Dr. Nitin Balakrishnan, Crystal Vision Laser Centre, Mumbai, India.

Dr. Shilpa Kodkany,Dr. Kodkany’s Eye Care Centre, Belgaum, India. .

No author has any financial or proprietary interest in any materials or methods mentioned

PURPOSE

To compare the results of Laser in situ keratomileusis (LASIK) & Mitomycin C assisted, Laser subepithelial keratomileusis (LASEK), to correct residual refractive errors following cataract surgery.

DESIGN Dual centre, comparative, retrospective

study.

METHODS Nineteen Patients (20 eyes) - 10 males & 9 females

had LASIK. Nineteen Patients (19 eyes) - 8 males & 11 females

had LASEK. Patient’s Age varied from 51 to 66 years. Interval between Cataract Surgery and Refractive

procedure – 3 to 36 months(mean 14 months). All Patients had Phakoemulsification with In the Bag

IOL implants. Pre-op Spherical Equivalent Refraction (SEQ) - + 4

to – 5 Diopters..

METHODS LASEK performed with 20% alcohol, for Mechanical Epithelial Debridement.

Ablated bed treated with 0.02% Mitomycin C for 90 seconds

LASIK flap made with Moria MII microkeratome, with a thickness of 130 or 90 microns.

Wavelight Allegreto eximer laser was used for all patients.With repetition rate of 200 Hz & optical zone of 6 or 6.5mm.Eyes with tracking difficulties were excluded.

Uncorrected Visual Acuity (UCVA),Best Spectacle-corrected Visual Acuity(BSCVA), percentage of eyes within Half diopter (D) of targeted refraction, targeted v/s achieved spherical equivalent correction and gain/ loss in Snellen’s lines were compared between the two groups.

Length of follow up - 6 months

RESULTS - UCVA

Postoperative period (months)

Per

cen

tag

e o

f ey

es with

UC

VA

≥ 2

0/20

Mean UCVA better in the LASIK group from 1 – 4 months

No significant difference in mean UCVA at 6 months

RESULTS - BSCVA

Postoperative period (months)

Per

cen

tag

e o

f ey

es with

BS

CV

A ≥

20/

20

Mean BSCVA better in the LASIK group from 1 to 3 months

No significant difference in mean BSCVA from 4 to 6 months

RESULTS - Post op Spherical Equivalent Refraction - 6 months

Post op Spherical Equivalent Refraction in D

Per

cent

age

of e

yes

RESULTS - Percentage of eyes within ± 0.5D of Targeted Refraction

RESULTS - Targeted v/s Achieved Spherical Equivalent Refraction(LASIK) Group

Targeted

20 eyes

Targeted v/s Achieved Spherical Equivalent Refraction(LASEK) Group19 eyes

RESULTS - CHANGE IN SNELLEN’S LINES OF BCVA

Per

cent

age

of e

yes

No eyes lost 2 or more Snellen’s lines of BCVA

6 eyes gained 1 Snellen’s line of BCVA in Both groups2 eyes gained 2 Snellen’s lines of BCVA in LASIK group v/s 1 eye in LASEK group

CONCLUSIONS Both Mitomycin C assisted LASEK and LASIK effective in

correcting post Cataract residual refractive errors. Short term superiority of LASIK over LASEK in the

immediate post-op period. Equally good refractive correction at 6 months Gain in Snellen’s lines in BCVA, almost equal in both

groups. Subepithelial Haze in LASEK group significantly less due

to Mitomycin C , which decreased from Grade I + in first 2 months to < grade 0.5 at 6 months.

Longer term studies required to determine refractive stability of the two procedures.

REFERENCES1.Ahn CS, et al. Initial results of PRK & LASIK performed by a single surgeon. J Cat Ref Surg 1999;25:1048-10552.Steinert RF, et al. Surgical correction of moderate myopia. II, PRK & LASIK are the treatments of choice. Surv Ophthal 1998;43:157-1793.Ayala MJ, et al. LASIK to correct residual myopia after cataract surgery. J Refract Surg 2001; 17: 12-164.Sanchez-Galeana CA, et al. LASIK & PRK for residual ref error after phakic IOL implantation. J Refract Surg 2001;17:299-3045.Guell JL, et al. LASIK for correction of residual ref errors from previous surgical procedures. Ophthalmic Surg Lasers 1999;30:341-3496. Artola A, et al. PRK for residual myopia after cataract surgery. J Cat Ref Surg 1999;25:1456-14607.El Danasoury MA, et al. Comparison of PRK with LASIK in correcting low myopia: a randomised study. Ophthalmology 1999;106 :411-4208.El-Maghraby A, et al. Randomised bilateral comparison of LASIK and PRKfor 2.5 to 8 D of myopia. 1999;106:447-457