Improvement In Uncorrected Distance Visual Acuity Research Articles

Long-term results of accelerated corneal collagen crosslinking in paediatric patients with progressive keratoconus: 10-year follow-up.

To evaluate the 10-year visual, refractive, and tomographic outcomes of epithelium-off accelerated corneal collagen cross-linking (ACCL) in paediatric patients with progressive keratoconus (KC) and to compare the stages in terms of re-progression. Patients under 18 years of age with progressive KC who underwent ACCL between 2010 and 2012 and completed at least 10 years of follow-up were included in this retrospective study. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive errors, and corneal tomography parameters were evaluated preoperatively and at 1, 5, and 10 years postoperatively. The effect of stage and age on re-progression was analysed. The study included 175 eyes of 97 patients (mean age: 14.46 ± 2.17 years). Improvement in UDVA and CDVA was observed in all postoperative periods compared to the preoperative period (each p-value < 0.05). The increase in spherical equivalent (SE), flattening of keratometry values, and decrease in thinnest corneal thickness (TCT) were statistically significant in the tenth year compared to preoperatively (each p-value < 0.05). Re-progression was observed in 16 eyes (9.14%). Haze was observed in 13 eyes (7.43%), 4 of which were permanent. Deep anterior lamellar keratoplasty was performed in 3 eyes (1.7%) and a second ACCL in 3 eyes (1.7%). ACCL is an effective and safe long-term strategy to prevent progression of KC in paediatric patients. In the light of this study with a 10-year follow-up re-progression rate of 9.14%, long-term follow-up of patients after ACCL for possible re-progression and the need for re-CCL or keratoplasty may be recommended.

Safety and efficacy of implantable phakic contact lens versus implantable collamer lens in myopia correction.

Phakic intraocular lenses (pIOLs) have proven to be excellent substitutes for excimer laser keratorefractive surgery in certain situations. We aimed to assess the efficacy and safety of two pIOLs, the implantable collamer lens (ICL V4c) versus the implantable phakic contact lens (IPCL V2), for myopic correction. In this prospective randomized clinical trial, we allocated eligible eyes with myopia > - 6 diopters into IPCL or ICL implantation groups, each including 100 eyes of 100 individuals. Preoperative and postoperative assessments at 3, 6, and 12 months included measurements of the spherical equivalent (SE), uncorrected distance visual acuity (UCDVA), best-corrected distance visual acuity (BCDVA), intraocular pressure (IOP), maximum keratometry (K1), minimum keratometry (K2), mean keratometry (Kmean), anterior chamber depth (ACD), anterior chamber angle (ACA), and endothelial cell density (ECD). The groups had comparable demographic characteristics and baseline visual and anatomical values (all P > 0.05). The UCDVA, BCDVA, and SE of the two groups were comparable at baseline and at all postoperative follow-up examinations (all P > 0.05). Both groups experienced significant improvements in UCDVA, BCDVA, and SE at three months postoperatively (all P = 0.001), and measurements remained stable for up to 12 months. Keratometry readings were comparable between the groups over the follow-up period and remained unchanged at all visits (all P > 0.05). The ACA in the ICL group was significantly decreased at three months postoperatively (P = 0.001) and then widened significantly at 6 and 12 months (both P = 0.001). In the IPCL group, the postoperative ACA was significantly decreased at three months (P = 0.001) and was comparable to that in the ICL group (P > 0.01). However, at the 6- and 12-month postoperative visits, the ACA was significantly narrower in the IPCL group than in the ICL group (both P = 0.001). The ACD in both groups was decreased at three months postoperatively (both P = 0.001) and remained stable until the end of the study. The ECD remained comparable between the groups at all postoperative visits (all P > 0.05). We did not observe a significant ECD reduction in either group at any postoperative follow-up visit (all P > 0.05). We encountered no serious complications in either group. ICL and IPCL had comparable safety and efficacy outcomes in terms of anterior chamber morphometrics, visual and refractive results, and corneal parameters. Further multicenter randomized clinical trials with longer follow-up periods, larger sample sizes, and measurement of additional anterior chamber and corneal morphometrics, vault, and other vision parameters are needed to verify these findings.

Customized corneal allogenic intrastromal ring segments (CAIRS) for keratoconus with decentered asymmetric cone.

Corneal allogenic intrastromal ring segments (CAIRS) refer to the intracorneal placement of fresh, unprocessed, processed, preserved, or packaged allogenic rings/segments of any type/length. We described uniform-thickness CAIRS previously. We now describe a new technique of customized CAIRS to personalize the flattening effect as per individual topography. A prospective interventional case series of patients with pericentral/ paracentral decentered cones and gradation of keratometry with one side steeper than the other was conducted. Individually customized tapered CAIRS with variable volume, arc length, taper length, and gradient of taper were implanted. In total, 32 eyes of 29 patients with at least 1-year follow-up were included. Special double-bladed trephines and a CAIRS customizer template allowed the creation of individually customized CAIRS. Mean uncorrected distance visual acuity (UDVA) and spectacle-corrected distance visual acuity improved from 0.22 to 0.47 (P = 0.000) and from 0.76 to 0.89 (P = 0.001), respectively. Significant improvement was seen in K1, K2, Km, Kmax, topographic astigmatism, Q-value, sphere, cylinder, spherical equivalent, Root Mean Square (RMS), Higher Order Aberrations (HOA), and vertical coma (P < 0.01, 0.05). There was no significant change in the width or height of CAIRS between 1 month and last visit on anterior-segment optical coherence tomography. Five eyes continued to remain at the same UDVA, 27 eyes had at least 2 lines, and 13 eyes had at least 3 or more lines improvement in UDVA. The maximum improvement in UDVA was 7 lines. A significant difference in flattening was obtained at different zones across the tapered CAIRS. Thus, differential flattening was achieved across the cone based on the customization plan. Personalized customization was possible for each cornea, unlike limited models of progressive-thickness synthetic segments. Allogenic nature, greater customizability, efficacy, and absent need for large inventories are advantages compared to synthetic segments.

Changes of retinal vessel density in low to moderate myopic eyes with orthokeratology evaluated by optical coherence tomography angiography.

To explore the effect of orthokeratology (OK) fitting on retinal vessel density in low to moderate myopia adolescents by using optical coherence tomography angiography. Children aged 10 to 14y with a cycloplegic spherical equivalent refraction of -0.50 diopter (D) to -5.00 D and astigmatism with more than -1.50 D were recruited. The enrolled adolescents were divided into OK group and spectacle group. During regular follow-up, adolescents were measured respectively at pre-wear, 1, 3, and 6mo after treatment. The follow-up included uncorrected distance visual acuity (UDVA), axial length (AL), superficial capillary plexus density (SCPD), deep capillary plexus density (DCPD), central retinal thickness (CRT), foveal avascular zone area (FAZ-A), foveal avascular zone perimeter (FAZ-P) and foveal vessel density in a 300-µm-wide region around foveal avascular zone (FD-300). The collected data were analyzed using statistical methods. By one month, SCPD significantly increased in the fovea and superior retina, and DCPD significantly increased inferiorly in OK group compared to spectacle group (P<0.05). By three months, there were significant increases in SCPD in the fovea and inferior retina, and DCPD in the parafovea, superior, and inferior retina in OK group (P<0.05), while the increase in SCPD and DCPD in the fovea were observed by six months (P<0.05). The FD-300 significantly increased at every follow-up in OK group compared to spectacle group (P<0.05). No significant differences in the CRT, FAZ-A and FAZ-P and FD-300 were observed between two groups (P>0.05). OK group showed a significant improvement in UDVA after wearing OK, compared to spectacle group (P<0.01), while the AL did not show a significant difference between two groups (P>0.05). Short-term OK worn can increase local retinal vessel density in adolescents with low-to-moderate myopia.

Effects of physical activity combined with different visual target presentation durations of ciliary-muscle training on visual acuity in children.

This study aimed to identify the effect of different durations of visual target presentation during ciliary-muscle training on children's kinetic visual acuity (KVA), uncorrected distance visual acuity (UDVA), axial length, and accommodative facility. Based on the ciliary-muscle regulation mechanism, an intervention program involving ciliary-muscle training with different durations of visual target presentation combined with physical education classes was designed. The intervention aimed to determine the effect of different ciliary-muscle training durations on children's visual acuity. A total of 153 children aged 10-11 years from a school in Suzhou (a major city located in southeastern Jiangsu Province, East China) were enrolled as participants in this 32-week intervention study. This study measured the participants' UDVA and KVA before, during (after the 16th week), and after (after the 32nd week) the experimental intervention. The accommodative facility was measured during and after the intervention. After 32 weeks of the intervention, the KVA and UDVA of each experimental group were significantly improved (p < 0.05). A high percentage in the improvement of KVA was observed in the 3-s and 1-s groups (25.53%, 21.74%), and the highest percentage in the improvement of UDVA was observed in the 3-s group (2.96%). Axial length increased significantly in all groups (p < 0.05), and there was a low percentage increase in the 1-s and 3-s groups (0.82%). The accommodative facility was significantly improved in all experimental groups, with a higher improvement percentage in the 3-s and 1-s groups (3.01% and 2.61%, respectively). After dividing the children in each group according to their visual acuity, the KVA of children in the 1-s group was significantly improved, the UDVA of children with myopia was significantly increased, and the accommodative facility of children with mild and moderate myopia was significantly improved. Moreover, the KVA, UDVA, and accommodative facility of children with mild and moderate myopia in the 3-s group were significantly improved. The KVA of children with emmetropia and the accommodative facility of children with mild and moderate myopia in the 5-s group were also significantly increased. In school physical education classes, the 1-s, 3-s, and 5-s ciliary-muscle regulating exercise could effectively improve the kinetic visual acuity, uncorrected distance visual acuity, and accommodative facility of children aged 10-11 years. Among them, the effects of the 1-s and 3-s durations are better than that of the 5-s duration, as it can reduce the growth rate of axial length and achieve better effects among children with mild and moderate myopia.

A Clinical Decision Tree to Support Keratoconus Patients Considering Corneal Cross-Linking Combined with Refractive Treatment.

To develop a fast and frugal decision tree to identify keratoconus patients most likely to benefit visually from the combination of corneal cross-linking (CXL) with topography-guided photorefractive keratectomy ("CXL plus"). The outcome of interest was an improvement in uncorrected distance visual acuity (UDVA) by at least two lines at the 12-month follow-up. Preoperative and 12-month follow-up data from patients who received CXL plus (n = 96) and CXL only (n = 96) were used in a recursive partitioning approach to construct a frugal tree with three variables (corneal thickness [>/< 430 um], patient interest in CXL plus [yes/no], and tomographic cylinder [</> 3 D]). In addition, we estimated the probability of the outcome from a multivariate logistic regression model for each combination of variables used in the decision tree. In the complete sample, 101/192 (52.6%) patients improved by at least two lines at the 12-month follow-up. Patients affirmative in all three answers had a 75.6% (34/45) probability of gaining at least two lines of improvement in UDVA by CXL plus. The statistical model estimated a 66.0% probability for a successful outcome. A fast and frugal tree consisting of three variables can be used to select a patient group with a high likelihood to benefit from CXL plus. The tree is useful in the preoperative counseling of keratoconus patients contemplating the CXL plus option, an intervention that is not fully covered by many health insurances.

Allograft corneal ring segment for keratoconus management: Istanbul nomogram clinical results.

To evaluate the clinical feasibility and visual outcomes of allograft corneal ring segment implantation for the treatment of keratoconus. This case series, included forty-four eyes of 32 patients with a 6-month follow-up. All cases were treated according to the Istanbul nomogram. In the Istanbul Nomogram, corneal tunnels of 4 × 7.5 mm diameters are created at depth of 200 μm and implanted with sterile allograft corneal rings (KeraNaturalTM, Lions VisionGift, Portland, OR, USA) at the cone location. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SE) and keratometric values were compared preoperatively versus postoperatively. There was significant improvement in UDVA, CDVA, SE and topographic keratometric values. The mean preoperative CDVA (Snellen, decimal) increased from 0.29 ± 0.20, to 0.56 ± 0.26 (P < 0.001), at the last visit. There was no statistically significant difference between preoperative and postoperative thinnest pachymetry values (P = 0.509). No major complications or adverse event were observed during and after the operation. The results of this pilot study show that sterile allograft corneal ring segments may be safe, effective and enhance the visual performance of keratoconus patients. Larger clinical studies are needed to demonstrate the effectiveness and safety with long term follow-up.

Visual recovery after immediate sequential bilateral cataract surgery at a veterans' hospital.

To answer patient questions about the expected timeline for recovery, the objective postoperative visual acuities were reviewed for patients undergoing immediate sequential bilateral cataract surgery (ISBCS). Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri. Retrospective chart review. All patients who underwent ISBCS in 2019 were evaluated. A total of 116 patients (232 eyes) were studied. Uncorrected distance visual acuity (UDVA) for postoperative day 0 or 1 (POD0/1), postoperative week 1 (POW1), and postoperative month 1 (POM1) were required for study inclusion. Patients with ocular comorbidities were not excluded, although all patients passed an initial screening to qualify for ISBCS. The outcome measures included POD0/1, POW1, and POM1 UDVA. Postoperative UDVA was stable or improved compared with preoperative corrected distance visual acuity (CDVA) for 48% (66/138) of eyes on POD0, 79% (74/94) of eyes on POD1, and 90% (209/232) of eyes on POW1. 83% of patients at POD1 and 90% of patients at POW1 had stable or improved visual acuity in at least 1 eye. 92% (214/232) of eyes had a POW1 UDVA of 20/40 or better. Of the 18 eyes with a postoperative POW1 UDVA of 20/50 or worse, 5 (28%) were known preoperatively to have limited visual potential. 99% (115/116) of patients had at least 1 eye 20/40 or better. Most of the patients who underwent ISBCS demonstrated meaningful improvement in UDVA compared with preoperative CDVA as early as POD1. These results serve to guide discussion of postoperative expectations with patients interested in ISBCS.

Effect of corneal epithelial remodeling on visual outcomes of topography-guided femtosecond LASIK.

To assess the effect of epithelial remodeling on visual outcomes over a 9 mm diameter corneal surface after topography-guided laser in situ keratomileusis (LASIK) for myopia correction using spectral-domain anterior segment optical coherence tomography (AS-OCT). Outpatient clinical practice at the Stanford University Byers Eye Institute in Palo Alto, California. Prospective nonrandomized observational study. Visual acuity, including uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), 5% and 25% contrast sensitivity CDVA, manifest refraction, and corneal epithelial thickness after topography-guided femtosecond LASIK were analyzed. Corneal epithelial thickness was mapped across 13 sections and 3 concentric zones using AS-OCT preoperatively and at 1 month, 3 months, 6 months, and 12 months postoperatively. 60 eyes of 30 patients with a mean age of 32.8 years (range 23 to 52 ± 7.03 years) undergoing myopic LASIK correction were assessed. In eyes with complete follow-up data (n = 30), mean preoperative UDVA was logMAR 1.48 ± 0.45 and logMAR -0.11 ± 0.08 at postoperative 12 months. Mean preoperative CDVA was logMAR -0.08 ± 0.11 and logMAR -0.13 ± 0.07 at 12 months. Linear mixed modeling demonstrated a significant correlation between improvement in UDVA and decreased superior and nasal corneal epithelial thickness and between improvement in CDVA and increased central epithelial thickness 12 months postoperatively. Improvement in UDVA and CDVA at 12 months after topography-guided femtosecond LASIK was correlated with nonuniform epithelial remodeling, including epithelial thickening in the central zone and thinning in the superior and nasal sections as measured by AS-OCT.

Comparison of visual outcomes between 120-µm and 140-µm cap thicknesses 12months after small incision lenticule extraction.

To compare visual and refractive outcomes as well as changes in high-order aberrations in patients with 120- versus 140-µm cap thicknesses 12months after small incision lenticule extraction. Ninety-four patients were randomized to receive small incision lenticule extraction with either a 120-µm cap thickness (n = 47) or a 140-µm cap thickness (n = 47) to treat myopia or myopic astigmatism, if not both. In an analysis of right eyes only during the 12-month follow-up period, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive outcomes, and high-order aberrations were evaluated. The distribution of patients by age and sex between the groups did not differ significantly (P = .803 and P = .680, respectively). CDVA, spherical and cylindrical refraction, and changes in total high-order aberration, spherical aberration, coma, and trefoil were similar between the groups at 6 and 12months, postoperatively. However, UDVA was statistically significantly higher in patients with 140-μm cap thicknesses than with 120-μm cap thicknesses at 6 and 12months postoperatively (P < .001 and P < .001, respectively). Patients with 140-µm cap thickness showed greater improvement in UDVA than ones with 120-µm cap thickness at 12-month follow-up (P = .005). Both 120- and 140-μm cap thicknesses in small incision lenticule extraction were safe and effective thicknesses for correcting myopia or myopic astigmatism. The patients with 140-μm cap thickness had better improvement in UDVA after 12-month follow-up compared to patients with 120-μm cap thickness.

Evaluation of Visual Outcome of 2 Phakic Posterior Chamber Implantable Lenses in High Myopia: A Comparative Study.

To evaluate and compare the visual outcomes of two phakic intraocular lenses in high myopia. A prospective comparative study was undertaken on 50 eyes of 26 patients {age ≥21 years and divided into two groups (implantable collamer lens [ICL] V4c, n=25 eyes and refractive implantable lens [RIL], n=25 eyes)}. Patients were evaluated for uncorrected distance visual acuity (UCVA), best-corrected distance visual acuity, manifest refractive spherical equivalent (MRSE), contrast sensitivity, intraocular pressure, dilated fundus examination, trabecular-iris angle (TIA), anterior chamber depth, horizontal white-to-white diameter, wavefront aberrometry, and endothelial cell (EC) count. All patients were followed up until 6 months and additionally evaluated for anterior chamber inflammation, cataract, and lens vault. The baseline parameters (UCVA, MRSE, and EC count) and postoperative improvement in UCVA, contrast sensitivity, MRSE, EC loss, safety index, and efficacy index were comparable between both the lenses. The improvement in aberrometric profile was significantly better in the ICL group. The mean postoperative vault was higher in RIL group (434.88±162.48 μm vs. 547.24±159.83 μm, P=0.0173); however, the vault was within normal range in both the groups. The decrease in mean TIA was significantly higher in RIL group (8.58 vs. 13.45 μm, P=0.0073). Acrylic phakic lens can be considered as a suitable alternative to collamer lens for refractive correction of high myopia. The collamer lenses showed slight superiority in some qualitative visual parameters; however, collamer lenses do not present with subjective complaints in the patients.

SPECIFIC CORNEAL PARAMETERS AND VISUAL ACUITY CHANGES AFTER CORNEAL CROSSLINKING TREATMENT FOR PROGRESSIVE KERATOCONUS.

To evaluate the effect of crosslinking (CXL) therapy on the change in the quality of visual acuity and the change in the topographic properties of the cornea - curvature, pachymetry, and change of astigmatism, coma abberation and CLMIaa (Cone Localisation and Magnitude Index). Aretrospective analytical study included 29 eyes of 24 patients who had progressed in the last 12 months and were suitable candidates for CXL surgery. The monitored parameters were the steepest, flatest and mean anterior instantaneous curvature (AICS, AICF, AICM) and the steepest, flatest and mean posterior instantaneous curvature (PICS, PICF, PICM) of the cornea, corneal thickness in the centre of the cornea (PACHC) and in the thinnest point of the cornea (PACHT), corneal astigmatism (ASTIG). coma (COMA), Cone Localization and Magnitude Index (CLMIaa) and uncorrected distance visual acuity (UDVA) with corrected distance visual acuity (CDVA). Data were analysed before surgery and 12 months after surgery. The AIC, COMA, CLMIaa and ASTIG parameters were analysed by paired t test. As the parameters of UDVA, CDVA, PIC and PACH did not meet the conditions of normal distribution, the Wilcoxon test was used to investigate the change in these parameters after CXL. Twelve months after the procedure, we recorded an improvement in UDVA (p=0.371) and CDVA (p=0.825), an increase in PICS, PICF and PICM (p=0.902; p=0.87 and p=0.555), adecrease in PACHCC (p=0.294) and adecrease in CLMIaa (p=0.113) that did not reach statistical significance. The decrease in PACHT (p=0.027), decrease in COMA (p=0.037) and decrease in anterior corneal curvature of AICS, AICF and AICM were statistically significant (p=0.019; p=0.010 and p=0.005). The decrease in the value of astigmatism did not show statistical significance, as p=0.297. CXL corneal therapy has been shown to be an effective method to stabilize the cornea in progressive keratoconus, and to improve the higher order of coma. This contributes to the possible improvement of UDVA and CDVA.

Combined implantation of toric and spherical intraocular lenses for low corneal astigmatism correction

Background: This study compared outcomes of combined toric versus spherical intraocular lens (IOL) implantation in patients with low corneal astigmatism.&#x0D; Methods: In this retrospective contralateral study, patients with corneal astigmatism who received combined toric (FIL 611 T, Soleko, Rome, Italy) and spherical IOL (FIL 611 T, Soleko, Rome, Italy) implants were recruited. Eyes were examined preoperatively and then again 3 months postoperatively. Postoperatively, uncorrected distance visual acuity (UCDVA), residual astigmatism, and spherical equivalent (SE) were compared between the toric IOL-implanted eyes and the spherical IOL-implanted fellow eyes.&#x0D; Results: Among the 46 included cases (age 69 ± 12.7 years [mean± standard deviation]; range: 60‒78 years), 86.9% of eyes (n = 40) in the toric IOL group had a postoperative refractive cylinder of ≤ 0.25 diopters (D), compared with 4.3% (n = 2) of eyes in the spherical IOL group. Both groups showed a statistically significant reduction in refractive cylinder and improvement in UCDVA after cataract surgery (both P = 0.01). Similarly, toric IOLs were superior (69.6%) to spherical lenses (2.2%) in obtaining a SE of ≤ 0.25 D.&#x0D; Conclusions: To our knowledge, no previous study had sought to compare low-power toric and spherical IOLs in low corneal astigmatism in the same patient's eyes. Our findings suggest that low-power toric IOLs may result in good refractive outcomes as compared with spherical IOLs implanted in the fellow eye of the same patient, although both result in significant UCDVA improvement. Well‐designed clinical research studies with a longer follow-up and more participants are necessary to confirm these findings.

Long-term results of MyoRing implantation in patients with keratoconus

ABSTRACT Clinical relevance: This study was conducted to evaluate five-year outcomes of MyoRing implantation in patients with keratoconus. The results showed that MyoRing implantation is a minimally invasive procedure and is safe and effective for improving visual acuity and refraction in most patients with keratoconus. Background: The long-term effects of MyoRing implantation on corneal features were studied. Methods: A total of 48 keratoconic eyes of 43 consecutive patients who had undergone MyoRing implantation using the Pocket Maker microkeratome (Dioptex, gmbh, Linz, Austria) and who had completed five years of follow‑ups were included in this retrospective study. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refraction and keratometry (K) readings were measured and assessed pre-operation, and five years post-operatively. As well, post-operation satisfaction was assessed using a validated questionnaire. Results: Five years post-operatively, there was a significant improvement in UDVA, CDVA, K readings, spherical equivalent (SE), and manifest sphere and cylinder (p < 0.001). Mean UDVA was 1.20 logMAR before the surgery and 0.42 after the surgery (p < 0.001). Mean CDVA was 0.63 logMAR before the surgery and 0.20 logMAR after the surgery (p < 0.001). SE was improved from −6.53 dioptres (D) before the surgery to −2.23 D after the surgery (p < 0.001). Moreover, the results show that the mean K was reduced by 2.82 D after the surgery (p = 0.001). Overall, 81% of patients were moderately to highly satisfied five years after surgery. Conclusion: MyoRing implantation was found to be a minimally invasive procedure, and is safe and effective for improving visual acuity and refraction in most patients with keratoconus.

Treatment effect with 2 photorefractive intrastromal cross-linking protocols in low-grade myopia through 24-month follow-up.

To assess the effect of two high-oxygen epi-on PiXL treatments for low-grade myopia. This prospective, randomized, intra-individually comparing, single-masked study included 23 healthy volunteers (46 eyes) aged 18-35years with mild myopia, -0.75 to -2.50 D manifest refractive spherical equivalent (MRSE). One eye was randomized to a 4.0-mm homogenous treatment zone and the fellow eye to a 4.0-mm annular zone (16:40min at 30mW/cm2 , fluence 15J/cm2 ). Uncorrected distance visual acuity (UDVA), MRSE, best spectacle-corrected visual acuity (BSCVA), Scheimpflug light scattering depths, mean keratometry (Kmean ) and endothelial cell count (ECC) were assessed through 24months. Similar improvements in UDVA were seen for the homogeneous and annular protocols at 1month: -0.52 (-0.59, -0.39) and -0.49 (-0.59, -0.39) logMAR, respectively (medians and interquartile ranges, IQR), p=0.91, and MRSE: +1.0 D (0.94, 1.31) and +1.0 D (0.69, 1.25), p=0.17. Light scattering depths were 496 (465, 527) and 349 (247, 378) µm, respectively, and the reduction in mean keratometry was -0.8 D (-1.1, -0.7) and 0 D (-0.1, 0.1), p<0.001. The treatment effect remained stable throughout 24months. At 1week, the participants reported less ocular discomfort with the annular protocol. No reductions were seen in BSCVA or ECC. No adverse events were reported. PiXL can reduce low-grade myopia and improve uncorrected vision in healthy eyes. The initial ocular discomfort may be reduced with an annular treatment zone. Further studies are needed to optimize PiXL treatment parameters.

Comparison of surgical repositioning rates and outcomes for hydrophilic vs hydrophobic single-piece acrylic toric IOLs.

To evaluate the comparative rotational stability and the repositioning rates and outcomes of a hydrophilic and hydrophobic acrylic monofocal toric intraocular lens (IOLs). Single center, Aravind Eye Hospital in Madurai, India. Retrospective cohort study. All patients had either an Auroflex hydrophilic acrylic toric IOL (n = 4603) or AcrySof hydrophobic acrylic toric IOL (n = 926) implanted between January 2015 and April 2019. Surgical repositioning was offered if the toric IOL was 15 degrees or greater misaligned or there was a 2-line or greater improvement in uncorrected distance visual acuity (UDVA) predicted with repositioning. A total of 5529 single-piece toric IOLs were implanted during the study period. There was no statistically significant difference between the hydrophilic and hydrophobic acrylic toric IOL groups in need for surgical repositioning (2.5% vs 1.9%; P = .34) or actual surgical repositioning rate (1.8% vs 1.5%; P = .59). A higher rate of surgical toric IOL repositioning was associated with younger age (62.7 vs 67.2 years; P < .0001), higher presurgical astigmatism (2.32 vs 1.99 diopters [D]; P < .0001), and with-the-rule astigmatism (4.7% vs 2.1% against-the-rule astigmatism; P = .002). In 95 eyes that underwent toric IOL repositioning, there was significant preoperative to postoperative improvement in UDVA (0.48 vs 0.12 logarithm of the minimum angle of resolution; P < .001), mean residual cylinder (1.79 vs 0.7 D; P < .001), and mean toric IOL misalignment (49.7 vs 5.4 degrees; P < .001). The repositioning outcomes were statistically similar with both toric IOL models. There were no major complications or recurrent toric IOL rotation after surgical repositioning. The hydrophilic acrylic toric IOL had comparable rates of postoperative misalignment and surgical repositioning with the hydrophobic acrylic toric IOL. Early postoperative surgical repositioning was both safe and effective with both toric IOLs.

Factors Associated With Improvement in Vision Following Femtosecond Astigmatic Keratotomy in Post-Keratoplasty Keratoconus Patients

To evaluate factors associated with improvement in vision following femtosecond astigmatic keratotomy (FSAK) in patients with keratoconus post-keratoplasty. Retrospective, interventional case series. The study took place in an institutional setting. This was a retrospective study that included patients with keratoconus who underwent FSAK for astigmatism following penetrating (PKP) or deep anterior lamellar keratoplasty (DALK). Success was defined as improvement in 3 Early Treatment Diabetic Retinopathy Study lines (doubling of the visual angle) of uncorrected distance visual acuity (UDVA) or best spectacle-corrected visual acuity (BSCVA). A total of 56 eyes in 56 patients with keratoconus were included. Following FSAK, there was a significant improvement in UDVA (1.30 ± 0.49 to 0.87 ± 0.58 logarithm of minimal angle of resolution [logMAR]; P < .001), BSCVA (0.40 ± 0.26 to 0.27 ± 0.29 logMAR; P <.001), and corneal astigmatism (8.69 ± 2.72 to 3.92 ± 2.13 diopter [D]; P < .001). Success was achieved in 60.7% (34/56) of cases, and this group had a higher proportion of previous PKP (73.5% vs 45.5%; P= .03), worse preoperative UDVA (1.42 ± 0.47 vs 1.11 ± 0.47 logMAR; P= .03), and a greater preoperative manifest cylinder (7.56 ± 2.26 vs 5.72 ± 2.12 D; P= .01). In multiple regression analysis, PKP (vs DALK) (odds ratio [OR]: 8.52; P= .009), worse preoperative UDVA (OR: 9.08, P= .02), and greater preoperative cylinder (OR: 1.51; P= .04) were independently associated with success, and, when combined, led to a sensitivity and specificity of 84.6% and 93.8%, respectively, in predicting success. The optimal cutoff predicting success with a preoperative cylinder was a cylinder >6.75 D. Approximately 60% of patients with keratoconus post-keratoplasty experience doubling of the visual angle following FSAK. Patients with previous PKP and a greater cylinder are more likely to benefit from this procedure. Separate nomograms for DALK and PKP patients may be warranted.

Photorefractive intrastromal corneal crosslinking for treatment of low myopia: clinical outcomes using the transepithelial approach with supplemental oxygen.

To evaluate the safety and efficacy of photorefractive intrastromal corneal crosslinking (PiXL) for the treatment of low myopia using the epithelium-on approach with supplemental oxygen. The Eye Foundation, Coimbatore, India. Prospective interventional case series. Myopic nonectatic eyes underwent PiXL using the Mosaic system. Ultraviolet-A (UV-A) irradiation of 365 nm wavelength was delivered in an accelerated (30 mW/cm) pulsed approach to provide a total fluence of 15 J/cm. Supplemental oxygen (concentration greater than 95%) was provided to increase the efficacy of the epithelium-on approach during the UV-A irradiation. Efficacy was determined by improvement in mean refractive spherical equivalent (MRSE), uncorrected distance visual acuity (UDVA), and keratometric flattening. Safety was determined by loss of lines of corrected distance visual acuity, endothelial cell loss, and adverse events. Fifty eyes of 26 patients with a mean age of 22.73 ± 3.74 years were included. A significant improvement in UDVA from baseline (logarithm of the minimum angle of resolution [logMAR] 0.63 ± 0.25) was noted at the 3-month (logMAR 0.08 ± 0.15) and 6-month (logMAR 0.13 ± 0.18) follow-up visits (P < .001). Significant keratometric flattening from baseline was noted at all follow-up visits (P < .001). No significant endothelial cell loss or adverse effects were noted. A significant correlation was noted between the change in MRSE and preoperative corneal biomechanics (deformation amplitude ratio, P = .029). Transepithelial PiXL with supplemental oxygen might be a safe and effective approach for reduction of myopia. The change in MRSE and keratometric flattening was greater in comparison with earlier protocols, including the epithelium-off approach.

Changes in Corneal Asphericity after MyoRing Implantation in Moderate and Severe Keratoconus.

PurposeTo evaluate the effect of MyoRing implantation on corneal asphericity in moderate and severe keratoconus (KCN).MethodsThis cross-sectional observational study comprised 32 eyes of 28 patients with KCN, who had femtosecond-assisted MyoRing corneal implantation. The primary outcome measures were preoperative and six-month postoperative corneal asphericity in 6-, 7-, 8-, 9-, and 10-mm optical zones in the superior, inferior, nasal, temporal, and central areas. The secondary outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, thinnest location value, and keratometry readings.ResultsA significant improvement in the UDVA and CDVA was observed six months after the surgery (P 0.001) with a significant reduction in the spherical (4.67 diopters (D)) and cylindrical (2.19 D) refractive errors. A significant reduction in the corneal asphericity in all the optical zones and in the superior, inferior, nasal, temporal, and central areas was noted (P 0.001). The mean thickness at the thinnest location of the cornea decreased from 437.15 30.69 to 422.81 36.91 μm. A significant corneal flattening was seen. The K1, K2, and Km changes were 5.32 D, 7 D, and 6.17 D, respectively (P 0.001).ConclusionMyoRing implantation is effective for improving corneal asphericity in patients with KCN. It allows successful corneal remodeling and provides a significant improvement in UDVA, CDVA, and refractive errors.

Management of Corneal Ectasia after LASIK with Phototherapeutic Keratectomy Combined with Photorefractive Keratectomy and Collagen Cross-Linking.

Background To evaluate the efficacy of phototherapeutic keratectomy (PTK) combined with photorefractive keratectomy (PRK) and riboflavin with ultraviolet-A collagen cross-linking (CXL), performed sequentially on the same day, in the management of corneal ectasia after LASIK. Methods This retrospective review comprised consecutive patients with corneal ectasia after LASIK. The patients were administered PTK and PRK on the previous corneal flap, and CXL was given on the same day by the same surgeon. The main outcome measures included age, sex, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent refraction, cylinder equivalent refraction, steep and flat keratometries (K), central corneal thickness (CCT), endothelial cell count, corneal haze, and ectasia stability. Mean follow-up period was 6, 12, and 24 months. Results Sixteen eyes of twelve patients were included in the study. Twenty-four months after administration of PTK combined with PRK and CXL, a significant improvement in UDVA was observed. Mean cylinder equivalent refraction was significantly reduced at 6, 12, and 24 months postoperatively. However, no significant reduction was observed in spherical equivalent refraction. A significant reduction in the flat K and steep K values was observed. No significant change in mean CCT value was observed. Mean endothelial cell count and morphology were unchanged between preoperative and postoperative patients. In addition, no obvious corneal haze was observed. Conclusions PTK combined with PRK and CXL on the same day is a safe and effective treatment in improving visual acuity in selected patients with corneal ectasia after LASIK.