Outcomes of spherocylinder treatments in the comprehensive refractive surgery LASIK study.

The CRS LASIK Study is a surgeon-sponsored collaborative project to evaluate LASIK outcomes with the Summit and VISX lasers. The current report includes 3-month outcomes in the first group of patients who underwent spherocylindrical corrections of 1 to 10 diopters of myopia and 1 to 4 diopters of astigmatism with the Summit Apex Plus and VISX Star lasers. Cohort selection criteria were applied to select 911 eyes that underwent surgery between April 1, 1996 and October 1, 1997 in the range of study. Eyes with preoperative best spectacle-corrected visual acuity of worse than 20/40 (0.5) were excluded. Outcomes were stratified according to myopic treatment range. One day uncorrected visual acuity was 20/40 or better in 83% of eyes with both lasers. At 3 months, 20/40 uncorrected acuity was found in 93% of Summit and 90% of VISX eyes in the -1.00 to -4.00 D group, in 88% of Summit and 84% of VISX eyes in the -4.01 to -7.00 D group, and in 67% of Summit and 70% of VISX eyes in the -7.01 to -10 D group. Three-month manifest refractive outcomes in the -1.00 to -4. 00 D group were within +/- 1 D of target in 91% of the Summit eyes, and 89% of the VISX Eyes. In the -4.01 to -7.00 D range, 72% of the Summit eyes and 74% of the VISX eyes fell within +/- 1 D, and in the -7.01 to -10 D range, the rates were 53% for Summit and 56% for VISX. No eyes lost two lines or more acuity with either laser. Three-month visual and refractive outcomes in LASIK are comparable with the Summit Apex Plus and VISX Star lasers. Loss of BSCVA of two lines or more was not seen. CRS LASIK Study protocols are ongoing to provide longer follow-up and to study other refractive indications.

Removal of corneal epithelium with phototherapeutic technique during multizone, multipass photorefractive keratectomy.

BACKGROUND: The therapeutic mode of the VISX 20/20 excimer laser was used to remove the corneal epithelium prior to performing photorefractive keratectomy (PRK) with a multizone, multipass technique. METHODS: A retrospective analysis was performed of 120 eyes of 90 patients that were treated for preoperative spherical refractive errors from -1.00 to -7.00 diopters (D) (mean -3.90 D, SD 1.54) by one surgeon (DGJ) over 7 months. RESULTS: Six-month follow-up was obtained in 76 eyes (63%). Sixty-nine eyes (91%) achieved a spherical equivalent refraction within +/-1.00 D of emmetropia. Regression of effect averaged -0.35 D (SD 0.53 D) from 1 to 6 months after surgery. Mean postoperative uncorrected visual acuity at 6 months was 20/25 (range 20/15 to 20/200). Seventy-three eyes (96%) achieved uncorrected visual acuity of 20/40 or better, 67 (88%) achieved uncorrected visual acuity of 20/25 or better, and 76 (71%) achieved 20/20 or better. Three eyes (4%) lost one line of spectacle-corrected visual acuity; no eye lost more than one line. There were no significant surgical complications. CONCLUSION: Removal of corneal epithelium with the Summit Excimed UV 200 LA excimer laser using multizone, multipass photoablation yields visual and refractive results that compare favorably with published PRK series with excellent short-term stability.

Sutureless homoplastic lamellar keratoplasty.

BACKGROUND: Previously, penetrating keratoplasty has been used to treat corneal cap complications related to keratomileusis. We sought to develop a technique to avoid the unnecessary use of penetrating procedures for lamellar problems, that would be technically easier than standard lamellar keratoplasty--sutureless homoplastic lamellar keratoplasty. METHODS: Five eyes with complications from automated lamellar keratoplasty underwent sutureless homoplastic lamellar keratoplasty utilizing an automated microkeratome and topical anesthesia. RESULTS: Three of the five eyes had improved vision; two eyes with final visual acuities of 20/20 and 20/30. The two remaining eyes had poor host stromal beds and required penetrating keratoplasty. The mean follow-up time was 13 months (range 3 to 36 months). All lamellar grafts were clear and well-seated at the last postoperative examination. CONCLUSION: Sutureless homoplastic lamellar keratoplasty is an alternative to penetrating keratoplasty in some eyes that have cap-related problems.

One-year results of a prospective multicenter study of the Casebeer system of refractive keratotomy. Casebeer Chiron Study Group.

PURPOSE: To evaluate the clinical results, predictability, stability, safety, and the patient satisfaction after refractive keratotomy for the correction of myopia and astigmatism using a defined protocol (the Casebeer system). METHODS: The authors enrolled 324 patients (615 eyes) in a prospective study conducted by 18 surgeons. All procedures were performed using ultrasonic pachymetry with the diamond knife blade set at a length of 100% of the temporal paracentral corneal thickness reading and four to eight centripental (Russian style) incisions with or without fixation of the globe. Straight transverse incisions were done for astigmatism in 222 (36%) eyes. One to eight repeated operations (enhancements) were done on 241 (39%) eyes. RESULTS: Mean baseline cycloplegic refraction was -3.68 +/- 1.59 diopters (D) (range, -0.88 to -8.25 D). One-year data were available for 546 eyes (89%). At 1 year, mean spherical equivalent cycloplegic refraction was -0.27 +/- 0.78 D (range, -3.13 to +3.00 D). There were 373 (68%) eyes with a refraction of +/- 0.50 D, and 483 eyes (89%) within +/- 1.00 D of emmetropia. Ten eyes (2%) were overcorrected by more than 1.00 D. Mean baseline refractive cylinder was 1.01 +/- 0.75 D (range, 0-5.75 D); at 1 year, the mean cylinder was 0.40 +/- 0.55 D (range, 0-2.50 D). Uncorrected visual acuity was 20/20 or better in 297 (54%) eyes and 20/40 or better in 93%. Six eyes (1%) lost two to three lines of spectacle-corrected visual acuity; the worst visual acuity was 20/30. Of patients responding to a standardized questionnaire, 320 (77%) wore no spectacles for distance or near vision; there was a significant increase in glare and fluctuation of vision from baseline; and 247 (90%) were very satisfied with the outcome. CONCLUSIONS: Refractive keratotomy using radial incisions with or without transverse incisions and following the Casebeer system effectively reduces and often eliminates myopia and astigmatism with a high degree of safety. Enhancement surgery was required in 39% of eyes. Glare and fluctuation of vision increased postoperatively but were rated mild, and patient satisfaction was high.

Intraoperative pachometry during automated lamellar keratoplasty: a preliminary report.

BACKGROUND: The hinge technique greatly improves the results of automated lamellar keratoplasty but makes it impossible to measure the thickness of the corneal cap with a micrometer. We developed a technique of measuring cap and stromal disc thickness with a pachometer and compared the results with those obtained with a micrometer. METHODS: Measurements of the thickness of the stromal disc and/or corneal cap were taken with the Mitutoyo micrometer and the Chiron Corneo-Gage System III pachometer in five myopic and three hyperopic cases undergoing automated lamellar keratoplasty with complete cap resection. The intended postoperative refraction was plano. Postoperative refractions were taken at two months. RESULTS: In most cases, the corneal cap measured thinner while the stromal disc measured thicker by the micrometer than by the pachometer because of the hydration status of the stromal bed. In both myopic and hyperopic cases, the thickness measurements taken with the pachometer correlated better with the postoperative spherical equivalent values than those taken with the micrometer. CONCLUSIONS: The thickness measurement of corneal resections by both micrometry and pachometry is greatly influenced by tissue hydration status. When hydration is similar, the pachometer provides more accurate thickness readings than does the micrometer, as determined by correlations with intended refractive results.

Severe ocular trauma without corneal rupture after radial keratotomy: case reports.

The vulnerability of the ocular coat to trauma following radial keratotomy is an issue of concern to both patients and physicians. Herein, we report two cases of eyes which were exposed to severe trauma after previously undergoing radial keratotomy procedures. In the first case, a woman sustained multiple facial bone fractures in a fatal airplane crash. In the second case, a man was involved in a case of blunt ocular trauma involving a high velocity racquetball. Rupture of the ocular coat did not occur in either case.

Phacoemulsification after T-hex keratotomy.

T-hex keratotomy surgically corrects manifest hyperopia. The typical patient presenting for this surgery is a presbyope who develops symptoms from latent hyperopia. These patients are older than typical radial keratotomy patients and are thus likely to develop senile cataracts sooner. The exact surgical approach to cataract surgery in such patients is unknown. We report a patient who had successful cataract extraction by phacoemulsification with implantation of a posterior chamber lens after a previous routine T-hex keratotomy. The preoperative workup and the surgical technique did not require modification.

Radial keratotomy in intact epikeratoplasty graft.

BACKGROUND: Epikeratoplasty can be used to flatten the cornea in keratoconus but is not a satisfactory tool to correct refractive errors in this setting. Radial and astigmatic keratotomy are unpredictable in keratoconus but can be used in an eye which has previously undergone epikeratoplasty for keratoconus. METHODS: We report a case of a pseudophakic eye with Keratoconus which received epikeratoplasty and subsequently underwent radial and astigmatic keratotomy in the graft. RESULTS: Before the refractive keratotomy, the patient had a refraction of -8.00 + 3.25 x 25. At 5 months after radial and astigmatic keratotomy, the patient had an uncorrected visual acuity of 20/60+ with a refraction of -0.50 + 2.00 x 28. CONCLUSIONS: This case demonstrates how different types of refractive corneal surgery can be combined to improve visual acuity in an individual patient. Whether the specific combination of epikeratoplasty and refractive keratotomy can be advocated in the treatment of keratoconus requires more experience with a greater number of patients.