Correction Of Myopia Research Articles

Anterior chamber phakic lens implantation after deep anterior lamellar keratoplasty. Retrospective cohort with 24‐month follow‐up

Aims/Purpose: To report the outcome of correction of high myopia with anterior chamber phakic intraocular lenses (IOLs) implantation after deep anterior lamellar keratoplasty (DALK).Methods: Retrospective study with 7 eyes of patients who underwent DALK. The main variables measured were corrected visual acuity (CVA) and uncorrected visual acuity (UCVA), spherical equivalent, and endothelial cell density (ECD). Follow‐up was performed up to 24 months after the lens implant.Results: The spherical equivalent (SE) recorded a mean of −14.16 (± 3.50) before the lens implant and −0.30 (±0.93) after the implant, with a mean difference of 13.85 (10.25 to 13.85) and a p‐value of <0.001. The mean of uncorrected visual acuity (UCVA) before the lens was 1.82 (±0.63), 6 months after lens implant was 0.22 (±0.07), and after 24 months, 0.30 (±0.14) with a p‐value of 0.001. Among patients, 85.71% had a UCVA equal to or better than 0.3 logMAR and 42.85% had a UCVA of 0.2 logMAR vs. 0% preoperatively. 71.42% of the patients had residual ametropia within ±1.00 D. The mean corrected visual acuity (CVA) was 0.31 (±0.06) before lens implantation, 0.12 (±0.04) 6 months post‐ implantation and 0.14 (±0.05) 24 months post‐implantation. All patients had improvement of UCVA of at least 10 lines of vision (range 10 to 14); at 6 months, 71.42% of patients had a gain of at least 2 lines of vision in CVA and at 24 months only one patient had a decrease in UCVA. The mean difference in ECD was 68.71 (95% CI 11.97 to 125.44), corresponding to a loss of 1.26% of cells per year.Conclusions: Phakic IOLs are an effective and stable procedure for management of high myopia after DALK, demonstrating stable safety and efficacy rates up to 24 months. The known risk of endothelial loss should be closely monitored, as such loss is higher compared to eyes with phakic IOL implants without DALK.

Performance of IOL calculation formulas that use measured posterior corneal power in eyes following myopic laser vision correction.

To compare the predictive accuracy of the biometer-embedded Barrett True-K TK and new total corneal power methods of intraocular lens (IOL) power calculation in eyes with prior laser vision correction (LVC) for myopia. Academic clinical practice. Retrospective case series. IOL power formulas were assessed using measurements from a swept-source optical coherence biometer. Refractive prediction errors were calculated for the Barrett True-K TK, EVO 2.0, Pearl-DGS, and HofferQST, which use both anterior and posterior corneal curvature measurements. These were compared with the Shammas, Haigis-L, Barrett True-K No History (NH), optical coherence tomography, and 4-formula average (AVG-4) on the ASCRS postrefractive calculator, and to the Holladay 1 and 2 with non linear axial length regressions (H1- and H2-NLR). The study comprised 85 eyes from 85 patients. Only the Barrett True-K TK and EVO 2.0 had mean numerical errors that were not significantly different from 0. The EVO 2.0, Barrett True-K TK, Pearl-DGS, AVG-4, H2-NLR, and Barrett True-K NH were selected for further pairwise analysis. The Barrett True-K TK and EVO 2.0 demonstrated smaller root-mean-square absolute error compared with the Pearl-DGS, and the Barrett True-K TK also had a smaller mean absolute error than the Pearl-DGS. The Barrett True-K TK and EVO 2.0 formulas had comparable performance to existing formulas in eyes with prior myopic LVC.

Evaluation of Intraocular Pressure in Eyes After Femtolasik Surgery

Introduction: Femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) surgery is a surgical procedure performed in the treatment of refractive errors. Given the changes in central corneal thickness, intraocular pressure may be lower and underestimated, which may lead to a late diagnosis of ocular hypertension/glaucoma. Aims: The aim of this study was to evaluate and compare intraocular pressure, by different methods, before and after FS-LASIK, for correction of myopia or myopic astigmatism. Methods: Retrospective and observational study, which included eyes undergoing FS-LASIK surgery (November 2020 to November 2022). The intraocular pressure values were measured (preoperatively, on the 1st, 3rd and 6th postoperative month) using contact tonometry (Goldmann applanation tonometry) and non-contact tonometry (by Corvis®ST according to the formulas: pachymetry – Ehlers, Shah, Dresden, Spoerl – and biomechanics – corrected and uncorrected). The intraocular pressure values obtained at 6 months with the different methods were compared with the Goldmann applanation tonometry intraocular pressure values obtained at baseline. Results: Ninety patients (of a total of 174 eyes) underwent FS-LASIK, with a preoperative spherical equivalent of -3.7±1.7. Preoperatively (mean ± standard deviation) Goldmann applanation tonometry was 15.0±1.9 mmHg; the intraocular pressure values obtained through the Corvis® ST (in mmHg) according pachymetry: Ehlers (13.5±2.6), Shah (14.3±2.3), Dresden (14.5±2.2) and Spoerl (14.5±2.1); and biomechanics: corrected (14.4±1.9) and not corrected (15.3±2.1), respectively. At 6 months postoperatively, all showed statistically significant differences, with the exception of Shah's formula (p=0.074); comparing the preoperative Goldmann applanation tonometry with each of the formulas at the end of the follow-up, the Ehlers formula did not present statistically significant differences (p=0.434), the Shah formula a value of p=0.047 and the others a value of p<0.001. Conclusion: Femtosecond laser-assisted laser in situ keratomileusis surgery underestimates intraocular pressure measurement by contact tonometry. In non-contact tonometry, at 6-month follow-up, the Shah formula appears to be less influenced by this bias. More studies are needed to evaluate the best method to assess I intraocular pressure measurement after FS-LASIK surgery.

Three-Month Clinical Outcomes to Correct Myopia or Myopic Astigmatism Using a Femtosecond Laser for Lenticule Creation With Automated Centration and Cyclotorsion Compensation.

To individually evaluate the clinical outcomes for right and left eyes in the first 3 months after laser-assisted lenticule extraction for myopia and myopic astigmatism with the use of the new ATOS femtosecond laser system (Smart-Sight; SCHWIND eye-tech-solutions). A total of 331 eyes from 168 patients (166 right eyes and 165 left eyes) consecutively treated with SmartSight lenticule extraction were retrospective analyzed after a 3-month follow-up period. Patients' mean age was 26 ± 6 years (range: 18 to 47 years) and mean preoperative spherical equivalent (SEQ) was -5.07 ± 1.92 diopters [D] (range: -1.50 to -11.25 D) with a mean astigmatism of -1.04 ± 0.85 D (range: 0.00 to -4.00 D). At 3 months of follow-up, visual acuity, SEQ and cylinder, safety index, efficacy index, corneal higher order aberrations, and intraocular pressure (IOP) were analyzed. Furthermore, refractive and visual outcomes were also analyzed for the right and left eyes individually. All lenticule extraction treatments were performed with the SmartSight treatment method of the SCHWIND ATOS femtosecond laser. At 3 months after surgery, mean SEQ was -0.12 ± 0.19 D and 98% of eyes were within ±0.50 D of the SEQ. All eyes were within ±1.00 D of the SEQ. Astigmatism of 0.50 D or less was achieved in 99% of eyes. The change in Snellen lines (difference between preoperative corrected distance visual acuity and postoperative uncorrected distance visual acuity) showed a gain of one or more lines in 13% and in 85% of the eyes the same was achieved. There was a loss of one or more lines at 3 months of follow-up in 1.6%. The safety index was 1.03 and efficacy index was 1.02. No significant difference between the right and left eyes was found. The 3-month follow-up data show that SmartSight treatment for correction of myopia and myopic astigmatism with the SCHWIND ATOS is a safe, efficient, and accurate procedure. It provided excellent results in terms of visual recovery, predictability, and higher order aberrations. [J Refract Surg. 2024;40(1):e30-e41.].

Refractive Outcome of Femtosecond Assisted Laser in situ Keratomileusis in 1564 cases of Myopia and Compound Myopic Astigmatism.

To determine the outcomes of Femtosecond Assisted Laser in situ Keratomileusis (Femto LASIK) on eyes with myopia and compound myopic astigmatism in terms of efficacy, safety, accuracy, predictability, and stability of the procedure. Quasi-experimental study. Place and Duration of the Study: Refractive Surgical Department, Armed Forces Institute of Ophthalmology (AFIO), Rawalpindi, Pakistan, from January 2014 to August 2019. Participants aged 18 years and above with upto -12D (dioptre of myopia, underwent preoperative detailed work-up with history, ocular examination, subjective refraction and assessment on topography, tomography, and aberrometry. Suitable candidates underwent Femto LASIK and were re-evaluated at 1stpostoperative day, end of 1stweek, 1month, 3 months, 6months and 1year. Results were analysed and represented in form of standard graphs for refractive surgery. Results: Postoperative UDVA (uncorrected distance visual acuity) of 20/40 was achieved in 99% of patients. Efficacy index was 1.02 + 0.15. Safety index was 1.04 + 0.199. None of the patients lost more than one line in postoperative CDVA (corrected distance visual acuity) when compared to preoperative CDVA. All the eyes (100%) were accurately treated within +1.0 DS of intended spherical equivalent (SEQ) range. Mean SEQ showed stability with 1% eyes recorded to have more than 0.5D change or more over 12 months. Femto LASIK is an effective, safe, accurate, predictable, and stable procedure for correction of myopia and compound myopic astigmatism. Femtosecond, Laser in situ Keratomileusis, Refractive surgery, Myopia, Compound myopic astigmatism, Uncorrected distance visual acuity.

Strategy of Surgical Treatment of Patients with Pigment Dispersion Syndrome and Myopia

Purpose: to conduct a prospective study of the results of surgical treatment of patients with pigment dispersion syndrome and complex myopic astigmatism. Materials and methods. As a result of a comprehensive examination of 10453 adult primary patients with complex myopic astigmatism, the diagnosis of pigment dispersion syndrome was made in 99 patients (0.94 %). The study group consisted of 22 people, 9 men and 13 women, with an average age of 29.4 ± 9.8. In the case of iridosonular contact, according to ultrasound biomicroscopy, laser basal iridectomy was performed at the first stage. In the case of normal intraocular pressure indicators, laser correction of myopia was made in patients of the study group within 6 months after laser basal iridectomy. Results. During biomicroscopy, a Krukenberg spindle was observed in 34 eyes (77.2 %), exogenous pigment was detected in 20 eyes (45.4 %) on the iris and lens, and sectoral illumination of the iris was detected in 5 (11.4 %). After laser basal iridectomy on 24 eyes (54.5 %) in all the studied meridians, we noted a tendency to deepen the posterior chamber, but the increase was statistically significant only at 12 hours (P < 0.05). The achieved decrease in the angle of the anterior chamber was statistically significant (P < 0.05) in the meridians of 3, 9 and 12 hours and ranged from 3.56 to 8.53 degrees in different meridians. Laser correction of complex myopic astigmatism was performed in 11 patients (22 eyes) using ReLEx® SMILE technology and 10 (20 eyes) patients using FemtoLASIK technology. At the end of the observation period after correction, refraction within ±0.5 dptr of the planned one was achieved in 88.1 % of cases (37 eyes), ±1.0 dptr — in 100 % of cases. The efficiency coefficient was 88.46 %, the safety coefficient was 92.8 %. Postoperative values of corneal-compensated IOP were comparable with preoperative indicators (P > 0.05). Conclusions. The analysis of the of surgical treatment results in the patients with pigment dispersion syndrome and myopia showed the absence of negative dynamics in the course, as well as high efficiency, safety and stability of the results achieved after laser correction. The applied algorithm for the management of patients with combined pathology with pigment dispersion syndrome and myopia is pathogenetically justified, safe, promotes the preservation of visual functions of patients and improves their quality of life.

OUTCOME COMPARISON OF LASER-ASSISTED IN SITU KERATOMILEUSIS IN VARIOUS DEGREE OF MYOPIA

Introduction: The femtosecond Laser-Assisted in Situ Keratomileusis (fs-LASIK) procedure is commonly used for myopia correction because of good efficacy, safety, and predictability. The aim of this study was to compare the outcome of the fs-LASIK procedure among myopia groups in Cicendo Eye Hospital from January to December 2021. Methods: This retrospective study included 212 patients (399 eyes) and the data were obtained from medical records from January 2021 to December 2021 using ICD-10 coding for LASIK (S0800), consisting of fs-LASIK procedures. The outcome variables were safety index, and efficacy index. Results: The median of safety index was not statistically significant different between groups, 1,00(0,50-1,67) in low myopia, 1,00(0,20-1,43) in moderate myopia, and 1,00(0,30-3,33) in high myopia. The median of efficacy index was statistically significant different between groups, 1,00(0,40-1,67) in low myopia, 1,00(0,20-1,43) in moderate myopia, and 1,00(0,30-3,33) in high myopia. The proportion of eye with UCVA > 6/12 on the first month after the procedure was higher in the mild myopia group (223;99,2%) than in moderate myopia (87;98,8%) and high myopia (77;88,5%) with p=0,0001. The proportion of eye with BCVA > 6/12 on the first month after the procedure was also higher in the mild myopia group (224;100%) than in moderate myopia (87;98,8%) and high myopia (82;94,3%) with p=0,0001. Conclusion: There was no statistically significant difference of the safety index between groups. The efficacy index was statistically significant different between groups.

Comparison of risk factors for OBL in FS-LASIK and SMILE correction for myopia and myopia astigmatism.

To find out the incidence and risk factors of opaque bubble layer (OBL) in eyes with myopia and myopic astigmatism following femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE). A total of 1076 eyes from 569 patients who had FS-LASIK or SMILE were included in the retrospective research. For each kind of surgery, eyes were separated into two groups: "OBL" groups and "no OBL" groups. In the FS-LASIK group, eyes that developed OBL were split into "hard OBL" and "soft OBL" groups. The incidence and size of OBL were analyzed after watching the surgical procedure videotaped during the operation and taking screenshots. Surgical parameters, including sphere, cylinder, keratometry, corneal thickness, flap thickness, cap thickness, lenticule thickness, and visual acuity, were compared. In the FS-LASIK surgery, the incidence of OBL was 63.2% (347 eyes). A thicker central corneal thickness (CCT) was the only independent risk factor affecting the OBL area (β = 0.126, P = 0.019). One hundred and thirty of these eyes had hard OBL, and the flap thickness of these eyes was thinner than that of those with soft OBL (P = 0.027). In the SMILE group, 26.6% (140 eyes) developed OBL. A higher flat keratometry (K) and a thicker residual stromal thickness (RST) were risk factors affecting the OBL area (β = 0.195, P = 0.024; β = 0.281, P = 0.001). The incidence of OBL differs between the FS-LASIK surgery and the SMILE surgery. There are differences in the factors influencing OBL between the two surgeries.

Refractive Surgery Overview

Advancements in technology and techniques are continuously shaping the field of refractive surgery for the correction of myopia, hyperopia, astigmatism, and presbyopia. As a result, more patients are seeking alternatives to spectacles or contact lenses. Clinicians must stay up-to-date with the latest options available for vision correction. This article aims to provide a comprehensive overview of the exciting progress being made in this area of clinical advancements and research.

Computer accomodography data for assessing tolerability of optical correction for myopia in near work

Aim – to study the results of computer accomodography in children with myopia optical correction in order to assess the optical correction tolerability during visual work at close distance.
 Material and methods. The study of myopia optical correction tolerance in near work included 45 children of school age. Subjective and objective research methods were used: a relative accommodation reserve study and computer accomodography.
 Results. The computer accomodography performed with glasses allowed to determine the nature of the ciliary muscle work in near vision. Computer accomodography data correlated with the value of relative accommodation reserve.
 Conclusion. We recommend to study the relative accommodation reserve and to use computer accomodography when choosing the optical correction for myopic children.

Comparison of myopic astigmatic correction after cross-assisted SMILE, FS-LASIK, and transPRK.

To compare astigmatic correction among cross-assisted small-incision lenticule extraction (SMILE), femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and transepithelial photorefractive keratectomy (transPRK). The Eye Hospital of Wenzhou Medical University, Zhejiang, China. Prospective comparison study. 154 right eyes of 154 patients with astigmatism of -1.00 to -2.75 diopters (D) were included in this study. 64 eyes, 42 eyes, and 48 eyes were receiving SMILE, FS-LASIK, and transPRK, respectively. The SMILE group used cross-axial alignment for head positioning for astigmatism correction. In the FS-LASIK and transPRK groups, static and dynamic cyclotorsion control were used. Changes in ocular parameters and vector analysis were assessed at 6 months postoperatively. The safety and efficacy indices were comparable among the 3 groups at 6 months postoperatively. Residual astigmatism was smallest in the SMILE group (-0.23 ± 0.25 D) compared with that in FS-LASIK (-0.40 ± 0.28 D, P = .009) and transPRK groups (-0.42 ± 0.32 D, P = .001). 53 (82.8%), 36 (85.7%), and 37 (77.1%) eyes achieved an angle of error within ±5 degrees, respectively ( P = .55). Notably, vector analysis showed that the difference vector, the magnitude of the error, and its absolute value were significantly smaller in the SMILE group than those in the other groups ( P < .05). In addition, the higher-order aberrations, especially coma, were significantly induced postoperatively in each group ( P < .001). Residual astigmatism magnitude was smallest by cross-assisted SMILE, followed by FS-LASIK and transPRK, and the astigmatism axial correction was comparable among groups.

Contributed Session I: The effects of monocular and binocular retinal image minification on eyestrain.

While corrective spectacles have been worn for centuries, relatively little is known about the physical and perceptual effects associated with their optical distortions. Retinal image minification, for example, is caused by myopic spectacle correction and may also occur in near-eye displays. Previous work suggests that different amounts of minification (or magnification) between the eyes can produce perceptual distortions and oculomotor discomfort, but the extent to which these effects are problematic is unknown. In our first study, forty observers wore minifying spectacles of 2% or 4% in both eyes (binocular), just one eye (monocular), or neither eye (control). After performing a task that incorporated reading, interacting with objects, and visual search, participants reported their symptoms. Overall, participants found monocular minification to be slightly more uncomfortable than the binocular counterpart. Monocular minification produced greater eyestrain and self-reported difficulty interacting with objects. In a second study, we investigated how these two symptoms change after one hour of adaptation to monocular 4% lenses. We found that both symptoms worsened during adaptation. Interestly, the difficulty interacting with objects declined soon after the lenses were removed, while eyestrain persisted. Taken together, these studies indicate specific types of discomfort during natural tasks that may be reduced through improving optical lens designs in the future.

The effect of different angle kappa on higher-order aberrations after small incision lenticule extraction

This study aimed to compare higher-order aberrations (HOAs) after small incision lenticule extraction (SMILE) in patients with different angle kappa. This is a retrospective report in which 341 right eyes of 341 patients who were subjected to SMILE, which used coaxially sighted corneal light reflex (CSCLR) as the treatment zone centered, treated by the same experienced surgeon (LHB) for correction of myopia and myopic astigmatism, preoperative and postoperative spherical equivalent (SE), angle kappa, total higher-order aberrations (total HOA), spherical aberration (SA), vertical coma (VC), horizontal coma (HC), oblique trefoil (OT), and horizontal trefoil (HT), were compared. SMILE showed outstanding performance in terms of safety, efficacy, and predictability. In addition, a comparison of preoperative and postoperative HOAs exhibited the difference of total HOA (P < 0.01), SA (P < 0.01), VC (P < 0.01), and HC (P < 0.01), which was statistically significant; however, for OT and HT with the longer follow-up time, the statistical difference gradually decreased. For stratification of angle kappa into groups based on decantation, angle kappa was divided into three major groups: r < 0.1 mm, 0.1 ≤ r < 0.2 mm, and r ≥ 0.2 mm; the changes of SA (F = 4.127, P = 0.021) and OT (F = 3.687, P = 0.031) exhibited significant difference after 1 year of SMILE. We performed a correlation analysis of all preoperative and postoperative parameters, and the results indicated that the preoperative total HOA was negatively correlated with preoperative cylindrical diopter (DC), and postoperative total HOA, SA, and coma were affected by spherical diopter (DS) and SE. Moreover, we also found a significant difference of SA and VC in the early postoperative with preoperative. SA was positively correlated with Y values and r of 1 year after SMILE. All of the analyzed parameters in the three groups, except for the trefoil, gradually increased over time; however, the trefoil could gradually stabilize over time. We also divided angle kappa into four groups by quadrants; the result showed that the effects of higher-order aberrations were markedly different from the various quadrants. Patients with large angle kappa were able to increase VC and SA postoperatively, and higher HOAs were more significant in patients with high myopia. The differences in quadrants exhibited a diversity of HOAs; this could be attributed to the corneal surface reestablishment and the alteration of angle kappa, but the trend was not apparent. Although all patients displayed increased HOAs after SMILE, the potential application of CSCLR as the treatment zone centered still showed excellent safety, efficacy, and predictability.

Digital Pupillometry and Centroid Shift Changes in Dominant and Nondominant Eyes.

To investigate the differences between dominant and nondominant eyes in a predominantly young patient population by analyzing the angle kappa, pupil size, and center position in dominant and nondominant eyes. A total of 126 young college students (252 eyes) with myopia who underwent femtosecond laser-combined LASIK were randomly selected. Ocular dominance was determined using the hole-in-card test. The WaveLight Allegro Topolyzer (WaveLight Laser Technologies AG, Erlangen, Germany) was used to measure the pupil size and center position. The offset between the pupil center and the coaxially sighted corneal light reflex (P-Dist) of the patients was recorded by the x- and y-axis eyeball tracking adjustment program of the WaveLight Eagle Vision EX500 excimer laser system (Wavelight GmbH). The patient's vision (uncorrected distance visual acuity [UDVA], best-corrected visual acuity (BCVA), and refractive power (spherical equivalent, SE) were observed preoperatively, 1 week, 4 weeks, and 12 weeks postoperatively, and a quality of vision (QoV) questionnaire was completed. Ocular dominance occurred predominantly in the right eye [right vs. left: (178) 70.63% vs. (74) 29.37%; p < 0.001]. The P-Dist was 0.202 ± 0.095 mm in the dominant eye and 0.215 ± 0.103 mm in the nondominant eye (p = 0.021). The horizontal pupil shift was - 0.07 ± 0.14 mm in dominant eyes and 0.01 ± 0.13 mm in nondominant eyes (p = 0.001) (the temporal displacement of the dominant eye under mesopic conditions). The SE was negatively correlated with the P-Dist (r = - 0.223, p = 0.012 for the dominant eye and r = - 0.199, p = 0.025 for the nondominant eye). At 12weeks postoperatively, the safety index (postoperative BDVA/preoperative BDVA) of the dominant and nondominant eyes was 1.20 (1.00, 1.22) and 1.20 (1.00, 1.20), respectively, and the efficacy index (postoperative UDVA/preoperative BDVA) was 1.00 (1.00, 1.20) and 1.00 (1.00, 1.20), respectively; the proportion of residual SE within ± 0.50 D was 98 and 100%, respectively. This study found that ocular dominance occurred predominantly in the right eye. The pupil size change was larger in the dominant eye. The angle kappa of the dominant eye was smaller than that of the nondominant eye and the pupil center of the dominant eye was slightly shifted to the temporal side under mesopic conditions. The correction of myopia in the dominant and nondominant eyes exhibits good safety, efficacy, and predictability in the short term after surgery, and has good subjective visual quality performance after correction. We suggest adjusting the angle kappa percentage in the dominant eye to be lower than that of the nondominant eye in individualized corneal refractive surgery in order to find the ablation center closest to the visual axis.

Five-year follow-up of a posterior chamber phakic intraocular lens with a central hole for correction of myopia

PurposeTo evaluate intermediate and long-term visual outcomes and safety of a phakic intraocular posterior chamber lens with a central hole (ICL V4c) for myopic eyes.MethodsRetrospective, consecutive case study of patients that uneventfully received a ICL V4c for myopia correction, with a 5-year postoperative follow-up. Department of Ophthalmology, Goethe University Frankfurt, Germany.ResultsFrom 241 eyes that underwent ICL implantation, we included 45 eyes with a mean age at surgery of 33 years ± 6 (18–48 years), with a 5 years follow-up. CDVA improved from 0.05logMAR ± 0.15 CDVA preoperatively to − 0.00 ± 0,07 at 5 years and did not change significantly from 3 to 5 years’ time (p = 0.266). The mean spherical equivalent (SE) improved from -10.13D ± 3.39 to − 0.45D ± 0.69. The change in endothelial cell count showed a mean decrease of 1.9% per year throughout the follow-up. Safety and efficacy index were 1.16 and 0.78, respectively. Cataract formation was seen in 2 of 241 eyes (0.8%), but in none of the 45 eyes that finished the 5-year follow-up.ConclusionsOur data show a good intermediate and long-term stability, efficiency, and safety of ICL V4c phakic lenses in myopic eyes comparable to other known literature.

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.

Central corneal distortion after small-incision lenticule extraction.

A 33-year-old woman with a prior history of small-incision lenticule extraction (SMILE) presented with gradual deterioration of vision in her right eye since the surgery. She had undergone bilateral SMILE for myopic correction (-7.00 diopters [D] in the right eye and -6.00 D in the left eye) 3 weeks prior. SMILE was performed with a Zeiss VisuMax femtosecond laser system, with a cap thickness of 120 µm, a cap diameter of 7.50 mm, and a lenticule diameter of 6.50 mm. At the completion of the surgery, loose epithelium was noted at the SMILE incision bilaterally, and bandage contact lenses were placed in both eyes. On the first postoperative day, the patient's uncorrected distance visual acuity (UDVA) was 20/40 in both eyes. The bandage lenses were removed from both eyes, with the epithelium intact. At the first-week postoperative visit, her visual acuity was recorded as 20/30 in the right eye and 20/20 in the left eye. She noticed her vision in the right eye was not as sharp as that in her left eye. She denied experiencing any pain, redness, or ocular surface irritations. She was advised to return to the clinic for a 1-month postoperative visit and continue with aggressive lubrication in both eyes. However, a week later, the patient returned for an emergency visit, citing significant central visual distortion in the right eye and difficulty working on the computer. At this visit, her UDVA and corrected distance visual acuity (CDVA) was 20/50 in the right eye and 20/15 in the left eye at both near and far distances. A slitlamp examination revealed mild central changes in the right eye. She once again denied any pain, redness, or irritation. She was advised to continue with artificial tears and return to the office in 1 week for further observation of the central distortion in her right eye. Upon returning to the clinic at the third postoperative week, the patient still complained of central visual changes in the right eye, with a visual acuity of 20/70. Further slitlamp examination revealed a nonspecific central haze in the same eye, but there was no corneal staining or signs of epithelial defects. Anterior segment ocular coherence tomography (AS-OCT) and NIDEK topography were performed, showing the same central distortion in the right eye (Figures 1 and 2JOURNAL/jcrs/04.03/02158034-202311000-00016/figure1/v/2023-10-18T004638Z/r/image-tiffJOURNAL/jcrs/04.03/02158034-202311000-00016/figure2/v/2023-10-18T004638Z/r/image-tiff). Based on the examination and images provided, what is your working medical diagnosis? What other medical conditions are in your differential diagnosis? What medical and/or surgical interventions would you recommend, if any?

SWOT analysis of ortho-K practice in India

PurposeOrthokeratology (ortho-K) has been well established as a methodology for myopia correction and control its progression. A SWOT analysis serves as a strategic planning tool for intervention hence the purpose of this study to establish and implement ortho-K practice in India. MethodThe study was conducted between December 2020 and June 2021. A prospective questionnaire-based study was conducted to elicit the responses in the SWOT study. Based on focus group discussion a set of five statements under strengths, weaknesses, opportunities and threats were identified. These were closed ended questions were based on a 5-point likert scale. The Content Validation Index (CVI) was computed for each item taking those answers relevant with a score of three and four on the Likert scale and omitting those with a score of one and two on the Likert scale as non-relevant. ResultsStrengths: ‘Ortho-K is an excellent option for myopia control’ was agreed by more than 50% of respondents. 67% of respondents agreed that advanced topographers has made ortho-K lens fitting easier. Weakness: More than 60% agreed that Ortho-K practice involves investment in instrumentation like topographers and trial lenses. 50% agreed that due to multiple follow up patients may be lost to follow up. Opportunity: ‘Pandemic has necessitated the need for optometrists to explore myopia control options such as ortho-K’ was agreed by more than 50%. Threats: ‘Reluctance from adults and parents to try overnight contact lenses for myopia correction/control’ was agreed by more than 50% of respondents. 62% agreed that atropine is perceived as an effective myopia control option by majority of the Indian ophthalmologists. ConclusionOrtho-K as an emerging modality for Myopia management in India through SWOT analysis, allows practitioners as well as CL industry to approach Ortho-K appropriately with novel designs and practice patterns that suits the market needs.

The Development of a Thick-Lens Post–Myopic Laser Vision Correction Intraocular Lens Calculation Formula

Purpose: To describe the development of the post-myopic laser vision correction (LVC) version of the PEARL-DGS IOL calculation formula and to evaluate its outcomes on an independent test set. Design: Retrospective, mono-centric case series Methods: A modified lens position prediction algorithm was designed along with methods to predict the posterior corneal curvature radius and correct the corneal power measurement error. A different set of previously operated eyes that underwent LVC was used to evaluate the prediction precision of the post-LVC formula. Results: Post-LVC PEARL-DGS formula significantly reduced mean absolute error (MAE) of prediction in comparison to Haigis-L, Shammas and ASCRS average formulas (p<0.001). It exhibited similar postoperative refractive precision as Barrett True-K No History formula (p=0.61). Conclusion: The post-LVC formula development process described in this paper performed as well as the state-of-the-art post-LVC formula on the present test set. Further studies are required to assess its efficacy in other independent sets.

Effective optical zone following small incision lenticule extraction: a review.

Small incision lenticule extraction (SMILE) is a "flapless" keratorefractive surgery with excellent safety, efficacy, stability, and predictability for myopia correction. A recent global multicenter study also reported good refractive outcomes for hyperopic SMILE. SMILE has shown advantages including improved biomechanical strength, fewer dry eye symptoms, less corneal denervation, and fewer surgery-induced higher-order aberrations over laser in situ keratomileusis (LASIK). However, night vision complaints, including glare, halos, and starbursts, could still occur after SMILE. These symptoms have been proven to be closely related to the effective optical zone (EOZ), which is defined as the achieved area of corneal ablation. A larger postoperative EOZ may indicate better visual quality, making EOZ an important safety parameter for keratorefractive surgeries. As SMILE has gained wider application globally, the EOZ following SMILE has also been increasingly studied in the field of refractive surgery. This review provides an update on topics related to the EOZ after SMILE, including its measurement and influencing factors, aiming to benefit the personalization of the surgical algorithm and ultimately improve the visual quality after the SMILE procedure.