Spherical Equivalent Values Research Articles

Influence of Capsular Tension Rings on the IOL-Capsule Complex in Patients With Long Axial Length: A Clinical Observation Based on SS-OCT.

To evaluate the influence of a capsular tension ring (CTR) on the intraocular lens (IOL)-capsule complex after cataract surgery in patients with long axial length. This was a prospective study. Patients underwent phacoemulsification and IOL implantation, with or without CTR implantation. Swept-source optical coherence tomography was performed at 1 day, 1 week, 1 month, and 3 months postoperatively to determine the postoperative aqueous depth (PAD), capsular bend index (CBI), and IOL tilt and decentration. Spherical equivalent values were obtained through subjective refraction and autorefraction. Root mean square was adopted to evaluate the indices listed above. Forty-three patients (56 eyes) were included in the study. Generalized estimating equation analysis of PAD showed a statistical difference between groups (P = .031). The RMS of the change in PAD was smaller in the CTR group than in the non-CTR group during the 3 months after surgery (P = .015). CBI in the CTR group increased more from 1 to 3 months after surgery than that in the non-CTR group (P = .025). The RMS of the change in vertical decentration was smaller in the CTR group than in the non-CTR group during the 3-month follow-up (P = .009). CTR implantation can stabilize the axial position of the IOL within the capsular bag after cataract surgery in patients with long axial length without affecting the refractive stability. The formation of capsular bend may be slightly delayed in the early stage after CTR implantation, but it accelerates from 1 to 3 months after surgery. [J Refract Surg. 2024;40(9):e654-e661.].

Comparison between a new transepithelial PRK vs. conventional alcohol-assisted PRK: Corneal densitometry and aberrometry study.

To describe and compare corneal densitometry, subjective refraction, visual acuity, and corneal higher order aberrations (HOA) after corneal refractive surgery using either alcohol-assisted photorefractive keratectomy (aaPRK) or single-step transepithelial PRK (tPRK). We conducted a retrospective and observational study. We analyzed 120 right eyes from 120 healthy consecutive myopic patients who underwent aaPRK or tPRK to correct myopia of up to 6 diopters and astigmatism of up to 2 diopters. The WaveLight EX500 excimer laser (Alcon Laboratories, Inc.) was used in all cases. Visual acuity, subjective refraction, and Pentacam AXL® measurements were performed at the preoperative visit and at 6-months follow-up visit. Pentacam AXL® software was used to assess corneal optical density in various annuli for different corneal depths and anterior corneal HOA (6 mm area of analysis). Preoperative spherical equivalent values were similar between groups preoperatively (-3.07 ± 1.52 and -3.38 ± 1.46 in the aaPRK and tPRK groups, respectively). There were no statistically significant differences in visual acuity and postoperative refraction between groups. Postoperative corneal densitometry did not show statistically significant differences in any of the areas studied and both surgical procedures obtained similar results. However, analysis of HOA showed statistically significant differences between the techniques (1.42 ± 0.39 and 1.80 ± 0.62 for the aaPRK and tPRK groups, respectively; p = 0.000). Both aaPRK and single-step tPRK gave comparable visual, refractive, and corneal density outcomes. Some differences were observed in HOA but were not clinically relevant.

Lower indoor spatial frequency increases the risk of myopia in children

Background/aimsAnimal models have shown that the absence of high-frequency visual information can precipitate the onset of myopia, but this relationship remains unclear in humans. This study aims to explore the...

Test-Retest of the Spot Vision Screener among Children with Ophthalmological Diseases including Strabismus.

The spot vision screener (SVS) has been widely used for eye health examinations of infants and young children. The purpose of this study was to evaluate the reproducibility of two SVS measurements in children with ophthalmological diseases. 29 patients aged 15 years or younger who visited our hospital for refraction examinations with SVS before and at least 60 minutes after administration of 2 drops of 1% cyclopentolate ophthalmic solution (before and after cycloplegia) were included in this study. Two SVS measurements were made before and after cycloplegia, respectively. Intraclass correlation coefficients (ICCs) and Bland-Altman analysis for spherical, spherical equivalent (SE), cylindrical, J0, and J45 values before and after cycloplegia were analyzed. The mean age ± standard deviation (SD) of the 29 patients was 7.6 ± 2.4 years. There were 11 males and 18 females. The mean spherical values based on the SVS before and after cycloplegia were 0.42 ± 1.67 diopter (D), and 1.47 ± 2.23 D for the first measurement and 0.60 ± 1.74 D, and 1.42 ± 2.27 D for the second measurement, respectively. The mean cylindrical values based on SVS before and after cycloplegia were -1.45 ± 0.96 D and -1.65 ± 0.89 D for the first measurement and -1.58 ± 1.13 D and -1.66 ± 0.91 D for the second measurement, respectively. The ICCs for the first and second spherical, SE, cylindrical, J0, and J45 values before cycloplegia were 0.95, 0.98, 0.83, 0.86, and 0.86, respectively. The ICCs for the first and second spherical, SE, cylindrical, J0, and J45 values after cycloplegia were 0.99, 0.99, 0,87, 0.73, and 0.80, respectively. The Bland-Altman analysis of the first and second spherical and SE values before cycloplegia showed fan-shaped variation as hyperopia increased. Two consecutive SVS refraction measurements have a high degree of reproducibility for spherical and SE values but a low degree for cylindrical, J0, and J45 values. From these results, multiple measurements are required to obtain reliable results for cylindrical values.

Clinical Result of One-Piece Aspheric Intraocular Lens in Mild Zonule-Weakness

Purpose: To compare the clinical outcomes of one-piece aspheric intraocular lens in the patient group with mild zonule weakness and control group.Method: Among the patients who underwent cataract surgery since 2017, 30 patients (average age of 68.26 ± 8.99 years, 14 men, 16 women) and 35 eyes were selected. Prior to surgery, information on LOCS staging, endothelial cell count, intraocular pressure, axial length, and corneal refractive index were analyzed retrospectively. The average follow-up period after surgery was 3 months. The absolute value of the difference between the spherical equivalent value and the target refractive value in the patient group and the control group at 1 month and 3 months after surgery was compared.Results: The absolute value of the difference in refractive value after 1 month in the patient group was found was 0.61 ± 0.41 Diopters and 0.51 ± 0.42 Diopters in the control group, showing no statistically significant difference (<i>p</i> > 0.05). After 3 months, the absolute value of the refractive value difference was 0.46 ± 0.27 Diopters in the patient group and 0.46 ± 0.32 Diopters in the control group, indicating no statistically significant difference (<i>p</i> > 0.05).Conclusions: The one-piece aspheric intraocular lens enVista MX60 does not show statistically significant clinical difference in the difference between the postoperative refractive value and the target refractive value in the patient group, so it may be actively considered for use in the patient with mild zonule weakness.

Agreement in non-cycloplegic and cycloplegic refraction between a photoscreener and a calibrated autorefractor

IntroductionPhotoscreeners have been shown to provide excellent measurements of the refractive error. However, whether they could be used for assessing cycloplegic refraction has not been examied. This study aimed to evaluate the agreement between cycloplegic and non-cycloplegic measurements obtained using a photoscreener and stationary autorefractor, respectively.MethodsThis study included all patients undergoing routine ophthalmic examination at the Hygeia Clinic (Poland) from June to July 2022. Each patient underwent non-cycloplegic and cycloplegic refraction assessments using the 2WIN photoscreener (Adaptica SRL, Padova, Italy) and an ARK-1 stationary autorefractor ARK-1 (Nidek Co Ltd., Tokyo, Japan), respectively. Each pair of assessments was conducted in random order, and all values were determined at a vertical distance of 12 mm. The agreement between cycloplegic and non-cycloplegic measurements was assessed using paired t-tests, Bland-Altman and ABCD ellipsoids.ResultsThis analysis included 82 patients, of which 52 were female. Their mean age was 34.39 ± 13.13 years. The non-cycloplegic spherical equivalent (SE) did not differ significantly between the 2WIN (− 1.22 ± 2.45) and ARK-1 (− 1.19 ± 2.96) devices (p = 0.580). However, the cycloplegic SE values demonstrated more negative values with the 2WIN device (− 1.13 ± 2.19) than with the ARK-1 device (− 0.75 ± 3.03; p = 0.007). The non-cycloplegic and cycloplegic measurements were strongly correlated between the devices (r = 0.9473 and 0.9411, respectively). However, the correlation between their cycloplegic shifts in SE was low (r = 0.2645). Ellipsoid refraction aligned better non-cycloplegic (ARK-1 = 1.00; 2WIN = 1.74) than with cycloplegic refraction (ARK-1 = 1.43; 2WIN = 1.90).ConclusionWhile the cycloplegic measurements obtained with the 2WIN photoscreener were strongly correlated with those obtained with the ARK-1 stationary autorefractor for most of the analyzed parameters, they should not be considered interchangeable.

Prevalence and Estimation of the Evolution of Myopia in Spanish Children.

Background: In recent decades, myopia has turned into a public health issue across the world. Between 1993 and 2016, the percentage of myopes increased from 10.4% to 34.2%. This study aims to analyze the myopia prevalence in Spanish children from five to seven years old over the last five years and to predict the rate of myopia in Spain by 2030. Methods: The sample consisted of children aged between 5 and 7, who underwent an optometric examination consisting of the measurement of visual acuity (VA) and determination of objective and subjective refraction. The cut-off points to define refractive error are established by the spherical equivalent (SE) value: hyperopia for an SE over or equal to +0.50 D; myopia for an SE under or equal to -0.50 D; and emmetropia when the SE is between -0.50 D and +0.50 D. Results: The myopia rate in Spanish children aged between five and seven was 19%. Myopia prevalence progressively increased as children grew up (p ≤ 0.001). It is estimated that, in the year 2030, the rate of myopia will be 30.2% [CI: 25.3-35.0], of which 81.9% [CI: 78.3-85.3] will have low myopia, 10.0% [CI: 7.2-12.8] moderate myopia, and 7.3% [CI: 4.9-9.7] high myopia. Conclusions: Nineteen percent of Spanish children between five and seven are myopes. In 2030, is expected that 30.2% of Spanish children between 5 and 7 years of age will be myopes. These estimations will support eye care professionals in recommending that children spend more time outdoors to prevent the onset of myopia and the use of methods to control myopia to avoid reaching these figures of high myopia.

Comparison of three techniques for simultaneous intraocular lens implantation in subluxated cataract surgery: Transconjunctival intrascleral, Z-suture knotless transscleral, and Cionni capsular tension ring assisted.

To evaluate and compare the clinical outcomes of three different methods of intraocular lens (IOL) implantation in the surgery of subluxated cataracts. In this retrospective, comparative, clinical interventional study, the medical records of patients who underwent IOL implantation with sutureless 27-gauge needle-assisted transconjunctival intrascleral (Group 1), Z-suture knotless transscleral (Group 2), and Cionni capsular tension ring (Cionni-CTR) assisted (Group 3) simultaneously with subluxated cataract extraction between June 2010 and June 2022 were evaluated. Demographic characteristics, follow-up times, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical and cylindrical refractive values, and spherical equivalent (SE) values of three groups were compared. Intraoperative and postoperative complications were recorded. There were 20 eyes in Group 1, 35 eyes in Group 2, and 40 eyes in Group 3. In all groups, statistically significant improvement was observed in postoperative UDVA and CDVA compared to preoperative values (each p < 0.05). There was no statistical difference between the groups in postoperative UDVA and CDVA values. (p = 0.130, p = 0.167 respectively). No significant difference was observed between the groups in terms of postoperative spherical, cylindrical, and SE values (each p > 0.05). The study suggests that three different IOL implantation techniques for simultaneous IOL implantation in subluxated cataract surgery have similar effects on visual and refractive outcomes.

Efficacy of 3D-printed eye model to enhance retinoscopy skills

We conducted a prospective study to evaluate the efficacy of simulation-based education using a three-dimensional (3D)-printed schematic eye model in improving the retinoscopy refraction skills of medical students. A schematic eye model was printed using a fused deposition modeling-based 3D printer. Twenty medical students randomized into 3D (n = 10) and control (n = 10) groups received a 1-h lecture on the principles and methods of manifest refraction and were shown how to use the retinoscope and sciascope bars. The 3D group additionally attended a tutorial on the schematic eye. Both groups performed refractive examinations on four eyes of volunteer patients, and the results were recorded as a baseline. Instructor feedback and refraction practice was provided with the 3D group or with control group. To account for subject fatigue, patients spent no more than 8 min on the examination. After a 1-h break to allow for fatigue and familiarity, refraction tests were repeated on four randomly selected eyes of patients. Students’ refraction readings were compared with the autorefractor values using a spherical equivalent value and blur strength. All participants measured the time required to complete the refraction test and reported their subjective confidence in the results of each refraction test. Refractive errors before and after training did not differ between the control and 3D groups, with a significant improvement in errors observed in both groups (p = 0.005 and 0.008, respectively). The time to complete refraction before and after training did not differ between the two groups, both of which showed a significant reduction in time (p = 0.005 and 0.028, respectively). Pre- and post-training confidence scores for the accuracy of each refraction on a 10-point Likert scale were not significantly different. However, when comparing score changes between pre- and post-training, only the control group showed a significant increase in confidence (p = 0.005). Tests for the non-inferiority of refractive errors after training indicated that the 3D group was non-inferior to the control group. In conclusion, training in retinoscopy refraction skills using a 3D-printed eye model resulted in significant improvement in accuracy and speed compared to practice with real patients. Except for better confidence in the control group, schematic eye model training was not inferior to practice with real patients.

Evaluation of Clinical Results of Implantation of Toric Intraocular Lenses Including their Rotational Stability.

The aim of the study was to evaluate the clinical results of the implantation of the toric intraocular lens Acrysof IQ Toric SN6AT3_8(Alcon Laboratories, Inc., Fort Worth, TX, USA), including an evaluation of its rotational stability. 30 eyes of 16 patients (4 males, 12 females; mean age 68 years) with regular corneal astigmatism ranging from -1.5 to -4.0 Dcyl were included in this retrospective study. All the patients underwent uncomplicated cataract surgery with the implantation of a toric intraocular lens (TIOL) at the Department of Ophthalmology of the Faculty of Medicine and Dentistry of Palacký University in Olomouc and University Hospital Olomouc during the course of 2020. Follow-up examinations were performed 3-6 months after cataract surgery. We monitored the resulting uncorrected distance visual acuity (UDVA), postoperative refraction, rotational stability of the implanted lens and subjective patient satisfaction. mean preoperative corneal astigmatism was -2.41 ±0.67 Dcyl. UDVA improved from a mean value of 0.45 ±0.25 (expressed in decimal Snellen optotype values) to 0.91 ±0.16. The spherical equivalent value of 0.41 ±2.92 improved to -0.11 ±0.27 postoperatively. The mean deviation from the planned axis was 4.87 ±4.75. Subjective satisfaction was rated by patients on a scale of 1-5, with a mean score of 1.5. TIOL implantation is a safe and effective solution for patients with corneal astigmatism and cataract. Our results demonstrate improved UDVA, rotational stability of the TIOL and subjective patient satisfaction with the outcome of the surgery.

Effect of Corneal Collagen Crosslinking with Riboflavin in Patients of Progressive Keratoconus: A Prospective Cohort Study

Introduction: Keratoconus is a non inflammatory disease characterised by progressive corneal thinning that results in a cone-like ectasia, irregular astigmatism, and decreased vision. Advanced disease can result in corneal scarring and blindness, necessitating penetrating keratoplasty. The only treatment believed to have the ability to stop or decrease the progression of keratoconus is Collagen Cross-Linking (CXL). Aim: To evaluate the efficacy of corneal collagen cross-linking with riboflavin (C3R) in patients with keratoconus by studying the outcomes in terms of Uncorrected Visual Acuity (UCVA), Best Corrected Visual Acuity (BCVA), manifest refraction, and corneal topography. Materials and Methods: A hospital-based prospective cohort study was conducted at the Regional Institute of Ophthalmology, Government Medical College, Thiruvananthapuram, Kerala, India from June 2017 to June 2018. Fifteen eyes of 12 patients who underwent corneal collagen cross-linking for progressive keratoconus were included. Routine ophthalmological examinations was done for all patients. Patients under the age of 35 years with progressive keratoconus, an average K value not exceeding 60 D, and who had not undergone any other surgical modalities of treatment were included in the study. Patients with scarred cornea or hydrops, active ocular infection, or pachymetry &lt;400 µm were excluded. Detailed informed consent was obtained from all patients before surgery. Preoperative UCVA, BCVA cylinder, Spherical Equivalent (SE), and topography values were obtained. All patients were followed-up at three and six months postoperative period to look for changes in UCVA, BCVA, manifest refraction, and corneal topography. Data were expressed as the mean±Standard Deviation (SD) pre- and postoperatively and analysed statistically using the paired t-test, with p&lt;0.05 considered statistically significant. Analysis was conducted using Statistical Package for Social Sciences (SPSS) version 16.0. Results: On follow-up at six months post-treatment, UCVA (log MAR) improved from 0.87±0.40 to 0.65±0.35 (p-value=0.001), and BCVA (log MAR) changed from 0.37±0.21 to 0.17±0.22 (p-value=0.001). K max decreased from 54.90±6.05 to 52.67±5.02 (p-value=0.001), and K min decreased from 48.14±4.24 to 45.93±4.07 (p-value=0.001). Astigmatism and SE also showed statistically significant improvement post-procedure (p-value 0.001 and 0.002, respectively). Astigmatism reduced from -3.50±1.58 to -2.90±1.37. SE reduced from -4.93±3.92 to -4.28±3.48. No significant complications were noted in any of the patients. Conclusion: The CXL is an effective procedure for stabilising the progression of keratoconus, thus reducing the burden of preventable blindness and the need for keratoplasty.

Evaluation of Risk Factors in Patients with Primary Open Angle Glaucoma and Ocular Hypertension

Objective: The purpose of our study was to compare the age, gender, intraocular pressure (IOP), central corneal thickness (CCT), spherical equivalent values, smoking, family history of glaucoma and additional systemic diseases in patients with primary open angle glaucoma (POAG) and patients with ocular hypertension (OHT); and to evaluate the relationships of these factors with each other. Material Methods: 40 patients with POAG, 40 patients with OHT and 40 individuals as control group were included in the study. Age, gender, IOP, CCT, spherical equivalent values, family history of glaucoma, history of consanguineous marriage, smoking, systemic diseases of each subject were recorded. Results: There was no significant difference in gender and average age between the groups (p=0.238 and p=0.51, respectively). IOP values was higher in POAG and OHT groups compared with the control group (p=0.000). CCT was higher in OHT group compared with the other groups (on the right, p=0.001 and p=0.008, respectively; on the left, p=0.013 and p=0.006, respectively). There was no significant correlation between IOP and CCT values. There was no significant difference in mean spherical equivalent values (on the right eye p=0.686; on the left eye p=0.640) . The incidence of diabetes mellitus, hypertension, hyperlipidemia and coronary artery disease was the similar in all groups (p=0.417, p=0.058, p=0.79, p=0.236, respectively). Family history of glaucoma is increased in POAG and OHT group compared with the control group (p=0.000). There was no significant difference in history of consanguineous marriage, smoking and alcohol consumption status among all groups (p=0.899, p=0.492, p=0,899, respectively). Conclusion: High IOP is the most important risk factor in the POAG and OHT groups. Individuals with OHT and thin CCT are at higher risk of developing POAG. The significant presence of a familial history of glaucoma in the POAG and OHT groups indicates that genetic factors could be a significant risk factor. Diabetes, hypertension, and high myopia are factors that increase the risk of glaucoma.

Effect of sutureless scleral fixed intraocular lens implantation on aphakic eyes: a system review and meta-analysis

BackgroundSutureless scleral fixed intraocular lens implantation (SF-IOL) has become one of the mainstream schemes in clinical treatment of aphakic eyes because of its advantages, such as avoiding dislocation of intraocular lens or subluxation caused by suture degradation or fracture and significant improvement of postoperative visual acuity. However, a consensus on the relative effectiveness and safety of this operation and other methods is still lacking. This study aimed to compare the efficacy and safety of sutureless SF-IOL with other methods. Aphakia means that the lens leaves the normal position and loses its original function, including absence or complete dislocation and subluxation of the lens which could cause anisometropic amblyopia, strabismus, and loss of binocular function in children and adolescents. For adults, the loss of the lens could lead to high hyperopia and affect vision. Above all this disease can seriously affect the quality of life of patients.MethodsLiterature about sutureless SF-IOL in PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, China Technical Journal VIP database, and Wanfang database published from 2000 to 2022 was reviewed. The weighted average difference was calculated by RevMan5.3 software for analysis. Two researchers independently selected the study and used the Cochrane collaboration tool to assess the risk of errors. Cochrane bias risk tool was used to evaluate the quality of evidence. This study is registered on PROSPERO (CRD42022363282).ResultsThe postoperative IOL-related astigmatism of sutureless SF-IOL was lower than that of suture SF-IOL, and there was statistical difference when we compared the absolute postoperative spherical equivalent after sutureless SF-IOL and suture SF-IOL. Indicating that the degree of refractive error after sutureless SF-IOL was lower. Meanwhile, the operation time of sutureless SF-IOL was shorter than that of suture SF-IOL. The subgroup analysis showed that the absolute postoperative spherical equivalent and astigmatism values in Yamane technique were lower than those in suture SF-IOL.ConclusionSutureless SF-IOL has the advantages of stable refraction, short operation time, and less postoperative complications. However, high-quality literature to compare these technologies is lacking. Some long-term follow-up longitudinal prospective studies are needed to confirm the findings.

Association between Anemia and Myopia in Korean Adults

Objectives: Anemia is a significant public health issue worldwide and has been associated with ocular changes. This study aimed to investigate the relationship between anemia and myopia in an adult population in South Korea.Methods: We analyzed the data of 8,672 participants aged 20 to 54 years in the fifth Korea National Health and Nutrition Examination Survey (KNHANES). Anemia was defined as hemoglobin levels &lt; 13 g/dL for men, &lt; 12 g/dL for women, and &lt; 11 g/dL for pregnant women. Anemia was subdivided into mild anemia (11-12.9 g/dL for men, 11-11.9 g/dL for women, and 10-10.9 g/dL for pregnant women) and moderate to severe anemia ( &lt; 11 g/dL for men and women and &lt; 10 g/dL for pregnant women) categories. Myopia was defined as spherical equivalent value ≤ -0.5 diopters. We performed multivariable logistic regression analysis to examine the relationship between anemia and myopia.Results: The prevalence of myopia was 43.5% in men and 56.5% in women. The prevalence of anemia was 0.9% in men and 14.5% in women. After adjusting for confounders, the risk of myopia was 1.28 times higher in women with anemia than in those without anemia (odds ratio, OR = 1.28, 95% confidence interval, CI = 1.02-1.60, &lt;i&gt;p&lt;/i&gt;= 0.036). The risk of myopia was 1.55 times higher in women with moderate to severe anemia than in those without anemia (OR = 1.55, 95% CI = 1.12-2.16, &lt;i&gt;p&lt;/i&gt;= 0.026). Anemia was not significantly associated with myopia in men.Conclusions: Women with anemia were at increased risk of myopia compared to those without anemia. The severity of anemia was also associated the risk of myopia.

Deep Transfer Learning for Ethnically Distinct Populations: Prediction of Refractive Error Using Optical Coherence Tomography.

The mismatch between training and testing data distribution causes significant degradation in the deep learning model performance in multi-ethnic scenarios. To reduce the performance differences between ethnic groups and image domains, we built a deep transfer learning model with adaptation training to predict uncorrected refractive errors using posterior segment optical coherence tomography (OCT) images of the macula and optic nerve. Observational, cross-sectional, multicenter study design. We pre-trained a deep learning model on OCT images from the B&VIIT Eye Center (Seoul, South Korea) (N = 2602 eyes of 1301 patients). OCT images from Poona Eye Care (Pune, India) were chronologically sorted into adaptation training data (N = 60 eyes of 30 patients) for transfer learning and test data (N = 142 eyes of 71 patients) for validation. Deep learning models were trained to predict spherical equivalent (SE) and mean keratometry (K) values via transfer learning for domain adaptation. Both adaptation models for SE and K were significantly better than those without adaptation (P < 0.001). In myopia/hyperopia classification, the model trained on circular optic disc OCT images yielded the best performance (accuracy = 74.7%). It also performed best in estimating SE with the lowest mean absolute error (MAE) of 1.58 D. For classifying the degree of corneal curvature, the optic nerve vertical algorithm performed best (accuracy = 65.7%). The optic nerve horizontal model achieved the lowest MAE (1.85 D) when predicting the Kvalue. Saliency maps frequently highlighted the retinal nerve fiber layers. Adaptation training via transfer learning is an effective technique for estimating refractive errors and K values using macular and optic nerve OCT images from ethnically heterogeneous populations. Further studies with larger sample sizes and various data sources are needed to confirm the feasibility of the proposed algorithm.

Sleep Quality is Associated with Axial Length Elongation in Myopic Children Receiving Orthokeratology: A Retrospective Study.

To identify potential demographic and lifestyle factors associated with progression of myopia with orthokeratology (ortho-k) treatment via follow-up of axial length (AL). In this retrospective observational study, demographics, ocular parameters, near-work distance, outdoor activities, and sleep quality were analyzed in 134 children with myopia aged 8~15 years using ortho-k and a follow-up for one year. Compared with the slow progression group, the participants in the fast progression group were younger in age (10.55 ±1.70 years vs 9.90 ±1.18 years, P = 0.009), demonstrated higher spherical equivalent (SE) value (-2.52 ±0.63 diopters (D) vs -3.05 ±0.89 D, P < 0.001), shorter near-work distance (P = 0.010), and poorer sleep quality (Pittsburgh sleep quality index [PSQI], 4.79 ±1.29 vs 3.81 ±1.38, P < 0.001) in the one-year follow-up. Furthermore, multivariate linear regression analyses showed that baseline age (B =-0.020, P = 0.020), SE (B = 0.0517, P < 0.001), and total PSQI (B=0.026, P = 0.001) were associated with axial elongation. Advanced logistic regression analyses demonstrated that shorter average near-work distance (P = 0.034), higher SE value (P = 0.023), and poorer sleep quality (P = 0.003) were associated with fast axial elongation. Sleep quality is one of the key factors associated with axial elongation in children with myopia after using ortho-k for one year. Further studies are required to confirm this observation and expand its practical applications.

Analysis of the relationship between lens morphology and aberrations in patients with myopia: a cross-sectional study.

To investigate the relationship between lens morphology and aberrations in patients with myopia. This cross-sectional study included 155 patients with myopia in their right eyes. Spherical power and cylindrical power were achieved by cycloplegic autorefraction. The eyes were divided into three groups for analysis based on their spherical equivalent (SE) values. The 4mm and 6mm ocular and internal aberrations were measured using the OPD-scan III. Lens parameters were measured using CASIA2, including lens thickness (LT), radius of anterior/posterior lens surface curvature (RAL/RPL), lens decentration (DEC), and lens tilt (TILT). The differences of lenticular parameters and aberration parameters among the three groups analyzed with ANOVA or Kruskal Wallis test. Pearson correlation or Spearman correlation analysis was performed to evaluate the relationships between the lens parameters and aberrations. A p value < 0.05 indicated statistical significance. The difference in LT, RAL, DEC and TITL among the three groups was statistically significant (p < 0.05). And there were differences among differences in internal high-order aberrations, spherical aberration, and coma aberration(p < 0.05).Spherical power was positively correlated with LT and TITL (p < 0.05) and negatively correlated with DEC, RAL, and RPL (p < 0.05). Cylindrical power was positively correlated with LT (p < 0.05) and negatively correlated DEC (p < 0.05); The lenticular parameters (LT, RAL, DEC, and TILT) were mainly correlated with the ocular and internal spherical aberration. LT and DEC were correlated with ocular and internal higher-order aberrations and comaaberration. DEC and LT were the main factors affecting aberrations in patients with myopia.

Non-invasive assessment of the tear film after LASIK.

The aim of the study was to compare the assessment of the ocular surface using classic methods with the newly developed keratoscopy-based MYAH (Topcon EU, Visia Imaging, Japan) device after femtosecond laser-assisted in situ keratomileusis (LASIK). This cross-sectional and observational study analyzed 80 eyes of 40 patients. Tear film and ocular surface evaluation were performed at baseline, postoperative week 1, and month 1. Measurements obtained using the Schirmer I test and invasive tear-film breakup time (I-TBT) were compared with non-invasive evaluation of the tear break-up time (NI-TBT), tear meniscus height (TMH) and blink analysis obtained using the MYAH device. Findings were correlated with the Ocular Surface Disease Index (OSDI) questionnaire in all subjects. The study included 80 eyes of 40 consecutive patients (21 males and 19 females) with a mean age of 26.6 ± 5.9 years (18-40 years) and a mean spherical equivalent value of -3.64 D (-9.63 to -0.25 D). There was a significant decrease in Schirmer I test (19.21 ± 8.4 vs. 16.61 ± 9.1 vs. 14.69 ± 9.86, p= 0.02, respectively) and I-TBT values (8.59 ± 3.4 vs. 7.4 ± 3.25 vs. 6.17 ± 3.01, p=0.03 respectively). OSDI values showed a significant increase after LASIK (11.56 ± 6.3 vs. 17.24 ± 7.5 vs. 14.71 ± 9.6, p=0.03, respectively). 5% level NI-TBT was significantly lower at 1 week 6.75 and 1 month 7.45 than baseline 13.2 at follow-up (p=0.037). Ocular protection index (6.6 vs. 2.3 vs. 2.6, p=0.009, respectively) and blink/minutes (18 vs. 17 vs. 15, p=0.002, respectively) values showed a statistically significant decrease. Our data detected a weak correlation between I-TBT and noninvasive first TBT, 5% level TBT parameters at month 1 follow-up. This study also found no correlation between contact lens use, older age, female gender, and pre-operative refractive error with the noninvasive MYAH dry eye parameters. This study demonstrated the ability of the new keratoscopy-based MYAH device to detect changes in the short term after LASIK surgery.

Effect of Keratoconus Stage and Classification Parameters on Deep Anterior Lamellar Keratoplasty Outcomes.

The aim of this study was to investigate the effect of the keratoconus (KC) stage according to the Amsler-Krumeich classification system and the parameters used in this classification on deep anterior lamellar keratoplasty outcomes. The preoperative KC stage was determined, and the presence of corneal scarring was noted. The preoperative and postoperative best-corrected visual acuity (BCVA), refractive error, mean central keratometry (K mean ) readings, topographic astigmatism, and minimum corneal thickness (CT) values were recorded. Intraoperative and postoperative complications were also noted. One hundred thirty-seven eyes (54 eyes in stage 3-83 eyes in stage 4) were included in the study. The mean follow-up period was 42.20 ± 24.36 months. There was no statistically significant difference between stage 3 and 4 KC groups for postoperative BCVA, K mean , CT, spherical equivalent, and topographic astigmatism values (each P value >0.05). The effect of preoperative BCVA, K mean , CT, and refractive error values on postoperative BCVA could not be demonstrated ( P = 0.264). In addition, no statistically significant correlation was found between postoperative and preoperative values (each P value > 0.05). Although intraoperative Descemet membrane perforation and postoperative early suture loosening were observed more frequently in stage 4 KC than in stage 3 KC, the 2 groups were statistically similar for these and other complications (each P value >0.05). The preoperative KC stage and the parameters used in classification are not useful in predicting postoperative deep anterior lamellar keratoplasty outcomes. The timing of the surgery should be planned with the awareness that the progression of the disease will not have a negative effect on outcomes.

The effect of hyperbaric oxygen therapy on corneal endothelial structure and anterior segment parameters

Purpose To assess the effect of hyperbaric oxygen therapy (HBOT) on corneal endothelial structure and anterior segment parameters in healthy eyes. Methods 17 eyes of 17 patients who were scheduled to receive HBOT for other than ophthalmologic indications were investigated in this prospective study. Central corneal thickness (CCT) and corneal endothelial properties were evaluated using a specular microscope. Endothelial cell density (ECD), average cell area (AVG), coefficient of variation in cell size (CV), percentage of hexagonal cells (HEX), CCT, intraocular pressure (IOP), spherical equivalent (SE), axial length (AL) and anterior chamber depth (ACD) values were measured before the HBOT, after the 1st session, and after the 20th session of therapy. Results 47% of the patients (n = 8) received HBOT because of avascular necrosis, 35% (n = 6) due to sudden hearing loss, 12% (n = 2) for diabetic foot, and 6% (n = 1) for wound infection. The mean IOP was 14,80 mmHg before HBOT, 14,20 mmHg after the 1st session, and 13,73 mmHg after the 20th session. The mean ACD was 3,38 mm before HBOT, 3,34 mm after the 1st session, and 3,16 mm after the 20th session. Although the mean IOP and ACD decreased after HBOT sessions, it was not statistically significant (p > 0.05). A significant reduction was observed in SE values after 20 sessions of HBOT compared to the values measured before HBOT (p = 0,009). The mean ECD was 2572,53 ± 261,51 cells/mm2 before HBOT, 2554,47 ± 236,13 after the 1st session, and 2563,13 ± 226,92 after the 20th session. When the corneal properties measured before and after HBOT sessions were compared, no significant difference was found in terms of CCT, ECD, AVG, CV, and HEX (p > 0.05). Conclusion We observed no significant change in CCT, corneal endothelial layer properties, and anterior segment morphology after the 1st session, and after the 20th session of HBOT. Although HBOT reduced IOP and ACD, it was not statistically significant. HBOT may lead to a significant decrease in SE values after the 20th session.