Advanced LASIK platform improves outcomes for topography-guided repair

Chicago-Topography-guided LASIK performed with a platform consisting of the Atlas 995 topographer, the CRS-Master software program for ablation planning, and the MEL-80 excimer laser (Carl Zeiss Meditec) offers a safe and highly successful method for improving outcomes in eyes with debilitating vision complaints after previous refractive excimer laser surgery, said Frank J. Goes, MD, at the refractive surgery subspecialty day meeting sponsored by the International Society of Refractive Surgery of the American Academy of Ophthalmology.

In an analysis of the first 14 patients, Dr. Goes found eight (57%) were completely free of symptoms after the first re-treatment and four others (29%) benefited markedly. The remaining two needed a second procedure to improve their subjective complaints. For the group, mean uncorrected visual acuity (UCVA) improved from 0.4 to 0.65, mean best-corrected visual acuity (BCVA) increased from 0.71 to 0.85, and contrast acuity improved from 0.4 to 0.8. Subjective complaints were reduced by 75%.

"This approach is proving itself to be a safe and valuable technique for enlarging optical zones or repairing and smoothing eyes that have previously undergone ablation surgery. With advances in refractive surgery, such cases are occurring less and less. There, however, are still many individuals who are suffering, even to the point of not being able to drive at night, and who could not be treated adequately with previously available technology," Dr. Goes said.

"The primary goal of the re-treatment is not to provide 20/20 uncorrected vision, but to eradicate or minimize the visual disturbances. So far, it has been very successful in achieving that goal. These patients are very grateful, and in no case has any patient been made worse. The pre-treatment counseling, however, must inform these candidates that they may need a second procedure for fine-tuning the results," he said.

The platform links the corneal topography information from the Atlas 995 topographer to the laser via the CRS-Master. That sophisticated software allows surgeons the options of using a straightforward routine mode, in which the program does all the ablation planning, or choosing interactive optimization, where the treatment plan can be reviewed and modified for adjustment of its depth or size. In addition, the system can also integrate wavefront information obtained with the WASCA aberrometer and perform a wavefront-guided or combination topographic- and wavefront-guided treatment.

"This updated platform uses a completely new algorithm that is very user-friendly and assures treatment reliability. The outcome is now less dependent on the surgeon's personal experience with re-treatment planning, but at the same time, it permits the surgeon to provide input when desired and be master of the calculations through the optimization mode," Dr. Goes said.

Dr. Goes also noted that the advanced MEL-80 laser plays an integral role in the success of the platform for re-treating these challenging eyes because it is designed to provide precise delivery of the ablation profile. The MEL-80 features a Gaussian beam with a small, 0.7-mm flying spot; an ultrafast, closed-loop infrared video tracking system that is easy to handle; and rapid shot delivery at a frequency of 250 Hz using ultra-high-efficiency beam-path transfer technology.