of her left eye (Figure 1) revealed mild irregularity that was most likely secondary to dryness.

Based on these findings, I gave her an updated left glasses prescription and dispensed a diagnostic soft multifocal lens with a power of –5.75D sphere/+2.00D (center distance), 20/20 distance and J1 near in both eyes.

Postoperative Refitting

Numerous studies have shown astigmatism changes post-blepharoplasty or -ptosis repair (Simsek et al, 2015; Zinkernagel et al, 2007; Brown et al, 1999; Holck et al, 1998; and others. Full list available at www.clspectrum.com/references .). Kim et al (2016) analyzed preoperative and postoperative corneal topographies of 50 eyes of 34 patients who had varying degrees of dermatochalasis or ptosis who underwent surgical correction. For those eyes undergoing levator resection, 50% showed decreased astigmatism, 19.2% showed increased astigmatism, and 30.8% had no change six weeks postoperatively.

Although there can be significant variability depending on a patient’s reason for ptosis and type of repair, this case example highlights that any patient undergoing oculoplastic lid surgery should be counseled about the potential for a postoperative refractive change. CLS

For references, please visit www.clspectrum.com/references and click on document #298.