Conventional vs wavefront-guided LASIK using the LADARVision4000 excimer laser

PURPOSE: To compare outcomes after LASIK surgery using the conventional LADARVision4000 laser and the wavefront-guided LADARWave CustomCornea wavefront system. METHODS: A prospective study was performed involving 140 myopic eyes receiving conventional or CustomCornea LASIK between May and October 2003. The preoperative manifest spherical equivalent refraction was limited to myopia < or = -7.00 diopters (D). The preoperative manifest cylinder was limited to < or = -2.50 D of astigmatism. Patients were evaluated for 3 months following surgery. Results evaluated were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity, manifest refraction, dilated wavefront measurements, contrast sensitivity, and patient responses to subjective questionnaires. RESULTS: For the CustomCornea eyes at 3 months, 80% (70/87) had UCVA > or = 20/20 and 95% (83/87) had UCVA > or = 20/25. For the conventional eyes at 3 months, 45% (9/20) had UCVA > or = 20/20 and 80% (16/20) had UCVA > or = 20/25. At the 3-month postoperative visit, 85% (74/87) of the CustomCornea eyes and 55% (11/20) of the conventional eyes were within +/- 0.50 D of their intended correction. At 1 and 3 months, the CustomCornea treated eyes had a statistically significant lower mean increase in higher order aberrations than conventionally treated eyes (P < .05). CONCLUSIONS: CustomCornea wavefront-guided LASIK surgery appears safe and effective and provides clinical benefits that appear to exceed those of conventional LADARVision surgery.     

Comparison of the toric implantable collamer lens and custom ablation LASIK for myopic astigmatism

PURPOSE: To compare the results of wavefront-guided custom LASIK and the Toric Implantable Collamer Lens (TICL) in the correction of myopic astigmatism. METHODS: This observational, non-randomized study compared clinical efficacy results from the TICL's US Food and Drug Administration Clinical Trial and published Summaries of Safety and Effectiveness of two wavefront-guided lasers: STAR S4 CustomVue excimer laser system (VISX Inc) and LADARVision4000 CustomCornea excimer laser system (Alcon Laboratories Inc). Preoperative myopic refractive error was divided into two groups: -3.00 to -7.00 diopters (D) and -7.00 to -11.00 D. RESULTS: The percentage of eyes with uncorrected visual acuity (UCVA) of 20/20 and 20/40 and predictability of manifest refraction spherical equivalent within +/- 0.50 and +/- 1.00 D in the three groups was similar with only one statistically significant difference (TICL versus Alcon within +/- 1.00 D: 97% versus 82%; P = .008). The TICL had significantly better postoperative best spectacle-corrected visual acuity (BSCVA) compared to preoperative BSCVA than both the VISX CustomVue and Alcon CustomCornea (P < .001). The TICL postoperative UCVA outcomes compared to preoperative BSCVA were significantly better than Alcon CustomCornea outcomes (P < .001). Additionally, almost half (48%) of the TICL cases had improvement in postoperative UCVA compared to preoperative BSCVA, whereas only 23% of the Alcon CustomCornea eyes showed improvement. CONCLUSIONS: Although comparable in clinical efficacy outcomes, the TICL had a significantly better postoperative improvement in BSCVA and significantly better postoperative UCVA than preoperative BSCVA. The TICL can be considered as an alternative to LASIK through the full range of use.     

Laser in situ keratomileusis for residual hyperopic astigmatism after conductive keratoplasty

PURPOSE: To report a case of laser in situ keratomileusis (LASIK) in a patient with previous conductive keratoplasty. METHODS: A 48-year-old man underwent conductive keratoplasty for low hyperopic astigmatism (manifest refraction OD: +2.25 -0.50 x 77 degrees; OS: +2.50 -0.50 x 105 degrees). Three months postoperatively, UCVA was 20/25 and BSCVA was 20/20 in both eyes; manifest refraction OD: -0.25 -0.75 x 110 degrees; OS: +0.75 -0.75 x 50 degrees. Sixteen months after the operation, regression of refractive outcome was (manifest) OD: +1.75 -1.25 x 90 degrees; OS: +2.50 -0.50 x 85 degrees; UCVA was 20/40 in the right eye and 20/63 in the left eye and BSCVA was 20/20 in both eyes. LASIK was performed for hyperopic regression in the left eye using an automated microkeratome (Alcon SKBM, 130-microm plate; Aesculap-Meditec MEL 70 excimer laser). RESULTS: LASIK was uneventful and no intraoperative or postoperative complications related to the previous conductive keratoplasty procedure or LASIK were observed. Three months after LASIK and 19 months after the initial conductive keratoplasty, the patient's left eye was emmetropic; UCVA was 20/20(-2), BSCVA was 20/20 and manifest refraction was +0.25 -0.25 x 35 degrees. There was a uniform increase in topographical steepening. Visual acuity, refraction and topographic findings remained unchanged at 6 months. CONCLUSIONS: Even though our experience is limited, treatment of hyperopia with LASIK in an eye with refractive regression following previous conductive keratoplasty resulted in a predicted refractive outcome, with no complications, and improvement in visual acuity at 6 months follow-up.     

Alcon LADARWave customcornea retreatments

PURPOSE: To present our experience performing wavefront-guided ablations for the treatment of residual refractive error following previous refractive surgery. METHODS: Four different cases are presented-1) primary wavefront-guided LASIK; 2) wavefront-guided lift-flap LASIK retreatment; 3) wavefront-guided photorefractive keratectomy (PRK) retreatment; and 4) wavefront-guided PRK over radial keratotomy retreatment. All procedures were performed with the Alcon CustomCornea laser platform. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, and wavefront analysis (6.5-mm pupil) were performed preoperatively and 3 months after CustomCornea retreatment. The Alcon LADARWave device was used for wavefront measurements. RESULTS: Total lower order and higher order aberrations were decreased following wavefront-guided retreatment, resulting in improved quality of vision. The maximum target offset (+ 0.75 diopters) can be used to prevent an overcorrection of defocus (myopia) when treating a significant amount of spherical aberration. CONCLUSIONS: Wavefront-guided ablation was an effective treatment for residual lower and higher order aberrations following previous refractive surgery. Custom ablation treatment algorithms need to be developed specifically for retreatment procedures.     

Nomogram adjustment of laser in situ keratomileusis for myopia and myopic astigmatism with the Alcon LADARVision system

PURPOSE: To evaluate the visual and refractive results of conventional (non-wavefront) laser in situ keratomileusis (LASIK) for treatment of myopia and myopic astigmatism using the Alcon LADARVision 4000 excimer laser system and nomogram adjustment techniques. METHODS: A retrospective analysis of 499 eyes that had LASIK for myopia and myopic astigmatism was performed. Preoperative manifest spherical equivalent refraction ranged from -0.43 to -6.00 D and preoperative astigmatism ranged from 0 to -4.75 D. Patients were evaluated during 3 months following surgery. RESULTS: One month after surgery, 72% of eyes examined (298/415 eyes) had uncorrected visual acuity (UCVA) of 20/20 or better. Three months after surgery, 83% of eyes examined (216/261 eyes) had UCVA of 20/20 or better. One and three months after surgery, 82% and 83% of eyes, respectively, were within +/-0.50 D of attempted correction; 97% of eyes were within +/-1.00 D at both 1 and 3 months. No eye lost more than 1 line of best spectacle-corrected visual acuity (BSCVA) at 3 months after surgery. At the 3-month examination, 83% of eyes had UCVA better than or equal to preoperative BSCVA. CONCLUSIONS: Conventional LASIK to correct myopia and myopic astigmatism was safe and effective using the Alcon LADARVision 4000 excimer laser system. Outcomes were substantially improved throughout development of an accurate nomogram, derived from continually updated regression analysis of previous refractive results.     

Wavefront-guided laser in situ keratomileusis with the Alcon CustomCornea and the VISX CustomVue: three-month results

PURPOSE: To evaluate and compare the visual and clinical outcomes of wavefront-guided laser in situ keratomileusis (LASIK) with the Alcon CustomCornea (Alcon Laboratories Inc, Fort Worth, Tex) and VISX CustomVue (VISX, Santa Clara, Calif) systems. METHODS: Ninety-three eyes of 56 patients (50 and 43 consecutive eyes on CustomCornea and CustomVue, respectively) were enrolled in a prospective multisurgeon clinical outcome study. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and manifest refraction were measured at 1 day, 1 week, 1 month, and 3 months postoperatively. Early treatment diabetic retinopathy study (ETDRS) visual acuity and contrast sensitivity were measured at 1 month and 3 months, and wavefront mapping at 3 months. RESULTS: Preoperatively, the CustomCornea group had a mean sphere of -3.90 +/- 1.62 diopters (D) (range -0.50 to -7.25 D), mean cylinder of +0.62 +/- 0.39 D (range 0 to +1.50 D), and mean manifest spherical equivalent refraction of -3.59 +/- 1.54 D. The CustomVue group had a sphere of -3.87 +/- 1.45 D (range -1.75 to -6.75 D), cylinder of +0.49 +/- 0.36 D (range 0 to +1.50 D), and manifest spherical equivalent refraction of -3.62 +/- 1.46 D. At 3 months, 98% of the CustomCornea group and 95% of the CustomVue group were within +/-0.50 D. Ninety-nine percent of eyes did not change >0.50 D (manifest spherical equivalent refraction) between 1 month and 3 months. CustomCornea eyes improved on contrast sensitivity testing and had a better profile than CustomVue for 20/15 Snellen and 20/12.5 ETDRS acuity. Both laser groups had a decrease in higher order aberrations with statistical significance for coma and spherical aberration in the CustomCornea group. CONCLUSION: Wavefront-guided LASIK with both systems is safe and effective.     

Outcome of LASIK in fleck corneal dystrophy

PURPOSE: To report the outcome of laser in situ keratomileusis (LASIK) in a patient with Fleck corneal dystrophy. METHODS: Case report and literature review. RESULTS: A 48-year-old Taiwanese man presented in November 2005, 6 years after bilateral myopic LASIK. He complained of loss of uncorrected distance visual acuity that was worse in the left eye. The patient did not report glare, halos, or other visual aberrations. Preoperative best spectacle-corrected visual acuity (BSCVA) was 20/25 OU, with a manifest refraction of -14 D OU. In November 2005, uncorrected visual acuity (UCVA) was 20/40 OD and 20/50 OS, and BSCVA was 20/25 in each eye with a manifest refraction of -1.00 sphere OD and -1.75 -1.25 x 115 OS. Slit-lamp examination was remarkable for several subtle, small, gray corneal opacities present throughout the corneal stroma. Confocal microscopy revealed refractile bodies within swollen keratocytes and normal surrounding stromal mileu. The clinical and confocal appearance was consistent with Fleck corneal dystrophy. CONCLUSION: In this patient with Fleck corneal dystrophy, corneal clarity and BSCVA were maintained 6 years after bilateral myopic LASIK, suggesting that LASIK does not stimulate visually significant exacerbation of Fleck corneal dystrophy.     

Expanded range customcornea algorithms for myopia and astigmatism: one-month results

PURPOSE: To evaluate the early clinical results achieved with an algorithm adjusted for an expanded range of correction in wavefront-guided customized ablation with the LADARVision4000 (Alcon Laboratories Inc, Fort Worth, Tex). METHODS: Fifty-five consecutive eyes from 31 patients underwent wavefront-guided, customablation laser in situ keratomileusis (LASIK) (Hansatome and BD 4000 microkeratomes, LADARWave aberrometer, LADARVision4000 laser system). These were normal myopic and astigmatic eyes that had never been operated on. The spherical equivalent refractive error was +0.30 to -8.13 diopters (D) (mean -4.26 +/- 2.14 D) and the astigmatism ranged from 0 to -3.75 D (mean -0.97 +/- 0.96 D). eyes were treated according to the CustomCornea protocol using the commercial LADARVision4000 platform. Patients were followed for at least 2 months and standard visual measurements were taken and recorded at 1 day and 1, 3, and 6 months after treatment. The results of treatment were assessed using the following parameters: uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA); manifest spherical equivalent refractive error; wavefront measurement of high order aberrations; and subjective reports of visual symptoms by patients. RESULTS: One month after LASIK, the mean manifest spherical equivalent refractive error was -0.18 +/- 0.41 D. Seventy-eight percent and 96% of eyes had manifest spherical equivalent refractive error within +/-0.50 D and +/-1.00 D of attempted correction, respectively, with 78% of eyes with 20/20 or better UCVA. Eyes with 20/16 and 20/12.5 BSCVA were 89% and 36%, respectively (55% and 7% preoperatively). The mean high order aberrations root-mean-square was 0.34 +/- 0.10 microm preoperatively and 0.35 +/- 0.09 microm postoperatively (6.0-mm pupil size). High order aberrations were either reduced, unchanged, or increased by <10% in 58% of eyes. Subjectively, patients reported no visual symptoms and had no complaints regarding the quality of their vision. CONCLUSION: The new optimized algorithm for higher refractive errors appears to be effective in improving BSCVA, and a minority of patients demonstrated an increase in the magnitude of high order aberrations when compared to preoperative aberrometry. A slight spherical equivalent refraction undercorrection will be addressed with future nomogram adjustments.     

Higher order aberrations after LASIK for myopia with alcon and wavelight lasers: a prospective randomized trial

PURPOSE: To evaluate the differences in higher order aberration outcomes between bilateral wavefront-guided and wavefront-optimized LASIK treatments on two closely matched patient groups 1 and 3 months following surgery. METHODS: Thirty patients were enrolled in the study and randomly assigned to undergo bilateral LASIK with either the Alcon CustomCornea laser system or the WaveLight Allegretto Wave laser system. Standard clinical outcomes such as visual acuity and manifest refraction were evaluated as well as quality of vision measures such as subjective questionnaires and higher order aberrations. All patients completed follow-up examinations for 3 months following surgery. RESULTS: At 1 and 3 months after surgery, the uncorrected visual acuity and the refractive outcome were similar for the two laser platforms, with 90% to 93% eyes being within +/- 0.5 D of intended outcome. At 1 and 3 months the Alcon CustomCornea group had a statistically significant lower amount of induced total higher order aberrations compared to the Allegretto Wave group (P < .05). CONCLUSIONS: LASIK for myopia with the Alcon CustomCornea and WaveLight Allegretto Wave systems is highly effective in terms of refractive outcome and uncorrected visual acuity. However, aberrations were statistically significantly greater after treatment with the WaveLight Allegretto Wave system than with the Alcon CustomCornea.     

Photorefractive keratectomy with 0.02% mitomycin C for treatment of residual refractive errors after LASIK

PURPOSE: To evaluate the efficacy and safety of prophylactic mitomycin C (MMC) during photorefractive keratectomy (PRK) over LASIK flaps for the treatment of residual refractive errors following LASIK. METHODS: In this single center, retrospective clinical study, 30 eyes of 33 patients (mean age 37.2 years) who had MMC (0.02%, 30 to 120 seconds) during PRK for the treatment of residual refractive errors following myopic LASIK were evaluated. The retreatment procedures were performed with a VISX S4 laser with iris registration. All patients underwent slit-lamp microscopy, manifest and cycloplegic refraction, corneal topography, pachymetry, pupillometry, and wavefront analysis pre- and postoperatively. All patients underwent follow-up at 1 day, 1 week, and 1, 3, and 6 months and thereafter as required. RESULTS: Mean time between LASIK and PRK retreatment was 67.3 months (range: 7 to 113 months). No intra- or postoperative complications occurred during primary LASIK or PRK retreatment. Mean spherical equivalent refraction of attempted correction with PRK was -0.94 diopters (D) (range: -2.38 to +0.75 D). At mean 7.1-month follow-up, the average uncorrected visual acuity (UCVA) improved from 20/50 (range: 20/30 to 20/200) to 20/28 (range: 20/15 to 20/70). Twenty-seven of 30 eyes showed improvement in UCVA. Two eyes had subjective improvement of glare symptoms (and objective improvement in higher order aberrations), and one eye lost one line of best spectacle-corrected visual acuity due to unrelated corneal abrasion in the postoperative period. None of the eyes in the cohort developed postoperative haze. CONCLUSIONS: Photorefractive keratectomy with prophylactic MMC (0.02%) is a safe and effective option for treating myopic regression following LASIK. A single intraoperative application of 0.02% MMC for as few as 30 seconds was effective in preventing postoperative haze formation.     

Laser in situ keratomileusis in a patient with presumed central cloudy corneal dystrophy of Francois

PURPOSE: To report a case of laser in situ keratomileusis (LASIK) surgery performed in a patient with likely central cloudy corneal dystrophy of Francois (CCDF). DESIGN: Observational case report. METHODS: A 48-year-old woman with likely CCDF had myopic LASIK to establish monovision. Outcome measures included visual acuity, manifest refraction, and slit-lamp examination. RESULTS: At 5-year follow-up, the patient had uncorrected visual acuity of 20/100, J1, in the right eye (OD) and 20/20 in the left eye (OS), consistent with monovision correction. Manifest refraction was -1.50 OD and -0.25 OS postoperatively; after retreatment at 1 year for regression, the left eye remained stable over the subsequent 4-year period. Slit-lamp examination revealed no progression of corneal opacities in either eye. CONCLUSIONS: LASIK may be safe and effective in patients with CCDF. Further observations of a greater number of patients are required to confirm these findings.     

Contralateral comparison of Alcon CustomCornea and VISX CustomVue wavefront-guided laser in situ keratomileusis: one-month results

PURPOSE: To evaluate the differences in outcomes between CustomCornea and CustomVue LASIK treatments on different eyes of the same patient 1 month after surgery. METHODS: Thirty-five patients were enrolled in two phases of a prospective study and treated with Alcon CustomCornea LASIK (Alcon Laboratories Inc, Fort Worth, Tex) on one eye and VISX CustomVue LASIK (VISX, Santa Clara, Calif) on the fellow eye. Twenty-five patients were treated in phase I without nomogram adjustments and ten patients were treated in phase II with nomogram adjustments made to the VISX CustomVue treatments only. Standard clinical outcomes such as visual acuity and manifest refraction were evaluated as well as quality of vision measures such as subjective questionnaires, contrast sensitivity, and higher order optical aberrations. RESULTS: In the phase I group, 92% of the CustomCornea eyes and 72% of the CustomVue eyes were within 0.50 diopters (D) of their attempted correction. In the phase II group, with a nomogram applied to the CustomVue eyes, 80% of the CustomCornea eyes and 100% of the CustomVue eyes were within 0.50 D of their attempted correction. There was no loss of 22 lines of best spectacle-corrected acuity for the CustomCornea or CustomVue eyes in either phase I or phase II. Wavefront analysis demonstrated that the CustomVue eyes had statistically significantly more spherical aberrations at 1 month compared to the CustomCornea eyes in the phase I and II groups. An average increase in mesopic contrast sensitivity at spatial frequencies was seen for the CustomCornea eyes in phase II and in only one spatial frequency for the CustomVue eyes in phase II. CONCLUSION: At 1 month after LASIK, the CustomCornea eyes showed superiority in the number of eyes seeing 20/20 or better uncorrected visual acuity, constrast sensitivity at 3 and 12 cpd, and the amount of postoperative spherical aberration. After nomogram adjustment, CustomVue eyes had a more accurate refractive outcome. Patients were satisfied or extremely satisfied with both systems, 92%-100%.     

Wavefront-guided surface ablation with prophylactic use of mitomycin C after a buttonhole laser in situ keratomileusis flap

PURPOSE: To describe the surgical outcome of a patient who had a previous buttonhole after laser in situ keratomileusis (LASIK) and 3 months later, had wavefront-guided photorefractive keratectomy (PRK) with topical mitomycin C 0.02%. METHODS: A 38-year-old man underwent bilateral LASIK for correction of myopic astigmatism. A buttonhole in his right eye LASIK flap occurred, but the surgeon decided to proceed with ablation due to the small size of the buttonhole. After LASIK, the patient complained of monocular diplopia in his right eye with 20/30 best spectacle-corrected visual acuity. Wavefront analysis showed a large amount of higher order aberrations, especially coma. Slit-lamp examination revealed a moderate buttonhole scar. Three months after LASIK, the patient underwent wavefront-guided PRK with application of topical mitomycin C 0.02% on the stromal bed, for a duration of 2 minutes. RESULTS: One month after wavefront-guided PRK, his uncorrected visual acuity was 20/25 in the right eye, with no symptoms. Best spectacle-corrected visual acuity in the right eye was 20/15 with +0.25 -0.50 x 110 degrees. No haze or scar was seen on slit-lamp examination. Wavefront analysis showed a decrease in higher order aberrations, especially coma and spherical aberration. CONCLUSIONS: Wavefront-guided PRK with prophylactic topical mitomycin C was effective in treating a patient with visual symptoms and loss of BSCVA after a LASIK flap buttonhole. No delayed epithelial healing, side effects or complications were noted due to mitomycin C.     

Laceration and partial dislocation of LASIK flaps 7 and 4 years postoperatively with 20/20 visual acuity after repair

PURPOSE: To report two cases of late ocular trauma resulting in laceration of corneal flaps 7 and 4 years (cases 1 and 2, respectively) after LASIK. METHODS: A 49-year-old man sustained laceration of the flap and interface foreign body debris from construction material in the right eye 7 years after uneventful LASIK (case 1). A 33-year-old man had partial dislocation of the flap 4 years after LASIK in the left eye (case 2) due to a penetrating wood chip accident. Surgical procedures were performed to remove the foreign bodies and reposition the flaps. RESULTS: In case 1, postoperative uncorrected visual acuity (UCVA) was 20/25 with manifest refraction of -0.50 -0.50 x 110 corrected to 20/20. In case 2, UCVA was 20/20 with piano refraction after LASIK retreatment. CONCLUSIONS: Corneal LASIK flaps are susceptible to penetrating trauma, which can occur >7 years after the procedure. Proper everamanage ment of the trauma and LASIK flap can restore excellent visual acuity.     

Prospective randomized trial of wavefront-guided laser in situ keratomileusis with the CustomCornea and CustomVue laser systems

PURPOSE: To compare visual function, safety, and higher-order aberrations (HOAs) after wavefront-guided laser in situ keratomileusis (LASIK) with the LadarVision CustomCornea (Alcon Laboratories, Inc.) and Star S4 CustomVue (Visx) laser systems. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Seventy-eight eyes of 39 patients with myopia with or without astigmatism were randomized for LASIK treatment in 1 eye with the CustomCornea laser; the other eye was treated with the CustomVue laser. Patients were followed for 6 months after surgery. The primary outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, and changes in HOAs. RESULTS: At 6 months, the mean logarithm of the minimum angle of resolution (logMAR) UCVA was -0.0135 +/- 0.07 (SD) in the CustomVue group and 0.0417 +/- 0.12 in the CustomCornea group (P = .023). Eighty-eight percent of eyes in the CustomVue group had 20/20 or better UCVA compared with 67% in the CustomCornea group (P<.02). At 6 months, 91% of eyes in the CustomVue group and 79% in the CustomCornea group were within +/-0.50 diopter (D) of emmetropia (P<.1); 88% and 50%, respectively, were within +/-0.25 D (P<.001). Both platforms led to a small increase in total HOAs. The CustomVue system reduced trefoil and induced less of an increase in total HOAs, whereas the CustomCornea platform increased trefoil but induced less of an increase in spherical aberrations and coma. CONCLUSIONS: Both laser systems were effective, safe, and predictable. Wavefront-guided LASIK with the CustomVue system resulted in better visual acuity, with more eyes having 20/20 acuity than in the CustomCornea group.     

Combined refractive lensectomy and laser in situ keratomileusis to correct extreme myopia

Refractive lensectomy followed by laser in situ keratomileusis (LASIK) was performed in both eyes of a severely myopic patient. An uncorrected visual acuity of 20/20 was achieved in the right eye with a manifest refraction of plano -0.25 x 65. Intentional monovision correction of the left eye left a manifest refraction of -0.75 diopter. Best corrected visual acuity improved by 1 Snellen line to 20/20 in both eyes. Follow-up evaluation will be required to assess the long-term refractive stability and the incidence of retinal detachment after combined refractive lensectomy and LASIK.     

Topography-guided LASIK with the wavelight laser after penetrating keratoplasty

PURPOSE: To report a case of topography-guided LASIK in a patient after previous penetrating keratoplasty. METHODS: A 20-year-old man who had previous penetrating keratoplasty in his right eye for keratoconus and was intolerant to spectacles and contact lenses underwent topography-guided LASIK. RESULTS: Three months postoperatively, the patient's uncorrected visual acuity in the right eye was 20/25(+2). Best spectacle-corrected visual acuity was 20/20, with a manifest refraction of +0.25 -0.75 x 40 degree. Conclusion: Topography-guided LASIK is a useful therapeutic modality to address corneal irregularity after penetrating keratoplasty.     

Comparison of laser in situ keratomileusis and photorefractive keratectomy for the correction of myopia of -6.00 diopters or less. Melbourne Excimer Laser Group

PURPOSE: To evaluate the safety and efficacy of laser in situ keratomileusis (LASIK) compared to photorefractive keratectomy (PRK) for the correction of low or moderate myopia (-0.50 to -6.00 D) at 6 months after surgery. METHODS: The study population comprised a non-randomized consecutive series of 622 eyes of 392 patients who were treated with the Nidek EC-5000 excimer laser. LASIK was performed using the ACS Chiron microkeratome on 314 eyes and surface PRK on 308 eyes. All patients were treated using a standard protocol, then assessed at 1, 3, and 6 months postoperatively. RESULTS: Forty-four percent of the LASIK group and 67% of the PRK group attended their 6-month examination. Eighty percent of patients (111 eyes) after LASIK and 65% (136 eyes) after PRK had an uncorrected visual acuity of 20/20 or better. Spherical equivalent refraction was within +/-0.50 D of intended refraction in 78% (109 eyes) for LASIK and 82% (170 eyes) for PRK. Loss of two more lines of best spectacle-corrected visual acuity at 6 months occurred in 1.4% (2 eyes) of the LASIK group and 1.0% (2 eyes) of the PRK group. CONCLUSION: At 1 month follow-up, the percentage of eyes that achieved 20/20 uncorrected visual acuity was greater in the LASIK group than in the PRK group. At 6 months, visual and refractive outcomes of LASIK and PRK were similar. Although flap related complications occurred only after LASIK, the overall risk of loss of best spectacle-corrected visual acuity was not significantly greater than for PRK.     

Chalazion as a cause of decreased vision after LASIK.

PURPOSE: To describe a post-LASIK patient with decreased vision and a chalazion of the upper eyelid. METHODS: A 46-year-old man was referred with decreased vision of 1 month's duration. He underwent bilateral uncomplicated LASIK for myopic astigmatism 1.5 years and bilateral enhancements 1 year previously. He had 20/20 uncorrected vision in both eyes after those procedures. He developed a chalazion of his right central upper eyelid 1 month prior with simultaneous blurring of vision. On our examination, his uncorrected visual acuity was 20/60 in the right eye. Complete eye examination including refraction, computerized corneal topography, and pachymetry were done. RESULTS: With a manifest refraction of +1.25 +0.50x80, the visual acuity in the right eye improved to 20/20. Computerized corneal topography revealed circular central corneal flattening in both eyes, much greater in the right eye than the left eye. The location of the chalazion with the right eye closed corresponded to the area of central corneal flattening. The central power from the corneal topography was 39.4 D OD and 40.8 D OS. He was diagnosed as having acquired hyperopia associated with chalazion-induced central corneal flattening of the right eye. Chalazion-induced hyperopic change on topography disappeared, and his uncorrected vision improved to 20/20 in the left eye as the chalazion resolved completely. CONCLUSION: In post-LASIK patients with decreased vision and topography changes late after surgery, periocular masses should be considered in the differential diagnosis. Decreased corneal thickness and rigidity after LASIK might be a predisposing factor to external compression-induced curvature changes.     

Laser in situ keratomileusis with Alcon CustomCornea

PURPOSE: To report the 3-month results of our first cases of laser in situ keratomileusis (LASIK) with Alcon's CustomCornea. METHODS: Wavefront analysis was performed using the LADARWave aberrometer and ablation was performed with the LADARVision4000 system. Thirty-one eyes of 17 patients were analyzed prospectively, at 1 and 3 months after CustomCornea surgery. Psychophysical tests were performed, including high and low contrast acuity, and contrast sensitivity under scotopic and photopic conditions. In addition, psychometric testing was performed using a subjective vision questionnaire. RESULTS: Mean spherical equivalent refraction improved from a baseline -3.05 +/- 1.92 D to +0.02 +/- 0.28 D at 3 months (28 eyes). At 3 months, 46.4% (13 eyes) had uncorrected visual acuity of 20/16, 92.7% (26 eyes) had 20/20, and 100% (28 eyes) had 20/25 uncorrected visual acuity. Three months after CustomCornea surgery, there was a statistically significant improvement in contrast sensitivity under both scotopic and photopic conditions, and a statistically significant increase in third and fourth order aberrations. There was a statistically significant improvement in visual quality as measured by the subjective vision index, increasing from a preoperative mean 66.62 to 87.63 at 3 months after surgery. CONCLUSIONS: CustomCornea was an improvement over conventional LASIK as measured by most psychophysical and psychometric parameters. The relationship between higher order aberrations and other psychophysical and psychometric measurements needs more analysis.