Peripheral corneal relaxing incisions after excimer laser refractive surgery

Outcomes of peripheral corneal relaxing incisions for residual astigmatism in patients after cataract surgery

PURPOSE

To evaluate the outcomes of peripheral corneal relaxing incisions (PCRIs) for correcting residual astigmatism in eyes after cataract surgery.

SETTING

Cullen Eye Institute, Baylor College of Medicine, Houston, Texas.

DESIGN

Retrospective case series.

METHODS

Retrospectively, we reviewed all consecutive cases that had previous cataract surgery and subsequent PCRIs by 1 surgeon. The PCRI length was determined according to a nomogram based on age and manifest refractive astigmatism. Visual acuity and manifest refractive astigmatism before and after the PCRIs were compared. Vector analysis was performed, and net refractive changes along the incision meridian were calculated.

RESULTS

Criteria were met by 111 eyes. After the PCRIs, mean uncorrected visual acuity was significantly improved, and the percentage of eyes with uncorrected distance visual acuity of ≥20/20 increased significantly by 36%; the mean refractive astigmatism magnitude decreased significantly, and the percentages of eyes with refractive cylinder of ≤0.25 diopters (D) and ≤0.50 D increased significantly by 63% and 75%, respectively (all P < .05). The vector magnitude difference between pre- and post-operative refractive astigmatism was 0.88 ± 0.38 D. The postoperative refractive astigmatism had significantly smaller centroid and variance values than the preoperative refractive astigmatism ( P < .05).

CONCLUSIONS

PCRIs are an effective approach for correcting low amounts of residual astigmatism in patients after cataract surgery.

Can opposite clear corneal incisions have a role with post-laser in situ keratomileusis astigmatism?

PURPOSE

To evaluate the astigmatic correcting effect of paired opposite clear corneal incisions (OCCIs) on the steep axis in patients with residual astigmatism after laser in situ keratomileusis (LASIK) MATERIALS AND METHODS: Thirty-one eyes of 24 patients with a mean age of 28.4 years ±2.46 (range, 19-36 years) were recruited for the study. Inclusion criteria included residual astigmatism of ≥1.5 diopter (D) after LASIK with inadequate residual stromal bed thickness that precluded ablation. The cohort was divided into two groups; group I (with astigmatism ranging from -1.5 D to -2.5 D) and group II (with astigmatism > -2.5 D). The steep axis was marked prior to surgery. Paired three-step self-sealing opposite clear corneal incisions were performed 1-mm anterior to the limbus on the steep axis with 3.2-mm keratome for group I and 4.1 mm for group II. Patients were examined 1 day, 1 week, 1 month, 3 months and 6 months, postoperatively. Visual acuity, refraction, keratometry, and corneal topography were evaluated preoperatively and postoperatively. Analysis of the difference between groups was performed with the Student t-test. P<0.05 was considered statistically significant.

RESULTS

The mean uncorrected visual acuity (UCVA) improved from 0.35±0.13 (range, 0.1-0.6) to 0.78±0.19 (range, 0.5-1) in group I and from 0.26±0.19 (range, 0.1-0.5) to 0.7±0.18 (range, 0.4-1) in group II. The increase in UCVA was statistically significant in both groups (P=0.001, both cases). The mean preoperative and postoperative keratometric astigmatism in group I was 2.0±0.48 D (range, 1.5-2.5 D) and 0.8±0.37 D (range, 0.1-1.4 D), respectively. The decrease in keratometric astigmatism was highly statistically significant in group II (P=0.001.). Mean surgically induced astigmatic reduction by vector analysis was 1.47±0.85 D and 2.21±0.97 D in groups I and II respectively. There were no incision-related complications.

CONCLUSIONS

Paired OCCIs were predictable and effective in correcting post-LASIK astigmatism and required no extra surgical skill or expensive instruments. OCCIs are especially useful in eyes with insufficient corneal thickness for LASIK retreatment.

[Evaluation and quality assurance of refractive surgery procedures by the German Ophthalmological Society and the Professional Association of German Ophthalmologists. Status: May 2011]

The Commission of Refractive Surgery (KRC), which is a combined commission of the German Ophthalmological Society (DOG) and the Professional Association of German Ophthalmologists (BVA), has made an up-to-date evaluation of the operative techniques for correction of refraction errors. In the revised guidelines drawn up by the KRC for evaluation and safeguarding the quality of refractive surgical procedures the description, area of application, limitations, side-effects and complications of each procedure are given according to the published scientific literature. By this means a comprehensive explanation for and investigation of patients should be safeguarded, optimal treatment results achieved and complications avoided. In this article all relevant forms of refractive surgery (photorefractive keratectomy, LASEK, EPI-LASIK, LASIK, Femto-LASIK, RELEX, conductive keratoplasty, astigmatic keratotomy, limbal relaxing incisions, intracorneal ring segments, corneal cross-linking, phakic intraocular lenses, refractive lens exchange, corneal presbyopia implants, INTRACOR) are described in detail and quality guidelines are established. Refractive surgical care and additional medical services possibly arising prior to or following this treatment are not basically covered by the statutory health insurance (GKV).

Basic knowledge of refractive surgery: correction of refractive errors using modern surgical procedures

INTRODUCTION

Refractive ophthalmic surgery allows refractive errors to be corrected permanently in a safe, effective, and reliable way with few complications.

METHODS

Selective literature review with special reference to the guidelines of the German Commission for Refractive Surgery.

RESULTS

With a total of almost 18 million treatments performed to date, laser in-situ keratomileusis (LASIK) is the most commonly used refractive surgical procedure worldwide. Alternatives to LASIK include surface ablation procedures (PRK, LASEK, Epi-LASIK) and phakic intraocular lens implantation. If ocular accommodation is lost, removal of the crystalline lens and implantation of modern multifocal intraocular lenses (refractive lens exchange) provide an alternative means of correcting myopia, hyperopia and presbyopia.

DISCUSSION

The treatment effect is maximized and complications kept to a minimum if strict inclusion criteria are applied and a high technical standard maintained during the procedure.

Surgical techniques in phacoemulsification

PURPOSE OF REVIEW

Recent advances in cataract surgical techniques are described, focusing on the evolution towards less traumatic surgery.

RECENT FINDINGS

Smaller incisions, split infusion, astigmatic management, and techniques of managing floppy iris syndrome are significant changes in the cataract surgical technique within the last 12-24 months.

SUMMARY

Surgeons need to learn the new techniques and instrumentation as cataract surgery moves towards less invasive surgery, with smaller incisions, more precise refractive outcomes, and fewer complications.