Eliane Mayumi Nakano

Intraoperative Microkeratome Complications in 47,094 Laser in situ Keratomileusis Surgeries

PURPOSE We evaluated the incidence and intraoperative microkeratome-related complications in laser in situ keratomileusis (LASIK). METHODS We present non-randomized, retrospective, comparative, interventional case series. We reviewed the records of patients who underwent LASIK from August 2000 to March 2004 at Excimer Laser Santa Cruz, São Paulo, Brazil (47,094 eyes). We identified 369 eyes (0.0078%) with an intraoperative complication. Data were collected regarding microkeratome, average keratometric power, and type of complication. RESULTS The Hansatome microkeratome was the most common microkeratome used (34,182 eyes; 73%), followed by the Automated Corneal Shaper-ACS (11,164 eyes, 24%) and the Nidek MK-2000 (1748 eyes, 3.7%). Intraoperative complications were more common with the ACS (1.26%) than with the Hansatome (0.63%) and MK-2000 (0.63%) (P<.001; P=.03; respectively). Complications included incomplete flaps (0.23%), buttonholes (0.13%), thin flaps (0.08%), and free flaps (0.08%). Buttonholes were more frequent with the ACS (0.34%) than with the Hansatome (0.06%) (P<.001) and free flaps were more common with the ACS (0.20%) and MK-2000 (0.29%) than with the Hansatome (0.04%) (P<.001). Keratometric power of eyes with intraoperative complications was significantly higher in the ACS group compared to the Hansatome group. CONCLUSIONS Intraoperative complications were more common with the ACS than with the Hansatome or MK-2000. Buttonholes were most frequent with the ACS, and the Hansatome had the lowest incidence of free flaps.

Confocal microscopy in early diagnosis of Acanthamoeba keratitis.

PURPOSE This study correlated confocal microscopic images obtained using the Nidek ConfoScan 2.0 System in corneas with clinical suspicion of Acanthamoeba keratitis, with diagnosis confirmed by either cytological and/or histological analysis. METHODS Fifteen eyes of 14 patients with a clinical diagnosis of Acanthamoeba keratitis underwent confocal microscopy evaluation. RESULTS Fifteen eyes of 14 patients (one bilateral case) showed Acanthamoeba keratitis alterations that ranged from massive infestation to cicatricial opacity in the stroma. Ten patients (71%) were females. Mean age was 26 years (range 19 to 37 yr). All patients were contact lens wearers. CONCLUSION Confocal microscopy was a useful, noninvasive technique in the diagnosis and treatment of Acanthamoeba keratitis, especially in those cases in which corneal scraping, cytological analysis, and culture are negative. It also eliminated the necessity of tissue biopsy, considered an invasive procedure.

Comparison of ketorolac 0.4% and nepafenac 0.1% for the prevention of cystoid macular oedema after phacoemulsification: prospective placebo-controlled randomised study

Purpose To compare the anti-inflammatory efficacy of ketorolac of tromethamine 0.4% and nepafenac 0.1% eye drops for prophylaxis of cystoid macular oedema (CME) after small-incision cataract extraction. Methods Patients were assigned randomly to three groups. Group 1 patients received a topical artificial tear substitute (placebo); group 2 received ketorolac tromethamine 0.4% (Acular LS, Allergan) and group 3 received nepafenac 0.1% (Nevanac, Alcon). The incidence and severity of CME were evaluated by retinal foveal thickness on optical coherence tomography (OCT) after 1, 4 and 12 weeks. Results One hundred and twenty-six eyes of 126 patients were included in this study. The between-group differences in visual outcomes, central corneal thickness and endothelial cell density were not statistically significant. In all retinal thickness measurements, an increase was detected starting from the postoperative first week until 12 weeks. There was no statistically significant difference between the three groups in any measurement performed by spectral-domain OCT. Conclusions Used prophylactically after uneventful cataract surgery, non-steroidal anti-inflammatory drugs were not efficacious in preventing macular oedema compared with placebo. Trial registration number ClinicalTrials: NCT02084576.

Cleaning Solutions as a Cause of Diffuse Lamellar Keratitis

PURPOSE To assess the capability of two microkeratome cleaning solutions in causing diffuse lamellar keratitis (DLK) in a rabbit model of laser in situ keratomileusis (LASIK). METHODS Two cleaning solutions (Palmolive 2:100 and Cidezyme 2:250) were tested. These solutions were diluted with balanced salt solution according to directions from the Hansatome microkeratome manual. Two additional solutions were prepared using an additional ten-fold dilution, creating a total of four study solutions. A LASIK flap was created in one eye each of 25 rabbits using the ALK Chiron microkeratome. The rabbits were divided into five study groups. The flaps were reflected and a drop of one of the study solutions (or BSS, control group) was placed on the interface. After 1 minute, the solution was washed out from the interface and the flap was repositioned. The eyes were examined at the slit lamp on postoperative days 1, 2, 3, 5, and 7. RESULTS In 12 eyes, a flap displacement was identified. Four eyes showed flap retraction and five others, epithelial ingrowth in flap margins. The incidence of these events did not differ among groups. Thirteen eyes were then evaluated for DLK. No DLK-like interface inflammation was seen in the studied eyes. CONCLUSION The cleaning solutions, when diluted as recommended by the microkeratome manufacturer, when in contact with the corneal stroma, and provided that the interface was washed with BSS did not cause DLK interface inflammation in rabbit LASIK models.

Comparison of laser epithelial keratomileusis with and without mitomycin C for wavefront customized surface ablations.

PURPOSE To investigate the efficacy of mitomycin C (MMC) in preventing haze formation in surface wavefront customized ablations with successful refractive treatment (laser epithelial keratomileusis [LASEK]) and to evaluate the safety of this technique on corneal stroma and endothelium. METHODS This study was a prospective, double-masked, randomized clinical trial involving 52 eyes (30 placebo and 22 MMC) of 26 patients. The manifest refractive spherical equivalent (MRSE), best spectacle-corrected visual acuity, uncorrected visual acuity, corneal pachymetry, topography, aberrometry, endothelial specular microscopy, contrast sensitivity, corneal confocal microscopy, and complaints of pain via a subjective questionnaire were recorded preoperatively and 90 days postoperatively. RESULTS The mean MRSE at 90 days postoperatively was -0.56 diopters (D) (-4.95 +/- 1.85 D, range: -8.00 to -1.62 D) for the MMC group and -0.49 D (-4.51 +/- 1.81 D, range: -7.75 to -2.25 D) for the placebo group. Higher order aberrations were similar between the placebo and MMC groups 90 days postoperatively (0.538 +/- 0.228 microm and 0.478 +/- 0.134 microm, respectively). Analysis of the endothelial cell count indicated a statistically significant decrease in endothelial cell density (P = .017) after LASEK, independent of MMC use. CONCLUSIONS The predictability of the final target refraction, induction of high order aberrations, and improvement in contrast sensitivity proved that the use of MMC was equally safe when compared to procedures that did not use MMC. In addition, the procedure was efficient in the prevention of corneal haze.

Wavefront Analysis in Asian-Brazilians

PURPOSE To compare the distribution of ocular higher order wavefront aberrations (third to sixth order) in the Brazilian population of Asian and non-Asian refractive surgery patients. METHODS Preoperative refractive and wavefront data were reviewed for 648 eyes in 324 patients who underwent custom ablation at the Excimer Laser Santa Cruz refractive surgery center in São Paulo, Brazil, from March 2002 to July 2005. Patients were divided into two groups: Asian patients and non-Asian patients, based on family history. Statistical analysis was performed to assess the differences between the groups with respect to manifest refractive spherical equivalent, astigmatism, pachymetry, OPD-root-square-mean (RMS) for a 6.0-mm pupil, total wavefront aberrations, third- to sixth-order higher order aberrations, and individual aberrations. RESULTS The mean spherical equivalent refraction in the Asian group of -4.38 diopters (D) was significantly higher than the spherical equivalent refraction of -3.46 D in the non-Asian group (t= -4.32; P=.00001). Comparison of the differences between groups with respect to higher order aberrations, coma, trefoil, quadrafoil, spherical aberration, higher order astigmatism, and pachymetry was not statistically significant. CONCLUSIONS Asian patients have a higher prevalence of myopia than non-Asian patients. No differences were noted in higher order aberrations between Asian and non-Asian patients.

Refractive outcome of Nidek OPD-scan customized ablations.

PURPOSE Custom ablation is an improved refractive laser treatment that aims to optimize the optical system of the eye. We report preliminary results of laser in situ keratomileusis (LASIK) using customized ablation and the Nidek OPD-Scan. METHODS We report a prospective, non-comparative interventional case series. After OPD-Scan analysis, patients underwent LASIK. Eighty-four eyes were included: 44 eyes were treated with Flex Scan, 22 eyes with customized ablation based on Nidek OPD-Scan analysis, and 18 eyes were treated with conventional (scanning slit) ablation. RESULTS Visual outcome did not differ among groups. No patient experienced a significant decrease (more than 1 Snellen line) in best spectacle-corrected visual acuity. CONCLUSIONS LASIK with the Nidek OPD-Scan system was safe and effective in this small group of patients.

Coleção fluídica na interface do LASIK causada por glaucoma secundário à ceratouveíte herpética: relato de caso

Herpes simplex virus infection is a frequent cause of intraocular inflammation or anterior uveitis. Ocular hypertension is a common feature in herpetic keratouveitis. We describe a fluid accumulation and flap displacement in late postoperative period (28 months) of LASIK associated with ocular hypertension caused by herpetic keratouveitis. This finding supports the theory that flap attachment after LASIK is only partial and the virtual space remains indefinitely. The presence of ocular hypertension may lead to corneal edema and fluid accumulation in the interface.

Microbiota aeróbia conjuntival nas conjuntivites adenovirais

Purpose: To study the aerobic bacterial conjunctival flora in patients with clinical diagnosis of acute viral conjunctivitis. Method: Thirty patients between 18 and 30 years with acute adenoviral conjunctivitis and 30 normal subjects underwent conjunctival culture examination. Material from the conjunc-tiva of patients with conjunctivitis was collected within the first 3 days of onset of the symptoms. Blood-agar and chocolate-agar plates were used for culture. Patients under any topical or systemic medication, contact lens wearers, patients with ocular or systemic disease were excluded. Results: Significant positivity in culture results of patients with adenoviral conjunctivitis was observed (33.3%, among which 50% were Haemophylus influenzae and 50% were Streptococcus pneumoniae), when compared to conjunctival culture of normal subjects (6.6% of coagulase-negative staphylococci). There was no clinical difference related to the isolation of bacteria in the conjunctival sample of all patients. Conclusion: Patients with clinically diagnosed viral conjunctivitis have a higher rate of positive cultures when compared to controls. Nevertheless, this finding does not correlate with clinical differences. Microorganisms isolated in the conjunctiva of patients with adenoviral conjunctivitis were different from those isolated in the conjunctiva of normal subjects.

Complete depigmentation of a small aperture corneal inlay implanted for compensation of presbyopia

We describe a case of late-onset remarkable depigmentation of a small aperture corneal inlay implanted for presbyopia compensation. The patient was a participant in a clinical trial designed to evaluate the safety and efficacy of the AcuFocusTM ACU-10R160, which is a 10 µm-thick polyimide film tinted with an organic dye. Inlay implantation occurred under mechanical microkeratome Lasik flaps set for a depth of 120 µm. The patient returned to the clinic 11 years after surgery and reported loss of near-vision acuity. Clinical examination showed the complete absence of pigments in the device and the total loss of the initial effect on near vision, despite normal distance vision. Manifest refraction remained stable during the follow-up period. Scheimpflug images characterized the loss of the small aperture effect on incoming light. Confocal analysis revealed small hyper-reflective round images on the endothelium and no signs of inflammation.