Outcomes of manual arcuate keratotomy with compression sutures for high regular postkeratoplasty astigmatism.

PURPOSE

To report functional and refractive outcomes of manual arcuate keratotomy (AK) with compression sutures for high regular postkeratoplasty astigmatism.

SETTING

Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany.

DESIGN

Retrospective analysis.

METHODS

This study included 90 eyes with high regular postkeratoplasty astigmatism (>4 diopters [D]) who received AK with compression sutures between 2010 and 2022. Functional and refractive outcomes were assessed by evaluating topographic indices and by performing vector astigmatism and Fourier analysis.

RESULTS

At last follow-up (mean 13.7 ± 16.6 months), corrected distance visual acuity improved from 0.59 ± 0.28 to 0.34 ± 0.25 logMAR. Cylinder magnitude decreased from 9.91 ± 2.88 to 5.42 ± 3.35 D. Surface asymmetry index, irregular astigmatism index, and corneal eccentricity index were equal to preoperative values, whereas surface regularity index approached normal values at last follow-up. Fourier analysis indicated a decrease in the regular astigmatic component, whereas nonregular components (asymmetry and higher-order irregularity) remained stable. In vector astigmatism analysis, target-induced astigmatism magnitude was 9.92 ± 2.86 D and surgically induced astigmatism magnitude was 10.16 ± 4.86 D (correction index of 0.91 ± 0.48) with a difference vector of 5.42 ± 3.35 D at last follow-up. Correction of astigmatism magnitude was adequate in 40% of the eyes, undercorrected in 30%, and overcorrected in 30%. Angle of error was <|22.5 degrees| in 88% resulting in a low risk of off-axis treatment.

CONCLUSIONS

AK with compression sutures is a simple, relatively effective, and safe surgical procedure for astigmatism reduction after keratoplasty. In case of regular astigmatism, the procedure does not increase corneal irregularities. The remaining refractive error might be further corrected by spectacles, contact lenses, or toric intraocular lens implantation (in-the-bag/add-on), thus reducing the need for repeat keratoplasty.