Spherical Equivalent Research Articles

Corneal Epithelial Remodeling Following Cylinder Correction With SMILE or FS-LASIK: A Contralateral Comparative Study.

To compare the corneal epithelial remodeling in eyes with high astigmatism that had small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). Seventy-four patients with myopic astigmatism of greater than -2.00 diopters (D) and little binocular difference in spherical equivalent were included in this contralateral comparative study. All patients received SMILE in one eye and FS-LASIK in the other eye randomly. The corneal epithelial remodeling pattern was mapped using the latest RTVue spectral-domain optical coherence tomographer (Optovue) by region. Satisfactory refractive correction was achieved in all enrolled eyes with either SMILE or FS-LASIK. The corneal epithelium gradually thickened following surgical cylinder correction, distributing mainly along the flat medium. The corneal epithelium proliferation is milder centrally but more pronounced in the mid-peripheral area after SMILE, compared with FS-LASIK. The flat-steep difference in corneal epithelial thickness (CET) is evident in the mid-peripheral and peripheral areas, which is more obvious in SMILE. Residual cylinder was positively correlated with CET in eyes that had FS-LASIK, but not SMILE. More importantly, these epithelial changes were positively correlated with the ablation depth and higher order aberrations following surgical refractive correction. The postoperative CET map varied between SMILE and FS-LASIK. In eyes with high astigmatism, SMILE surgery is followed by milder and more stable corneal epithelial thickening. Moreover, the corneal epithelium is sensitive to stromal ablation and corneal remodeling is crucial to the postoperative visual quality. This study rigorously distinguished the CET difference between SMILE and FS-LASIK in astigmatic eyes and shed light on subsequent research. [J Refract Surg. 2024;40(10);e728-e741.].

Intraoperative Aberrometry versus Preoperative Biometry for Intraocular Lens Power Calculations: A Report by the American Academy of Ophthalmology

To evaluate the published literature to compare intraoperative aberrometry (IA) with preoperative biometry-based formulas with respect to intraocular lens (IOL) power calculation accuracy for various clinical scenarios. Literature searches in the PubMed database conducted in August 2022, July 2023, and February 2024 identified 157, 18, and 6 citations, respectively. These were reviewed in abstract form, and 61 articles were selected for full-text review. Of these, 29 met the criteria for inclusion in this assessment. The panel methodologists assigned a level of evidence rating to each of the articles; 4 were rated level I, 19 were rated level II, and 6 were rated level III. Intraoperative aberrometry performed better than traditional vergence formulas, including the Haigis, HofferQ, Holladay, and SRK/T, and similarly to the Barrett Universal II and Hill-RBF with respect to minimization of spherical equivalent (SE) refractive error. For toric IOLs, IA outperformed formulas that only considered anterior corneal astigmatism and was similar to formulas like the Barrett Toric Calculator (BTC), which empirically account for the contribution from the posterior cornea. In eyes with a history of corneal refractive surgery, IA performed similarly to the Barrett True-K and slightly better than other tested methods, including the Haigis-L, Shammas, and Wang-Koch-Maloney formulas. Intraoperative aberrometry corresponds well with modern vergence formulas, including the Barrett Universal II, Hill-RBF, BTC, and Barrett True-K. It has greater accuracy than traditional vergence-based IOL power calculation formulas in eyes with and without a history of corneal refractive surgery. Proprietary or commercial disclosure may be found after the references.

Corneal Epithelial Remodeling After Hyperopic SMILE: A 4-Year Study.

The purpose of this study was to investigate dynamic changes in corneal epithelial thickness (ET) after hyperopic small incision lenticule extraction (SMILE). This observational study included 18 eyes of 16 patients who were scheduled for hyperopic SMILE. High-resolution spectral-domain optical coherence tomography and a custom image segmentation algorithm were applied to measure corneal dynamic ET over a central 6 mm area. ET was analyzed among different corneal sectors (central, pericentral, and peripheral) at baseline and multiple postoperative time points (1 day, 1 month, 6 months, 2 years, and 4 years). Correlation analysis was performed between ET changes and preoperative and intraoperative parameters. The mean spherical equivalent of hyperopia correction was +2.64 ± 1.00 D, and the average age of enrolled 16 patients was 32.4 ± 10.8 years. At the last follow-up, 72% of eyes kept or improved corrected distance visual acuity, with 2 eyes that lost 2 lines. 72% of eyes were within ±1.0 D of target refraction, and 56% were within ±0.5 D. Average ET decreased by 11.0% (5.9 ± 2.3 μm) from 53.2 ± 3.5 μm to 47.4 ± 4.2 μm 4 years postoperatively (P<0.001). The ET at center 2 mm decreased most significantly by 14.5% (7.9 ± 2.9 μm), followed by the pericentral area by 10.5% (5.6 ± 2.3 μm). ET and front corneal curvature stabilized 1 month after surgery. No correlation was found between refraction regression and ET changes. Hyperopic SMILE induced significant central ET thinning. ET remodeling in the 6 mm area stabilized after 1 month and did not underlie refractive changes.

Comparative study of visual and refractive outcomes of laser assisted in situ Keratomileusis versus small incision lenticule extraction versus implantable collamer lens for moderate to high myopia correction

Background Myopia represents a condition of refraction, in which parallel light rays converge in front of the resting eye retina. Aim To compare the laser assisted in situ keratomileusis (LASIK) visual and refractive outcomes versus small incision lenticule extraction (SMILE) versus implantable collamer lens (ICL) while correcting cases having moderate to high myopia. Patients and methods Our research involved 60 eyes having moderate to severe myopia ranging from –3 to –10 dioptres. They divided into three equal groups, group A: through LASIK, group B: through SMILE, and group C: received an ICL. Preoperative uncorrected visual acuity, Corrected distance visual acuity, and Manifest and cycloplgic refraction assessments were accomplished. Results Postoperative uncorrected visual acuity exhibited no significant variation among groups A and B, yet a significant variation was documented among groups A and C as well as among groups B and C P less than 0.001. The postoperative spherical error showed no significant variation among groups A and B nor among groups B and C yet exhibited significant variation among groups A and C P=0.002. Postoperative astigmatism was no significant variation among groups A as well as B, yet a significant variation was documented among groups A and C in addition to between groups B and C. Postoperative spherical equivalent was a significant variation among groups A and C P less than 0.001 and among groups B and C P less than 0.001. Conclusion Visual outcomes were comparable between LASIK, SMILE, and ICL. The three procedures exhibited superior effectiveness, safety, stability, and accuracy in the treatment of moderate and high myopia.

Relationship between dry eye disease and myopia: A systematic review and meta-analysis

Background/objectivesDry eye disease (DED) and myopia are common ocular disorders. This systematic review and meta-analysis investigated the association between DED and myopia. MethodsPubMed and EMBASE were searched for articles published between 1984 and 2022. Study quality was assessed using the Joanna Briggs Institute Critical Appraisal Checklist, and analysis was conducted using the DerSimonian–Laird random-effects model. ResultsOf the 1,313 studies identified, 15 studies on DED and myopia were included. The meta-analysis revealed that the overall prevalence of subjective DED symptoms in the myopia population was 45.1 % (95 % confidence interval: 0.287–0.616). There was a significant association between DED and myopia. The myopia population had higher Ocular Surface Disease Index scores and shorter tear film breakup times than the non-myopia population. Additionally, the meta-regression analysis showed that spherical equivalent was significantly associated with the prevalence of DED symptoms in adults with myopia. ConclusionInterventions to prevent DED are required in the myopia population. Enhancing patient awareness and self-management for DED, in addition to early screening and detection, is especially critical for younger populations who are at a higher risk of developing myopia.

The outcomes of first-generation (visumax 500) and second-generation (Visumax 800) keratorefractive lenticule extraction surgeries for astigmatism

To evaluate the efficiency, predictability, and residual astigmatism between first- and second-generation keratorefractive lenticule extraction (KLEx) surgeries in a prominent astigmatism population. A retrospective cohort study was conducted, and individuals who underwent first- and second-generation KLEx surgeries were enrolled. A total of 31 and 35 eyes were categorized into first and second KLEx groups, respectively. Visual acuity, refraction, topographic parameters, and surgical indices were recorded. Independent t tests were used to compare the postoperative uncorrected distance visual acuity (UDVA), spherical equivalent (SE), and residual astigmatism between the two groups. The difference in UDVA was not significant three months after KLEx surgery (P = 0.509), and the SEs three months after surgery also presented similar values between the two groups (P = 0.552). The first KLEx group demonstrated greater residual astigmatism than did the second KLEx group throughout the three-month follow-up period (all P < 0.05). The values of surgically induced astigmatism (SIA), difference vector (DV), magnitude of error (ME) and correction index (CoI) were significantly better in the second KLEx group via vector analysis (all P < 0.05). Old age, high steep keratometry (K), high topographic cylinder, large angle kappa, and a small optic zone were correlated with greater residual astigmatism in the first KLEx group (all P < 0.05), whereas only a small optic zone was significantly correlated with greater residual astigmatism in the second KLEx group (P = 0.047). The second-generation KLEx is correlated with a lower risk of residual astigmatism.

A Competition for the Diagnosis of Myopic Maculopathy by Artificial Intelligence Algorithms

Myopic maculopathy (MM) is a major cause of vision impairment globally. Artificial intelligence (AI) and deep learning (DL) algorithms for detecting MM from fundus images could potentially improve diagnosis and assist screening in a variety of health care settings. To evaluate DL algorithms for MM classification and segmentation and compare their performance with that of ophthalmologists. The Myopic Maculopathy Analysis Challenge (MMAC) was an international competition to develop automated solutions for 3 tasks: (1) MM classification, (2) segmentation of MM plus lesions, and (3) spherical equivalent (SE) prediction. Participants were provided 3 subdatasets containing 2306, 294, and 2003 fundus images, respectively, with which to build algorithms. A group of 5 ophthalmologists evaluated the same test sets for tasks 1 and 2 to ascertain performance. Results from model ensembles, which combined outcomes from multiple algorithms submitted by MMAC participants, were compared with each individual submitted algorithm. This study was conducted from March 1, 2023, to March 30, 2024, and data were analyzed from January 15, 2024, to March 30, 2024. DL algorithms submitted as part of the MMAC competition or ophthalmologist interpretation. MM classification was evaluated by quadratic-weighted κ (QWK), F1 score, sensitivity, and specificity. MM plus lesions segmentation was evaluated by dice similarity coefficient (DSC), and SE prediction was evaluated by R2 and mean absolute error (MAE). The 3 tasks were completed by 7, 4, and 4 teams, respectively. MM classification algorithms achieved a QWK range of 0.866 to 0.901, an F1 score range of 0.675 to 0.781, a sensitivity range of 0.667 to 0.778, and a specificity range of 0.931 to 0.945. MM plus lesions segmentation algorithms achieved a DSC range of 0.664 to 0.687 for lacquer cracks (LC), 0.579 to 0.673 for choroidal neovascularization, and 0.768 to 0.841 for Fuchs spot (FS). SE prediction algorithms achieved an R2 range of 0.791 to 0.874 and an MAE range of 0.708 to 0.943. Model ensemble results achieved the best performance compared to each submitted algorithms, and the model ensemble outperformed ophthalmologists at MM classification in sensitivity (0.801; 95% CI, 0.764-0.840 vs 0.727; 95% CI, 0.684-0.768; P = .006) and specificity (0.946; 95% CI, 0.939-0.954 vs 0.933; 95% CI, 0.925-0.941; P = .009), LC segmentation (DSC, 0.698; 95% CI, 0.649-0.745 vs DSC, 0.570; 95% CI, 0.515-0.625; P < .001), and FS segmentation (DSC, 0.863; 95% CI, 0.831-0.888 vs DSC, 0.790; 95% CI, 0.742-0.830; P < .001). In this diagnostic study, 15 AI models for MM classification and segmentation on a public dataset made available for the MMAC competition were validated and evaluated, with some models achieving better diagnostic performance than ophthalmologists.

Laser-Assisted In Situ Keratomileusis in Flat, Normal, and Steep Corneas.

To compare laser-assisted in situ keratomileusis (LASIK) outcomes in patients with different corneal curvatures. This is a retrospective comparative chart review. Patients included in this study underwent wavefront-optimized myopic LASIK between January 2013 and December 2022 at Care-Vision Laser Center, Tel-Aviv, Israel. Patients were divided into 3 groups based on the steepness of the cornea (steep keratometry) (flat: <42 diopters [D], normal: 42-46 D, and steep: >46 D). Case-by-case matching was performed to verify that baseline parameters (age, preoperative visual acuity, and refractive error) were similar between groups. Primary outcome measures were postoperative corrected/uncorrected distance visual acuity, efficacy index, safety index, spherical equivalence, and astigmatism. After matching, 300 eyes were included in each group, which were similar in baseline parameters. There were no significant postoperative differences between flat, normal, and steep corneas regarding safety index (1.01 vs. 1.02 vs. 1.01, P = 0.95), efficacy index (1.03 vs. 1.02 vs. 1.02, P = 0.94), logarithm of the minimum angle of resolution corrected distance visual acuity (0.01 vs. 0.01 vs. 0.01, P = 0.17), logarithm of the minimum angle of resolution uncorrected distance visual acuity (0.02 vs. 0.03 vs. 0.02, P = 0.65), proportion of patients with spherical equivalence within 0.50 D (73.0% vs. 73.7% vs. 69.3%, P = 0.45) or 1.00 D (93.3% vs. 94.7% vs. 91.7%, P = 0.34) of the target, and proportion of patients with astigmatism within 0.50 D (86.7% vs. 82.3% vs. 80.3%, P = 0.11) or 1.00 D (98.7% vs. 98.7% vs. 99.0%, P = 0.91) of the target. Longer term follow-up of a smaller set of patients revealed similar results. No significant differences were found between flat, normal, and steep corneas following wavefront-optimized myopic LASIK. Thus, this procedure may be safely and effectively performed across a wide range of corneal curvatures.

Clinical Outcomes of Iris-Supported Phakic Toric Intraocular Lenses in Corneal Ectasia.

Our aim was to evaluate the visual and refractive outcomes of iris-fixated phakic toric intraocular lenses (IOLs)for visual rehabilitation in eyes with stable corneal ectasia. We conducted a study looking at the clinical outcomes of iris-fixated toric IOLs (Artisan) in 33 eyes of 27 patients diagnosed with mild-to-moderate corneal ectasia at a single center (Queen Victoria Hospital, East Grinstead, UK). The main outcome measures were functional improvement [accuracy of post-operative spherical equivalent (SE), astigmatic correction, topographic parameters, uncorrected and corrected distance visual acuity (UCVA, CDVA)] and safety of the procedure: endothelial cell count and intra- and post-operative complications. Eighteen males and nine females of mean age 38.85 were included in the study with a mean follow-up of 18months. All patients had ectasia due to keratoconus except one with post-refractive laser ectasia. Twelve patients had crosslinking, eight had intracorneal rings, and eight had previous keratoplasties. Mean pre-operative logMAR UCVA was 0.75 ± 0.35 improving to 0.02 ± 0.17 (p = 0.000). Mean pre-operative logMAR CDVA was 0.16 ± 0.17 improving to 0.02 ± 0.17 (p = 0.000). Mean pre-operative (SE) was -3.5 ± 3.9 improving to -2.75 ± 1.39 (p = 0.000) with up to 36-42months of follow-up. The mean value of endothelial cell density in the overall sample was 2252.54 ± 473.24cells/mm2 pre-operatively and 2126.75 ± 365.21cells/mm2 at 24-36months of follow-up visit. Two patients have intra-operative hyphemia secondary to iris prolapse. Implantation of iris-fixated phakic toric IOLs has shown high efficacy and safety in patients with mild-to-moderate astigmatism in corneal ectasia.

Evaluation of Refraction Outcomes From the QuickSee Wavefront Autorefractor Versus Subjective Clinical Refractometry in Children With Restricted Access to Eye Care in Amazonas, Brazil.

Background This study compared the refraction measurements of the QuickSee wavefront autorefractor with those from clinical refraction measurements in preschool and elementary school children from public schools in Amazonas, Brazil. Methodology Refractometry was performed on 368 eyes from 368 healthy Brazilian public school students aged 4 to 7 years using both the QuickSee and subjective clinical methods under cycloplegia. Only right-eye data were analyzed. The results were converted into spherical equivalents and vector magnitudes for comparison. Results The difference in spherical equivalents between QuickSee and subjective clinical refractometry under cycloplegia was +0.38 ± 0.60 Diopters (D) (p < 0.0001). Along the 90° axis, the vector difference was +0.20 ± 0.33 D (p < 0.0001), and the oblique vector difference was +0.03 ± 0.22 D (p = 0.0395). Conclusions While a statistically significant difference was found between the QuickSee and subjective clinical refractometry results, the difference was not clinically meaningful. The strong agreement between these methods supports the utility of QuickSee as an effective tool for refractive assessment in children with limited access to eye care. These findings provide confidence in using QuickSee in public school settings as a reliable alternative for vision screening.

Comparative Analysis of Refractive Outcomes Using Optical and Ultrasound Biometry in Phacoemulsification Cataract Surgery

Background: Accurate biometry is critical for optimal visual outcomes in cataract surgery. Both optical and ultrasound biometry are widely used, but their comparative effectiveness remains under evaluation.Objective: To compare the refractive outcomes of optical and ultrasound biometry in patients undergoing elective phacoemulsification cataract surgery.Methods: This prospective cohort study included 352 patients aged 30-60 years undergoing elective phacoemulsification with in-the-bag IOL implantation. Patients were randomly assigned to either optical biometry using the Zeiss IOL Master 700 or ultrasound biometry with Axis Nano contact A-mode echography. Visual acuity and spherical equivalent were measured at baseline and 4 weeks post-operatively. Data were analyzed using SPSS version 25, with independent t-tests comparing outcomes between groups.Results: The mean post-operative visual acuity was 0.83 ± 0.22, with a mean spherical equivalent of -0.88 ± 0.16. No significant difference was found between the ultrasound (-0.89 ± 0.17) and optical biometry (-0.87 ± 0.16) groups (p=0.152, 95% CI -0.06 to 0.01).Conclusion: Both optical and ultrasound biometry provide comparable refractive outcomes in cataract surgery, with no significant difference in post-operative spherical equivalent.

Effectiveness of Defocus Incorporated Multiple Segments in Slowing Myopia Progression in Pediatric Patients as a Function of Age: Three-Year Follow-Up.

Background: The purpose of this study is to evaluate the effectiveness of Defocus Incorporated Multiple Segments (DIMSs) in slowing myopia progression in pediatric patients as a function of age. Methods: This was a non-randomized experimenter-masked retrospective controlled observational study of European individuals aged 6-16 years with progressive myopia but no ocular pathology. We retrospectively reviewed the charts of the participants allocated to receive DIMS spectacles (Hoya® MiyoSmart®) or single-vision spectacle lenses (control group). Cycloplegic spherical equivalent (SE) and axial length (AL) were measured at baseline and at 12-, 24-, and 36-month follow-ups. The results were stratified by age into four groups: patients wearing DIMS spectacles older or younger than 10 years of age (group A, 20 patients mean age 13.6 ± 2.2, and group C, 20 patients mean age 9.0 ± 1.2) and age-matched control groups (group B, 18 patients mean age 13.2 ± 2.5, and group D, 22 patients mean age 8.5 ± 0.9). Results: At 36 months, SE and AL increase were significantly reduced in groups A and C, respectively, compared to groups B and D (p < 0.05). Linear regression analysis showed a significant correlation (p < 0.05) between patient age and myopia progression for SE in groups A and C, but only in group A for AL. Groups B and D did not show any significant correlation (p > 0.05). Conclusions: DIMS spectacles seem to slow myopia progression in pediatric patients; however, their effectiveness shows the greatest results in children older than 10 years of age. Moreover, our findings suggest that AL may be the more reliable parameter for evaluating myopia progression.

Analysis of third and fourth corneal high-order aberrations before and after small incision lenticule extraction (SMILE) in myopic and myopic astigmatic eyes using ray tracing aberrometry

BackgroundAim is to analyze alterations in third and fourth corneal higher-order aberrations using a ray tracing aberrometer (iTrace) induced by SMILE (small incision lenticule extraction) refractive surgery on Algerian patients; and also to investigate how corneal aberrations vary with spherical equivalent (SE), corneal central thickness (CCT), and age. Design Prospective, non-randomized case series that were carried out at the Chiali Smile Center, Algiers, Algeria.ParticipantsA total of 219 eyes from 110 myopic patients, with and without astigmatism, successfully concluded the ultimate follow-up. Participants exhibited an average age of 32.48 years, with preoperative mean corneal high-order aberrations (CHOA) measuring 0.005 ± 0.036 μm.MethodsA tracking trend analysis of high-order aberrations (HOAs) was conducted on the three groups of patients, assessing total corneal high-order aberrations after SMILE over periods of two, six, and twelve months.ResultsA substantial increase in total corneal high-order aberrations following SMILE, with a P value < 0.05. Conversely, there was a noteworthy and significant decrease in vertical trefoil for all groups (P value = 0.000). Interestingly, the corneal higher-order aberrations were more pronounced after two months compared to the six and twelve-month intervals. Spherical aberration demonstrated a significant increase with the extent of preoperative myopia and preoperative spherical equivalent both before and after SMILE surgery (P < 0.05), particularly in cases of high myopia. Moreover, there were significant reductions in preoperative and postoperative vertical coma (P = 0.047, P = 0.004, respectively) corresponding to the degree of preoperative myopia, with a more substantial decrease in vertical coma observed in cases of low myopia.ConclusionIn the post-SMILE period, a notable increase in vertical coma and spherical aberrations was observed, accompanied by a significant decrease in vertical trefoil across all eyes. These aberration changes were identified to be closely associated with the spherical equivalent.

Effect of virtual reality-based visual training for myopia control in children: a randomized controlled trial

BackgroundTo assess the efficacy and safety of virtual reality-based visual training (VRVT) in myopia control among children.MethodsThe randomized, parallel-group, single-blind clinical trial conducted at the Department of Ophthalmology of Shanghai Tenth People’s Hospital enrolled 65 low-myopic children (aged 8 to 13 years) with cycloplegic spherical equivalent (SE) between − 0.50 and − 3.00 diopters (D), astigmatism less than − 1.00 D, anisometropia less than 1.50D, and best corrected visual acuity (BCVA) more than 0.0 logarithm (LogMAR) of the minimum angle of resolution. The participants were enrolled in December 2020, and the follow-up of this study concluded on August 2021. Children were assigned randomly to the intervention group (VRVT plus single-vision spectacle [SVS]) and the control group (only SVS without receiving VRVT). The intervention group was administered for 20 min per day with VRVT under parental supervision at home. The primary outcome was changes in axial length (AL) at 3 months. Macular choroidal thickness (mCT) was regarded as a key secondary outcome.ResultsAmong 65 participants (mean age: 10.8 years, 52.3% male), 60 children (92.3%) who completed the 3-month intervention and 6-month follow-up were included in the analysis (30 in the intervention group and 30 in the control group). The changes of AL were 0.063 ± 0.060 mm (95% confidence interval [CI], 0.074 to 0.119 mm) in the intervention group and 0.129 ± 0.060 mm (95% CI, 0.107 to 0.152 mm) and in the control group at 3 months (t = − 2.135, P = 0.037), and the mean difference between the two groups was 0.066 mm. The change of mCT were 22.633 ± 36.171 μm (95% CI, 9.127 to 36.140 μm) in the intervention group and − 3.000 ± 31.056 μm (95% CI, − 14.597 to 8.597 μm) in the control group at 3 months (t = 2.945, P = 0.005). VR vertigo was the most common adverse event which was occurred in two children (2/30, 6.67%) in the intervention group.ConclusionsVRVT is a promising method for myopia control in children with good user acceptability. Among children aged 8 to 13 years with low-myopia, nightly use of VRVT resulted in slowing myopia progression.Trial registrationThis protocol was registered with ClinicalTrials.gov (NCT06250920), retrospectively registered on 01 February 2024.

The lack of causal link between myopia and intraocular pressure: Insights from cross-sectional analysis and Mendelian randomization study

ObjectiveThis study aimed to explore the potential causal relationship between intraocular pressure (IOP) and myopia. MethodsThe study included 3,459 patients who underwent corneal refractive surgery at our institution between 2021 and 2023. Preoperative data on IOP, spherical equivalent (SE), axial length (AL), and corneal thickness (CCT) were collected. The association between IOP and myopia was investigated through rank correlation analysis, and causal inference was examined using Mendelian randomization (MR) methods, including MR-Egger, weighted median, mode-based estimation, simple mode, and inverse variance weighted (IVW) approaches. Utilizing summary statistics from genome-wide association studies (GWAS), IOP was considered as the exposure, with myopia as the outcome variable. IVW method was employed for the primary analysis, supplemented by sensitivity analyses. ResultsCross-sectional analysis revealed a non-significant association between corrected IOP (cIOP) and myopia (r = -0.019, P = 0.12). MR analysis indicated a non-significant genetic causal relationship between cIOP and myopia under the IVW method (OR = 1.001; 95 % CI [0.999–1.003], P = 0.22), a finding corroborated in replication samples (OR = 0.98; 95 % CI [0.96–1.00], P = 0.099). ConclusionThis study did not find a direct causal link between IOP and the development of myopia. These findings challenge the traditional role attributed to IOP in the progression of myopia and highlight the complex, multifactorial process of myopia development. This provides a new perspective on understanding the intricate mechanisms behind myopia progression.

Longitudinal refractive errors over 36 months in Hispanic and Black children.

This study brings awareness of racial/ethnic difference of refractive error characteristics in clinics. This study aimed to assess longitudinal change in refractive errors over a 36-month period in Hispanic and Black children. Children (2.4 to 15 years old) were studied. Cycloplegic refraction was measured annually. Spherical equivalent was calculated. Astigmatism was evaluated by magnitude of cylinder and power vector (J0 and J45). Absolute value of interocular spherical equivalent difference was used to calculate anisometropia. Mixed-linear model was used to analyze longitudinal annual change in spherical equivalent, cylinder, J0, and J45 over 36 months. A total of 485 participants (310 Black, 175 Hispanic) met the criteria. At the baseline examination, prevalence of myopia, emmetropia, and hyperopia was 39% (n = 187), 31% (n = 150), and 30% (n = 148), respectively. Spherical equivalent of Black children was not significantly different from that in Hispanic children (0.10 ± 2.92 vs. -0.37 ± 2.05 D, p=0.06); however, the Hispanic children had a significantly higher cylinder compared with Black children (Hispanic: 1.46 ± 1.57 D vs. Black: 0.92 ± 1.07 D; p<0.001). Both J0 (p<0.001) and J45 (p=0.01) were significantly different between two groups; the Hispanic children had more with-the-rule astigmatism and oblique astigmatism than the Black children. Prevalence of anisometropia (≥1 D) was higher in Black children (14%) compared with Hispanic children (5%, p=0.006). Over 36 months, spherical equivalent significantly decreased an average of 0.69 D (0.23 D/y, p<0.001) for both groups; neither astigmatism nor anisometropia changed significantly (p>0.05). Astigmatism in the Hispanic children was significantly higher than in Black children. However, the Black children had a higher prevalence and degree of anisometropia than the Hispanic children.

Ocular biometric parameters in South-Indian children with myopia - A hospital-based retrospective descriptive analysis.

This study aims to profile the ocular biometric parameters in a large group of children of South-Indian ethnicity who visited our outpatient children's department and were diagnosed with myopia. Children <15 years old diagnosed with myopia (Jan 2022-Oct 2023) and who had ocular biometry readings recorded were included. Their demographics, axial length (AL), anterior chamber depth (ACD), spherical equivalent (SE), corneal radius of curvature (CR), and AL/CR ratio were analyzed. The study included 3728 myopic children; the mean age was 11.85 (4-15) years, and 52.8% were girls. Mean SE was -3.98 D. The mean (SD) AL, ACD, CR, and AL/CR ratio were 24.64 (1.32), 3.73 (0.40), 7.61 (0.27), and 3.24 (0.16), respectively. Female gender was associated with shorter AL, ACD, CR, and AL/CR ratios (P < 0.001) across all age groups. There was a significant increase in ACD with age in both sexes (P < 0.001). A 1-unit (mm) increase in AL was associated with an SE increase of -1.65 D (CL: -1.70 to -1.60). AL/CR ratio could explain 71% of the total variance in SE (P < 0.001). SE showed a mild correlation with age (rho = 0.14, P < 0.001) and ACD (rho = -0.03, P = 0.041) and a stronger correlation with AL (rho = -0.68, P < 0.001) and AL/CR (rho = -0.83, P < 0.001). In this hospital-based study, AL and AL/CR ratios strongly correlate with SE, and the AL/CR better explains the total variance in SE than AL alone in children with myopia.

Clinical efficacy evaluation of the implantation of a diffractive trifocal intraocular lens in high myopia eyes: Two-year follow-up.

To evaluate the long-term subjective and objective visual quality after implantation of a diffractive trifocal intraocular lens (IOL) in high myopic eyes. A total of 53 eyes from 38 patients with high myopia who underwent phacoemulsification and trifocal IOL implantation were investigated. The visual acuity, contrast sensitivity, diopter, defocus curve, and objective visual quality at 1 month, 3 months, 1 year, and 2 years after surgery, as well as the satisfaction questionnaire and VF-14 scale, were statistically analyzed. The average age was 53.14 ± 4.70 years. The average preoperative spherical equivalent was -10.77 ± 3.98 D. Two years after surgery, 94.3% of the patients achieved an uncorrected distance visual acuity of 0.1 (LogMAR), and 84.9% and 94.3% of the patients had SE within ±0.50 D and ±1.0 D, respectively. The defocus curve was smooth and at a high value within the range of 0 D to -2.50 D. In CS or objective visual quality, there was no significant difference at 3 months, 1 year, and 2 years after operation (all P > 0.05). The rate of spectacle independence was 100%. The proportion of patients with moderate or severe glare and halo was 10.5% and 13.2%, respectively. Furthermore, 23.7%, 26.3%, and 18.4% of the patients had difficulties in reading small font, doing delicate tasks, and driving or riding at night, respectively. The diffractive trifocal IOL implantation provided good distance, intermediate, and near uncorrected visual acuity for patients with cataracts and high myopia. It was safe, effective, predictable, and stable. It provided long-term good visual quality after surgery, with high spectacle independence and high patient satisfaction.

Long-term follow-up after lens-sparing vitrectomy for complications of retinopathy of prematurity.

To report the long-term anatomical and functional results of lens-sparing vitrectomy (LSV) for stage 4 retinopathy of prematurity (ROP). Retrospective study. This is a study of 23 eyes of 16 patients with stage 4 ROP who underwent lens-sparing vitrectomy at a tertiary care center and had a minimum of 2 years of follow-up. The main outcome measures are the retinal status and visual outcome at the final follow-up. After a mean follow-up of 7.36 years, the lenses remained clear in 69.57%; anatomical success in terms of the attached retina was achieved in 19/23 eyes (82.61%) and vision of ≥6/24 was achieved in 8/23 eyes (34.78%), whereas navigational vision (≥1/60) was achieved in 16/23 (69.56%). The mean spherical equivalent was -8.50 + 6.39 diopters. High myopia (≥7 dsph) was noted in 43.47% of patients. The severity of myopia was not related to previous lasers and was less severe in eyes with posterior pole residual folds compared to normalized fundus or eyes with macular drag but no fold. At the final follow-up, 3/16 (18.75%) patients had bilateral blindness due to total retinal detachments and 11/16 (68.75%) had recorded functional vision in one or both eyes, whereas two others could potentially be having vision but could not be evaluated. The long-term results of lens-sparing vitrectomy for stage 4 ROP are favorable with a majority retaining clear lenses and attached retina and two-thirds having functional vision.

Visual outcomes with implantable Collamer lens versus small incision lenticule extraction in moderate-high myopia: A pilot study.

To compare the visual outcomes of implantable Collamer lens (ICL) with small incision lenticule extraction (SMILE) in cases of moderate-high myopia. A prospective comparative study was conducted on 60 eyes of 30 patients with moderate-high myopia (-3D to -8D with astigmatism ≤1 D) at a tertiary eye care center. Patients underwent either SMILE or ICL in both eyes and had a postoperative follow-up of 1 year. The manifest refractive spherical equivalent was -5.22 ± 1.05 D and -5.4 ± 1.17 D in the SMILE and ICL groups, respectively (P = 0.53). The mean sphere and cylinder were comparable between the groups. The mean uncorrected visual acuity improved from 1.18 ± 0.19 logMAR to 0.03 ± 0.07 logMAR in SMILE and 1.14 ± 0.25 logMAR to 0.011 ± 0.04 logMAR in the ICL group. The efficacy for SMILE was 83.3% and that for ICL was 93.3%. Safety and predictability (±0.5D) for both was 100%. A significant increase was observed in ocular aberration with a decrease in modular transfer function in the eyes that underwent SMILE, whereas no significant change in the eyes that underwent ICL. A significant difference was observed in all parameters of ocular aberration except corneal trefoil, corneal astigmatism, and PSF between the two groups at the final follow-up. The contrast sensitivity at final follow-up was higher in ICL cases when compared to SMILE. The quality of vision (QoV) score suggested a better QoV with ICL; however, the difference was not statistically significant. Both SMILE and ICL are safe in patients with moderate-high myopia. The efficacy, contrast sensitivity, and postoperative ocular aberration profile are better in cases undergoing ICL.