Pupil response to tropicamide following corneal crosslinking.

PURPOSE: To evaluate the effect of corneal crosslinking (CXL) with ultraviolet A (UVA) irradiation on pupil response to tropicamide 0.5% instillation. METHODS: This prospective interventional study enrolled 17 patients (19 eyes) with progressive keratoconus who underwent CXL with UVA irradiation. Central corneal thickness (CCT) was evaluated with the use of anterior segment optical coherence tomography (Visante OCT 3.0). Pupil diameter was measured with the use of Colvard infrared pupillometer before the instillation of tropicamide 0.5% and after the instillation of tropicamide every 5 minutes for total duration of 30 minutes. Corneal epithelial integrity was examined with the use of fluorescein dye staining. Measurements were performed 1 day preoperatively and 1 month postoperatively, with emphasis on simulating the same light conditions regarding the pupil measurements. RESULTS: No intraoperative or postoperative complications were observed in any of the patients. Mean CCT decreased significantly (p<0.001) 1 month postoperatively. Mean postoperative pupil size did not change significantly at any time point compared to the mean preoperative measurements. CONCLUSIONS: The CXL procedure seems not to impair effectiveness of topical drugs, using pupil size measurements after tropicamide 0.5% instillation.

PresbyLASIK approach for the correction of presbyopia.

PURPOSE OF REVIEW: The aim of this review is to offer a comprehensive overview of the different PresbyLASIK approaches, which have been published in peer-reviewed journals. RECENT FINDINGS: Comprehensive search was conducted in scopus using keywords presbyLASIK, presbyopia, LASIK, corneal multifocality. We reviewed binocular uncorrected and corrected distance and near visual acuity, and loss of lines of best corrected visual acuity, for presbyopic patients among three different basic treatment modalities. SUMMARY: Additional trials and standards for reporting results for presbyopic approaches are necessary. Careful patient selection and counseling is imperative in all PresbyLASIK treatments.

Outcomes after accommodative bioanalogic intraocular lens implantation.

PURPOSE: To evaluate the outcomes after Wichterle Intraocular Lens-Continuous Focus (Medicem, Kamenné Zehrovice, Czech Republic) accommodative bioanalogic intraocular lens implantation. METHODS: In this prospective case series, 50 eyes of 25 patients (mean age: 65.3 ± 8.4 years; range: 53 to 83 years) were included. All patients underwent routine cataract surgery and Wichterle Intraocular Lens-Continuous Focus implantation. RESULTS: Mean follow-up was 11.44 ± 2.46 months (range: 9 to 17 months). Both monocular uncorrected and corrected distance visual acuity statistically and significantly (P < .05) improved from 0.31 ± 0.17 (20/63 Snellen) (range: counting fingers to 0.7) to 0.74 ± 0.19 (20/25 Snellen) (range: 0.2 to 1) and from 0.61 ± 0.19 (20/32 Snellen) (range: 0.2 to 1) to 0.82 ± 0.13 (20/25 Snellen) (range: 0.4 to 1), respectively. Target postoperative refraction was -0.5 diopters (D) and preoperative and 1-year postoperative spherical equivalent refraction were 0.72 ± 2.71 D (range: -7.25 to 2.37 D) and -0.24 ± 0.65 D (range: -1.0 to 1.0 D), respectively. No eyes lost lines of corrected distance visual acuity during the follow-up period, whereas 88% of patients gained one or more lines of corrected distance visual acuity. Uncorrected intermediate and near visual acuity were J2 (Snellen 20/25) or better in 72% of patients. No complications occurred intraoperatively or postoperatively. The evaluation of the mean values of root mean square of third and fourth order higher-order aberrations at 1 year postoperatively revealed a mean negative spherical aberration of -0.18 ± 0.13 µm. CONCLUSIONS: Wichterle Intraocular Lens-Continuous Focus accommodative bioanalogic IOL implantation provides satisfactory visual acuity for far, intermediate, and near distances and the promising results remain stable throughout the follow-up period.

Long-term visual outcomes after Crystalens(®) HD intraocular lens implantation.

PURPOSE: Our purpose was to evaluate the long-term visual outcomes after bilateral implantation of Crystalens(®) HD (Bausch and Lomb, Inc.) accommodative intraocular lenses. METHODS: In this study, 25 patients (50 eyes) who underwent cataract surgery and bilateral Crystalens HD accommodative intraocular lens implantation were included. The Crystalens HD lens was implanted in the bag in both eyes, without any intra- or postoperative complications. The visual parameters measured before and after surgery were: uncorrected distance visual acuity, corrected distance visual acuity (CDVA) (using the Early Diabetic Retinopathy Study [EDTRS] logMAR charts), uncorrected intermediate visual acuity, and uncorrected near visual acuity using a Birkhäuser reading chart, at a distance of 66 cm and 33 cm for intermediate and near vision, respectively, directly illuminated by a lamp of 60 watts. After surgery, the patients were evaluated at 1, 3, 6, 12, 24, and 36 months. RESULTS: The mean age was 68.70±7.1 (range: 54 to 83) years. The mean follow-up was 42.72±0.49 (range: 42.33 to 43.27) months. The uncorrected distance visual acuity improved from 0.56±0.41 (range: 0 to 2) preoperatively to 0.19±0.13 (range: 0 to 0.38) (logMAR scale) at the last follow-up visit, and the CDVA improved from 0.17±0.18 (range: 0 to 0.7) preoperatively to 0.05±0.05 (range: -0.02 to 0.22) at the last follow-up visit. No eyes lost lines of CDVA during the follow-up period, while 54% of patients gained one or more lines of CDVA. The uncorrected intermediate and near visual acuity was J2 or better in 71% and 69% of our patients, respectively. CONCLUSION: Crystalens HD implantation seems to provide an improvement in visual acuity for far, intermediate, and near distances.

Refractive corneal inlay for near vision improvement after cataract surgery.

UNLABELLED: We present the case of a patient who had refractive corneal inlay implantation for near vision improvement after bilateral cataract surgery. The patient had a history of bilateral cataract, and a 2-step procedure was suggested to improve her near and distance visual acuities. The first step was bilateral cataract extraction with a power target of plano intraocular lens implantation. Six months later, a refractive corneal inlay, Presbia Microlens, was implanted in the nondominant eye in the intracorneal pocket made with the femtosecond laser. No intraoperative or postoperative complications occurred. The bilateral uncorrected near visual acuity improved from less than Jaeger (J)6 to J1 and remained stable during the 2-year follow-up. The refractive corneal inlay is a safe, simple, and efficient method for improving near visual acuity in patients after cataract surgery. FINANCIAL DISCLOSURE: Dr. Pallikaris is the chair of the medical advisory board of Presbia Coöperatief U.A. No other author has a financial or proprietary interest in any material or method mentioned.

Thin-flap laser in situ keratomileusis with femtosecond-laser technology.

PURPOSE: To evaluate the results of thin-flap laser in situ keratomileusis (LASIK) using a femtosecond-laser platform for flap creation. SETTING: Institute of Vision and Optics, Faculty of Medicine, University of Crete, Heraklion, Greece. DESIGN: Prospective interventional case series. METHODS: Patients had LASIK with the FS200 femtosecond laser for flap creation and the Allegretto Wave Eye-Q excimer laser. Flap thickness was set at 105 µm. All eyes were examined 1 month postoperatively. Flap thickness was assessed with anterior segment optical coherence tomography using the manual flap tool at 5 locations on a horizontal B scan. RESULTS: This study comprised 50 eyes of 25 patients (mean age 28 years ±5.72 [SD]); 42 eyes completed 6 months of follow-up. Preoperatively, the mean sphere was -3.61 ± 1.87 diopters (D) and the mean cylinder, -1.08 ± 1.23 D. Six months postoperatively, no eye lost lines of corrected distance visual acuity (CDVA), 29% gained 1 line, and 7% gained 2 lines. The mean spherical equivalent was -0.03 ± 0.42 D (range -0.88 to +0.88 D); 86% had an uncorrected distance visual acuity of 20/20 or better. The mean central flap thickness at 1 month was 102.98 ± 6.33 µm (range 91 to 114 µm). There were no intraoperative or postoperative complications. CONCLUSIONS: No significant complications occurred after treatment with this new femtosecond-laser platform in thin-flap LASIK. Clinical (visual and refractive) results were satisfactory in terms of safety, predictability, and stability.

Visual outcomes and safety of a refractive corneal inlay for presbyopia using femtosecond laser.

PURPOSE: To evaluate the outcomes and safety of a refractive inlay (Flexivue Micro-Lens, Presbia Coöperatief U.A.) for the corneal compensation of presbyopia. METHODS: This prospective, interventional clinical study comprised 47 emmetropic presbyopes with a mean age of 52±4 years (range: 45 to 60 years). The inlay was inserted, centered on the line of sight, inside a corneal pocket created in the patient's nondominant eye, using a femtosecond laser. Follow-up was 12 months. Visual acuity, corneal topography, wavefront aberrometry, contrast sensitivity, structural corneal alterations, and questionnaires were evaluated. RESULTS: Twelve months after surgery, uncorrected near visual acuity was 20/32 or better in 75% of operated eyes, whereas mean uncorrected distance visual acuity (UDVA) of operated eyes was statistically significantly decreased from 0.06±0.09 logMAR (20/20) (range: -0.08 to 0.26) preoperatively to 0.38±0.15 logMAR (20/50) (range: 0.12 to 0.8) (P<.001), and mean binocular UDVA was not significantly altered (P=.516). Seventeen patients lost one line of corrected distance visual acuity in the operated eye. No patient lost 2 lines in CDVA in the operated eye. Overall, higher order aberrations increased and contrast sensitivity decreased in the operated eye. No tissue alterations were found using corneal confocal microscopy. No intra- or postoperative complications occurred. CONCLUSIONS: Twelve months after implantation, the Flexivue Micro-Lens intracorneal refractive inlay seems to be an effective method for the corneal compensation of presbyopia in emmetropic presbyopes aged between 45 and 60 years old.

Combined transepithelial phototherapeutic keratectomy and corneal collagen cross-linking for progressive keratoconus.

PURPOSE: To compare the outcomes of corneal collagen cross-linking (CXL) for the treatment of progressive keratoconus using 2 different techniques for epithelial removal: transepithelial phototherapeutic keratectomy (t-PTK) versus mechanical epithelial debridement. DESIGN: Prospective, comparative, interventional case series. PARTICIPANTS: Thirty-four patients (38 eyes) with progressive keratoconus were enrolled. METHODS: All patients underwent uneventful CXL treatment. Sixteen patients (19 eyes) underwent epithelial removal using t-PTK (group 1) and 18 patients (19 eyes) underwent mechanical epithelial debridement using a rotating brush (group 2) during CXL treatment. Visual and refractive outcomes were evaluated along with corneal confocal microscopy findings preoperatively and at 1, 3, 6, and 12 months postoperatively. MAIN OUTCOME MEASURES: Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, and keratometry readings. RESULTS: No intraoperative or postoperative complications were observed in any of the patients. In group 1, logarithm of the minimum angle of resolution mean UDVA and mean CDVA improved from 0.99 ± 0.71 and 0.30 ± 0.26 preoperatively to 0.63 ± 0.42 (P = 0.02) and 0.19 ± 0.18 (P = 0.008) at 12 months postoperatively, respectively. In group 2, neither mean UDVA nor mean CDVA demonstrated a significant improvement at 12 months postoperatively (P>0.05). In group 1, mean corneal astigmatism improved from -5.84 ± 3.80 diopters (D) preoperatively to -4.31 ± 2.90 D (P = 0.015) at the last follow-up, whereas in group 2 there was no significant difference at the same postoperative interval (P>0.05). No endothelial cell density alterations were observed throughout the follow-up period for both groups (P>0.05). CONCLUSIONS: Epithelial removal using t-PTK during CXL results in better visual and refractive outcomes in comparison with mechanical epithelial debridement.

Visual outcomes and safety of a small diameter intrastromal refractive inlay for the corneal compensation of presbyopia.

PURPOSE: To investigate the outcomes and safety of an intrastromal refractive inlay (Invue Lens, Biovision AG) for the corneal compensation of presbyopia. METHODS: This prospective, noncomparative, interventional clinical study comprised 45 emmetropic presbyopes with a mean age of 52.3 ± 3.3 years (range: 47 to 58 years). The refractive inlay was inserted in the non-dominant eye within a corneal pocket that was created using a mechanical microkeratome. Last follow-up was 12 months in all patients and examinations were scheduled at 1 week and 1, 3, 6, and 12 months after surgery. Visual, wavefront, contrast sensitivity, and topographic outcomes as well as structural corneal alteration were evaluated. RESULTS: Twelve months after surgery, uncorrected near visual acuity was 20/32 or better in 98% of operated eyes and binocularly, whereas uncorrected distance visual acuity was 20/40 or better in 93% of operated eyes and 20/25 or better in all patients binocularly. Three patients lost one line of corrected distance visual acuity in the operated eye. Overall, higher order aberrations were increased and contrast sensitivity was decreased in the operated eye. No tissue alterations were found using corneal confocal microscopy. No intra- or postoperative complications occurred. CONCLUSIONS: The intracorneal refractive inlay (Invue Lens) seems to be an effective surgical method for the corneal compensation of presbyopia in emmetropes aged between 45 and 60 years.

Unilateral sulcus implantation of the crystalens HD.

PURPOSE: To evaluate the results after unilateral sulcus implantation of the Crystalens HD (Bausch & Lomb) accommodative intraocular lens (IOL). METHODS: This retrospective interventional case series comprised six eyes from three patients who underwent cataract surgery and bilateral Crystalens HD accommodative IOL implantation. The Crystalens HD was implanted in the bag in one eye (non-sulcus group) and, due to posterior capsule rupture, the lens was positioned in the ciliary sulcus in the fellow eye (sulcus group). RESULTS: Mean patient age was 66.3 ± 4.9 years (range: 60 to 72 years). Mean follow-up was 14.3 ± 3.2 months (range: 12 to 18 months) for the non-sulcus group and 14 ± 2 months (range: 12 to 16 months) for the sulcus group. Uncorrected distance visual acuity improved from 20/100 to 20/33 in the non-sulcus group and from 20/63 to 20/32 in the sulcus group during last follow-up. Corrected distance visual acuity improved from 20/35 to 20/20 in the non-sulcus group and from 20/27 to 20/23 in the sulcus group. Regarding near vision, all eyes in the sulcus group and 66.7% of eyes in the non-sulcus group achieved J1-J2 (Birkhauser reading chart). None of the eyes had any intra- (except posterior capsule rupture in the sulcus cases) or postoperative complications. CONCLUSIONS: Based on this small series, ciliary sulcus implantation of the Crystalens HD seems to be associated with no significant morbidity and provides satisfactory visual acuity outcomes.

Corneal collagen cross-linking with riboflavin and ultraviolet-A irradiation in patients with thin corneas.

PURPOSE: To report the outcomes after corneal collagen cross-linking (CXL) treatment with riboflavin and ultraviolet-A (UVA) irradiation in patients with thin corneas (minimum corneal thickness less than 400 µm after epithelial removal and before riboflavin instillation). DESIGN: Prospective case series. METHODS: Twelve patients (14 eyes, with minimum corneal thickness less than 400 µm after epithelial removal) were included in the study. All patients underwent riboflavin-UVA-induced CXL using the standard CXL (Dresden) protocol. Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) (decimal scale), manifest refraction (diopters, D), and topography were evaluated at baseline and at 1, 3, 6, and 12 months follow-up. Images of the endothelium were acquired with a modified confocal scanning laser ophthalmoscope. RESULTS: No intraoperative or postoperative complications were observed in this patient series. Mean minimum preoperative corneal thickness at the apex of the cone after epithelial removal and before riboflavin instillation was 373.92 ± 22.92 µm (range 340-399 µm). UDVA and CDVA improved from 0.25 ± 0.15 and 0.40 ± 0.20 to 0.27 ± 0.17 and 0.49 ± 0.20 respectively at the last follow-up examination. There was a reduction of the mean keratometry readings from 51.99 ± 5.57 D to 49.33 ± 4.82 D at the last follow-up. A significant decrease of endothelial cell density was observed (preoperative: 2733 ± 180 cells/mm(2) [range 2467-3016], last follow-up visit: 2441 ± 400 cells/mm(2) [range 1448-2920], P < .01). CONCLUSIONS: CXL in thin corneas with minimum corneal thickness less than 400 µm after epithelial removal seems to result in a significant endothelial cell density decrease postoperatively. This finding was not related to other intraoperative or postoperative complications.

Long-term results of phakic refractive lens implantation in eyes with high myopia.

PURPOSE: To evaluate the long-term results of phakic refractive lens (PRL; Carl Zeiss Meditec) implantation in eyes with high myopia. METHODS: In this retrospective, noncomparative, interventional case series, 143 myopic eyes of 82 patients were treated for high myopia with the implantation of the silicone PRL in the posterior chamber. RESULTS: Mean follow-up was 3.8±1.7 years (range: 1 to 6 years). Six years postoperatively (n=34), a statistically significant reduction was noted in the cycloplegic spherical equivalent from -14.08±4.00 diopters (D) (range: -24.88 to -4.75 D) before PRL implantation to -0.45±0.62 D (range: -1.00 to 1.00 D) (P<.001). At 6 years, 67.6% (23 eyes) and 91.2% (31 eyes) were within ±0.50 and ±1.00 D of target refraction, respectively. Mean logMAR uncorrected and corrected distance visual acuity improved significantly (P<.001) (counting fingers preoperatively in all eyes to 0.17±0.15 [range: 0.54 to -0.06] and 0.19±0.19 [1.00 to -0.08] to 0.07±0.10 [range: 0.30 to -0.10], respectively). Complications included anterior capsule damage (3 eyes), temporary intraocular pressure increase (14 eyes), pigment dispersion (1 eye), and PRL decentration (1 eye). No eyes presented any signs of cataract up to 6 years postoperatively. CONCLUSIONS: Long-term results show that PRL implantation is an effective and safe method for treating high myopia.

Management of post laser in situ keratomileusis ectasia with simultaneous topography guided photorefractive keratectomy and collagen cross-linking.

A thirty-nine year old man was referred to our institute due to progressive decreased visual acuity five years after bilateral Laser in situ Keratomileusis (LASIK). Topography revealed signs of post - LASIK ectasia. Patients' left eye was treated with simultaneous Topography Guided Photorefractive Keratectomy (PRK) followed by Corneal Collagen Cross Linking (CXL). Twelve months after the combined procedure both uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) showed significant improvement while topographic findings revealed an improvement of the astigmatic pattern. All higher order aberrations showed a significant decrease twelve months postoperatively. Combined topography guided PRK and corneal cross linking could represent an alternative treatment for post - LASIK ectasia.

Unintended epithelium-only flap creation using a femtosecond laser during LASIK.

PURPOSE: to present a patient in whom, during LASIK with the IntraLase femtosecond laser (Abbott Medical Optics), unintended epithelial (instead of anterior stromal) flaps were created in both eyes. METHODS: a 28-year-old man underwent bilateral LASIK using the IntraLase femtosecond laser programmed to create 100-microm flaps. Flap creation was performed uneventfully in both eyes but flap thickness was thinner than attempted. The flaps were easily torn during flap lift because they appeared to consist of epithelium only. Therefore, the procedure was immediately converted to photorefractive keratectomy with the use of mitomycin C. RESULTS: re-epithelialization occurred 3 days after the procedure in both eyes. Three months after treatment, uncorrected distance visual acuity was 20/25 in the right eye and 20/20 in the left eye with no signs of corneal haze on slit-lamp examination. CONCLUSIONS: despite the advantages of the IntraLase femtosecond laser in the creation of a LASIK flap, complications in terms of flap thickness may occur.

Interface corneal stromal irregularities after flap creation using femtosecond laser.

PURPOSE: To report a case of interface corneal stromal irregularities after flap creation with the advanced IntraLase femtosecond (150 Hz) laser system (Abbott Medical Optics, Inc.). METHODS: Case report. RESULTS: An 18-year-old man underwent bilateral laser in situ keratomileusis (LASIK) using the IntraLase femtosecond laser to create 110-µm flaps. The procedure was uneventful in the left eye. In the right eye, after flap lifting a central irregular stromal interface was noted. The created flap was thicker than expected (139 µm) as measured intraoperatively with ultrasound pachymetry. The excimer laser ablation procedure was performed and the flap was repositioned. On the first postoperative day and during the 6-month follow-up period, uncorrected distance visual acuity was 20/20 in both eyes. CONCLUSIONS: Interface corneal stromal irregularities may occur after femtosecond corneal flap creation during LASIK.

Mitomycin C aqueous humor concentration after photorefractive keratectomy: an experimental study.

PURPOSE: To evaluate mitomycin C (MMC) aqueous humor concentration after photorefractive keratectomy (PRK). METHODS: In this experimental study, twenty-four eyes of 12 male pigmented rabbits were divided into 4 groups and studied at the Institute of Vision and Optics, Department of Medicine, University of Crete, Greece. Eyes in groups 1 and 2 underwent PRK to correct -5 diopters (D) in a 6-mm optical zone, while sponges soaked with 0.02% MMC were applied on the exposed corneal stroma for 60 and 120 seconds, respectively. Similarly, eyes in groups 3 and 4 underwent PRK to correct -10 D in a 6-mm optical zone, while sponges soaked with 0.02% MMC were applied on the exposed corneal stroma for 60 and 120 seconds, respectively. Aqueous humor was extracted from all rabbit eyes 10 minutes after MMC application and high-performance liquid chromatography was performed immediately to detect and quantify MMC levels. RESULTS: The mean aqueous humor concentration of MMC was 0.23+/-0.03 microg/mL, 0.39+/-0.05 microg/mL, 0.28+/-0.04 microg/mL, and 0.52+/-0.16 microg/mL in groups 1, 2, 3, and 4, respectively. The effect of application time and correction on aqueous humor MMC concentration was significant (p<0.0001 and p=0.019), while the exposure time had a greater impact on aqueous humor MMC concentration when compared with the attempted correction. CONCLUSIONS: Both exposure time of MMC on the corneal stroma and the attempted correction was correlated with MMC aqueous humor concentrations.

Thin LASIK flap creation using the SCHWIND Carriazo-Pendular microkeratome.

PURPOSE: To study the outcomes of LASIK after intended thin flap creation using the SCHWIND Carriazo-Pendular microkeratome with the 90-microm head. METHODS: Forty-seven eyes of 26 patients (mean age 28.78+/-6.98 years) underwent LASIK with a superior hinge flap using the 90-microm head of the SCHWIND Carriazo-Pendular microkeratome. Evaluation included flap parameters (thickness, diameter, hinge size), complications, and visual outcome. RESULTS: No intraoperative or early postoperative complications were observed. The mean flap thickness was 79.88+/-6.94 microm (range: 70 to 93 microm). Mean flap diameter was 9.25+/-0.45 mm (range: 8.5 to 11 mm) whereas mean hinge size was 4.63+/-0.66 mm (range: 3 to 6.5 mm). No eye lost lines of best spectacle-corrected visual acuity, and all eyes were emmetropic within one diopter postoperatively. CONCLUSIONS: The SCHWIND Carriazo-Pendular microkeratome with the 90-microm head seems to have increased accuracy in intended creation of thin flaps.

Comparison of Epi-LASIK and off-flap Epi-LASIK for the treatment of low and moderate myopia.

PURPOSE: To compare the early postoperative course and the 1-year clinical results of off-flap Epi-LASIK and Epi-LASIK for the treatment of low and moderate myopia. DESIGN: Pilot double-masked, randomized, comparative study. PARTICIPANTS: Fifty-six patients (112 myopic eyes). METHODS: Epithelium was separated in all eyes with the use of Centurion SES epikeratome (Norwood Abbey EyeCare, Vic, Australia). The first eye treated and surgical method in the first eye were randomized. One eye of each patient underwent standard Epi-LASIK, whereas in the contralateral eye, the epithelial sheet was not retained on the photoablated stroma (off-flap Epi-LASIK eyes). Mean preoperative spherical equivalent was -3.50+/-1.22 diopters (D; range, -1.75 to -6.37 D) in Epi-LASIK eyes and -3.61+/-1.22 D (range, -1.50 to -6.50 D) in off-flap Epi-LASIK eyes (P>0.05, paired Student t test). Excimer laser corneal ablation was performed using the Allegretto 200Hz (Wavelight Laser Technologie AG, Erlangen, Germany). Patients were followed up daily until the epithelial healing was complete and at 1, 3, 6, and 12 months. MAIN OUTCOME MEASURES: Epithelial healing time, subjective pain score, and uncorrected visual acuity (UCVA) were evaluated during the first postoperative days. Uncorrected visual acuity, spherical equivalent refraction, best spectacle-corrected visual acuity, haze scores, and wavefront aberrations were recorded at all subsequent intervals. RESULTS: Time of epithelial healing did not differ significantly in Epi-LASIK and off-flap Epi-LASIK eyes (4.76+/-0.84 days in Epi-LASIK eyes vs. 4.54+/-0.93 days in off-flap Epi-LASIK eyes). No significant difference in UCVA was found after the 2 techniques during the first postoperative days. Subjective pain score was lower in off-flap Epi-LASIK eyes at 2 postoperative hours, whereas no significant difference in pain scores was noted between the 2 techniques at the other intervals. There was no significant difference in spherical equivalent, line gain or loss, haze scores, and higher-order aberrations between Epi-LASIK and off-flap Epi-LASIK eyes at any interval. Uncorrected visual acuity was significantly better in Epi-LASIK eyes only at 6 months (-0.05+/-0.08 in Epi-LASIK eyes vs. 0.00+/-0.07 in off-flap Epi-LASIK eyes). Preoperative wavefront aberrations did not change significantly 1 year after either procedure. CONCLUSIONS: Epi-LASIK and off-flap Epi-LASIK had equal visual and refractive results for the treatment of low and moderate myopia in this study. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Endothelial cell density after photorefractive keratectomy for moderate myopia using a 213 nm solid-state laser system.

PURPOSE: To evaluate whether photorefractive keratectomy (PRK) for moderate myopia using a solid-state laser with a wavelength of 213 nm alters the corneal endothelial cell density. SETTING: University refractive surgery center. METHODS: The corneal endothelium was analyzed preoperatively and 1, 6, and 12 months postoperatively using corneal confocal microscopy (modified HRT II with a Rostock Cornea Module, Heidelberg Engineering) in 60 eyes (30 patients). Patients were randomized to have myopic PRK using a 213 nm wavelength solid-state laser (study group) or a conventional 193 nm wavelength excimer laser (control group). Three endothelial images were acquired in each of 30 preoperative normal eyes to evaluate the repeatability of endothelial cell density measurements. Repeated-measures analysis of variance was used to compare the variations in endothelial cell density between the 2 lasers and the changes in endothelial cell density over time. RESULTS: There were no statistically significant differences in sex, age, corneal pachymetry, attempted correction, preoperative endothelial cell density, or postoperative refractive outcomes (uncorrected visual acuity, best spectacle-corrected visual acuity, and spherical equivalent refraction) between the 2 groups (P>.05). The coefficient of repeatability of endothelial cell density was 131 cells/mm(2). The measured endothelial cell count per 1.0 mm(2) did not significantly change up to 1 year postoperatively in either group (both P>.05). No statistically significant difference was found between the 2 groups in any postoperative interval (P>.05). CONCLUSION: Photorefractive keratectomy for moderate myopia using a 213 nm wavelength solid-state laser or a conventional 193 nm wavelength excimer laser did not significantly affect corneal endothelial density during the 1-year postoperative period.