Preoperative Manifest Refraction Spherical Equivalent Research Articles

Ray-tracing-guided myopic LASIK: real-world clinical outcomes.

To assess effectiveness of individualized ray-trace based laser in situ keratomileusis (LASIK) for correction of myopia in everyday clinical practice. Single-site private practice. Retrospective nonrandomised unmasked chart review. Consecutive, myopic eyes (range ≤-8.25 diopters [D] sphere; astigmatism 0 to -4.25 D) treated with ray-trace based LASIK were included. Patients underwent wavefront, tomography, and biometry assessment using the InnovEyes Sightmap diagnostic device. The ray-trace based algorithm (InnovEyes algorithm) then generated an individualized 3D eye model and calculated a customized LASIK ablation profile. Postoperative visual acuity, refractive error and whole eye higher-order aberrations (HOAs) were evaluated over 3 months. The procedure was performed on 400 eyes (200 patients). Mean preoperative manifest refraction spherical equivalent was -3.39 ± 1.58 D (right eye -3.84 ± 1.63 D, left eye -3.98 ± 1.75 D). At month 3, uncorrected distance visual acuity (UDVA) was ≥20/20 in all eyes, ≥20/16 in 89% (right eye 90%, left eye 89%), ≥20/12 in 51% (54% right eye; 47% left eye), and 20/10 in 8% (right eye 8%; left eye 9%) of eyes respectively. UDVA was within 1 line of preoperative corrected distance visual acuity in 98% of eyes (right eye 98.5%; left eye 98%) and 39% of eyes (right eye 38%; left eye 39%) gained 1 line improvement. There was a statistically but not clinically significant increase in total HOAs (right eye 0.06 ± 0.133 μm; left eye 0.057 ± 0.125 μm; P < .001). The spherical aberration decreased (right eye -0.047 ± 0.095 μm, P < .001; left eye -0.051 ± 0.091 μm, P < .001). Ray-trace based LASIK was safe and effective for correction of myopia with and without astigmatism. Approximately, half the eyes achieved ≥20/12.5 UDVA and 8% achieved 20/10. There was no clinically significant increase in total whole eye HOAs.

Long-term results of hyperopic ablations using alcohol-assisted PRK and FS-LASIK: comparative study.

To evaluate the long-term visual and refractive outcomes of hyperopic excimer ablation using alcohol-assisted photorefractive keratectomy (PRK) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). American University of Beirut Medical Center, Beirut, Lebanon. Retrospective, matched comparative study. Eyes that underwent alcohol-assisted PRK were compared to matched eyes that underwent FS-LASIK. All patients were followed up for at least 3 years after surgery. The refractive and visual outcomes of each group were compared at different postoperative time points. The main outcome measures were spherical equivalent deviation from target (SEDT), manifest refraction, and visual acuity. 83 eyes underwent alcohol-assisted PRK and 83 matched eyes underwent FS-LASIK. Preoperative manifest refraction spherical equivalent was 2.44 ± 1.18 diopters (D) and 2.20 ± 0.87 D ( P = .133) in the PRK and FS-LASIK groups, respectively. Preoperative manifest cylinder was -0.77 ± 0.89 D and -0.61 ± 0.59 D ( P = .175) for the PRK and LASIK groups, respectively. 3 years postoperatively, SEDT was 0.28 ± 0.66 D and 0.40 ± 0.56 D for the PRK and LASIK groups, respectively ( P = .222), whereas manifest cylinder was -0.55 ± 0.49 D and -0.30 ± 0.34 D for PRK and LASIK, respectively ( P < .001). The mean difference vector was 0.59 ± 0.46 for PRK and 0.38 ± 0.32 for LASIK ( P < .001). 13.3% of PRK eyes and 0% of LASIK eyes had >1 D of manifest cylinder ( P = .003). Both alcohol-assisted PRK and FS-LASIK are safe and effective for the treatment of hyperopia. PRK induces slightly more postoperative astigmatism than LASIK. Larger optical zones and recently introduced ablation profiles that lead to a smoother ablation surface might improve the clinical results of hyperopic PRK.

Detection of Static and Dynamic Stereopsis after Femtosecond Laser Small Incision Lenticule Extraction for High Myopia.

Purpose The purpose of this study is to test binocular visual function after femtosecond laser small incision lenticule extraction (SMILE) for high myopia. The traditional Titmus stereotest and dynamic stereotest based on the visual perception biological model were used for comparative analysis. Methods A total of 43 patients were enrolled in this prospective study. At Week 1, Month 1, and Month 3 after surgery, the Titmus stereotest and dynamic stereotest generated by MATLAB were conducted. Dynamic stereopsis consists of randomly flickering Gabor spots and is divided into two models of high energy and low energy according to flicker frequency. Results The preoperative manifest refraction spherical equivalent was −7.21 ± 0.70 D. The preoperative anisometropia was 0.52 ± 0.54D. The quartiles of static stereoacuity in preoperation and 3 follow-ups were as follows: 50.00 (25.00, 100.00) in preoperation, 63.00 (40.00, 63.00) at Week 1, 40.00 (32.00, 63.00) at Month 1, and 40.00 (25.00, 50.00) at Month 3. Static stereopsis improved at Month 1 and Month 3 compared with preoperation and Week 1 (P < 0.05). There were statistically significant differences in high energy dynamic stereopsis at Week 1 and Month 1 compared to preoperation (P < 0.05). In addition, significant differences in low energy dynamic stereopsis were detected between Month 1 and preoperation and also at Month 3 compared to Month 1 (P < 0.05). Conclusion Most high myopia patients have a dynamic stereopsis deficiency before refractive correction. SMILE surgery can improve both static and dynamic stereopsis early in the postoperation period. However, in the long term, there is no significant difference or even a decrease in dynamic stereopsis.

Evaluating the Ectasia Risk Score System in Cancelled Laser In Situ Keratomileusis Candidates.

Purpose To evaluate the ectasia risk score system in cancelled laser in situ keratomileusis (LASIK) candidates at an academic hospital.Methods LASIK candidates who had been cancelled by a surgeon considering the patient age, preoperative central corneal thickness, residual stromal bed thickness, or preoperative manifest refraction spherical equivalent were retrospectively reviewed, and their Randleman ectasia risk score system score was calculated.ResultsThe mean ectasia score of 194 eyes (97 patients) was 4.5 2.67; 40 (20.6%), 46 (23.7%), and 108 (55.7%) eyes were classified as low-, moderate-, and high-risk eyes, respectively. The topography was abnormal in 69% of the patients. The mean manifest refraction spherical equivalent, central corneal thickness, and estimated residual stromal bed thickness were 4 (+0.50 to –15.50) diopters, 520 (439 to 608) µm, and 312.38 (61.5 to 424.12) µm, respectively. The main cause of cancellation in low- and moderate-risk patients (86 eyes) was the presence of unstable refractive error in the past year.ConclusionAlthough promising, some other criteria, such as stable refraction, should be added to this scoring system to achieve greater practicality since a main cause of cancelling LASIK candidates in this study was the presence of unstable refraction.

Five-Year Results of Combined Small-Aperture Corneal Inlay Implantation and LASIK for the Treatment of Hyperopic Presbyopic Eyes.

To evaluate the efficacy of simultaneous laser in situ keratomileusis (LASIK) and small-aperture corneal inlay (KAMRA; AcuFocus, Inc) implantation in hyperopic presbyopic eyes at 5 years postoperatively. This was a retrospective single-center study of patients with hyperopia and presbyopia who underwent simultaneous LASIK and corneal inlay implantation by two experienced refractive surgeons. These patients were regularly observed for 5 years and evaluated with serial corneal tomographies and refractive assessments for uncorrected near visual acuity (UNVA), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), distance-corrected near visual acuity (DCNVA), and manifest refraction spherical equivalent (MRSE). Twenty-four eyes of 24 patients were included. Mean age was 53.63 ± 4.11 years (range: 47 to 63 years) and mean preoperative MRSE was +1.52 ± 0.64 diopters (D) (range: +0.50 to +3.00 D). UNVA was 0.04 ± 0.06 logMAR at 1 month and 0.02 ± 0.05 logMAR (J1+ equivalent) at 5 years postoperatively. In comparison, preoperative DCNVA was 0.44 ± 0.20 (J5/J6 equivalent) (P < .001). At 5 years postoperatively, UDVA was 0.16 ± 0.18 logMAR (20/30 Snellen equivalent), and 23 of 24 eyes (95.8%) had UNVA of J3 or better. Two eyes (8.3%) lost one line of CDVA. One corneal inlay needed readjustment but none were explanted. Eight eyes (25%) developed regression in UNVA with hyperopic shift, which responded to a 3- to 4-month course of topical steroids, with 3 eyes showing patchy haze on the undersurface of the corneal inlay. Simultaneous LASIK and KAMRA inlay implantation, evaluated for 5 years postoperatively, shows some efficacy and predictability in improving UDVA and UNVA in hyperopic presbyopic eyes. However, late-onset regression with hyperopic shift, possible loss of CDVA, and occasional haze remain challenges. [J Refract Surg. 2020;36(8):498-505.].

Analysis of pre-operative factors affecting range of optimal vaulting after implantation of 12.6-mm V4c implantable collamer lens in myopic eyes

BackgroundTo evaluate clinical factors affecting postoperative vaulting in eyes that had achieved optimal vaulting within the range of 250–750 μm following implantation of 12.6-mm V4c implantable collamer lenses (ICL).MethodsA total of 236 eyes of 236 patients that had achieved optimal vaulting following implantation of a 12.6-mm V4c ICL were retrospectively analyzed. Associations between postoperative vaulting and age, preoperative anterior chamber depth (ACD), preoperative axial length (AL), preoperative white-to-white diameter, preoperative pupil size, preoperative sulcus-to-sulcus diameter, and preoperative manifest refraction spherical equivalent were investigated using simple regression, stepwise multiple regression, and multinomial logistic regression analyses.ResultsMean central vaulting at the 6-month follow-up was 519.0 ± 112.8 μm. Variables relevant to postoperative vaulting were, in order of influence, preoperative ACD (β = 0.305, p < 0.001), preoperative pupil size (β = 0.218, p < 0.001), and preoperative AL (β = 0.171, p = 0.006). Low preoperative pupil size was associated with low optimal vaulting (250 to 450 μm), relative to that observed in the mid optimal vaulting group (451 to 550 μm) (odds ratio = 0.532, P = 0.021). Increasing preoperative ACD was associated with high optimal vaulting (551 and 750 μm), relative to that observed the mid optimal vaulting group (odds ratio = 6.340, P = 0.034).ConclusionsMyopic eyes with greater preoperative ACD, larger pupil size, and longer AL are predisposed to higher postoperative vaulting following 12.6-mm V4c ICL implantation. Therefore, the extremes of these parameters should be considered when choosing V4c ICL size.

Safety, efficacy and refractive outcomes of LASIK surgery in patients aged 65 or older

Report on the safety, efficiency and refractive outcomes of LASIK surgery in patients aged 65 or older. This study includes a case series of patients ≥65years that underwent corneal refractive surgery during the period June 2010 to June 2015 at Hospital Zambrano Hellion, Monterrey, Mexico. Inclusion criteria were normal topography, central corneal thickness >500μm, preoperative manifest refraction spherical equivalent (MRSE) up to -8.5D and +6.0D, cylinder up to -6.0D, CDVA of 20/25 or better and with no other ocular pathology. A total of 44 eyes (24 patients) were included. Mean age was 67.2±2.1years (range 65-80), with mean follow-up of 12.2±1.3months. Conventional LASIK was performed in 20 patients (group 1, 36 eyes) to improve UDVA (10 eyes myopic LASIK and 26 eyes hyperopic LASIK) and presbyopic LASIK (monovision) in 4 patients (group 2, 8 eyes) to restore near-vision performance. Preoperative MRSE group 1 was myopic: -2.79±1.88D; hyperopic +2.19±1.88D; and +2.10±0.87D in group 2. Preoperative UDVA in group 1 was 0.67±0.30 LogMAR; 0.46±0.18 LogMAR; and Jaeger ≥4 in 90% in group 2. Postoperative MRSE: -0.29±0.86D (myopic LASIK) (p<0.001), +0.34±0.62D (hyperopic LASIK) (p<0.001) and -1.25±0.59D (non-dominant eye) in presbyopic LASIK. Postoperative UDVA in myopic LASIK was 0.15±0.30 (p=0.001) and 0.11±0.11 (p<0.001) for hyperopic LASIK. In group 2, binocular UDVA was 0.16±0.17 (p=0.12) and UNVA was ≥J2 in 100% of the patients. Even though elder patients may present greater LASIK restrictions due to lens and other ocular age-related changes, patients ≥65years that were candidates for conventional and presbyopic LASIK showed satisfactory and safe refractive and visual outcomes.

V4B implantable collamer lens versus Intacs corneal rings to manage anisometropic myopic amblyopia in children

ObjectiveTo compare the safety and efficacy of phakic intraocular lens (PIOL) versus intrastromal corneal ring segments (Intacs), for correcting high myopic anisometropia in amblyopic children. DesignNonrandomized prospective multi-center study. ParticipantsThirty children, aged between 4 and 12 years, with unilateral high myopic anisometropic amblyopia were included in this study. MethodsPatients who were prospectively subdivided into group A, with mean preoperative manifest refraction spherical equivalent (MRSE) of −12.96 ± 4.17 D, underwent unilateral phakic posterior chamber intraocular lens implantation. Patients with mean preoperative MRSE of −8.60 ± 1.16 D in group B were treated by Intacs corneal rings. Pre- and postoperative visual acuity, ocular examination, stereoacuity, axial biometry measurements, cycloplegic refraction, and endothelial cell counts were performed in all patients. ResultsGroup A revealed prevention of amblyopia with improvement in spectacle-corrected distance visual acuity, where 4–6 lines were achieved in 77% of children, 2–3 lines in 4%, and just 0–1 lines restricted to 19% of children. Improvement in stereoacuity was noted in 93.33% of group A cases, whereas group B showed fewer cases of successfully improved vision, with 4–6 lines in 70% of children, 2–3 lines in 3%, and just 0–1 lines restricted to 27% of children. Improvement in stereoacuity was noted in 86.66% of cases. Two cases of cataract and 1 case of glaucoma with 1 case of uveitis were noted in the implantable contact lens (ICL) group. ConclusionsPosterior chamber PIOLs or Intacs may provide a safe alternative in treating anisometropic myopic patients. Intacs implantation is safer with fewer complications than ICL. However, ICL implantation is advantageous over the corneal ring segment procedure owing to the wide range of errors to correct.

Enhancement after Small-Incision Lenticule Extraction: Incidence, Risk Factors, and Outcomes

To report the incidence, risk factors, and outcomes of enhancement after small-incision lenticule extraction (SMILE). Retrospective cohort study. Five hundred twenty-four eyes of 307 patients who underwent SMILE at Singapore National Eye Center between February 2012 and March2016. The data collected included patient age at primary SMILE, gender, race, preoperative and postoperative manifest refraction spherical equivalent (MRSE), preoperative and postoperative uncorrected distance visual acuity and corrected distance visual acuity, the occurrence of suction loss during the procedure, and the need for enhancement. All enhancements were carried out by performing an alcohol-assisted photorefractive keratectomy (PRK) procedure with application of mitomycin C (MMC). Incidence, prevalence, preoperative and intraoperative risk factors for enhancement, and outcomes after enhancement. The prevalence of enhancement was 2.7%, and 71.4% eyes had enhancement within 1 year of primary SMILE. The incidence of enhancement was 2.1% and 2.9% at 1 and 2 years, respectively. Age older than 35 years, preoperative MRSE more than-6.00 diopters (D), preoperative myopia more than 6.00 D, preoperative astigmatism more than 3.00 D, and intraoperative suction loss were significant risk factors for enhancement after SMILE after adjusting for all other covariates (odds ratios, 5.58, 4.80, 1.41, 3.06, and 2.14, respectively; P= 0.004, 0.021, 0.022, 0.002, and 0.020, respectively). In the patients who underwent bilateral SMILE, the first-operated eye had a marginal trend toward significance for enhancement (P= 0.054). There was no gender or racial difference. In the 14 eyes requiring enhancement, the uncorrected distance visual acuity before enhancement ranged from 20/80 to 20/25, and the mean attempted enhancement spherical equivalent was-0.50±0.86 D. The uncorrected distance visual acuity improved in most patients (92.9%) after enhancement. The 2-year incidence of enhancement after SMILE was 2.9%. Risk factors associated with enhancement included older age at SMILE procedure, greater preoperative MRSE, greater preoperative myopia, greater preoperative astigmatism, and the occurrence of intraoperative suction loss. Clinical outcomes of using PRK with application of MMC for enhancement were good.

Accommodative changes after SMILE for moderate to high myopia correction.

BackgroundTo investigate accommodative response and accommodative lag changes after femtosecond laser small incision lenticule extraction (SMILE) for moderate to high myopia correction.MethodsA total of 32 eyes of 32 patients with no strabismus who underwent SMILE were enrolled in this prospective clinical study. The accommodative response was obtained viewing monocularly with spherical equivalent refractive error corrected, using an open-field autorefractor at different stimulus levels (2.00D, 2.50D, 3.00D, 4.00D and 5.00D) for the right eye before a standard SMILE surgery and at 1-month follow-up after surgery.ResultsThe mean age of the patients were 23.34 ± 2.90 years and the mean preoperative manifest refraction spherical equivalent was −5.74 ± 1.98 diopters. Significant differences were detected in both preoperative and postoperative accommodative responses to different stimulus levels (P < 0.001). Multiple linear regression model analysis revealed preoperative manifest refractive spherical equivalent (P = 0.006) and preoperative accommodative lag (P = 0.04) showed a significant impact on postoperative accommodative lag.ConclusionsThis is the first report of accommodative changes after SMILE. Our preliminary results showed that a decrease in postoperative accommodative lag that might be related to the relief of the visual discomfort symptom.

Range of refractive independence and mechanism of action of a corneal shape–changing hydrogel inlay: Results and theory

To demonstrate the independence of visual performance over a range of preoperative refraction and age in presbyopes implanted with a corneal shape-changing inlay (Raindrop Near Vision Inlay). Two multispecialty clinics, Monterrey and Tijuana, Mexico. Prospective case series. The nondominant eyes of patients were implanted with the hydrogel corneal inlay beneath a femtosecond flap, centered on the pupil. Clinical outcomes included uncorrected near, intermediate, and distance visual acuity (UNVA, UIVA, and UDVA) and patient-assessed task performance in good light and dim light. Statistical analyses assessed the dependencies on preoperative age (45 to 60 years) and preoperative manifest refraction spherical equivalent (MRSE) (-0.5 to +1.5 diopters [D]). Using the inlay effect derived from wavefront measurements, an eye model was created through which letter charts were simulated. The study evaluated eyes of 188 patients. Postoperative UNVA, UIVA, and task performance at these distances in good light was independent of age and preoperative MRSE (P > .05). Postoperative UDVA was weakly dependent on preoperative MRSE, but distance task performance in good light was not (P > .05). In the treated eye, the mean postoperative UNVA was 20/25, UIVA was 20/25, and UDVA was 20/32. The clinical outcomes are explained by consideration of zones within the pupil generating good near, intermediate, and distance image quality. This was confirmed by visual acuity simulations. The continuous center-near power profile induced by the corneal shape-changing inlay provides good visual acuity and performance from distance through near over a 2.0 D range of preoperative refraction and presbyopic age. Drs. Steinert, Schwiegerling, Barragán-Garza, and Chayet are consultants to Revision Optics, Inc. Drs. Lang and Holliday and Mr. Roy are employees of Revision Optics, Inc. Drs. Steinert, Schwiegerling, Barragán-Garza, and Chayet have no financial or proprietary interest in any material or method mentioned.

Effect of mitomycin-C on the variance in refractive outcomes after photorefractive keratectomy

To compare the variance in manifest refraction spherical equivalent (MRSE) after photorefractive keratectomy (PRK) with mitomycin-C (MMC), PRK without MMC, and laser in situ keratomileusis (LASIK) for the treatment of myopic astigmatism. Jules Stein Eye Institute, University of California, Los Angeles, Los Angeles, California, USA. Retrospective case series. Patients were classified into 3 groups of preoperative refraction-matched eyes as follows: PRK with MMC 0.02%, PRK without MMC, and LASIK. The preoperative and postoperative MRSE, preoperative corrected distance visual acuity, and postoperative uncorrected distance visual acuity (UDVA) were analyzed. Each group comprised 30 eyes. Follow-up was at least 6 months in the LASIK group and 12 months in the 2 PRK groups. There were no statistically significant differences in the mean preoperative MRSE (P=.95) or postoperative MRSE (P=.06) between the 3 groups. The mean postoperative MRSE was -0.07 diopter (D) ± 0.47 (SD), -0.14 ± 0.26 D, and 0.02 ± 0.25 D in the PRK with MMC 0.02% group, PRK without MMC group, and LASIK group, respectively. The variance in the postoperative MRSE in the PRK with MMC 0.02% group was significantly higher than that in the PRK without MMC group (P=.002) and in the LASIK group (P=.001). There was no statistically significant difference in the mean postoperative UDVA between the 3 groups (P=.47). Refractive outcomes after PRK for myopia were more variable when MMC 0.02% was used. This should be weighed against the advantage of intraoperative MMC use in reducing haze after PRK.

Randomized dose-response analysis of mitomycin-C to prevent haze after photorefractive keratectomy for high myopia

To evaluate the safety and efficacy of mitomycin-C (MMC) 0.01% (0.1 mg/mL) in preventing haze formation after wavefront-guided photorefractive keratectomy (PRK) for higher myopia at 3 exposures. United States Navy Refractive Surgery Center, San Diego, California, USA. Double-masked randomized prospective trial. Sixty-, 30-, and 15-second exposures of MMC 0.01% were compared in wavefront-guided PRK for higher myopia. One eye received MMC (surgical sponge) and the other a placebo. All eyes received a 4-month tapering postoperative topical steroid regimen. Endothelial cell densities, haze scores, high- and low-contrast acuities, and manifest refraction were measured preoperatively and 1, 3, 6, and 12 months postoperatively. Outcomes were analyzed as repeated measures over time. The mean preoperative manifest refraction spherical equivalent was -5.98 diopters (D) (range -4.4 to -8.0 D). No eye developed more than trace haze. There was a significant difference in haze scores between MMC-treated eyes and untreated eyes at 1 and 3 months (P=.034) but no difference at 6 and 12 months. Endothelial cell densities decreased in the treated eyes and untreated eyes at all 3 exposures at 1 month but returned to baseline by 6 months. There was no difference in acuities or refractions with or without MMC. Mitomycin-C may not be needed to prevent haze after modern PRK with a 4-month steroid taper. There was no clinically significant difference in haze formation between MMC eyes and control eyes at the concentration and exposures used.

Long-Term Visual and Refractive Outcomes following Surface Ablation Techniques in a Large Population for Myopia Correction

To evaluate the visual and refractive outcome for four wavefront-guided surface ablation (WGSA) techniques (LASEK, LASEK flap-off [LASEK FO], Epi-LASIK, and Epi-LASIK flap-off [Epi-LASIK FO]) in a large myopic population. This retrospective review included 1000 myopic eyes (spherical equivalent [SE] -1.0 to -8.0 diopters [D]) treated with WGSA (VISX STAR S4 with IR) using four different epithelial management techniques. Flaps were either retained (163 Epi-LASIK, 361 LASEK) or discarded (277 Epi-LASIK FO, 199 LASEK FO). Eyes in each group were stratified to either low, mild, moderate, or high myopia based on preoperative SE. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), predictability, lines lost, and haze were compared at 3, 6, and 12 months. At 1 year, UDVA and CDVA of ≥20/20 and 20/15 were comparable across the four procedure groups and within each subgroup of myopia. Predictability was less than or equal to ±0.5 D of intended correction in 96% to 99% of eyes. LASEK FO and Epi-LASIK FO outperformed the EPI-LASIK in achieved MRSE, especially in the high myopia category (-0.012, 0.040, and -0.27 D, respectively, P < 0.05). No eyes lost more than one line of CDVA; and 50% to 60% of eyes in each group gained one or more lines. No significant haze was recorded in any group. There was no statistically significant difference between groups in the preoperative MRSE and efficacy indices except for LASEK FO. At 1 year, there was no statistically significant difference in visual outcomes between techniques for any degree of myopia. However, the MRSE achieved with LASEK FO and Epi-LASIK FO were closer to emmetropia.

Pilot Study of a New Posterior Chamber Phakic Intraocular Lens (Epi.Lens) for High Myopia

To report the first safety and efficacy results of a new posterior chamber phakic intraocular lens (PIOL) (Epi.Lens, Acri.Tec/Carl Zeiss Meditec) implanted in the ciliary sulcus to correct high myopia. The Epi.Lens was implanted for the first time in 48 consecutive eyes of 25 patients in an ongoing two-center clinical study. Pre- and postoperative manifest refraction, uncorrected (UDVA) and corrected distance visual acuity (CDVA), intraocular pressure, slit-lamp and funduscopic examination, and ultrasound biomicroscopy were evaluated. Follow-up examinations were performed at 1, 3, 6, 12, and 24 months postoperatively. For each patient, the latest follow-up data were considered. The study cohort consisted of highly myopic patients with mean preoperative manifest refraction spherical equivalent of -9.90 ± 2.53 D, which was reduced to -0.26 ± 0.84 D postoperatively. Two (4.2%) eyes lost one line of CDVA postoperatively, whereas 19 (40%) met and 27 (56%) eyes exceeded preoperative CDVA values, thus improving mean CDVA from 0.83 ± 0.30 to 1.03 ± 0.26. Mean postoperative UDVA (0.85 ± 0.37) was similar to preoperative CDVA (0.83 ± 0.30). When considering all eyes with good visual potential (preoperative CDVA ≥ 1.00 [20/20] [n=25]), 20 (80%) achieved postoperative UDVA ≥ 1.00 (20/20), and 24 (96%) achieved UDVA ≥ 0.80 (20/25). One lens with a small diameter showed contact of the Epi.Lens and crystalline lens with subsequent slight anterior subcapsular cataract; however, CDVA was 1.00 (20/20) at last follow-up 2 years postoperatively. The results of this Epi.Lens pilot study demonstrate good safety and efficacy. The preliminary data are encouraging, and longer follow-up results are anticipated.

Visual Outcomes After Epi-LASIK and PRK for Low and Moderate Myopia

To evaluate visual outcomes following epi-LASIK compared to photorefractive keratectomy (PRK). Of a total 294 patients aged ≥21 years, 145 (290 eyes) underwent epi-LASIK and 149 (298 eyes) underwent PRK for low to moderate myopia or myopic astigmatism. Epi-LASIK was performed with the Amadeus II epikeratome (Abbott Medical Optics) and PRK with the Amoils rotary epithelial brush (Innovative Excimer Solutions). All ablations were performed using the same excimer laser system. Outcome measures included intraoperative complications, corneal reepithelialization, postoperative pain, uncorrected distance visual acuity (UDVA), manifest refraction spherical equivalent (MRSE), corrected distance visual acuity (CDVA), corneal haze, and quality of vision. Mean preoperative MRSE was -2.97±1.19 diopters (D) for epi-LASIK versus -2.95±1.06 D for PRK. Complete reepithelialization was achieved by postoperative day 4 in 46.9% of epi-LASIK eyes versus 92.4% of PRK eyes, with superior UDVA at postoperative day 1 in the PRK group (P=.002). Using Fisher exact test, a significantly higher percentage of epi-LASIK eyes compared to PRK eyes achieved 20/15 or better at 1 month (25.8% vs 17.8%, P=.031), 3 months (62.3% vs 49.3%, P=.004), 6 months (77.1% vs 57.9%, P<.001), and 12 months (75.9% vs 61.9%, P=.002). A change in MRSE >0.50 D occurred in 8.4% of epi-LASIK eyes within the 3- and 12-month interval versus 17.7% of PRK eyes (P=.04). No differences were noted between the two procedures in CDVA or clinically significant haze. Epi-LASIK showed superior refractive efficacy and stability but required more time for wound healing, resulting in inferior early visual outcomes and a tendency to overcorrect higher refractive errors compared to PRK. Both treatments were safe and comparable in terms of pain and haze formation.

Optimizing the vault of collagen copolymer phakic intraocular lenses in eyes with keratoconus and myopia: Comparison of 2 methods

To compare 2 methods for optimizing the final central vault of a collagen copolymer posterior chamber phakic intraocular lens (pIOL) (Visian Implantable Collamer Lens) in eyes with keratoconus and myopia. Private practice, Beverly Hills, California, USA. Comparative interventional study. The length of the pIOL to implant in keratoconic eyes with myopia was selected based on the white-to-white (WTW) distance or the sulcus-to-sulcus (STS) distance using the pIOL manufacturer's protocol. The final central vault distance was compared a minimum of 3 months postoperatively. The pIOL length was based on WTW measurements in 8 eyes of 6 patients and on STS measurements in 8 eyes of 5 patients. There was no significant difference between the 2 groups in the mean preoperative WTW distance, STS distance, or manifest refraction spherical equivalent (MRSE) (P = .22, P = .37, and P = 1.00, respectively). The mean postoperative vault was 1.03 corneal thickness ± 0.72 (SD) in the WTW group and 1.18 ± 0.35 corneal thickness in the STS group (P = .61). The vault distance was less than 1.0 corneal thickness in 3 eyes (37.5%) in the WTW group and 1 eye (12.5%) in the STS group. A small postoperative vault was associated with a high preoperative MRSE (P = .03). The WTW and STS methods both provided adequate final central pIOL vault in keratoconic eyes with myopia. The STS calculations gave greater final vault and higher vault predictability, although the difference between the 2 methods was not statistically significant.

Outcomes of Myopic LASIK With and Without NIDEK Active Torsion Error Correction

To compare refractive outcomes and higher order aberrations of eyes that underwent LASIK for myopia with astigmatism with or without active cyclotorsion error correction. This was a contralateral eye study of 48 eyes of 24 patients who underwent LASIK using the NIDEK Advanced Vision Excimer laser platform (NAVEX), treating one eye with active cyclotorsion error correction (TEC eyes) and the fellow eye without active cyclotorsion error correction (without TEC eyes). Postoperatively, the refractive outcomes, including postoperative astigmatism and higher order aberrations were compared between groups using the t test. A P value <.05 was considered statistically significant. Three-month postoperative outcomes are presented. Preoperative manifest refraction spherical equivalent was -3.59+/-1.60 diopters (D) (range: -1.25 to -6.75 D) for the TEC group and -3.82+/-1.89 D (range: -1.38 to -8.63 D) for the without TEC group. No statistically significant differences were noted in postoperative visual acuity between groups (P>.05). The TEC eyes had statistically significant lower postoperative cylinder (0.28+/-0.27 D [range: 0 to -0.75 D] for the TEC group vs 0.49+/-0.30 D [range: 0 to -1.00 D] for the without TEC group; P=.02). A mean decrease in root-mean-square (RMS) of higher order aberration was noted in the TEC eyes, and a mean increase was noted in RMS of higher order aberration for the without TEC eyes at both 5- and 6-mm pupil diameters. The TEC eyes had statistically significantly lower RMS of higher order aberration (P<.01). Active torsion error correction with the NIDEK NAVEX platform statistically significantly increases the predictability of astigmatism correction and reduces the induction of higher order aberrations of eyes undergoing LASIK.

NIDEK Optimized Prolate Ablation for the Treatment of Myopia With and Without Astigmatism

To report the ocular and corneal higher order aberrations of a pilot trial of optimized prolate ablations for the treatment of myopia. In this prospective study, patients were treated using optimized prolate ablation or conventional ablation. Five patients underwent bilateral optimized prolate ablation treatment, and nine patients were randomized to receive optimized prolate ablation (OPA group) in one eye and conventional ablation (control group) in the other eye. The mean preoperative manifest refraction spherical equivalent was -4.13+/-1.17 diopters (D) (range: -8.00 to -1.50 D), with a mean cylinder of -0.42+/-0.32 D (range: -1.00 to 0.00 D). Predictability, contrast sensitivity, and corneal and ocular aberrations were analyzed out to 6 months postoperatively. Postoperative predictability was similar between the two groups. There was an increase in mesopic contrast sensitivity in the OPA group, and the OPA group had higher mesopic contrast sensitivity postoperatively. At 6 months postoperatively, the root-mean-square (RMS) of the total ocular higher order aberrations was 0.47 microm for the OPA group and 0.75 microm for the control group. Ocular spherical aberration was 0.04 microm for the OPA group and 0.22 microm for the control group. Six-month postoperative RMS of corneal spherical aberration was 0.25 microm for the OPA group and 0.46 microm for the control group. The preliminary outcomes in this study indicate that optimized prolate ablation-treated eyes had less induction of higher order aberration and spherical aberrations postoperatively. Better contrast sensitivity was noted in eyes that underwent optimized prolate ablation treatment compared with preoperatively.

Photorefractive Keratectomy for Primary Myopia Using NIDEK Topography-guided Customized Aspheric Transition Zone

To report the outcomes of topography-guided photorefractive keratectomy (PRK) for the treatment of myopia with or without astigmatism using the customized aspheric transition zone (CATz) ablation algorithm. In this study, 335 eyes underwent PRK using the NIDEK Advanced Vision Excimer laser platform (NAVEX). Mean preoperative manifest refraction spherical equivalent was -4.42+/-3.46 diopters (D) (range: -14.50 to -0.50 D). Mean preoperative sphere was -3.94+/-3.43 D (range: -13.00 to -1.00 D), and mean preoperative cylinder was -0.96+/-1.05 D (range: -5.50 to 0.00 D). Refractive outcomes out to 1 year postoperatively were analyzed. At least 6 months postoperatively, all eyes maintained or gained lines of best spectacle-corrected visual acuity (BSCVA). There was a 51% increase in the eyes that read 20/16 or better uncorrected compared with preoperative BSCVA. At 1 year postoperative, 252/280 (90%) eyes had BSCVA 20/20 or better. Refractive outcomes within +/-0.50 D were observed in 223/275 (81%) eyes at 3 months, 228/300 (76%) eyes at 6 months, and 187/280 (67%) eyes at 1 year. Topography-guided PRK using CATz for the treatment of low, moderate, and high myopia is safe, effective, and predictable.