Laser in situ keratomileusis for correction of residual astigmatism after cataract surgery Eun Chul Kim, M.D. , Man Soo Kim,M.D. Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea No financial relationship

Introduction high amount of corneal astigmatism after cataract surgery delays visual recovery compromises the ultimate optical outcome. Spectacle correction distortion due to meridional magnification, difficulties with binocular function. Contact lenses :not all patients can tolerate contact lenses

Introduction : To reduce corneal astigmatism Intraoperative method variation in size, location, and type of incision adjust suture depth preplaced sutures to facilitate wound closure use of surgical keratometers suture adjustment technique selective suture cutting Postoperative method Wound revision Corneal wedge resection Tensioning suture Astigmatic keratotomy Transverse keratotomy Photorefractive keratectomy (PRK) Laser in situ keratomileusis(LASIK)

Purpose To evaluated the effect of laser assisted in situ keratomileusis (LASIK) procedure on eyes with residual astigmatism after cataract surgery.

Methods Retrospectively reviewed the medical records of 11 eyes of 11 patients who had undergone cataract surgery from March 2002 to November 2005. Cataract Operation : 10 eyes: Phacoemulsification + PCL implanatation : 1 eye: Extracapsular cataract extraction + PCL transscleral fixation+ ant. vitrectomy LASIK (11 eyes) was performed on 11 eyes The ablation zone 6.0 mm the transition zone 8.0 mm minimum of 250 μm of the stromal bed was maintained

Methods Inclusion criteria of astigmatic correction refractive myopic or mixed astigmatism over 2.0D Stable refraction (change less than 0.50 D between two consecutive examinations) symptomatic anisometropia, Inability to wear spectacles Contact lens intolerance no history of systemic collagen vascular disease no history of ocular disease(e.g. glaucoma, retinopathy) central corneal thickness greater than 500 μm

Results : Refraction and visual acuity Before eximer laser surgery 6 Months After eximer laser surgery NO Age /Sex Procedure *UCVA Manifest Refraction †BCVA UCVA BCVA 1 86/M LASIK 0.1 +1.00 -5.5 x 180˚ 0.4 0.63 +0.50 -1.25 x 180˚ 0.8 2 59/F 0.25 +0.75 -3.5 x 150˚ 1.0 +0.50 -0.25 x 150˚ 3 66/M 0.2 -2.50 -2.00 x 85˚ -0.50 -0.75 x 90˚ 4 52/F -1.75 -3.00 x 175˚ -0.50 -0.75 x 170˚ 5 78/F -3.00 -4.50 x 180˚ 0.32 -0.25 -1.00 x 180˚ 6 60/M 0.5 +1.00 -2.50 x 25˚ +0.50 -0.50 x 30˚ 7 67/M 0.3 +0.50 -3.50 x 155˚ -0.25 -1.25 x 155˚ 8 68/M -1.25 -2.50 x 175˚ -0.50 sphere 9 20/M 0.08 -2.00 -5.75 x 165˚ -0.75 -1.50 x 165˚ 10 72/F -1.5 -3.25 x 95˚ -1.00 -1.00 x 90˚ 11 57/M +0.25 -2.75 x 30˚ -0.50 -0.50 x 30˚ *: UCVA = uncorrected visual acuity, †BCVA = best corrected visual acuity At 6 months after refactive surgery, best corrected visual acuity was equal to or better than preoperatively

Spherical equivalent refraction and cylinderical refraction Spherical equivalent and cylinderical refraction decreased significantly after LASIK. ( * = p <0.05)

Postoperative visual acuity UCVA and BCVA were improved at 2 weeks after surgery and were stable until 6 months after surgery. (* = p<0.05) The final BCVA was improved by 1 line in 4 eyes (36.4%) and was unchanged in 7 eyes (63.6%) at 6 months.

Reduction of Astigmatism(%) Change of astigmatism NO Preoperative Astigmatism (D) Postoperative Net Decrease in Astigmatism (D) Reduction of Astigmatism(%) 1 -5.5 x 180˚ -1.25 x 180˚ 4.25 77.27 2 -3.5 x 150˚ -0.25 x 150˚ 3.25 92.86 3 -2.00 x 85˚ -0.75 x 90˚ 1.25 62.50 4 -3.00 x 175˚ -0.75 x 170˚ 2.25 75.00 5 -4.50 x 180˚ -1.00 x 180˚ 3.5 77.78 6 -2.50 x 25˚ -0.50 x 30˚ 80.00 7 -3.50 x 155˚ -1.25 x 155˚ 64.29 8 -2.50 x 175˚ 2.5 100.00 9 -5.75 x 165˚ -1.50 x 165˚ 73.91 10 -3.25 x 95˚ -1.00 x 90˚ 69.23 11 -2.75 x 30˚ 81.82 Mean±SD -3.52±1.17 -0.80±0.44 2.73±0.96 77.70±11.20 The mean percentage of astigmatic correction was 77.70±11.20% (range 64.29 to 100%) at 6 months after refactive surgery

Predictablility for refraction and astigmatism Follow up ±0.25 D ± 0.50 D ± 0.75 D ± 1.00 D * SE † C SE C 2weeks 4(36.4) 7(63.6) 9(81.8) 10(90.9) 11(100) 1month 3(27.3) 6(54.5) 8(72.7) 2months 1(9.1%) 5(45.4) 6months 2(18.2) *: SE= spherical equivalent refraction, † : Cylinder refraction After 6 months after surgery, 4 eyes (36.4%) had a spherical equivalent refraction within ± 0.50 D, and 9 eyes (81.8%) were within ±1.00 D. Four eyes (36.4%) had a cylinder refraction within ± 0.50 D and 8 eyes (72.7%) were within ±1.00D.

Conclusion LASIK an effective, predictable, stable procedure for correction of residual myopic or mixed astigmatism over 2.0 D with a low spherical component after cataract surgery.