Epi-Bowman keratectomy versus alcohol-assisted photorefractive keratectomy: wound healing and complications.

PURPOSE: In Epi-Bowman Keratectomy™ (EBK), a new dynamic multi-blade single-use device (Epi-Clear™, Orca Surgical, Israel) is utilized to remove the epithelium by sweeping movements across the corneal surface. Epithelial cells are discarded. Alcohol or other chemical agents are not utilized. We wanted to compare clinical results of Epi-Clear photorefractive kertectomy (PRK) to alcohol-assisted PRK. STUDY DESIGN: Retrospective, comparative study. METHODS: Consecutive case series: Adult patients seeking laser vision correction of myopia or myopic astigmatism without ocular diseases or prior surgery were included. The Epi-Clear PRK group comprised 50 consecutive eyes of 27 patients and the PRK group 50 eyes of 25 patients. RESULTS: No intraoperative complications occurred. Epi-Clear PRK: At day 1, day 4, and 3 months, uncorrected distance visual acuity (UDVA) was 0.41/0.47/0.93 (decimal scale); epithelial defect diameter was 4.7/0.2/0 (mm); pain level was 3.8/0.3/0 (visual analogue scale, 0-10), respectively. At 3 months, efficacy index was 0.86 and spherical aberrations were unchanged. Three eyes (6%) showed (presumably sterile) infiltrates. PRK: At day 1, day 4, and 3 months, UDVA was 0.56/0.46/1.15; epithelial defect diameter was 6.3/0.2/0 (mm); pain level was 5.0/0.3/0, respectively. At 3 months, efficacy index was 1.1 and spherical aberrations were unchanged. CONCLUSION: The new method of epithelial debridement with Epi-Clear before laser ablation seems to offer fast epithelial removal without nicking Bowman's layer (as observed with the laser microscope). However, we found significantly inferior results of Epi-Clear PRK compared to alcohol-assisted PRK. Furthermore, after Epi-Clear PRK corneal infiltrates as a new type of postoperative complication were observed.

Repeatability and reproducibility of manifest refraction.

PURPOSE: To evaluate the intraexaminer repeatability and the interobserver reproducibility of manifest refraction. SETTING: Tertiary referral center. DESIGN: Retrospective study. METHODS: Patients attending at least 2 preoperative refractions before undergoing subsequent refractive surgery were included. All manifest refractions were performed by 1 of 4 experienced optometrists using an automated phoropter according to a standard protocol. The first manifest refraction was performed after obtaining automated refraction and measuring the spectacles of the patient. The second refraction was typically refined from the first also considering wavefront refraction and tomography/topography. RESULTS: The latest 2 manifest refractions of 1000 eyes obtained at 2 separate visits showed a mean pairwise absolute difference of 0.16 ± 0.19 diopter (D) (range 0 to 1.38 D) in spherical equivalent (SE). This SD was better than 0.25 D (the minimum measurement increment of refraction itself). The 95% limit of agreement (LoA) was within 0.50 D for sphere, cylinder, and SE. The SD of the astigmatism axis was approximately 10 degrees, and the 95% LoA was within 22 degrees (the difference in axis decreasing significantly with the measured cylinder magnitude). The SD for corrected distance visual acuity (CDVA) was half a Snellen line and the 95% LoA was within 1.5 lines (with increasing deviation with worse vision). There were no clinically meaningful differences in reproducibility (2 optometrists) compared with repeatability (same optometrist) in sphere, axis, and CDVA. CONCLUSIONS: Reproducibility was 0.16 D irrespective whether refractions were performed by 1 or 2 different optometrists. Obtaining multiple refractions preoperatively might increase the predictability of surgery and decrease the enhancement rate.

Small incision lenticule extraction for the correction of high myopia.

PURPOSE: Excimer laser-based refractive procedures can have less predictable results when used for correcting high myopia than when used for moderate myopia. Small incision lenticule extraction might overcome this weakness. However, small incision lenticule extraction is only Food and Drug Administration approved for use in myopic eyes up to -8 D with astigmatism of -3 D or less. We report outcomes of small incision lenticule extraction in highly and moderately myopic eyes and compare these to modern laser-assisted in situ keratomileusis. METHODS: Retrospective, observational consecutive case series. Inclusion criteria: attempted myopic spherical correction ⩾-8 or-3 to -7.75 D with astigmatism ⩽-3 D, and corrected distance visual acuity of 1.0 (decimal scale) or better. RESULTS: A total of 62 highly myopic and 407 moderately myopic eyes were included. At 3 months postoperatively, the highly myopic eyes had a mean spherical equivalent refraction of -0.28 ± 0.41 D (range: -1.13 to +0.75 D). Mean uncorrected distance visual acuity was 1.0. Mean efficacy index was 0.84. Mean safety index was 1.03. Uncorrected distance visual acuity same or better than corrected distance visual acuity: 61%. Astigmatism was ⩽0.5 D in 90% and ⩽1 D in 100%. The results in the moderately myopic eyes were comparable. CONCLUSION: We found equally good visual and refractive outcomes after small incision lenticule extraction for the correction of high and of moderate myopia combined with an astigmatic correction of up to 3 D, respectively.

Clinical outcomes of small incision lenticule extraction versus advanced surface ablation in low myopia.

PURPOSE: To compare the visual and refractive outcomes of small incision lenticule extraction and advanced surface ablation for low myopia or myopic astigmatism. METHODS: Retrospective, observational case series of our first 50 consecutive small incision lenticule extraction patients compared to refraction-matched 50 advanced surface ablation treatments with attempted spherical equivalent correction ⩽-3.5 D, astigmatism ⩽-1.5 D, and corrected distance visual acuity of 1.0 (decimal scale) or better. Only one eye per patient was included. RESULTS: Small incision lenticule extraction: mean attempted spherical equivalent correction was -2.80 ± 0.63 D. Uncorrected distance visual acuity was 0.85 and 1.0 at days 1 and 5, respectively. At 3 months, mean spherical equivalent refraction was 0.02 ± 0.32 D (range: -0.5 to +0.75 D), mean cylinder was -0.24 ± 0.21 D (range: 0 to -0.75 D), mean uncorrected distance visual acuity was 1.27, mean efficacy index was 0.96, and mean safety index was 1.05. Uncorrected distance visual acuity was same or better than corrected distance visual acuity in 96%, astigmatism ⩽0.5 D in 98% and ⩽1 D in 100% of eyes, respectively. Advanced surface ablation: mean attempted spherical equivalent correction was -2.75 ± 0.5 D. Uncorrected distance visual acuity was 0.72 and 0.61 at days 1 and 5, respectively. At 3 months, mean spherical equivalent refraction was 0.22 ± 0.32 D, mean cylinder was -0.27 ± 0.27 D, mean uncorrected distance visual acuity was 1.21, mean efficacy index was 1.03, and mean safety index was 1.08. CONCLUSION: Small incision lenticule extraction for low myopia was found to be safe and effective with outcomes at 3 months similar to those obtained with advanced surface ablation while offering a quicker visual recovery.

Varifocal Versus Monofocal LASIK in Presbyopic Hyperopic Eyes.

PURPOSE: To compare varifocal (SupraCor; Technolas Perfect Vision GmbH, Munich, Germany) to monofocal (Zyoptix TissueSaving; Bausch & Lomb, Rochester, NY) LASIK in patients with hyperopic presbyopia. METHODS: In this prospective, non-randomized, comparative case series, consecutive patients with hyperopia, presbyopia, and emmetropia as target refraction were bilaterally treated with varifocal (8 patients) or monofocal (7 patients) LASIK. The study was designed for 35 patients, but was terminated early after interim analysis. Outcomes (preoperative and 1 day, 1 week, 1 month, and 3 months postoperative) were: monocular and binocular uncorrected near visual acuity (UNVA), distance-corrected near visual acuity (DCNVA), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), low-contrast UDVA and CDVA, efficacy, and safety. RESULTS: Preoperative data were similar in both groups. Monocular and binocular UNVA were not significantly different between both groups at any follow-up visit. At 3 months, mean monocular UNVA was 0.40 logMAR in both groups. Monocular DCNVA and binocular CDVA were not significantly different between groups. Monocular mean CDVA was 0.00 ± 0.06 logMAR after varifocal LASIK and -0.06 ± 0.04 logMAR after monofocal LASIK. The efficacy index was 0.9 after vari-focal LASIK and 0.88 after monofocal LASIK (not significant). The safety index was 1.08 after varifocal LASIK and 1.125 after monofocal LASIK (not significant). CONCLUSIONS: With emmetropia as target refraction, varifocal ablations yielded no additional benefit compared to monofocal ablations in hyperopic presbyopic LASIK. The authors speculate that epithelial remodeling masks the impact of a varifocal ablation pattern and that a myopic postoperative refraction (modified monovision) may be necessary to further improve near and intermediate vision. These results demonstrate the value of a control group in studies evaluating presbyopia corrections. [J Refract Surg. 2019;35(7):459-466.].

Small-incision lenticule extraction for the correction of myopic astigmatism.

PURPOSE: To report the outcomes of small-incision lenticule extraction (SMILE) in myopic eyes with astigmatism of 1.0 to 3.0 diopters (D). SETTING: Center for Refractive Surgery, Eye Department, St. Francis Hospital, Muenster, Germany. DESIGN: Retrospective case series. METHODS: Inclusion criteria were myopia of -0.5 D or more, astigmatism between -1.0 D and 3.0 D, and decimal corrected distance visual acuity (CDVA) of 1.0 or better. RESULTS: The study comprised 206 eyes. Preoperatively, the mean attempted spherical equivalent (SE) correction was -5.45 ± 2.37 D (range -1.25 to -11.38 D) and the mean cylinder was -1.52 ± 0.57 D (range -1.0 to -3.0 D). Three months postoperatively, the mean SE refraction was -0.07 ± 0.38 D (range -1.25 to +1.00 D) and the mean cylinder was -0.32 ± 0.29 D (range 0.0 to -1.5 D). The mean decimal uncorrected distance visual acuity (UDVA) was 1.13, the mean efficacy index was 0.87, and the mean safety index was 1.00. The UDVA was the same as or better than the CDVA in 67% of cases. The angle of error was ±5 degrees in 67% and ±15 degrees in 94% of cases, and the residual astigmatism was 0.5 D or less in 88% and 1.0 D or less in all patients. CONCLUSION: Small-incision lenticule extraction for the correction of myopic astigmatism was safe and effective, with outcomes comparable to those reported for laser in situ keratomileusis using modern eye-tracking systems.

Flap Melting Over Corneal Inlay for Hyperopic Correction.

PURPOSE: To report two cases of flap melting over corneal inlays for hyperopic correction several years after implantation. METHODS: The corneal inlay (+6.00 diopters [D]; PermaVision intracorneal lens; Anamed Inc., Lake Forest, CA) was implanted underneath a LASIK flap in two patients. RESULTS: Visual acuity and slit-lamp findings of both patients were stable for several years. At 9 years postoperatively, the first patient presented with a sudden loss of corrected distance visual acuity (CDVA) due to partial flap melting over the inlay while the surrounding anterior cornea showed opacification. The inlay was explanted immediately. Three years after explantation, CDVA returned to 1.0. Similarly, the second patient presented 11 years postoperatively with loss of vision, opacification, and partial flap melting. The inlay was explanted. Two years later, CDVA recovered. CONCLUSIONS: Potentially severe biocompatibility issues of corneal inlays may occur even after several uneventful years. [J Refract Surg. 2018;34(11):775-778.].

Atypical endophthalmitis after intraocular collamer lens implantation.

Unilateral endophthalmitis occurred after bilateral immediately sequential intraocular collamer lens (Visian Implantable Collamer Lens) implantation for the correction of myopic astigmatism in a 49-year-old woman. The surgeries and initial recovery were unremarkable. However, after 3 days, the patient noticed increasing blurring of vision in the left eye and presented to our clinic. The anterior segment of this eye was quiet, while the vitreous cavity was densely infiltrated. Immediate explantation of the corrective lens and vitrectomy combined with intravitreal antibiotic injection were performed. Staphylococcus epidermidis was detected in the vitreous tap and treated with intravenous antibiotics, antibiotic eyedrops, and parabulbar injections of dexamethasone. The corrected distance visual acuity recovered to 20/20 over a 6-month period. However, a cataract developed thereafter.

Corneal Ectasia After LASIK Combined With Prophylactic Corneal Cross-linking.

PURPOSE: To report a case of unilateral corneal ectasia following LASIK surgery combined with prophylactic corneal cross-linking (CXL) in a young patient. METHODS: Case report. RESULTS: Preoperative topography was unremarkable in both eyes with a minimum corneal thickness of 554 µm in the right eye and 546 µm in the left eye. Preoperative corrected distance visual acuity (CDVA) was 1.0 (20/20 Snellen) in both eyes with a refraction of +1.25 -2.75 × 10 in the right eye and +0.50 -2.00 × 163 in the left eye. LASIK combined with CXL was uneventful. After 12 months, postoperative topography was unremarkable with an uncorrected distance visual acuity (UDVA) of 1.0 in both eyes. Two years after surgery, the patient presented with a loss of vision (UDVA 0.25) and an inferior steepening on topography in the left eye. Standard CXL was performed to arrest further progression. CONCLUSIONS: This report illustrates that the currently used prophylactic CXL protocol in combination with LASIK may not be effectively preventing corneal ectasia in every case. [J Refract Surg. 2017;33(1):50-52.].