Hyperopic refraction accompanied by irregular astigmatism after radial keratotomy: two-step technology for optical rehabilitation

Session Details

Session Title: Advanced Tools for Outcome Assessment

Session Date/Time: Tuesday 17/09/2019 | 08:30-10:30

Paper Time: 09:14

Venue: Free Paper Forum: Podium 4

First Author: : I.Mushkova RUSSIA

Co Author(s): :    N. Maychuk   A. Ignatyev                          

Abstract Details

Purpose:

To assess clinical results of the optical rehabilitation in patients with hyperopic refraction accompanied by irregular astigmatism after Radial Keratotomy (RK) with two-step technology included native lens extraction and IOL implantation with targeted myopic refraction followed by trans-epithelial topography-guided photorefractive keratectomy (TT-PRK).

Setting:

Sv. Fyodorov Eye Microsurgery Federal State Institution, Moscow, Russia.

Methods:

79 eyes with hyperopic refraction accompanied by irregular astigmatism after RK were divided into Main Group (MG) corrected by elaborated two-step technology - 44 eyes, and Control group (CG) corrected by phacoemulsification of the native lens and IOL implantation for the correction of post-RK refractive disorders – 35 eyes. Examination before and 1 year post-operatively included UCVA, BSCVA, efficacy, safety, accuracy, spherical equivalent of the refraction (SE), corneal topography, Scheimpflug tomography were performed in all patients. TT-PRK was performed at excimer laser MicroScan-Visum 500 Hz with topography-guided ablation, calculated with KeraScan software (both “OptoSystems”, Russia).

Results:

Mean SE decreased from 6.79±1.53D to -0.43±0.29D in MG, from 5.21±1.21D to -1.73±1.13D in CG. UCVA increased from 0,20±0,16 to 0,76±0,17 in MG, from 0.10±0.14 to 0.37±0.16 in CG; BSCVA from 0,46±0,17 to 0,83 ± 0,14 in MG, from 0.31±0.18 to 0.65±0.21 in CG. Keratotopography indexes decreased in MG: SRI from 0.77±0.31 to 0.46±0.13, SAI 1.50±0.88 to 0.67±0.36 and were stable in the CG (SRI: 0.70±0.28 and 0.71±0.30, SAI: 1.34±0.77 and 1.33±0.78 (pre- and post-op. respectively)). 68.2% in MG and 45.7% in CG gained ≥1 lines. 65.9% in MG and 28.6% in CG were ±0.5D of intended SE.

Conclusions:

Two-step technology of the clinical rehabilitation in patients with hyperopic refraction accompanied by irregular astigmatism after RK included native lens extraction and IOL implantation with targeted myopic refraction followed by trans-epithelial topography-guided photorefractive keratectomy (TT-PRK) showed better clinical results compare to the intraocular correction of post-RK refractive disorders. This may be caused by the elimination of the corneal irregularity and higher predictability of corneal “fine-tuning” allowed to correct any refractive errors in elaborated technology in contrast to the IOL calculation, which is as well known may be challenged in case of damaged cornea.

Financial Disclosure:

None