PERRY S. BINDER, MS MD*PERRY S. BINDER, MS MD*San Diego, California

*Dr. Binder is a paid consultant to Abbott Medical Optics, Inc. *Dr. Binder is a paid consultant to Abbott Medical Optics, Inc. and is and is

Owner of Outcomes Analysis SoftwareOwner of Outcomes Analysis Software

Purpose: To evaluate three approaches to treat post-radial keratotomy refractive errors: Surface Ablation, Mechanical Microkeratome LASIK, Femtosecond LASIK (IntraLASIK).

Methods: One surgeon. Retrospective database analysis of 105 eyes that received one of the three approaches: PRK (27 eyes), microkeratome LASIK (MK) (49 eyes), IntraLASIK (IL) (29 eyes). PRK performed with out MMC; mechanical MK and IntraLase w 160 um attempted flap thickness.

Results: 51 eyes w Hyperopic astigmatism: All 3 had improved UCVA and slight loss of 1-2 lines of BSCVA. PO MRSE was -0.21, -0.46 and -0.88 for PRK, MK, IL. Increase in Mean K was 1.45 D, 1.12 D and 3.06 IL. 34 w myopic astigmatism:Smallest loss of BSCVA w IL. PO MRSE was -0.41 D, -0.51 D, and -0.46 D for PRK, MK, and IL. Reduction in Mean K was 0.53 D, 0.73 D, and 2.04 D respectively. “Pizza pie” in 7 MK and 2 IL cases. Enhancements more difficult for LASIK cases.

Conclusions: All three procedures had a loss of 1-2 lines of BSCVA but significant improvement in UCVA with similar refractive errors; greatest change in Mean K with IL. PRK had best results for hyperopic astigmatism, IL for myopic astigmatism. No clear winner between these approaches based on analysis of a heterogeneous RK population (differences in time from RK to surgery, no. of incisions, original refractive errors, patient age, previous RK enhancements, etc.)

Methods Excimer Lasers: Summit Apex Plus,

LADARVision 4000, VISX S2-4, Allegretto 200

Microkeratomes: ACS, SKBM, BD 4000

160 um flaps were attempted

Femtosecond Laser: IntraLase 10-60 kHz

160 um flaps were attempted

Surgical Indications

Under or overcorrected RK/AK eyes >5 years after surgery

No external disease

No keratometry or pupil selection

No restriction based on BSCVA

No RK/AK wound epithelializationNo RK/AK wound epithelialization

Excluded cases with diurnal refractive change Excluded cases with diurnal refractive change >1 D>1 D

Results: Eyes OperatedHyperopic Astigmatism Presented

Total

Eyes

HyperopicAstigmatis

m

MyopicAstigmatis

m

Hyperop

ia

Myopia

PRK 27 18 7 1 1

MK LASIK

49 21 15 6 5

IntraLaseLASIK

29 12 12 1 3

Totals 105

51 34 8 9

Smaller is better

Smaller is better

Steeper is better

% %

Complications

• One slipped flap w SKBM MK• Three “Pizza Pie”: 2 MK, 1 IL• Enhancements:

• PRK = 5• MK = 7• IL = 2

Conclusions: Treatment of Refractive Errors after RK

• There are many variables in the PostOp RK eye to consider; a much larger series is

required to stratify these variables• Similar improvement in Mean K, UCVA BSCVA, SphEq. • Greater Loss ≥ 2 Lines BSCVA w IL and MK

vs PRK, but numbers too small to be statistically significant• PRK best ± 0.5 D for Hyperopic Cyl; IL best

for Myopic Astigmatism• IL with fewest enhancements• No clear “Winner”