Adriana dos Santos Forseto

Laser in situ keratomileusis to correctrefractive errors after keratoplasty

PURPOSE To assess the safety and effectiveness of excimer laser in situ keratomileusis (LASIK) to correct refractive myopia, astigmatism, or both after keratoplasty. SETTING Eye Clinic Day Hospital, São Paulo, Brazil. METHODS Twenty-two eyes that had previously had corneal transplantation were studied. Laser in situ keratomileusis was performed using the Chiron automated microkeratome and the VISX Twenty-Twenty B excimer laser. RESULTS Mean follow-up after LASIK was 10.09 months +/- 3.87 (SD). The spherical equivalent refraction dropped from -4.55 +/- 3.66 D before LASIK to -0.67 +/- 1.24 D after surgery. At the last examination, 72.7% of patients had a refractive error within +/- 1.00 D of emmetropia and 54.5% had uncorrected visual acuity of 20/40 or better. Vector analysis of astigmatic correction showed an index of success of 54.0%. Best spectacle-corrected visual acuity was unchanged in 8 cases, improved in 9, and decreased in 5. Significant endothelial cell loss, keratoplasty wound dehiscence, and other serious complications did not develop in any eye. CONCLUSION The correction of refractive error with LASIK in postkeratoplasty patients proved to be safe, effective, and predictable. Further studies with longer follow-up are needed to determine the methods clinical value.

Estudo laboratorial das micoses oculares e fatores associados às ceratites

PURPOSE: To analyze the frequency and the etiology of mycotic infectious eye diseases diagnosed by culture at the Ocular Diseases Laboratory of the Federal University of Sao Paulo (LOFT-UNIFESP), Sao Paulo, SP, Brazil, and the factors associated with fungal keratitis. METHODS: We retrospectively analyzed the 14,391 laboratory requests regarding infectious eye diseases between 1975 and May 2003. For the fungal culture proven examinations we observed the morphologic type of the isolated fungus, the gender and age of the patient, the site of ocular involvement, the year of identification, and the factors associated with keratitis cases, according to the identified etiologic agent. Results were considered significant if p<0.05. RESULTS: We verified 296 (2.05%) ocular mycosis cases with 265 keratitis (89.5%), 27 intraocular infections (9.1%), and 4 infections at other sites (1.3%). Filamentous fungi were isolated in 233 cases (78.7%) 74.7% being male (n=174) and 25.3% female (n=59). Yeasts were isolated in 63 cases (21.3%) 49.2% being male (n=31) and 50.8% female (n=32). Ages varied between 2 and 99 years in the filamentous fungi group and between 14 and 88 years in the yeast group. The most frequently found etiologic agents of the filamentous fungi isolations were Fusarium (n=137; 58.8%), Aspergillus (n=28; 12.0%), and Penicillium (n=12; 5.2%); and in yeasts, Candida (n=59; 93.7%). Regarding keratitis, 95.1% had at least one associated factor. Ocular trauma was significantly associated with filamentous fungi keratitis (p=0.0002); and previous surgeries (p=0.0002), ocular (p=0.0002) and systemic diseases (p=0.0002) with yeast keratitis. The use of topic antibiotics showed association with filamentous fungi keratitis, at a lower statistical significance (p=0.0224). CONCLUSIONS: Laboratory analysis showed predominance of filamentous fungi over the yeasts, and keratitis was the main observed ocular infection. Fungal keratitis involved at least one associated factor in most cases.

Anterior chamber intraocular lens for high myopia: five year results.

Purpose: To evaluate the effectiveness of the surgical correction of high myopia 5 years after anterior chamber intraocular lens (IOL) implantation and to analyze the lens position and related complications. Setting: Federal University of São Paulo‐Escola Paulista de Medicina, São Paulo, Brazil. Methods: This prospective study comprised 26 eyes that were implanted with an anterior chamber IOL (model ZB5M) and had a minimum follow‐up of 5 years. Before and after surgery, manifest and cycloplegic refractions were done; slitlamp examination was performed; anterior chamber depth was measured; and keratometry, ophthalmoscopy, and central corneal endothelial cell count were performed. At the last follow‐up, computerized biomicroscopy of the anterior segment was also done. Results: The spherical equivalent decreased from −16.5 diopters (D) ± 4.1 (SD) preoperatively to −0.9 ± 0.9 D postoperatively. At the last examination, 57.7% of eyes had a spherical equivalent refraction within ±1.0 D of emmetropia. Of eyes with a preoperative best spectacle‐corrected visual acuity of 20/40 or better, 73.3% had an uncorrected visual acuity of 20/40 or better postoperatively. The mean tilt caused by the IOL was 4.4 ± 2.7 degrees (range 0.5 to 12.2 degrees) and the mean IOL decentration, 0.3 ± 0.2 mm (range 0.02 to 0.8 mm). The mean decrease in the endothelial cell count was 1.5%, with a mean cell density of 2808 ± 305 cells/mm2 preoperatively and 2765 ± 242 cells/mm2 postoperatively. Pupillary ovalization was observed in 12 eyes (46.1%). Conclusions: The anterior chamber IOL safely and effectively corrected high myopia.

Diagnosis of epithelial ingrowth after penetrating keratoplasty with confocal microscopy.

Purpose: To report confocal microscopy use in the clinical diagnosis of epithelial ingrowth after penetrating keratoplasty (PKP). Methods: A 36-year-old female patient with keratoconus developed a well-delimited posterior hazy membrane covering the inferior two thirds of the cornea 3 months after an uneventful PKP. A posterior corneal line was present resembling an endothelial graft rejection line, but with no keratic precipitates or corneal edema. Ocular hypertension was not observed. Confocal microscopy was performed to elucidate the diagnosis. Results: Confocal microscopy showed epithelium and stroma with normal findings. Two distinct cellular types were presented at the endothelium layer. Enlarged endothelial cells were observed in the superior part of the cornea up to the leading edge of the hazy membrane. In the middle and inferior part of the graft, the cells were larger, with polygonal shape and easily recognizable hyperreflective nuclei, suggestive of epithelial cells. With these confocal microscopy findings, the patient was promptly submitted to another PKP. Histologic analysis confirmed the diagnosis of epithelial ingrowth. Conclusion: Confocal microscopy imaging technique seems to be a useful tool in the early diagnosis of epithelial ingrowth after PKP.

Laser in situ keratomileusis for undercorrection after radial keratotomy.

PURPOSE To assess the safety and efficacy of excimer laser in situ keratomileusis (LASIK) in treating residual myopia and/or astigmatism following refractive keratotomy. METHODS Fourteen eyes that had previously undergone radial and/or arcuate keratotomy were included. The surgeries were performed using the Chiron Automated Microkeratome and the VISX 20/20B excimer laser. RESULTS Average follow-up was 12.64+/-5.02 months. Mean spherical equivalent refraction was reduced from -3.48+/-3.52 D preoperatively to -0.04+/-0.87 D postoperatively. At the last follow-up examination there were 8 eyes (57.1%) with a refraction within+/-0.50 D, and 10 eyes (71.4%) within +/-1.00 D of emmetropia. Uncorrected visual acuity was 20/20 or better in 4 eyes (28.6%) and 20/40 or better in 10 eyes (71.4%). Vector analysis of the astigmatic correction showed an index of success of 80%. There was no significant loss (> or = or =2 lines) of spectacle-corrected visual acuity. We observed interface epithelial ingrowth in one eye. CONCLUSIONS The correction of residual myopia and/or astigmatism with LASIK in eyes with prior refractive keratotomy proved to be safe and effective. Careful preoperative evaluation may help to avoid complications such as reopening of incisions during surgery or postoperative ingrowth of epithelium beneath the corneal flap.

Corneal suture for the correction of hyperopia following radial keratotomy.

PURPOSE To report the visual and refractive changes observed after double concentric corneal suture to correct hyperopic shift after radial keratotomy (RK). METHODS This retrospective consecutive case series comprised 17 eyes (15 patients) that underwent two concentric corneal sutures (modified Grene Lasso suture) to correct hyperopic shift after RK. All surgeries were performed by the same surgeon between 2000 and 2003. RESULTS The mean time after RK was 11.6 +/- 3.2 years. The mean follow-up was 20.3 +/- 11.3 months. The spherical equivalent refraction was reduced from a preoperative mean of +4.38 +/- 2.87 diopters (D) to -0.54 +/- 2.59 D at last postoperative follow-up (P < .001). No statistically significant difference was observed in mean refractive astigmatism before and after the corneal suture (P = .15). Before surgery, no eye presented with best spectacle-corrected visual acuity (BSCVA) > or = 20/20. At final follow-up, 3 (17.6%) eyes attained this level. Seven (41.2%) eyes improved their BSCVA by > or = 2 Snellen lines. One (5.9%) eye lost 2 Snellen lines of BSCVA. CONCLUSIONS Corneal suture can be used to correct RK-induced hyperopia, improving the corneal asphericity in an attempt to stabilize these corneas. It appeared to be effective even for high degrees of hyperopia and in cases with associated irregular astigmatism or open incisions.

Estudo comparativo entre duas plataformas para realização de Lasik personalizado para correção de miopia e astigmatismo: Alcon CustomCornea® versus Bausch & Lomb Zyoptix®

PURPOSE: To compare the visual and clinical outcomes of Wavefront-guided laser in situ keratomileusis (Lasik) with Alcon CustomCornea® and Zyoptix® systems. METHODS: A prospective, randomized, masked and bilateral study was conducted. Fifty patients with preoperative spherical equivalent ranging from -1.00 to -6.50 D were enrolled for customized ablation in both eyes. All of them were submitted to Lasik CustomCornea® treatment in one eye and Zyoptix® in the other eye. Uncorrected visual acuity, best correct visual acuity (BCVA), manifest refraction, wavefront measurements, and contrast sensitivity testing were performed preoperatively and postoperatively at 1, 3 and 6 months. RESULTS: Preoperatively manifest refractive spherical equivalent was -3.29 ± 1.56 D in the CustomCornea® group and -3.22 ± 1.50 D in the Zyoptix® group. At 6 months, 86% of CustomCornea® eyes and 70% of Zyoptix® eyes had UCVA > 20/20. One hundred percent of the CustomCornea® group and 88% of the eyes in the Zyoptix® were within 0.50 D of emmetropia. In both groups, the contrast sensitivity improved. Spherical aberration increased in both groups, with the CustomCornea® group showing lower levels (p<0,001). CONCLUSION: There were no differences between the systems according to safety and effectiveness. The Zyoptix® platform showed greater spherical aberration.

Descemet Membrane Detachment in Femtosecond Laser-Assisted Cataract Surgery.

Purpose: To report a case series of 4 patients with Descemet membrane detachment (DMD) after undergoing femtosecond laser-assisted cataract surgery incisions. Methods: Case report. Results: DMD was noted at the secondary incision (n = 2) or at the main incision (n = 2). All the secondary incision and 1 main incision DMD were resolved with intraoperative maneuvers. Delay in recognizing DMD intraoperatively at the principal incision in 1 case led to inadvertent aspiration of a part of it and persistent postoperative corneal edema. This complication was handled with Descemet membrane endothelial keratoplasty 1 month after initial surgery. Conclusions: DMD can occur after femtosecond laser-assisted cataract surgery, although it is a rare complication as it is in traditional phacoemulsification. The surgeon must be prepared to recognize it, manage it intraoperatively, and treat it postoperatively to reduce the risk of permanent damage to the eye.

Toric Intraocular Lens Misalignment Inducing Astigmatism After Refractive Surgery

PURPOSE To report the unexpected induction of astigmatism after phacoemulsification and toric intraocular lens (IOL) implantation in an eye with previous corneal refractive surgery. METHODS Case report of a 46-year-old man with bilateral nuclear cataract and previous photorefractive keratectomy. Because corneal topography identified regular corneal astigmatism at the central optical zone, phacoemulsification and implantation of a one-piece hydrophobic acrylic toric IOL were performed. RESULTS Unexpected induction of astigmatism occurred in the first operated eye despite proper alignment of the IOL according to the preoperative calculations using simulated K values to determine toric IOL power and alignment. A retrospective qualitative analysis of corneal topography showed mismatching of the steepest meridian, leading to an off-axis IOL. Secondary IOL rotation improved both uncorrected and corrected distance visual acuity. CONCLUSIONS Qualitative analysis of the corneal topography is mandatory during the assessment of toric IOL alignment in eyes with previous corneal refractive surgery to identify the actual location of the steepest meridian.

Complicações per e pós-operatórias em 1000 olhos submetidos a LASIK

Purpose: To analyze the incidence, type, management and evolution of complications in laser in situ keratomileusis (LASIK). Methods: Retrospective non-comparative case series. LASIK was performed in 1000 eyes using the Hansatome® or the Automated Corneal Shaper® microkeratomes, and the VISX 20/20B or the Chiron Technolas 217C excimer lasers. Intraoperative, early and late postoperative complications were reviewed. Results: Mean preoperative spherical equivalent (SE) was -4.29 ± 3.20D. Average follow-up was 6.05 ± 6.69 months. There were 5 (0.5%) intraoperative microkeratome-related flap complications (3 thin flaps, 1 buttonhole and 1 small flap). The most frequent early postoperative complication was microwrinkled flaps (6.4%), followed by interface debris (4.1%), the non-diffuse intralamellar keratitis (1.1%), haze (0.4%), interface epithelial ingrowth (0.4%) and dislocated flaps (0.3%). Most of these reported events were successfully managed. Late refraction-related complications were analyzed in 655 eyes with a minimum follow-up of 3 months. At the last examination, mean SE was -0.26 ± 0.76D. Eight per cent were undercorrected by more than -1.00D and 1.67% was overcorrected by more than +1.00D. Reoperation was necessary in 28 eyes (4.27%). Five cases (0.76%) lost 2 or more lines of best spectacle corrected visual acuity. There were no sight-threatening complications. Conclusion: LASIK is a safe refractive procedure with few complications.