OUTCOMES OF FEMTOSECOND LASER ASTIGMATIC KERATOTOMY VERSUS TORIC INTRAOCULAR LENS IMPLANTATION IN TREATMENT OF ASTIGMATIC PATIENTS UNDERGOING FEMTOSECOND CATARACT SURGERY

To evaluate the outcomes of Intrastromal Femtosecond laser-assisted Arcuate Keratotomy (ISAK) versus Toric Intra Ocular Lens (IOL) implantation in patients undergoing Femtosecond Laser-assisted Cataract Surgery in the treatment of eyes with low to moderate corneal astigmatism.

 

Egypt Air Hospital, Cairo, Egypt.

 

In this prospective interventional case series, 80 eyes with age-related cataracts and low to moderate-grade corneal astigmatism (1.0–3.0D) patients were randomly classified into two main groups.

Group 1: Includes 40 eyes that were treated with Intrastromal femtosecond Laser Astigmatic keratotomy (ISAK) using Catalys Femto Laser Cataract System.

Group 2:  Includes 40 eyes that were treated with femtosecond laser-assisted cataract surgery and Toric IOL implantation.

The study included both male and female patients aged more than 45 years and excluded patients with pre-existing corneal or retinal pathology. All patients were subjected to medical history taking and comprehensive preoperative ophthalmological examination including corrected distance visual acuity (CDVA), autorefraction, keratometry, full slit lamp and fundus examinations, biometry (IOL Master 500) and specular microscopy, corneal topography (Cirrus Pentacam) and ocular aberrometry (iDESIGN). Patients were evaluated postoperatively at 1 week, 1 month and 3 months after surgery measuring visual acuity, subjective and objective refraction, and utilizing Pentacam topographer, keratometry and idesign aberrometery to evaluate and assess corneal astigmatism and high order aberrations.

 

Eighty eyes were included in this study. Results showed that the refractive astigmatism was significantly reduced in both the toric IOL group and ISAK group (P<0.001) while corneal astigmatism was significantly reduced in the ISAK group (P <0.05). There was a marked improvement in both uncorrected and best-corrected distance visual acuity in both groups. The mean postoperative astigmatism in the toric IOL group was 0.50 ± 0.13 while in the ISAK group was 0.75 ± 0.50. At 3 months postoperatively, the toric IOL group demonstrated stable results with a significant decrease in need of spectacle correction, especially in cases with astigmatism ≥ 1.50 D, while the ISAK group demonstrated a slight correction under-correction at the 3 month follow-up assessment and decreased efficacy in moderate grade astigmatism. High order aberrations were higher in the ISAK group at 3 months follow-up than the toric IOL group. The angle of error of astigmatism in the ISAK group was ≤ 15°.

Both toric IOL and ISAK are effective in the correction of low to moderate-grade astigmatism. However, in our study toric IOL showed superior and more stable results in correction of astigmatism especially, if the magnitude of astigmatism was ≥1.50 diopter. Meanwhile, the ISAK group demonstrated slight under-correction and decreased efficacy at 3 months follow up as well as a higher incidence of high order aberrations.