Associations between corneal curvature and other anterior segment biometrics in young myopic adults.

To investigate the associations between corneal curvature (CC) and other anterior segment biometrics in young myopic adults. In this retrospective multi-center study, 7893 young myopic adults were included. CC and other anterior segment biometrics were measured by Scheimpflug imaging (Pentacam). CC was defined as SimK at central 3 mm area, and other anterior segment biometrics included white-to-white corneal diameter (WTW), central corneal thickness (CCT), corneal volume (CV) at 3 mm, 5 mm, and 7 mm area, anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), anterior corneal eccentricity (ACE) and asphericity (ACAP), posterior corneal eccentricity (PCE) and asphericity (PCAP), anterior chamber depth (ACD), and anterior chamber volume (ACV). Univariate regression analyses were used to assess the associations between CC and other anterior segment biometrics, and multivariate regression analyses were further performed to adjusted for age, gender and spherical equivalent. CC was higher in patients of female gender and higher myopia (all P < 0.05). Eyes in higher CC quartiles had lower WTW, thinner CCT, lower CV at 3 mm and 5 mm, lower ACD, and lower ACV (all P < 0.001), but had larger ACA, larger PCA, less PCE and less PCAP (all P < 0.001), compared to eyes in lower CC quartiles. The trends of CV at 7 mm, ACE and ACAP were inconsistent in different CC quartiles. After adjusting for age, gender and spherical equivalent with multivariate linear regression, CC was positively correlated to CV at 7 mm (ßs = 0.069), ACA (ßs = 0.194), PCA (ßs = 0.187), ACE (ßs = 0.072), PCAP (ßs = 0.087), and ACD (ßs = 0.027) (all P < 0.05), but was negatively correlated to WTW (ßs = - 0.432), CCT (ßs = - 0.087), CV-3 mm (ßs = - 0.066), ACAP (ßs = - 0.043), PCE (ßs = - 0.062), and ACV (ßs = - 0.188) (all P < 0.05). CC was associated with most of the other anterior segment biometrics in young myopic adults. These associations are important for better understanding of the interactions between different anterior segment structures in young myopic patients, and are also useful for the exploration of the pathogenesis of myopia.

Quantitative evaluation of corneal irregularity and scarring after infectious keratitis using anterior segment optical coherence tomography.

PURPOSE: Corneal scars after infectious keratitis lead to insufficient transparency and irregular astigmatism, affecting visual acuity; therefore, they should be accurately evaluated to estimate visual function. This study aimed to quantitatively evaluate corneal irregularity and scarring after infectious keratitis using anterior segment optical coherence tomography (AS-OCT). METHODS: This was an observational clinical study. We included patients who had corneal scarring after treatment of infectious keratitis between 2014 and 2021 at University of Tokyo Hospital. We retrospectively examined best spectacle-corrected visual acuity (BSCVA), average keratometric power, central corneal thickness (CCT), and four components of the Fourier harmonic analysis including spherical and asymmetry components, as well as regular astigmatism and higher-order irregularity. We included anterior and posterior corneal data and compared results with those of contralateral healthy eyes. Additionally, we quantitatively evaluated the densitometry of the cornea obtained using AS-OCT. RESULTS: A total of 122 eyes of 61 patients were examined; male predominance was observed (n = 37), and the mean patient age was 55.3 ± 19.4 years. Comparisons with contralateral healthy eyes showed that BSCVA worsened (0.30 ± 0.83 and 0.93 ± 1.36 logMAR, respectively, P = 0.003), and CCT (531.1 ± 46.2 and 591.8 ± 132.4 µm, respectively, P < 0.001) and corneal densitometry (84.4 ± 11.8 and 111.9 ± 19.2 grayscale units, respectively, P < 0.001) increased significantly in affected eyes. The asymmetry component and higher-order irregularities that were not corrected with spectacles significantly increased (both P < 0.001), and there were no significant differences in the changes among the bacterial, fungal, herpetic, and acanthamoeba types of keratitis. CONCLUSION: Corneal scarring persisted after treatment for infectious keratitis, and the asymmetry and irregularities of corneal astigmatism increased as visual acuity deteriorated. AS-OCT with the Fourier harmonic analysis was useful for evaluating corneal topographic changes in patients with corneal scarring after keratitis.

Preoperative geometric parameters predict the outcome of lamellar keratoscleroplasty in patients with limbal dermoids.

PURPOSE: To find preoperative simple geometric parameters to predict the outcome of lamellar keratoscleroplasty in patients with corneal limbal dermoids. METHODS: We retrospectively analyzed the data of 30 patients with limbal dermoids who underwent lamellar keratoscleroplasty and were followed up for more than 6 months. Seven geometric parameters were used to analyze the relationship with postoperative visual acuity, astigmatism, and scar formation and investigated for their influence on postoperative outcome. These seven parameters included the cornea-invaded area of dermoid, dermoid area, the cornea-invaded length of dermoid, the corneal limbus invaded length of dermoid, dermoid size, bed size, graft size. Furthermore, we divided patients with corneal limbal dermoids into amblyopia group and non-amblyopia group, and analyzed the clinical characteristics of the amblyopia group. RESULTS: The mean age of the patients at surgery was 10.6 ± 5.83 years. The 7 geometric parameters, preoperative and postoperative astigmatism of the amblyopia group were higher than those of the non-amblyopia group (all P < 0.05). Among the geometric parameters analyzed, the r coefficients between the cornea-invaded length of dermoid and postoperative visual acuity and astigmatism were the highest (r = 0.854, r = 0.714). The r coefficient between the corneal limbus invaded length of dermoid and the postoperative scar was the highest (r = 0.375). The r coefficient between age and postoperative steroid-induced high intraocular pressure was the highest (r = - 0.416). In univariate regression analysis, the cornea-invaded length of dermoid was significantly correlated with postoperative visual acuity (ß = 0.270, P < 0.001) and postoperative astigmatism (ß = 1.362, P < 0.001). Among the geometric parameters analyzed, the cornea-invaded length of dermoid had best stratified patients in grouping with or without amblyopia (cutoff > 2.24). CONCLUSION: The cornea-invaded length of dermoid was the most important related factor of postoperative visual acuity, astigmatism, and amblyopia. The corneal limbus invaded length of dermoid was the most important related factor of postoperative scar formation. The geometric parameters and astigmatism in patients with amblyopia were larger than those in patients without amblyopia.

Corneal topography in preterm children aged 2 years to 12 years with or without retinopathy of prematurity.

OBJECTIVES: To evaluate corneal topography in full-term and preterm children with or without retinopathy of prematurity (ROP). METHODS: We enrolled children aged from 2 years to 12 years between January 2019 and May 2021 in the following four groups: full-term (group 1), premature without ROP (group 2), untreated premature with ROP (group 3), and laser-treated and/or intravitreal injection (IVI) of anti-vascular endothelial growth factor (VEGF)-treated premature with ROP (group 4). Corneal topography was measured with the Galilei Placido-dual Scheimpflug analyzer G4 every half year, and was compared among the groups using generalized estimating equation models at approximately 7 years of age. RESULTS: We included 77, 178, 45, and 131 participants in groups 1, 2, 3, and 4, respectively. The mean (standard deviation) number of visits per patient was 2.9 (1.4). Compared with full-term eyes, premature eyes demonstrated steeper anterior corneal curvature (p = 0.016 and p = 0.008 for the mean and steep K, respectively), higher anterior and posterior corneal astigmatism (p = 0.036 and p = 0.016, respectively), and thinner thinnest pachymetry (p < 0.001). The laser-treated ROP eyes displayed steeper anterior corneal curvature (p = 0.040 for steep K) and higher anterior corneal astigmatism (p = 0.005) than the IVI-treated eyes. Moreover, they exhibited high cone location and magnitude index (1.96) reaching the cut-off for detecting keratoconus (1.82). CONCLUSIONS: The premature status led to greater corneal ectasia, and laser treatment for ROP caused further corneal steepness. Higher anterior corneal astigmatism was associated with laser treatment. The ROP pathology and IVI anti-VEGF treatment exerted a marginal effect on corneal topography.

KCTD1 and Scalp-Ear-Nipple ('Finlay-Marks') syndrome may be associated with myopia and Thin basement membrane nephropathy through an effect on the collagen IV α3 and α4 chains.

INTRODUCTION: Scalp-Ear-Nipple syndrome is caused by pathogenic KCTD1 variants and characterised by a scalp defect, prominent ears, and rudimentary breasts. We describe here further clinical associations in the eye and kidney. METHODS: Fifteen affected members from two unrelated families with p.(Ala30Glu) or p.(Pro31Leu) in KCTD1 were examined for ocular and renal abnormalities. The relevant proteins were studied in the eye and kidney, and the mutation consequences determined from mouse knockout models. RESULTS: Five males and 10 females with a median age of 40 years (range 1-70) with pathogenic variants p.(Ala30Glu) (n = 12) or p.(Pro31Leu) (n = 3) in KCTD1 were studied. Of the 6 who underwent detailed ophthalmic examination, 5 (83%) had low myopic astigmatism, the mean spherical equivalent of 10 eyes was 2.38D, and one (17%) had hypermetropic astigmatism. One female had a divergent strabismus.Five individuals had renal cysts (5/15, 33%), with renal biopsy in one demonstrating a thinned glomerular basement membrane identical to that seen in Thin basement membrane nephropathy (AD Alport syndrome).In the eye, KCTD1 and its downstream targets, TFAP2, and the collagen IV α3 and α4 chains localised to the cornea and near the retinal amacrine cells. In the kidney, all these proteins except TFAP2 were expressed in the podocytes and distal tubules. TFAP2B and COL4A4 knockout mice also had kidney cysts, and COL4A3 and COL4A4 knockout mice had myopia. CONCLUSION: Individuals with a pathogenic KCTD1 variant may have low myopic astigmatism and represent a further rare genetic cause for a thinned glomerular basement membrane.

Comparison study between pilocarpine and tropicamide drops on corneal topography and their effect on IL-6 and TNF-α levels in tear.

Corneal stability is essential for contact lenses and refractive surgery. It seems that paralyzing eye drops or expansion of the ciliary muscle affect the radius of curvature and the strength of the cornea, and this effect is to increase the strength of the cornea during muscle spasm and decrease it in the relaxed state of the muscle. On the other hand, different factors (such as contact lens wear, ocular surface disorders, trauma, dry eye, and immunosuppression) could alter the immune defense mechanisms of the outer eye and permit microorganisms to invade the cornea. Therefore, the present study compared Pilocarpine and tropicamide drop on corneal topography and their effect on IL-6 and TNF-α levels in tear. This prospective study was performed on sixty normal and healthy eyes of sixty volunteers with a mean age of 38.19 years and without any ocular pathology. Volunteers were divided into two groups of thirty. In the first group, corneal topography of both eyes was measured before and 30 minutes after instillation of topical tropicamide 1% in only one eye. The other eye was the control eye, and no drop was given. The same routine was performed in the second group, except that subject received one drop of Pilocarpine 2% in one eye. Statistical comparison between groups for the central corneal power, corneal radius, and corneal astigmatism was performed using paired t-test. IL-6 and TNF-α levels in tear were analyzed using two Luminex commercial assays with Bio-Plex 200TM System (Bio-Rad, Hercules, California, USA). In group 1, no significant changes were found in corneal radius, power, and astigmatism. However, in group 2 subjects who received pilocarpine eye drops, the mean corneal radius value decreased significantly by 0.05 mm. The mean corneal power increased by +0.32 D. There was no significant difference change in corneal astigmatism in both groups. Evaluation of IL-6 levels in tears showed a significant difference between the control and treatment groups (P = 0.041). But no significant difference was observed between the Pilocarpine and the Tropicamide groups (P = 0.761). Evaluation of TNF-α level in tears also showed no significant difference between these groups (P = 0.088). Pilocarpine induced ciliary muscle contraction, which may cause pressure on the corneal limbus and scleral spur, resulting in changes in corneal curvature. But tropicamide eye drop did not affect corneal radius and other corneal parameters, and corneal topography can be carried out after the installation of tropicamide eye drop.

Un estudio de prevalencia de error de refracción en niños entrecerrados (6-12 años) asistiendo al Hospital Dr. Aso-Eye Shahed / A study of Prevalence of Refractive Error in Squinted children (6-12 years) attending shahed Dr. Aso-Eye Hospital

Determinar la prevalencia del error de refracción (RE) como causa en los ojos en los niños en niños de esta edad (6-12 años) en la ciudad de Sulaimania. El estudio de tasa de prevalencia entre los pacientes que asisten al Shahed Dr. Aso Eye Hospital para el período del 1 de octubre de 2008 al 1 de junio de 2009. Un total de 116 niños (6-12 años) asisten al departamento de entrecerrares durante aproximadamente 8 meses. El estudio incluyó ambos sexos, eran niños de 55 años y niñas 61. Se sometieron a un examen ocular completo. Encontramos que (72) pacientes (62.02 %) tenían un error de refracción, incluyen: 33 pacientes (45.9 %) = hipermetropia (H); 22 pacientes (29.16%) = miopía [m]; 18 pacientes (24.3%) astigmatismo (AST.); 4 mixtos; 6 h-as. y 8 m-as. En conclusiones, la causa más frecuente del entrecerrar de la infancia a este ancho [6-12 años) es el error refractivo, mientras que las otras causas en su conjunto constituyen solo 1/3 de las causas, y el error de refracción más común es la hipermetropía

To determine the prevalence of refractive error (RE) as a cause in squinted in children in this aged (6-12 years) in Sulaimania city. The prevalence rate study among patient attending Shahed Dr. Aso eye hospital for the period from 1st October 2008 - 1st June 2009. A total of 116 children ( 6-12 years) attending squint department for about 8 months. The study included both sexes, were boys 55 and girls 61. Underwent full ocular examination. We found that (72) patients (62.02%) had refractive error, include: 33 patients (45.9 %) = Hypermetropia (H); 22 patients (29.16%) = Myopia [M]; 18 patients (24.3%) Astigmatism (Ast.); 4 mixed; 6 H-Ast. and 8 M-Ast. In conclusions, the most prevalent cause of childhood squint at this aged [6-12 years) is refractive error while the other causes as a whole constitute only 1/3 of the causes, and most common refractive error is hypermetropia

Ten-year longitudinal investigation of astigmatism: The Yamagata Study (Funagata).

Despite numerous investigations into ocular or corneal astigmatism, the dynamic nature of astigmatism remains poorly understood. To reveal potential associations between age and astigmatism, 264 Japanese participants who underwent systemic and ophthalmological examinations in Funagata Town (Yamagata Prefecture, Japan) were evaluated over a 10-year period. Astigmatism was evaluated with regard to the cylinder power, cylinder axis, and vector analyses. Whereas the refractive cylinders showed age-related increases in patients in their 40s to 60s, the corneal cylinders did not change over 10 years. Nevertheless, cylindrical axis of the cornea demonstrated a continuous shift toward against-the-rule (ATR) astigmatism. Vector analyses revealed that the astigmatic shift toward ATR progressed continually after patients reached their 40s, although the shift did not accelerate with age. These novel insights may pave the way for the development of potential strategies for vision correction, including refractive surgeries, and vision-quality maintenance in the elderly.

Mediators of the Effect of Corneal Cross-Linking on Visual Acuity for Fungal Ulcers: A Prespecified Secondary Analysis From the Cross-Linking-Assisted Infection Reduction Trial.

PURPOSE: The purpose of this study was to determine whether astigmatism or corneal scarring is mediating the reduced visual acuity among patients with fungal keratitis randomized to corneal cross-linking (CXL). DESIGN: This was a prespecified exploratory outcome from an outcome-masked, 2 × 2 factorial design, randomized controlled clinical trial. STUDY PARTICIPANTS: Consecutive patients presented with moderate vision loss from a smear-positive fungal ulcer at Aravind Eye Hospital, Madurai, India. INTERVENTION: Study eyes were randomized to one of 4 treatment combinations using an adaptive randomization protocol. The treatment arms included (1) topical natamycin 5% alone, (2) topical natamycin 5% plus CXL, (3) topical amphotericin B 0.15% alone, and (4) topical amphotericin 0.15% plus CXL. Best spectacle-corrected visual acuity (BSCVA), contact lens over-refraction, and scar size and depth as measured by a masked study ophthalmologist using a standardized protocol were recorded at 3 months. Pentacam Scheimpflug imaging was also obtained at 3 months. MAIN OUTCOME MEASURES: BSCVA and contact lens over-refraction, infiltrate and/or scar size and depth, total astigmatism of the front and back of the cornea, total lower-order and higher-order aberrations of the anterior and posterior cornea, and total densitometry of the anterior, central, and posterior stroma were recorded. We performed a mediation analysis looking at the proportion of the effect of CXL on BSCVA that was mediated through scar size, scar depth, astigmatism and density. RESULTS: BSCVA at 3 months was available for 99 of 111 patients (89%) who had a mean of 0.82-LogMAR (SD 0.68). Three-month infiltrate and/or scar size ( P < 0.001), depth ( P < 0.001), and densitometry ( P = 0.001) were statistically significant predictors of 3-month BSCVA. Astigmatism seemed to mediate 23% of the effect of CXL on BSCVA, whereas scar size mediated 23%, scar depth 17%, and densitometry 7%. CONCLUSIONS: Corneal scarring and astigmatism are mediators of worse visual acuity after cross-linking in fungal keratitis. Corneal densitometry may be a helpful cornea-specific variable for clinicians and researchers in determining the effect of corneal scarring on visual acuity in specific patients and as an objective study outcome. TRIAL REGISTRATION: NCT02570321.

Characteristics of astigmatism before and 1 month after blepharoptosis surgery in patients with acquired ptosis.

In this study, we aimed to evaluate the characteristics of astigmatism preoperatively and 1 month postoperatively in patients with age-related ptosis (AP) and contact lens-related ptosis (CLP), and investigate surgery-induced astigmatism (SIA) using the Jaffe vector analysis and the Cravy method. Consecutive patients who underwent blepharoptosis surgery between January 2019 and December 2019 were included. The patients were divided into AP and CLP groups. Computerized corneal topography was used to assess the magnitude and axis of corneal astigmatism. Astigmatism was classified as with-the-rule (WTR), against-the-rule (ATR), or oblique astigmatism (OA) pre- and postoperatively. SIA was calculated by vector analysis using the Cravy and Jaffe methods. The correlation between SIA and margin reflex distance (MRD) was calculated. One hundred and eight eyes from 58 patients (AP group: 85 eyes from 45 patients, CLP group: 23 eyes from 13 patients) were included. The AP group (73.8±7.6 years) was significantly older than the CLP group (47.7±6.6 years). The MRD increased significantly after treatment in both groups. The proportions of WTR, ATR, and OA were 52%, 22%, and 25%, and 86%, 9%, and 4% in the AP and CLP groups, respectively. A shift in astigmatism type was observed in 41% and 13% of patients in the AP and CLP groups, respectively. The average SIA measured using the Cravy method was 0.11±1.22 D in the AP group and -0.28±1.07 D in the CLP group (WTR astigmatism). The SIA calculated using the Jaffe method was 0.78±0.70 D in the AP group and 0.82±0.88 D in the CLP group. There was no significant correlation between SIA calculated using the Cravy and Jaffe methods and MRD. ATR was most common in age-related ptosis and WTR was most common in contact lens-related ptosis. Upper eyelid re-positioning may affect visual functions due to astigmatic changes in the short term postoperatively.

Comparison of corneal irregular astigmatism by the type of corneal regular astigmatism.

We investigated the relation between corneal regular and irregular astigmatism in normal human eyes. In 951 eyes of 951 patients, corneal irregular astigmatism, such as asymmetry and higher-order irregularity components, was calculated using the Fourier harmonic analysis of corneal topography data within the central 3-mm zone of the anterior corneal surface. The eyes were classified by the type of corneal regular astigmatism into four groups; minimum (< 0.75 diopters), with-the-rule (WTR), against-the-rule (ATR), and oblique astigmatism. The mean age was significantly different among the four groups (P < 0.001); patients with WTR astigmatism were the youngest, followed by those with minimum, oblique, and ATR astigmatism. Significant inter-group differences were found among the four groups in asymmetry (P = 0.005) and higher-order irregularity components (P < 0.001); the largest was in eyes with oblique astigmatism, followed by ATR, WTR, and minimum astigmatism. The stepwise multiple regression analysis revealed that corneal regular astigmatism pattern significantly influenced the amount of corneal irregular astigmatism after controlling for confounding factors (P < 0.001). Corneal irregular astigmatism, such as asymmetry and higher order irregularity components, was the largest in eyes with oblique astigmatism, followed by those with ATR, WTR, and minimum astigmatism, even after adjustment for age of subjects.

Distribution and internal correlations of corneal astigmatism in cataract patients.

The aim of the study is to explore the distribution patterns and internal correlations of the morphological parameters of the cornea in patients with age-related cataract. The Pentacam HR was used to measure anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA), total corneal astigmatism (TCA) and keratometric corneal astigmatism (KCA). With age, the proportion of with-the-rule (WTR) ACA decreased from 65.31% to 23.63%, while the against-the-rule (ATR) ACA increased from 26.53% to 56.20%. PCA exceeded 0.50 D in 9.14% of eyes, while 76.35% of them were ATR. The magnitude of ACA was positively correlated with PCA in the whole sample, with a more significant correlation in WTR eyes (sr = 0.349, P < 0.001). The vector summation effect of PCA to ACA changed from compensation to augmentation with aging. In 57.53% of WTR eyes, KCA was overestimated by an average of 0.21 ± 0.17 D, while it was underestimated by 0.38 ± 0.27 D in 87.62% of ATR eyes. In conclusion, among age-related cataract patients, ACA and TCA gradually shifted from WTR to ATR with aging, while most PCA remained as ATR. Ignoring the age-related changes and real PCA might cause overestimation of WTR astigmatism and underestimation of ATR astigmatism.

Prediction of distance visual acuity in presbyopic astigmatic subjects.

This study was aimed to determine the effect of the amount of astigmatism on distance visual acuity, and to provide a prediction formula of visual acuity according to astigmatism, in a presbyopic population. We comprised 318 eyes of 318 consecutive patients (158 phakic and 160 pseudophakic subjects) without any eye diseases, except for refractive errors with astigmatism of 3 diopter or less. We assessed the relationship of the spherical equivalent visual acuity (SEVA) with astigmatism, and also provided a regression formula of visual acuity according to astigmatism in such subjects. We found a significant correlation between the SEVA and the amount of astigmatism (r = 0.715, p < 0.001) in the entire study population. We obtained similar results, not only in phakic eyes (r = 0.718, p < 0.001), but also in pseudophakic eyes (r = 0.717, p < 0.001). The regression formula was expressed as follows: y = 0.017x2 + 0.125x - 0.116 (R2 = 0.544), where y = logMAR SEVA, and x = astigmatism. We also found no significant differences in the SEVA for matched comparison among the with-the-rule (WTR), against-the-rule (ATR), and oblique (OBL) astigmatism subgroups (p = 0.922). These regression formulas may be clinically beneficial not only for estimating the visual prognosis after astigmatic correction, but also for determining the surgical indication of astigmatic correction.

Optical performance of progressive addition lenses (PALs) with astigmatic prescription.

The progressive addition lens (PAL) is a spectacle lens design with progressive refractive power changes across the lens surface to provide sharp vision at different viewing distances for patients with reduced accommodative strength. It has gained in popularity not just for presbyopic patients, but also patients with occupational (office, driving, or digital device) and therapeutic (e.g., myopia control) needs. However, despite the increasing prevalence of astigmatism in adults > 40 years old who rely on PAL correction, no metric is available to reflect the optical variation in PALs with astigmatic prescriptions. Based on recent studies, four novel optical metrics sensitive to variation of refractive power across the lens surface of PALs have been developed. These metrics were used to compare the optical performance of PALs of various prescriptions, designs, and manufacturers. For each lens, the refractive power profile was first measured with a Moire-deflectometry-based instrument.The data was then exported and analyzed using a two-dimensional error map for each of the four metrics. The results revealed significant impacts of astigmatic prescription, providing evidence for the usefulness of these metrics in quantifying the optical performance of PALs for patients with astigmatic prescriptions.

The contribution of ocular residual astigmatism to anterior corneal astigmatism in refractive astigmatism eyes.

To determine the distribution of ocular residual astigmatism (ORA) in astigmatic eyes and the influence on the anterior corneal (ACA) and refractive astigmatism (RA). A total of 165 children met the inclusion criteria. Right eyes' data were analyzed. Using Thibos vector analysis to calculate ORA. Spearman correlation analysis was used to obtain the correlation between the magnitude of ORA, ACA and RA. The median magnitude of ORA in astigmatic eyes was 0.57 D, with interquartile range was 0.42 D. And they were main against-the-rule (57.6-75.8%) and oblique astigmatism (13.9-34.5%) ORA. The ORA in 140 eyes (84.8%) acted as an offset to ACA, meanwhile, 25 eyes (15.2%) superimposed it. About 98% (97.9-98.4%) against-the-rule and 75% (73.9-82.5%) oblique ORA counteracted ACA, nevertheless, all with-the-rule ORA had a superimposed effect on ACA. For with-the-rule ACA, about 86% (85.4-85.9%) ORA worked to offset it. There was statistically correlations between ORA and ACA (r = 0.17, P = 0.03), ORA and RA (r = - 0.27, P = 0.001). The magnitude of ocular residual astigmatism was relatively small in children's astigmatic eyes. Both against-the-rule and oblique ORA can counteract with-the-rule ACA.

Ocular manifestations in classic homocystinuria.

BACKGROUND: Classic homocystinuria (HCU), or cystathionine beta-synthase (CBS) deficiency, is a rare inborn error of methionine metabolism. Main clinical features may include skeletal and vascular manifestations, developmental delay, intellectual disability and eye disorders. MATERIAL AND METHODS: This is an observational and retrospective study aiming at describing eye abnormalities presented by a cohort of late-diagnosed HCU patients. Data regarding ophthalmological evaluation included visual acuity, refraction, biomicroscopy, Perkins tonometry, fundus examination, retinography, biometry, ocular ultrasound, optical coherence tomography, anterior segment photography and topography. RESULTS: Ten patients with HCU (20 eyes) were included. The most frequent findings were ectopia lentis(n = 20) and myopia (n = 9). Biometry, ultrasound, OCT and topography findings were available for four patients. One patient had keratoconus; one had abnormal retinal pigmentation; and two had lens surgery scars with irregular astigmatism. CONCLUSIONS: Eye abnormalities are very frequent in late-diagnosed HCU patients. The presence of ectopia lentis should always raise the diagnostic hypothesis of HCU.

Effects of orthokeratology on biological parameters and visual quality of adolescents with low-grade corneal astigmatism myopia.

OBJECTIVE: To investigate the effects of orthokeratology on biological parameters and visual quality of adolescents with low-grade corneal astigmatism myopia. PATIENTS AND METHODS: In this study, a total of 41 myopic adolescents were prescribed with orthokeratology glasses in our hospital from February 2018 to March 2019 and voluntarily cooperated with relevant examinations before and after wearing orthokeratology lenses. Patients' uncorrected distant visual acuity (UCVA-D), uncorrected near visual acuity (UCVA-N) and naked eye near stereoacuity before wearing glasses, 1 month, and 3 months after wearing glasses were observed. The corneal astigmatism of patients was observed. The corneal endothelial cell density was observed. The dynamic adjustment function (NP, AF, NRA, PRA) values of patients were observed. The comparison of biological indexes in different time periods was observed. The changes of corneal curvature before wearing orthokeratology lens, 1 month and 3 months after wearing orthokeratology lens were observed. RESULTS: There were significant changes of patients 1 month after wearing orthokeratology lenses (p < 0.05), while there was no significant difference between 3 months after wearing the orthokeratology lenses and 1 month after wearing the orthokeratology lenses (p < 0.05). Patients' NCAV-D and UCVA-N were recorded by a conversion method of 5 points. There were differences in the NCVA-D, NCVA-N, naked eye near stereoacuity before, 1 month, and 3 months after wearing glasses (p < 0.05). By observing patients' biological indicators and dynamic adjustment, it was found that there were statistically significant differences in NP, AF, BRA and PRA before wearing the glasses, 1 month and 3 months after wearing the glasses (p < 0.05). CONCLUSIONS: The use of orthokeratology can greatly correct myopia patients' vision, improve their stereoscopic vision, control the progression of myopia, and improve their eye regulation, which is of high safety and great short-term effect.

Analysis of astigmatism outcomes after horizontal rectus muscle surgery in patients with intermittent exotropia.

This study examined the factors affecting corneal curvature change after lateral rectus recession and medial rectus resection surgery in patients with intermittent exotropia. This was a retrospective cross-sectional study in intermittent exotropia patients who underwent rectus resection surgery. The study involved 41 male and 42 female patients (mean age: 9.55 ± 5.03 years, range: 3-28 years). Corneal astigmatism analysis was performed using the Galilei G4 Dual Scheimpflug Analyzer. The values of simulated and ray tracing corneal keratometry (K) of astigmatism, including axis changes, were determined preoperatively and at 1 week and 3 months postoperatively. The factors found to affect corneal curvature change were sex, extent of surgery, and axial length. Simulated and ray tracing changes were significant preoperatively and at 1 week and 3 months after rectus resection surgery (p < 0.05); however, there were no differences in astigmatism (D) at any time. The spherical equivalent had a myopic change after rectus resection surgery with cycloplegic refraction, and in ray tracing mode, flat K was decreased at 1 week from baseline and increased 3 months later. Steep, mean K, and axis increased continuously from baseline to 1 week and 3 months. Astigmatism, in contrast, was increased at 1 week, but decreased at 3 months, with no return to baseline. Univariable linear regression analyses showed that the extent of surgery had an effect on flat K change and that sex had an effect on steep K and axis. Additionally, axial length affected steep K and astigmatism, while age had no effect on any variable. Ray tracing values were significantly different from simulated values. In ray tracing mode, rectus resection surgery may result in astigmatism shifted toward with-the-rule, and myopic changes may be caused by differences in thickness and flexibility of the sclera. Notably, age did not affect any variable.

Short and long term outcomes after small-incision lenticule extraction: A tertiary referral centre experience.

PURPOSE: The objective of this study is to evaluate the preoperative and short- and long-term postoperative results in terms of visual acuity, refractive error, and corneal wavefront aberrations in patients with myopia and myopic astigmatism undergoing small incision lenticule extraction (SMILE). METHODS: Seventy-nine eyes of 52 myopes with or without astigmatism (41 right and 38 left) were enrolled in this retrospective study. The measurements included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SE) and wavefront aberrations. All the measurements before and after SMILE surgery were systematically recorded. RESULTS: Mean preoperative UDVA was 1.19±0.24 logMAR and improved to 0.06±0.17 logMAR at the 3-year postoperative follow-up. At the conclusion of the 3-year follow-up, UDVA was better than or equal to 20/20 and 20/25 in 73% and 84% of eyes, respectively. At 1 month postoperatively, CDVA was 0.05±0.23 logMAR and significantly lower than the preoperative CDVA, 0.02±0.04 log MAR (P>0.05). However, at 1 year and 3 years after surgery, CDVA showed a significant increase compared to preoperative CDVA. At the conclusion of the 3-year follow-up, SE was -0.47 D, and 69.6% and 83.5% of the eyes were within±0.50 D and±1.00 D, respectively, of the intended correction. HOA's, coma, and spherical aberration increased significantly. No significant change in trefoil was detected. CONCLUSION: This study showed that SMILE produces a stable, safe outcome for surgical treatment of myopia and myopic astigmatism.

Scleral lens wear following penetrating keratoplasty: changes in corneal curvature and optics.

PURPOSE: Visual rehabilitation following penetrating keratoplasty is the primary indication for approximately 15% of all scleral lens fittings. Since corneal biomechanics are altered following penetrating keratoplasty, the aim of this study was to quantify changes in anterior corneal optics following short-term scleral lens wear in eyes with corneal grafts. METHODS: Scheimpflug images were obtained before and after a period of scleral lens wear (mean 6.3 ± 1.4 h), from eyes that had previously undergone penetrating keratoplasty (10 eyes of nine participants, mean age 31 ± 9 years). Corneal power and thickness data were examined over the central 6 mm, including regional analyses of the central (0-3 mm) and the mid-peripheral cornea (3-6 mm annulus) using customised software to deterime corneal power vectors M (best fit sphere), J0 (90/180 astigmatism) and J45 (45/135 astigmatism). Anterior corneal aberrations were extracted using corneal elevation data. RESULTS: Corneal power vector J45 increased following lens wear (by 0.22 ± 0.05 D, p = 0.003) across the central 6 mm, while M displayed regional variations following lens wear indicating larger changes further from the corneal centre (p = 0.004). The change in corneal power vector M was also correlated with the magnitude of central corneal swelling (r = 0.65, p = 0.04). The anterior corneal aberration terms of oblique astigmatism, hoirzontal coma, and spherical aberration also varied following lens wear (all p ≤ 0.01). The mean change in the corneal spherocylinder derived from the elevation data following lens wear was +0.14/-0.54 × 44 for a 6 mm corneal diameter. CONCLUSIONS: Clinically significant alterations in anterior corneal topography and higher order aberrations were observed following short-term scleral lens wear in eyes that had undergone penetrating keratoplasty. Spherocylindrical changes were approximately double the magnitude and more oblique in orientation compared to previous reports of healthy eyes. Changes in corneal power vector M may be related to epithelial corneal oedema.