Lines Of Corrected Distance Visual Acuity Research Articles

Single-step transepithelial photorefractive keratectomy in high myopia: qualitative and quantitative visual functions.

To investigate quantitative and qualitative optical outcomes of single-step transepithelial photorefractive keratectomy (TransPRK) in high myopia. In a prospective interventional case-series, 30 eyes with high myopia (-6.00 to -8.75 D) with (up to -3.00 D) or without astigmatism were enrolled from Bina Eye Hospital, Tehran, Iran. One-step TransPRK was performed with aberration-free aspherical optimized profile and SCHWIND AMARIS 500 laser. One-year follow-up results for refraction, visual acuities, vector analysis, ocular wave-front (OWF) and corneal wave-front (CWF) higher order aberrations (HOA), contrast sensitivity (CS), and post-operative haze were assessed. After the surgery, both photopic and mesopic CSs significantly improved (both P<0.001). We detected significant induction of OWF coma and trefoil (P<0.001 for both) HOAs; CWF coma (P=0.002), spherical (P<0.001), and tetrafoil (P=0.003) HOAs in 6 mm analysis diameter; and CWF trefoil (P=0.04) HOA in 4 mm analysis diameter. The range of mean induction observed for various HOAs was 0.005-0.11 µm. The 86.7% of eyes reached an uncorrected distance visual acuity of 20/20 or better; 96.7% of eyes were within ±0.5 D of targeted spherical refraction. In vector analysis, mean correction index value was 1.03 and mean index of success was 0.22. By 12mo after the operation, no eye lost any number of corrected distance visual acuity lines. We detected no corneal haze greater than 1+ throughout the follow-up. Our findings show promising effects of single-step TransPRK on quality of vision in high myopic eyes. It also improves refraction and visual acuity.

Secondary intraocular lens implantation: Complication rates, visual acuity, and refractive outcomes

To compare complication rates, visual acuity, and refractive outcomes of secondary intraocular lens (IOLs) implantation. Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. Retrospective case series. All secondary IOLs placed by the anterior segment service were reviewed. Preoperative data, operative reports, and data from each subsequent postoperative visit were evaluated. Patients were divided into 5 groups based on the final IOL position: (1) sulcus with optic capture, (2) sulcus without optic capture, (3) anterior chamber (AC), (4) iris-fixated, and (5) transscleral-sutured. Complication rates, visual acuity, and refractive outcomes were compared for each group. The sulcus with and without optic capture groups had the lowest complication rates and best visual acuity outcomes. There was no difference in final corrected distance visual acuity (CDVA) between the transscleral-sutured IOL, iris-fixated IOL, and AC IOL groups, although the AC IOL group had the lowest rates of early postoperative complications and a significant improvement in vision. The transscleral-sutured IOL group had the highest complication rates, and 25% of patients in the iris-fixated IOL group lost 2 or more lines of CDVA. When a secondary IOL cannot be placed withinthe capsular bag, sulcus with optic capture is the bestalternative, followed by sulcus without optic capture. There was no difference in visual acuity outcomes between transscleral-sutured IOLs, iris-fixated IOLs, and AC IOLs. Anterior chamber IOLs resulted in fewer early complications.

Visual and refractive outcomes of combined excimer laser ablation with accelerated corneal collagen cross-linking in subclinical keratoconus

Purpose: The purpose of the study was to evaluate efficacy, safety, and stability of visual and refractive outcomes of combined photorefractive keratectomy (PRK) with accelerated corneal collagen cross-linking (CXL) in subclinical keratoconus. Materials and Methods: This retrospective study included 140 eyes (75 patients) with subclinical keratoconus which underwent simultaneous topography-guided PRK with acceleratedCXL (2.7 J/cm2). Outcome measures were pre- and postoperative uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), manifest refraction, and keratometry. Results: Refractive and keratometric parameters demonstrated statistically significant improvement from baseline to postoperative 12 months. UDVA of ≥20/20 was achieved in 90.7% (127/140) eyes and ≥20/40 in 96.4% (135/140) eyes at last follow-up. Regarding refractive outcomes, 94.3% (132/140) eyes were within ± 1.00 D of attempted refractive correction and 82.9% (116/140) eyes had astigmatism of ≤0.25D postoperatively as compared to 22.9% (32/140) eyes at preoperative levels. Regarding safety, 90.7% (127/140) eyes maintained their preoperative CDVA and 7.2% (10/140) eyes lost ≥2 lines of CDVA. Complications included corneal haze in 7.14% (10/140) and corneal ectasia in 0.7% (1/140) eyes. Conclusion: During the 12-month follow-up, combined topography-guided PRK and accelerated CXL provided good visual and refractive outcomes offering spectacle independence in subclinical keratoconus eyes; however, development of one case of ectasia (0.7%) indicates compromised safety and seems to suggest that utilizing 2.7 J/cm2 energy for CXL procedure may not be adequate.

Retreatment of residual error after femtosecond laser-assisted in-situ keratomileusis in correcting high hyperopia

Purpose The aim of the present study was to evaluate the results of femtosecond laser-assisted in-situ keratomileusis (LASIK) in correcting high hyperopia. Patients and methods The study was carried out at El-Gowhara Eye Center, Ismailia, Egypt. A prospective case series study was carried out. Hyperopic eyes with a spherical equivalent (SE) greater than or equal to +3.00 D were corrected by LASIK. The flaps were created with the VisuMax femtosecond laser. The refractive ablations were performed with the 500-kHz Amaris excimer laser. Full cycloplegic refraction was the target refraction. Patients were divided into two groups. Group A included patients with residual refractive errors less than or equal to +0.50 D of the target refractions and had no further LASIK retreatment, and group B included patients with residual refractive errors greater than +0.50 D of the target refractions along with retreatment 1 month after the primary LASIK. The refractive predictability and stability of the treated and retreated eyes were followed-up for 6 months after LASIK. Results Sixty-four patients (115 eyes) received primary hyperopic femtosecond LASIK. The mean±SD age of all patients was 40.30±13.4 years with a range of 21–64 years. The preoperative mean±SD cycloplegic SE refraction was +4.29±1.5 D with a range from +3.00 to +9.00 D. One month after the primary LASIK treatment, 79.1% (91 eyes) of the treated patients had a mean cycloplegic SE refraction of +0.36±0.13 D (group A). After 6 months of follow-up, 62.6% of eyes (n=72) had an uncorrected distance visual acuity of 0.3±0.21 log MAR. Four (3.5%) eyes lost one line of corrected distance visual acuity (CDVA) (Snellen). Five (4.3%) eyes lost two lines of CDVA (Snellen). Seven (6.1%) eyes gained one line of CDVA (Snellen). Twenty-one (18.3%) eyes gained two lines of CDVA (Snellen). The mean±SD cycloplegic SE refraction was +0.41±0.32 D. In group B (20.9%) (24 eyes), patients had a mean±SD cycloplegic SE refraction of +2.41±0.96 D at the first month after primary LASIK. These patients required a second-stage LASIK retreatment by lifting the original flap. After 6 months of follow-up, 83.3% of eyes (n=20) had an uncorrected distance visual acuity of 0.6±0.13 log MAR. Seven (29.2%) eyes gained one line of CDVA (Snellen). Two (8.3%) eyes lost one line of CDVA, and two (8.3%) eyes lost two lines of CDVA (Snellen). The mean±SD cycloplegic SE refraction was +0.25±0.21 D. No epithelial ingrowth was recorded in both groups. Conclusion Femtosecond LASIK for the correction of high hyperopia is predictable and safe; 79.1% of the patients underwent correction during the primary treatments, and 20.9% were totally corrected after retreatments. No cases of epithelial ingrowth were recorded over the 6-month follow-up period.

Refractive outcomes and safety of the implantable collamer lens in young low-to-moderate myopes.

PurposeTo evaluate visual and refractive outcomes and safety of implantable collamer lens (ICL) implantation in low-to-moderate myopia.SettingPrivate Practice – Dougherty Laser Vision, Westlake Village, CA, USA.MethodsA chart review was performed in 56 (104 eyes) consecutive patients who underwent implantation of the Visian ICL V4 model. Inclusion criteria were age between 21 and 40 years, spherical equivalent between −3.00 D and −10.00 D, and cylinder up to −5 D. Data on visual acuity, refraction, and complications were collected.ResultsThe mean time to the last postoperative visit was 13.1±14.0 months (range, 2 to 50 months). The mean preoperative spherical equivalent was −6.96±1.60 D and the mean preoperative cylinder was −1.03±0.88 D. The mean preoperative corrected distance visual acuity (CDVA) was 20/20 (range, 20/15 to 20/80) that remained unchanged at last postoperative visit. At the last postoperative visit, the spherical equivalent was −0.08±0.01 D and the cylinder was 0.29±0.71 D. Comparison of postoperative uncorrected distance visual acuity (UCDVA) to preoperative CDVA indicated that 27 eyes (26%) had better postoperative UCDVA and 61 eyes (59%) had UDVA equivalent to the preoperative CDVA. Postoperatively, 4 eyes lost 1 line of CDVA and no eyes lost >1 line of CDVA. There were 32 eyes that gained at least ≥1 of CDVA. There were no intraoperative complications. Postoperatively, 3 patients (6 eyes) had dry eye, and 1 patient complained of nighttime halos in 1 eye. At the last postoperative visit, there were no eyes with lens opacity or glaucoma.ConclusionICL implantation for low and moderate myopia up to −10 D in patients up to 40 years of age was safe, accurate, and efficacious. ICL implantation may be a good alternative to laser in situ keratomileusis for young myopes less than −10.00 D.

Comparison of microkeratome assisted sub-Bowman keratomileusis with photorefractive keratectomy

PurposeTo compare the outcomes of photorefractive keratectomy (PRK) and thin-flap Laser-Assisted in Situ Keratomileusis/sub-Bowman keratomileusis (SBK) with intended flap thicknesses of 100μm using the One Use-Plus SBK microkeratome. MethodsNinety-eight eyes of 52 subjects with myopic manifest refraction spherical equivalent (MRSE) of up to −5 diopters (D), a stable refraction for 1year and a corrected distance visual acuity (CDVA) of at least 20/20 in each eye which had undergone SBK or PRK were reviewed retrospectively. Primary outcome measures were MRSE, uncorrected distance visual acuity (UDVA), CDVA, pachymetry and higher order aberrations (HOA). All patients were seen at 1 and 3days, 1week, and 1, 3, and 6months after surgery. ResultsBoth MRSE and UDVA showed a statistically significant improvement at postoperative 1, 3 and 6months from baseline in both SBK and PRK groups. At postoperative 6months, 100% of eyes were within ±0.50 D of attempted correction in both groups. However, SBK group demonstrated better outcomes with 81% of eyes within ±0.13 D, compared to 70% eyes in the PRK group. Both SBK and PRK group demonstrated similar refractive astigmatism accuracy at postoperative 6months, with 88% of eyes having cylindrical error ⩽0.25 D. None of eyes lost any lines of CDVA in the PRK, and 2% eyes lost one line of CDVA in SBK group at postoperative 6months. ConclusionThe visual and refractive outcomes after both PRK and microkeratome assisted SBK are comparable, albeit with a higher complication rate in the SBK group.

Long-term Results of Small-incision Lenticule Extraction in High Myopia.

Objectives:To evaluate two-year results of small-incision lenticule extraction (SMILE) for correction of high myopia.Materials and Methods:Forty-five eyes of 35 patients with mean spherical equivalent (SE) of -7.10±0.95 D who underwent routine SMILE by a single surgeon and were followed for at least 2 years were analyzed by retrospective chart review. SMILE was performed with a Visumax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Follow-up intervals were at 1, 6, 12, and 24 months after surgery. Uncorrected and best corrected distance visual acuity (CDVA), corneal wavefront measurements, and all complications were recorded.Results:After 2 years, 86% of eyes with plano target had an uncorrected distant visual acuity (VA) of 20/20 or better. Two percent of eyes lost 1 line of CDVA, while 32% gained 1 line. The mean SE after 2 years was -0.30±0.50 D. Corneal total high-order aberrations (HOA) increased from 0.43 to 0.92 μm at postoperative 12 months. There were metallic foreign bodies at the corneal interface in 1 eye of 1 patient which caused no decrease in VA.Conclusion:SMILE for high myopia seems safe and effective in light of two-year follow-up results. The procedure caused a moderate increase in HOA.

Laser in situ keratomileusis for high hyperopia with corneal vertex centration and asymmetric offset.

To investigate refractive outcomes and induction of corneal higher order aberrations (HOA) in eyes that underwent laser-assisted in situ keratomileusis (LASIK) for high hyperopia correction using an aberration neutral profile with corneal vertex centration and asymmetric offset. A total of 24 consecutive patients (38 eyes) who underwent LASIK by one surgeon using AMARIS 750S excimer laser and a Carriazo-Pendular microkeratome for flap creation were retrospectively analyzed. Eyes targeted for plano and with correction in the maximum hyperopic meridian strictly higher than +4D were included in the retrospective analysis. Patients were reviewed at 1, 3, and 6 months postoperatively. Postoperative monocular corrected distance visual acuity (CDVA) and uncorrected distance visual acuity (UDVA), manifest refraction, and corneal wavefront aberrations were compared with respective preoperative metrics. Mean preoperative spherical equivalent and refractive astigmatism was +4.07 ± 0.90 D and 1.37 ± 1.26 D, respectively, reducing to +0.28 ± 0.58D (p<0.0001) and 0.49 ± 0.47 D (p = 0.0001) at the last postoperative visit. Six months postoperatively, 78% of eyes achieved a UDVA of 20/25 or better. No eye lost more than 2 Snellen lines of CDVA at any follow-up. There was a statistically significant induction of vertical trefoil (+0.104 ± 0.299 µm, p<0.05), vertical coma (-0.181 ± 0.463 µm, p<0.01), horizontal coma (+0.198 ± 0.663 µm, p<0.05), spherical aberration (-0.324 ± 0.281 µm, p<0.0001), secondary vertical trefoil (+0.018 ± 0.044 µm, p<0.01), and secondary horizontal coma (+0.026 ± 0.083 µm, p<0.05). Laser-assisted in situ keratomileusis for high hyperopia using corneal vertex centration with asymmetric offset results in significant improvement in refraction and visual acuity although affected by significant induction of some higher order aberrations.

Short-term outcomes of small-incision lenticule extraction (SMILE) for low, medium, and high myopia.

To determine the safety, efficacy, and predictability of small-incision lenticule extraction at 6-month follow-up, depending on the level of the myopic refractive error. The surgeries were performed by a surgeon new to this technique. Seventy-one subjects with a mean age of 31.86 ± 5.57 years were included in this retrospective observational study. Subjects were divided into 3 groups depending on the preoperative spherical equivalent (SE): low group from -1.00 D to -3.00 D, medium from -3.25 D to -5.00 D, and high from -5.25 D to -7.00 D. Manifest refraction, corrected distance visual acuity (CDVA), and uncorrected distance visual acuity (UDVA) were measured before surgery and at 6 months after the treatment. In total, 1.4% of the eyes lost 1 line of CDVA after the procedure, whereas 95.8% remained unchanged and 2.8% gained 1 line. A significant undercorrection (p = 0.031) was found in the high myopia group (median -0.50 D), whereas the low and medium groups remained near to emmetropia. In terms of efficacy, no statistically significant intergroup differences for postoperative UDVA (p = 0.282) were found. The vector analysis also showed undercorrection of the preoperative cylinder, even though the standard deviations decreased from 0.9 D in the x axis and 0.7 D in the y axis to 0.24 D and 0.27 D, respectively. Small-incision lenticule extraction might be a safe, effective, and predictable procedure even for inexperienced surgeons. No differences in efficacy were found among myopia levels even though undercorrections were found for SE and cylinder in high myopia.

Simultaneous Topography-Guided Photorefractive Keratectomy and Accelerated Corneal Collagen Cross-Linking for Keratoconus.

To study the evolution of visual and refractive outcomes through the first year after simultaneous topography-guided photorefractive keratectomy (t-PRK) and corneal collagen cross-linking (CXL) in keratoconus. This retrospective case series included 85 eyes of 66 patients with a mean age of 26.3 ± 5.7 years, which underwent simultaneous t-PRK with accelerated CXL. Patients were examined for uncorrected distance visual acuity and corrected distance visual acuity (CDVA), flat and steep keratometry readings, and manifest refraction spherical equivalent at 1, 3, 6, and 12 months. At 12 months, all study parameters demonstrated a statistically significant improvement with uncorrected distance visual acuity 0.46 ± 0.49 logMAR (vs. 0.86 ± 0.39 logMAR preoperatively), CDVA 0.11 ± 0.12 logMAR (vs. 0.41 ± 0.27 logMAR preoperatively), manifest refraction spherical equivalent -2.80 ± 4.47 D (vs. -4.51 ± 4.68 D preoperatively), flat keratometry 43.84 ± 3.24 D (vs. 44.61 ± 3.12 D preoperatively), and steep keratometry 46.05 ± 3.94 D (vs. 48.10 ± 3.68 D preoperatively). Although 90.6% eyes gained 1 or more lines of CDVA, no eyes lost any lines of CDVA. In all, 37.6% of the eyes demonstrated an improvement of 4 or more lines of CDVA with a maximum improvement of 11 lines of CDVA in 1 eye. Simultaneous t-PRK with accelerated CXL improved the spherocylindrical refraction and visual function of keratoconus eyes, and the outcomes were stable through 12 months' follow-up. Future studies with longer follow-up and larger data set are necessary to validate the results of the current study and evaluate the long-term safety and efficacy.

Outcomes of implantation of modified capsule tension rings with multiple black occluder paddles for eyes with congenital and acquired iris defects: Report 3

To evaluate the safety and efficacy of Morcher 50F iris diaphragm implantation to manage moderate to large defects of the human iris. Stein Eye Institute, UCLA, Los Angeles, California, USA. Prospective nonrandomized interventional case series. The demographic, preoperative, and postoperative data of patients who had implantation of modified capsular tension rings and followed to 1year were reviewed. Safety measures included loss of corrected distance visual acuity (CDVA), surgical complications, adverse events, and secondary surgical interventions. Efficacy measures included CDVA with glare, daytime and nighttime glare symptom scores, and subjective cosmesis scores. The study comprised 12 patients. The median CDVA was 20/70 before surgery and 20/20 after surgery. There were no lost lines of CDVA and no intraoperative complications. The most common postoperative complication was posterior capsule opacification. Two adverse events were unrelated to the device. Four patients had secondary surgical interventions, the most common of which was laser capsulotomy. The median CDVA with glare improved from less than 20/400 before surgeryto 20/50 after surgery. One patient worsened. The median subjective daytime glare symptom score improved from 9 to 3 on a 10-point scale (P=.001). The median nighttime subjective glare symptom score improved from 8 to 2 (P=.001). The subjective cosmetic appearance of the eye stayed the same or improved for all patients (P=.031). Iris diaphragm implantation was relatively safe and effective for reducing light and glare sensitivity in eyes with iris defects when combined with cataract extraction and intraocular lens implantation. None of the authors has a financial or proprietary interest in any material or method mentioned.

Long-term Visual and Refractive Outcomes After LASIK for High Myopia and Astigmatism From −8.00 to −14.25 D

To evaluate outcomes of high myopic LASIK using the MEL 80 excimer laser (Carl Zeiss Meditec, Jena, Germany). Retrospective analysis of 479 consecutive high myopic LASIK procedures (318 patients) using the MEL 80 excimer laser and VisuMax femtosecond laser (Carl Zeiss Meditec) in 77% of cases or zero compression Hansatome microkeratome (Bausch & Lomb, Rochester, NY) in 23% of cases. Inclusion criteria were preoperative spherical equivalent refraction (SEQ) of between -8.00 and -14.25 diopters (D) and corrected distance visual acuity (CDVA) of 20/20 or better. Patients were observed for a minimum of 1 year. Flap thickness was between 80 and 160 µm and optical zone was between 5.75 and 6.50 mm. Standard outcomes analysis was performed. Mean attempted SEQ was -9.39 ± 1.22 D (range: -8.00 to -14.18 D) and mean cylinder was -1.03 ± 0.84 D (range: 0.00 to -4.50 D). Mean age was 37 ± 9 years (range: 21 to 60 years) with 54% female patients. Postoperative SEQ was ±0.50 D in 55% and ±1.00 D in 83% of eyes after primary treatment. After re-treatment, 69% of eyes were within ±0.50 D and 95% were within ±1.00 D. UDVA was 20/20 or better in 89% of eyes after final treatment. One line of CDVA was lost in 3% of eyes and no eyes lost two or more lines. Statistically significant increases (P < .001) were measured in contrast sensitivity (CSV-1000) at 12 and 18 cycles per degree. The MEL 80 excimer laser was found to achieve high efficacy and safety for treatment of high myopia between -8.00 and -14.25 D and up to -4.50 D of cylinder. [J Refract Surg. 2016;32(5):290-297.].

Sixteen-year follow-up of hyperopic laser in situ keratomileusis

To assess the long-term efficacy and safety of hyperopic laser in situ keratomileusis (LASIK). Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. Prospective cohort study. Hyperopic LASIK was performed using a mechanical microkeratome, an optical zone of 6.5mm, and a blend zone of 1.5mm. Simple hyperopia was treated. The mean patient age was 51.6years (range 34 to 60years). Preoperatively, the mean spherical equivalent (SE) was +3.74 diopters (D) (range +1.25 to +6.50 D). The mean attempted correction was +3.64 D (range +1.5 to +6.0 D). The mean follow-up was 16.5years. The mean SE was +0.28 D (range -1.0 to +1.5 D) at 12months, +0.84 D (range -0.75 to +3.35 D) at 5years, and +1.74 D (range -0.75 to +4.13 D) at 16years, representing an increase in hyperopia of +1.47 D±1.43 (SD) between 1year and 16years (P<.0001) and of +1.13±0.8 D between 5years and 16years (P<.03). The uncorrected distance visual acuity improved at 16years (P<.0001); corrected distance visual acuity (CDVA) was unchanged (P<.2). The efficacy index was 0.5 and the safety index, 1.09. One eye (3%) lost 2 lines of CDVA. Keratometry remained stable between 1year and 16years (P<1.0). Four eyes (12%) had cataract surgery, and 2 (6%) had laser iridotomy. There was no ectasia. After hyperopic LASIK, an increase in hyperopia occurred between 1 and 5years and 16years. At 16years, efficacy was limited but with no sight-threatening complications. Dr. Marshall was a consultant to Summit Technology, Inc. Dr. O'Brart holds a noncommercial research grant from Alcon Laboratories, Inc. None of the other authors has a financial or proprietary interest in any material or method mentioned.

Long-Term Comparison of Simultaneous Topography-Guided Photorefractive Keratectomy Followed by Corneal Cross-linking versus Corneal Cross-linking Alone

To compare the results of corneal collagen cross-linking (CXL) alone with combined simultaneous topography-guided photorefractive keratectomy plus CXL (tPRK-CXL) for progressive keratoconus for a 3-year interval. Prospective, comparative interventional case series. Forty-eight patients (60 eyes) with progressive keratoconus. Thirty eyes underwent combined tPRK with a solid-state laser (maximum ablation depth, 50 μm) followed by CXL, and 30 eyes underwent CXL alone. Groups were matched in terms of age and keratoconus stage. Corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), keratometry, and corneal confocal microscopy. Mean follow up was 39±11 months. Mean age at operation was 28±5.82 years. Before surgery, average CDVA in the tPRK-CXL group was 0.26±0.17 logarithm of the minimum angle of resolution (logMAR), and in the CXL group was 0.24±0.18 logMAR (P= 0.58). At last follow-up, CDVA was 0.09±0.10 logMAR in the tPRK-CXL group and 0.15±0.12 logMAR in the CXL group (P < 0.05). In both groups, no patient lost more than 2 lines of Snellen visual acuity, whereas 19 eyes and 8 eyes in the tPRK-CXL group and in the CXL group, respectively, gained 2 or more lines of CDVA. Before surgery, average UDVA was 0.83±0.54 logMAR in the tPRK-CXL group and 0.86±0.62 logMAR in the CXL group (P= 0.79). At last follow-up, UDVA was 0.27±0.25 logMAR in the tPRK-CXL group and 0.69±0.58 logMAR in the CXL group (P < 0.001). Before surgery, steep and flat keratometry had no significant differences between groups, and at last follow-up, both steep and flat keratometry readings were significantly flatter in the tPRK-CXL group compared with the CXL group. Depth of CXL treatment, as evaluated by confocal microscopy, was 269.8±31.8 μm in the CXL group and 299.7±29.8 μm in the tPRK-CXL group (P<0.001). No differences were found in endothelial cell density. Simultaneous tPRK followed by CXL in this series of keratoconus patients offered significantly improved vision to treated patients in comparison with CXL alone, and similar results regarding postoperative stability. Safety concerns regarding corneal thickness were taken into account in treatment planning.

Quality control outcomes analysis of small-incision lenticule extraction for myopia by a novice surgeon at the first refractive surgery unit in Nepal during the first 2 years of operation

To evaluate the outcomes of small-incision lenticule extraction for myopia using the Visumax femtosecond laser at the first refractive surgery unit in Nepal during the first 30 months of operation. Tilganga Institute of Ophthalmology, Kathmandu, Nepal. Retrospective noncomparative case series. Consecutive myopic small-incision lenticule extraction procedures by a fellowship-trained surgeon were evaluated. Inclusion criteria were a preoperative spherical equivalent (SE) refraction up to -10.00 diopters (D) and corrected distance visual acuity (CDVA) of 20/20 or better. Outcomes analysis using the Standard Graphs for Reporting Refractive Surgery was performed over a 3-month follow-up. Three-month data were available for 1396 eyes. The mean attempted SE was -5.78 D ± 1.81 (SD) (range -0.96 to -10.00 D) and the mean cylinder, 0.79 ± 0.69 D (range 0.00 to 5.25 D). Postoperatively, the mean SE relative to target was -0.28 ± 0.29 D (range -1.31 to +1.50 D) and was within ± 0.50 D in 80% of eyes and ± 1.00 D in 99% of eyes. The uncorrected distance visual acuity was 20/20 or better in 95% of eyes and 20/25 or better in 99% of eyes. One line of CDVA was lost in 2% of eyes; no eye lost 2 or more lines. There was a small improvement in contrast sensitivity (P < .01). The outcomes of myopic small-incision lenticule extraction up to -10.00 D performed at the first refractive surgery unit in Nepal by a fellowship-trained surgeon with no corneal refractive surgery experience were as safe and effective as outcomes in previous studies. Dr. Reinstein is a consultant to Carl Zeiss Meditec AG and has a proprietary interest in the Artemis technology (Arcscan, Inc.) through patents administered by the Center for Technology Licensing at Cornell University, Ithaca, New York, USA. Drs. Pradhan and Carp have travel expenses to conferences paid by Carl Zeiss Meditec AG. No other author has a financial or proprietary interest in any material or method mentioned.

Eighteen-year follow-up of hyperopic photorefractive keratectomy

To investigate the long-term efficacy of hyperopic photorefractive keratectomy (PRK). University Hospital, London, United Kingdom. Prospective case series. Patients with a follow-up of 18 years ± 0.7 (SD) attended for examination. All had spherical corrections with a 6.5 mm optical zone and 1.5 mm blend zone. Twenty-five patients (45 eyes) were included. The mean preoperative spherical equivalent (SE) refractive error was +4.11 ± 1.8 diopters (D) (range +1.125 to +7.25 D). Between 1 year and 18 years, in eyes that had no cataract surgery (n = 34), there was a +1.14 ± 1.48 D increase in the mean SE (P < .0002). The increase between 7.5 years and 18.0 years did not reach clinical significance (P = .1). Uncorrected distance visual acuity improved at 18 years (P < .02). Corrected distance visual acuity (CDVA) was reduced (P < .001). The efficacy index was 0.47, and the safety index was 0.83. Six eyes (18%) lost 2 lines of CDVA, of which 4 eyes had preexisting cataract. Keratometry remained stable between 1 year and 18 years (P = .2). Forty percent still had traces of peripheral haze, and 4 (9%) had Salzmann-like changes. Eleven eyes (24%) had cataract surgery and 4 (9%) had laser iridotomy. There was no evidence of ectasia. Hyperopic PRK showed an increase in hyperopic SE between 1.0 year and 7.5 years but was generally stable thereafter. The efficacy was limited. Peripheral haze was evident in 40% of cases with Salzmann-like changes in some. Ocular comorbidity in relationship to cataract was common and reduced CDVA. Dr. Marshall was a consultant to Summit Technology, Inc. No author has a financial or proprietary interest in any material or method mentioned.

Single-Step Transepithelial PRK vs Alcohol-Assisted PRK in Myopia and Compound Myopic Astigmatism Correction

Transepithelial photorefractive keratectomy (tPRK), where both the epithelium and stroma are removed in a single-step, is a relatively new procedure of laser refractive error correction. This study compares the 3-month results of myopia and compound myopic astigmatism correction by tPRK or conventional alcohol-assisted PRK (aaPRK).This prospective, nonrandomized, case–control study recruited 148 consecutive patients; 93 underwent tPRK (173 eyes) and 55 aaPRK (103 eyes). Refractive results, predictability, safety, and efficacy were evaluated during the 3-month follow-up. The main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and mean refractive spherical equivalent (MRSE).Mean preoperative MRSE was −4.30 ± 1.72 D and −4.33 ± 1.96 D, respectively (P = 0.87). The 3-month follow-up rate was 82.1% in the tPRK group (n = 145) and 86.4% in aaPRK group (n = 90), P = 0.81. Postoperative UDVA was 20/20 or better in 97% and 94% of eyes, respectively (P = 0.45). In the tPRK and aaPRK groups, respectively, 13% and 21% of eyes lost 1 line of CDVA, and 30% and 31% gained 1 or 2 lines (P = 0.48). Mean postoperative MRSE was −0.14 ± 0.26 D in the tPRK group and −0.12 ± 0.20 D in the aaPRK group (P = 0.9). The correlation between attempted versus achieved MRSE was equally high in both groups.Single-step transepithelial PRK and conventional PRK provide very similar results 3 months postoperatively. These procedures are predictable, effective, and safe for correction of myopia and compound myopic astigmatism.

Five-year functional outcomes and vault of −20 diopter myopic phakic intraocular lens implantation

To evaluate refractive and visual outcomes and complications associated with phakic intraocular lens (pIOL) implantation to correct high myopia. Fernández-Vega Ophthalmological Institute, Oviedo, Spain. Retrospective observational case series. Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), refraction, vault, and adverse effects were evaluated after 5 years with Visian ICMV4 pIOL. Mean spherical equivalent (SE) dropped from -18.32 ± 2.37 diopters (D) preoperatively to -0.88 ± 0.52D 5 years postoperatively; 61% of eyes were within ±0.75 D of the target. The mean Snellen decimal CDVA and UDVA were 0.73 ± 0.23 and 0.55 ± 0.26, respectively. More than 50% of eyes achieved 20/25 or better CDVA postoperatively. Four eyes had lost 2 or 1 lines of CDVA, 10 eyes had not lost any lines from preoperatively, and 46 eyes had gained 1 or more lines of CDVA 5 years postoperatively. The safety index was 1.26 ± 0.32. Forty eyes had UDVA of 20/40 or better postoperatively. The efficacy index was 0.99 ± 0.42. At 5-year follow-up, the mean central vault was 475.28 ± 216.38 μm. No eyes showed central contact between the pIOL and crystalline lens. Nevertheless, 10 eyes showed peripheral contact with a central vault between 150 and 260 μm. Two eyes developed anterior subcapsular cataract, although only 1 eye required cataract surgery. Predictability, safety and effective outcomes of posterior pIOL of (- were good, as well as postoperative complications over the long term. A central vault of 260 μm was enough to prevent the peripheral contact between the pIOL and crystalline lens in eyes with high myopia. The authors have no proprietary interest in any of the materials mentioned in this article.

Small-incision lenticule extraction (SMILE): outcomes of 722 eyes treated for myopia and myopic astigmatism

To study the outcomes of small-incision lenticule extraction (SMILE) for treatment of myopia and myopic astigmatism. Retrospective study of patients treated for myopia or myopic astigmatism with SMILE, using a VisuMax(®) femtosecond laser (Carl Zeiss Meditec, Jena, Germany), at the Department of Ophthalmology, Odense University Hospital, Odense, Denmark. Inclusion criteria were corrected distance visual acuity (CDVA) of 20/25 or better before surgery and no ocular conditions other than myopia up to -10.00 diopters (D) with astigmatism up to 3.00 D. Of the 729 treatments, 722 were included. The spherical equivalent (SE) refraction averaged -6.82 ± 1.66 diopters (D) before surgery. After 3months, 88% of eyes were within ±0.50 D of the intended refraction, whilst 98% were within ±1.00 D. The mean difference between attempted and achieved SE refraction at 3months after surgery was -0.06 ± 0.01 D (range: -1.25 to 1.25 D). In eyes with emmetropia as target refraction (n = 362), 63% had uncorrected distance visual acuity (UDVA) of 20/25 or better 1day after surgery, rising to 83% at 3months after surgery. The average gain in CDVA from before surgery to 3months after surgery was 0.07 ± 0.03 (logMAR). However, 12 eyes (1.6%) lost 2 or more lines of CDVA from before surgery to 3months postoperatively. Simultaneous treatment of up to 3.00 D of astigmatism was not associated with less predictable refractive outcomes. In the short term, SMILE seemed predictable, efficient, and safe for treatment of myopia and myopic astigmatism.

One-Year Clinical Outcomes of a Two-Step Surgical Management for Keratoconus-Topography-Guided Photorefractive Keratectomy/Cross-Linking After Intrastromal Corneal Ring Implantation.

To present the results of same-day topography-guided photorefractive keratectomy (TG-PRK) and corneal collagen cross-linking (CXL) after intrastromal corneal ring (ISCR) implantation in patients with keratoconus. Thirty-three patients (41 eyes) aged between 19 and 45 years were included in this prospective study. All patients underwent a femtosecond laser-enabled (Intralase FS; Abbott Medical Optics, Inc.) placement of intracorneal ring segments (Kerarings; Mediphacos, Brazil). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and keratometry readings remained stable for 6 months. Same-day PRK and CXL was subsequently performed in all patients. After 12 months of completion of the procedure, mean UDVA in log of minimal angle of resolution was significantly improved (0.74±0.54-0.10±0.16); CDVA did not improve significantly but 85% of eyes maintained or gained multiple lines of CDVA; mean refraction spherical equivalent improved (from -3.03±1.98 to -0.04±0.99 D), all keratometry readings were significantly reduced, from preoperative values, but coma did not vary significantly from preoperative values. Central corneal thickness and corneal thickness at the thinnest point were significantly (P<0.0001) reduced from 519.76±29.33 and 501.87±31.50 preoperatively to 464.71±36.79 and 436.55±47.42 postoperatively, respectively. Safety and efficacy indices were 0.97 and 0.88, respectively. From 6 months up until more than 1 year of follow-up, further significant improvement was observed only for UDVA (P<0.0001). Same-day combined TG-PRK and CXL after ISCR implantation is a safe and effective option for improving visual acuity and visual function, and it halts the progression of the keratoconus. The improvements recorded after 6 months of follow-up were maintained or improved upon 1 year after the procedure.