Correction of irregular postkeratoplastic astigmatism in patients with cataract

Abstract

Introduction. Penetrating keratoplasty (PKP) is known to lead to the occurrence of post-keratoplasty astigmatism (PA) that is often of a high degree and irregular shape. Phacoemulsification (PE) with implantation of toric intraocular lenses (toric IOLs) is able to compensate for regular PA. However, this method is not effective enough with irregular PA.The aim was to conduct a clinical and functional analysis of the combined method for correcting irregular postkeratoplastic astigmatism (PA) in patients with cataract.Materials and methods. The study has been conducting from February 2018 to September 2022. We operated on 27 eyes (27 patients) aged 38 to 52 years. Of these, there were 17 men and 10 women. All patients with a history of 4–6 years ago underwent penetrating keratoplasty for stage IV keratoconus and pellucid marginal degeneration of the cornea. In all patients, an irregular form of PA was noted according to keratotopography. Surgical treatment of these patients took place in 2 stages. At the stage I, in order to correct irregular PA and increase sphericity and regularity of the penetrating corneal graft, MyoRing was implanted into the intrastromal pocket having been formed in it using a femtosecond laser. One year after the MyoRing implantation, the stage II was performed – cataract phacoemulsification (CPE) with implantation of an intraocular lens (IOL). The follow-up period after the CPE with the IOL implantation was 1 year.Results. One year after the MyoRing implantation into the penetrating corneal graft, a slight increase in visual acuity was noted. However, there was a pronounced decrease in corneal astigmatism by an average of 4.9 times, an increase in sphericity and regularity of the penetrating corneal graft according to keratotopography, as well as an increase in its biomechanical properties. One month after the operation, there was an increase in uncorrected visual acuity (UCVA) by 6.8 times and best corrected visual acuity (BCVA) – by 3.9 times, a decrease in the cylindrical component of refraction to –0.65 ± 0.28 D that no longer changed.Conclusions. The combined method for correcting irregular PA in patients with cataract by MyoRing implantation into a penetrating corneal graft followed by CPE with IOL implantation showed a high refractive result, stability and safety in the late postoperative period.