Astigmatism and maternal myopia as important factors affecting success rate of DIMS lens treatment.

OBJECTIVE: To assess the efficacy of myopia control spectacle lenses (defocus incorporated multiple segments/DIMS) in slowing myopia progression among a diverse Central European paediatric population and investigate the contribution of baseline parameters on treatment outcomes. METHODS AND ANALYSIS: This retrospective observational study included 62 individuals aged 4-17 years (mean±SD: 10.21±2.70) with progressing myopia but without ocular pathology with a range of -0.88 to -8.25 D spherical equivalent refraction (SER) (-3.73±1.56), coupled with astigmatism up to -3.25 D cylindrical. All participants were prescribed DIMS (Hoya MiyoSmart) spectacles. Key outcome variables were cycloplegic SER, measured for all participants and axial length (AL), assessed in a subset of patients, recorded at baseline, 6 months and 12 months. Quality of life assessments were conducted at baseline, at 2 weeks, and 3, 6, 9 and 12 months. Additionally, parental myopic dioptre was recorded when applicable. RESULTS: At the 12-month mark, myopia progression in patients (mean±SE: -0.40±0.05) mirrored findings from prior European DIMS studies, but with 50% of patients showing no progression. A multivariate analysis of covariance model revealed that baseline astigmatism and younger age adversely affected therapy outcomes in both SER and AL, while severe maternal myopia led to greater SER progression. In contrast, only young age but not astigmatism was associated with AL increase in a comparable group of children with myopia, part of the LIFE Child Study, wearing single-vision spectacles. Patients reported consistent satisfaction with treatment, with minimal side effects, which diminished over the year. CONCLUSION: In the European population, astigmatism, young age and severe maternal myopia are risk factors for suboptimal outcomes following DIMS therapy. Further research is necessary to elucidate the impact of astigmatism on myopic defocus therapy.

Development of a Machine-Learning-Based Tool for Overnight Orthokeratology Lens Fitting.

Purpose: Orthokeratology (ortho-K) is widely used to control myopia. Overnight ortho-K lens fitting with the selection of appropriate parameters is an important technique for achieving successful reductions in myopic refractive error. In this study, we developed a machine-learning model that could select ortho-K lens parameters at an expert level. Methods: Machine-learning models were established to predict the optimal ortho-K parameters, including toric lens option (toric or non-toric), overall diameter (OAD; 10.5 or 11.0 mm), base curve (BC), return zone depth (RZD), landing zone angle (LZA), and lens sagittal depth (LensSag). The analysis included 547 eyes of 297 Korean adolescents with myopia or astigmatism. The dataset was randomly divided into training (80%, n = 437 eyes) and validation (20%, n = 110 eyes) sets at the patient level. The model was trained based on clinical ortho-K lens fitting performed by highly experienced experts and ophthalmic measurements. Results: The final machine-learning models showed accuracies of 92.7% and 86.4% for predicting the toric lens option and OAD, respectively. The mean absolute errors for the BC, RZD, LZA, and LensSag predictions were 0.052 mm, 2.727 µm, 0.118°, and 5.215 µm, respectively. The machine-learning model outperformed the manufacturer's conventional initial lens selector in predicting BC and RZD. Conclusions: We developed an expert-level machine-learning-based model for determining comprehensive ortho-K lens parameters. We also created a web-based application. Translational Relevance: This model may provide more accurate fitting parameters for lenses than those of conventional calculations, thus reducing the need to rely on trial and error.

Optical Quality and Visual Performance With Different Toric Contact Lens Designs.

OBJECTIVES: To evaluate the optical quality of different toric contact lens (CL) designs and compare their on-eye visual correction performance. METHODS: Twenty soft CL wearers aged 20 to 39 years were enrolled. Two daily disposable silicone-hydrogel toric CLs were tested: the "Eyelid Stabilized Design" (ESD-CL) and prism-ballast design (PB-CL); a spherical daily disposable silicone hydrogel CL (spherical CL) was used as a control. On-eye performance was compared for corrected distance visual acuity (CDVA), astigmatism, and ocular higher-order aberrations (HOAs); astigmatism and ocular HOAs were measured with a wavefront sensor. The subjective quality of vision, rated for "blurred vision" and "double vision," lens rotation, and fitting were also compared. RESULTS: The ESD-CLs, PB-CL, and no-CL provided better CDVA than spherical CL ( P <0.05). Compared with spherical CL and no CL, PB-CL and ESD-CLs caused significantly lesser astigmatism ( P <0.05). Coma was significantly lesser with ESD-CLs than that with PB-CL ( P <0.05); total HOAs did not differ among the four conditions. The subjective ratings for blurred and double vision were significantly lower with ESD-CLs than those with spherical CL ( P <0.05). CONCLUSIONS: Toric CLs provide a better CDVA than spherical CLs. However, differences in coma and subjective symptoms may occur because of the design of toric CLs.

Clinical performance and Willingness To Pay for soft toric contact lenses in low and moderate astigmats.

PURPOSE: To determine clinical performance and the 'Willingness To Pay' for toric vs. spherical soft contact lenses in an astigmatic population. METHODS: In the clinical study, subjects with binocular low to moderate astigmatism (-0.75DC to -1.50DC) wore pairs of soft toric (Biofinity toric) and spherical (Biofinity) contact lenses in random sequence. Visual acuity (high and low contrast, monocular and binocular), subjective comfort and subjective vision were recorded. In the economics study, first subjects who had participated in the clinical study were presented with a series of randomised economic scenarios in order to determine their Willingness To Pay a premium (i.e. an increase) for toric lenses. Then, a similar set of scenarios were presented to a much larger group of online respondents and again, Willingness To Pay was established. RESULTS: For the four measures of visual acuity, the Biofinity toric lens out-performed the Biofinity spherical lens by 0.6 to 1.1 lines.. Subjective vision performance was statistically significantly better with the toric lens for the distance task only. Comfort scores were not significantly different. Similar findings for Willingness To Pay were established for the clinical subjects and for the online respondents. The Willingness To Pay premium (additional fee) for a monthly supply of toric lenses (over spherical lenses) was between £13 and £16, if a toric lens provides better vision and similar comfort, as shown in the clinical study. CONCLUSION: Consumers are willing to pay a monthly premium of around 50% to benefit from the typical experience of better vision and similar comfort for toric vs. spherical lenses. The level of additional cost for toric lenses compared to their spherical equivalents is less than this in the market, so eye care professionals should consider that toric lenses are delivering a greater clinical return than anticipated by wearers for the relatively small increase in price.

Long-term variations and influential factors of the treatment zone of wearing orthokeratology lenses.

PURPOSE: To investigate the variation trend of the treatment zone (TZ) during 12 months of Orthokeratology (Ortho-K) from the perspective of the treatment zone size (TZS), decentration (TZD) and the weighted Zernike defocus coefficient of the treatment zone (Cweighteddefocus). METHODS: 94 patients were included in this retrospective study, who were fitted with a 5-curve vision shaping treatment (VST) lens (n = 44) or a 3-zone corneal refractive therapy (CRT) lens (n = 50). The TZS, TZD and Cweighteddefocus up to 12 months were analyzed. RESULTS: TZS (F(4,372) = 10.167, P＜0.001), TZD (F(4,372) = 8.083, P＜0.001) and Cweighteddefocus (F(4,372) = 7.100, P＜0.001) were significantly increased with time during overnight Ortho-K treatment. The TZS increased sharply from 1 week to 1 month of overnight Ortho-K (F = 25.479, P <.001) and stayed smooth then. It showed growing tendency from 6 to 12 months (F = 8.407, P =.005). The TZD (F = 16.637, P <.001) and Cweighteddefocus (F = 13.401, P <.001) increased significantly until 1 month and kept stable until 12 months (all P＞0.05). The univariant linear regression analysis showed that TZS of the last visit was correlated with baseline myopia (ß = 0.219, P =.034). Also, the greater final Cweighteddefocus was correlated with higher baseline myopia (ß = -0.589, P＜0.001) and higher corneal astigmatism (ß = -0.228, P =.007) at the onset of lens wear with the multiple linear regression. CONCLUSION: The TZS, TZD and Cweighteddefocus kept stable after 1 month of Ortho-K while the TZS had an increasing trend after 6 months. Children with higher myopic eyes or higher corneal astigmatism at baseline tended to have smaller TZS and greater Cweighteddefocus at 12 months.

Factors influencing treatment zone size in orthokeratology.

PURPOSE: The aim of this study was to analyze the influence of corneal topography, contact lens parameters and degree of myopia on the treatment zone (TZ) and peripheral plus ring (PPR) size in orthokeratology. METHODS: In this retrospective study the topographic zones of the right eyes of 106 patients (73 female, 22.16 ± 8.96 years) were analyzed in the tangential difference map of the Oculus Keratograph 5M (Oculus, Wetzlar, Germany). Using the MB-Ruler Pro 5.4 software (MB-Softwaresolutions, Iffezheim, Germany) the horizontal, vertical, longest, shortest diameters and area of the TZ; horizontal, vertical, total diameters and width of the PPR were measured. Correlations were determined between these zones and the subjects' baseline parameters (myopia; corneal diameter, radii, astigmatism, eccentricity, sagittal height; contact lens radii, toricity and total diameter) for three back optic zone diameter (BOZD) groups (5.5, 6.0 and 6.6 mm). A stepwise linear regression analysis was performed to test for TZ and PPR predictability. RESULTS: In the group of BOZD 6.0 correlations were found between the amount of myopia and the short TZ diameter (r = -0.25, p = 0.025); the steep corneal radius and the vertical diameter (r = -0.244, p = 0.029), the longest diameter (r = -0.254, p = 0.023) and the area (r = -0.228, p = 0.042) of the TZ; the amount of astigmatism and PPR width (r = 0.266, p = 0.017); eccentricity of the steep corneal meridian and PPR width (r = -0.222, p = 0.047). BOZD correlated significantly positively with all zones (p < 0.05). The best prediction model (R2 = 0.389) resulted with the TZ area as the outcome variable. CONCLUSION: The amount of myopia, topography and contact lens parameters influence TZ and PPR in orthokeratology. Describing the TZ by its area may provide the most accurate representation of its size.

Orthokeratology in adults and effect on quality of life.

OBJECTIVE: To determine changes in various ocular parameters of adults wearing orthokeratology (ortho-k) lenses and their levels of satisfaction and quality of life (QoL) after commencing treatment. METHODS: Adults aged 18-38 years, with mild to moderate myopia and astigmatism < 1.50D, were wearing ortho-k lenses for one year. Data collection, which included history taking, refraction, axial length (AL), corneal topography, corneal biomechanics, and biomicroscopy examination, was performed at baseline and every 6 months during the study period. The level of satisfaction with the treatment and QoL was determined via questionnaires. RESULTS: Forty-four subjects completed the study. AL was shortened significantly at the 12-month visit: AL -0.03 (-0.45 to 0.13) mm compared to baseline (p < 0.05). A significant number of subjects in both groups presented with overall and central corneal staining, but the majority were mild (Grade 1). Central endothelial cell density was reduced by 40/mm2 (loss rate 1.4 %) (p < 0.05). High scores were obtained in the satisfaction questionnaire, with no significant differences between visits. At the 12-month visit, NEI-RQL-42 total score, dependence on correction, activity limitation, appearance, and satisfaction with the treatment all significantly increased compared to baseline values. CONCLUSIONS: Results suggest that ortho-k can be an effective and safe myopia correction technique for adults with low to moderate myopia, improving daytime vision without serious adverse events. Satisfaction with ortho-k lens wear was high, particularly those who were dependent on vision correction and found spectacles or contact lenses limiting specific activities or cosmetically undesirable.

The effects of base curve aspheric orthokeratology lenses on corneal topography and peripheral refraction: A randomized prospective trial.

BACKGROUND: To investigate the effects of orthokeratology (ortho-k) lenses with aspheric and spherical base curve designs on corneal refractive power (CRP) and peripheral refraction. METHODS: Children aged 8 to 12 years with myopia between -0.75 D to -4.00 D, astigmatism ≤1.00 D, and corneal astigmatism ≤1.50 D were randomly assigned to the base curve aspheric (BCA) and base curve spherical (BCS) ortho-k lens groups. CRP was assessed for the central 8 mm cornea along horizontal and vertical meridians, and peripheral refraction was measured at 10°, 20°, and 30° along the nasal and temporal retina. Primary measurements included relative corneal refractive power change (RCRPC) and relative peripheral refraction change (RPRC). RESULTS: The 3-month results of the 33 and 29 subjects (right eye only) in the BCA and BCS groups, respectively, were obtained. Nonsignificant differences were found in the baseline data between the two groups (p > 0.05). At the 3-month follow-up visit, the mean RCRPC in the BCA group (2.08 ± 0.65 D) was significantly greater than that in the BCS group (1.32 ± 0.81 D) (F1,51 = 25.25, p < 0.001). The BCA group (-1.82 ± 0.65 D) exhibited a larger absolute RPRC than the BCS group (-0.98 ± 0.54 D) (F1,57 = 33.73, p < 0.001). CONCLUSIONS: It was found that the BCA ortho-k lens resulted in a more aspheric treatment zone and a more myopic relative peripheral refraction (RPR) along the horizontal meridian. The more myopic RPR was contributed by a more hyperopic central refraction and a more myopic peripheral refraction in the BCA group.

Clinical Outcomes of a Randomized Trial with Contact Lenses for Astigmatic Myopia Management.

SIGNIFICANCE: There are limited treatment options for myopia management of patients with moderate to high astigmatism. This work directly compares toric orthokeratology and soft toric multifocal lenses to show differences in visual acuity and patient satisfaction that could impact clinical care. Toric orthokeratology caused reduced visual acuity but was preferred subjectively for vision and overall. PURPOSE: This study aimed to quantify objective and subjective clinical differences between toric orthokeratology and soft toric multifocal contact lenses in the same cohort of myopic wearers with moderate to high astigmatism. METHODS: Thirty adults with refractive myopia (plano to -5.00 D) and astigmatism (1.25 to 3.50 D) were fitted empirically with both toric orthokeratology and soft toric multifocal contact lenses. Participants wore lenses for 10 days in random order, separated by a 14-day washout period. High-contrast visual acuity, low-contrast visual acuity, and glare logMAR visual acuity were measured. Surveys ascertained subject preference for comfort, vision, handling, and cost. Friedman, Wilcoxon signed rank, and χ2 tests were performed. RESULTS: A subset of participants (n = 17) who achieved good vision with both lens types was analyzed. High-contrast and glare acuity with toric orthokeratology were reduced by one line compared with soft toric multifocal lenses (both 0.00 vs. -0.10, P ≤ .003). Participants preferred toric orthokeratology for vision ( P ≤ .03) but soft toric multifocal lenses for handling ( P ≤ .006). When forced to choose between lens types, participants preferred toric orthokeratology for vision and overall (both P ≤ .007). CONCLUSIONS: Participants who achieved good vision with both lens types preferred toric orthokeratology over soft toric multifocal lenses, despite reduced high-contrast and glare visual acuity. Further research is needed to understand the relationship between visual performance and patient satisfaction.

Peripheral Refraction With Toric Orthokeratology and Soft Toric Multifocal Contact Lenses in Myopic Astigmatic Eyes.

Purpose: There has been little research on myopia management options for patients with astigmatism. This study quantified changes in peripheral refraction induced by toric orthokeratology (TOK) and soft toric multifocal (STM) contact lenses. Methods: Thirty adults with refractive error of plano to -5.00 D (sphere) and -1.25 to -3.50 D (cylinder) were enrolled. Cycloplegic autorefraction was measured centrally, ±20 degrees, and ±30 degrees from the line of sight nasally (N) and temporally (T) on the retina. Measurements were made at baseline, after 10 ± 2 days of TOK wear (without lenses on eye), and after 10 ± 2 days of STM wear (with lenses on the eyes) and compared with repeated-measures analysis of variance. Results: Compared to baseline, TOK induced a myopic shift in defocus (M) at all locations (all P < 0.01), but STM only induced a myopic shift at 20 T in both eyes and 30 N/T in the left eye (all P < 0.01). TOK resulted in more myopic defocus than STM at all locations (all P < 0.05) except 20 T in the left eye. TOK induced more J0 astigmatism at all locations (all P < 0.02), except 20 N in the right eye; J0 with STM was different than baseline at 20 N in both eyes and 30 N in the right eye (all P < 0.02). TOK induced more J0 astigmatism than STM at all locations (all P < 0.01), except 20 T in the left eye. Differences in J45 astigmatism, when significant, were clinically small. Conclusions: Greater amounts of peripheral myopic defocus and J0 astigmatism were induced by TOK compared to STM, which may influence efficacy for myopia management.

Refractive status, biometric components, and functional outcomes of patients with threshold retinopathy of prematurity: systemic review and a 17-year longitudinal study.

OBJECTIVE: To assess the long-term refractive status, visual outcome, astigmatism, and the change in biometric optic components in older adolescents up to age 17 years with threshold retinopathy of prematurity (ROP) treated with diode laser. METHODS: A retrospective, longitudinal study in which cycloplegic refraction, keratometry, and the biometric measurement of optic components were performed on 28 consecutive preterm eyes with laser-treated threshold ROP at age 17 years. The study results were statistically analysed and compared with age-matched full-term control. RESULTS: All patients with ROP had myopia (average spherical equivalent of - 6.35 D, ranges from - 1.25 to - 12.38 D), and 12 eyes (43%) were highly myopic (spherical equivalent < - 6.0 D). Threshold ROP eyes exhibited a significantly poorer visual acuity (P < 0.001), greater cylinder refractive error (P < 0.001), higher corneal astigmatism (P < 0.001), and flatter horizontal corneal curvature (P = 0.01) compared with age-matched controls. Biometric optic components analysis revealed a significant shallower anterior chamber depth (P < 0.001), thicker lens (P < 0.001), and shorter axial length (P = 0.021) in laser-treated ROP eyes compared with age-matched controls. CONCLUSIONS: In this 17-year longitudinal study, a higher prevalence of myopia and astigmatism was observed in laser-treated threshold ROP eyes compared with age-matched control eyes. Myopia and astigmatism in laser-treated ROP eyes typically progress through adolescence after school age. Therefore, we recommend that preterm patients with laser-treated threshold ROP should attend regular follow-up not only for refractive status but also for structural change of anterior segment until their adolescence.

Fixation instability, astigmatism, and lack of stereopsis as factors impeding recovery of binocular balance in amblyopia following binocular therapy.

Dichoptic therapy is a promising method for improving vision in pediatric and adult patients with amblyopia. However, a systematic understanding about changes in specific visual functions and substantial variation of effect among patients is lacking. Utilizing a novel stereoscopic augmented-reality based training program, 24 pediatric and 18 adult patients were trained for 20 h along a three-month time course with a one-month post-training follow-up for pediatric patients. Changes in stereopsis, distance and near visual acuity, and contrast sensitivity for amblyopic and fellow eyes were measured, and interocular differences were analyzed. To reveal what contributes to successful dichoptic therapy, ANCOVA models were used to analyze progress, considering clinical baseline parameters as covariates that are potential requirements for amblyopic recovery. Significant and lasting improvements have been achieved in stereoacuity, interocular near visual acuity, and interocular contrast sensitivity. Importantly, astigmatism, fixation instability, and lack of stereopsis were major limiting factors for visual acuity, stereoacuity, and contrast sensitivity recovery, respectively. The results demonstrate the feasibility of treatment-efficacy prediction in certain aspects of dichoptic amblyopia therapy. Furthermore, our findings may aid in developing personalized therapeutic protocols, capable of considering individual clinical status, to help clinicians in tailoring therapy to patient profiles for better outcome.

Visual acuity increase in meridional amblyopia by exercises with moving gratings as compared to stationary gratings.

The aim of the present work was to investigate the effect of a novel therapy based on pleoptic exercises combined with standard occlusion in patients with meridional amblyopia. The exercising system itself, termed focal ambient visual acuity stimulation (FAVAS), consists of sinusoidally modulated circular gratings, which were implemented as a background pattern in computer games binding the children's attention. For the assessment of therapeutic effects, we tested for the development of best-corrected visual acuity (BCVA) in patients trained with a gaming field background of moving gratings (Moving) compared to patients treated with stationary gratings (Stationary). Patients with amblyopia (caused by strabismus, refraction, or both) and astigmatism were randomly allocated to two groups, all of whom received a standard occlusion regimen. In combination with occlusion, using a crossover design, the first group (Moving-Stationary group) was alternately exercised for 10 days with a series of Moving followed by 10 days with Stationary and the second group (Stationary-Moving group) vice versa. The treatment-dependent training effect on BCVA was measured with respect to the alignment of the least vs. the most ametropic meridian in both groups. BCVA was examined using a meridionally direction-sensitive visual test inventory, and we estimated the monocular BCVA in all patients along four meridians: 0°, 45°, 90°, and 135° before and after Moving as compared to Stationary treatments. The Moving-Stationary group consisted of 17 children (34 eyes) aged 10 to 13 (average 11.6 ± 0.3) years. The Stationary-Moving group consisted of 20 children (40 eyes) aged 9 to 14 (average 12.5 ± 0.4). In both groups, visual acuity increased significantly only with Moving combined with occlusion. Thereby, the visual acuity (logMAR) along different meridians showed a statistically significant improvement induced by Moving if testing was coincident with alignment of the directional optical characters close to the most ametropic meridian in the Moving-Stationary group (0.73 ± 0.32 to 0.41 ± 0.22, p < 0.01) and also in the Stationary-Moving group (0.48 ± 0.27 to 0.33 ± 0.18, p < 0.01). Significant improvement was also induced by Moving if tested in alignment with the perpendicular orientation close to the least ametropic meridian, although with a smaller amount, in the Moving-Stationary group (0.49 ± 0.23 to 0.37 ± 0.21, p < 0.01) as well as in the Stationary-Moving group (0.33 ± 0.18 to 0.28 ± 0.16, p < 0.01). After Stationary combined with occlusion, however, there was no statistically significant improvement, regardless of the meridian. Visual training of patients with meridional amblyopia by a series of online exercises using attention-binding computer games which contained moving gratings as a background stimulus (Moving) resulted in a statistically significant improvement in visual acuity in the most refractive meridian, and to a lesser extent, in the least refractive meridian. No statistically significant improvement was achieved after the respective exercising series in the sham condition with stationary gratings (Stationary).

Is soft toric contact lenses fitting a feasible option to improve optical quality and visual performance in corneal ectasia?

OBJECTIVES: To assess the feasibility of fitting soft toric contact lenses (STCL) in corneal ectasias and their impact on optical quality and visual performance. METHODS: A total of 22 eyes were fitted with a molded STCL: 11 eyes/9 subjects with corneal ectasia and 11 healthy eyes/11 subjects. Wavefront aberrations were analyzed using a Hartmann-Shack aberrometer. Visual performance was measured under photopic (85 cd/m 2) and mesopic (≤3 cd/m 2) conditions. High-(96 %) and low- (10 %) contrast VA (HCVA and LCVA respectively) were assessed using the ETDRS charts and contrast sensitivity (CS) using the Pelli-Robson chart. RESULTS: After STCL fitting in the ectatic corneas, oblique astigmatism increased 0.15±0.17 µm and 0.34 ± 0.36 µm for 3 mm- and mesopic pupil diameters, respectively. Mean defocus decreased 1.41 ± 0.36 µm and 2.17 ± 0.85 µm for the same pupil diameters. More positive values of vertical coma were found with a change of 0.05 ± 0.06 µm and 0.12 ± 0.10 µm for 3 mm and mesopic pupil diameters, respectively. Comparing changes between both groups, with a 3 mm pupil aperture, statistically significant differences (p < 0.05) were detected in oblique astigmatism, defocus, vertical secondary trefoil and horizontal secondary coma. In the group with corneal ectasia, photopic HCVA and LCVA improved 0.09 ± 0.11 logMAR and 0.12 ± 0.15 logMAR respectively. In mesopic conditions, HCVA, LCVA and CS improved 0.11 ± 0.12 logMAR, 0.18 ± 0.15 logMAR and 0.11 ± 0.07 log. units, respectively. CONCLUSIONS: The analyzed molded soft toric contact lens is a feasible option for good vision in corneal ectasia with moderate irregularity and negative vertical coma.

Glasses Versus Observation for Moderate Bilateral Astigmatism in 1- to <7-Year-Olds.

PURPOSE: To compare visual outcomes in children with moderate bilateral astigmatism treated with glasses with those who were merely observed. DESIGN: Retrospective case series. METHODS: The medical records of all children 1 to <7 years of age who were diagnosed with moderate bilateral astigmatism (+1.25 to +3.25 diopters [D]) at a single institution over a 12-year period were retrospectively reviewed. Children with anisometropia ≥1.00 D, hyperopia ≥+3.00 D, myopia ≥-3.00D, amblyopia, or strabismus at diagnosis were excluded. Observation or full spectacle correction of astigmatism was at the provider's discretion. Kaplan-Meier rates of developing amblyopia and strabismus were assessed over a minimum follow-up of 18 months. RESULTS: Eighty-five (6.9%) of 1235 subjects met the inclusion criteria; 58 (68.2%) were prescribed glasses while 27 (31.8%) were observed. The groups differed by mean age at diagnosis (3.56 ± 1.42 years for observed vs 4.31 ± 1.36 years for glasses [P = .03]) and mean amount of astigmatism (1.73 ± 0.43 D for observed vs 2.00 ± 0.51 D for glasses [P = .02]). By 4 years of follow-up, the Kaplan-Meier rate of developing amblyopia was 8.3% (95% confidence interval [CI] 0%-19.4%) in the observed group and 10.3% (95% CI 1.5%-19.1%) in the glasses group [P = .74] while strabismus was 7.1% (95% CI 0%-20.6%) among those observed and 7.1% (95% CI 0.4%-13.8%) of those prescribed glasses [P = .60]. CONCLUSIONS: Rates of amblyopia and strabismus were similar and modest in this cohort of children with moderate bilateral astigmatism treated with glasses vs observation. These results suggest that prescribing glasses for these children may be no better than observation in preventing the development of amblyopia or strabismus.

Sensorless astigmatism correction using a variable cross-cylinder for high lateral resolution optical coherence tomography in a human retina.

High lateral resolution (∼5µm) optical coherence tomography (OCT) that employs a variable cross-cylinder (VCC) to compensate for astigmatism is presented for visualizing minute structures of the human retina. The VCC and its sensorless optimization process enable ocular astigmatism correction of up to -5.0 diopter within a few seconds. VCC correction has been proven to increase the signal-to-noise ratio and lateral resolution using a model eye. This process is also validated using the human eye by visualizing the capillary network and human cone mosaic. The proposed method is applicable to existing OCT, making high lateral resolution OCT practical in clinical settings.

Small incision lenticule extraction (SMILE) combined with allogeneic intrastromal lenticule inlay for hyperopia with astigmatism.

PURPOSE: To quantitatively evaluate outcomes after small incision lenticule extraction (SMILE) combined with allogeneic intrastromal lenticule inlay for hyperopia with astigmatism. METHODS: It's a retrospective cohort study. Twenty-four eyes of 15 patients with more than 0.75 diopters (D) of astigmatism in hyperopic eyes were enrolled in this study. The hyperopic eye with astigmatism was first treated with SMILE to correct astigmatism; then a lenticule was extracted from a donor myopic eye and subsequently implanted into the hyperopic eye with astigmatism. Patients were examined preoperatively and 1 day, 1 week, 1,3 months and 1 year after surgery. The main outcome measures were the uncorrected and corrected distance visual acuity (UDVA and CDVA), uncorrected near visual acuity (UNVA), spherical equivalent (SE), corneal topography, anterior segment optical coherence topography (OCT) and ocular response analyzer (ORA) parameters: corneal hysteresis (CH) and corneal resistance factor (CRF). Repeated-measures analyses of variance (ANOVA) and post hoc tests were used to analyze data of different follow-up visits. RESULTS: The mean preoperative cylinder was 1.95±1.04(D). The UDVA (from 0.37±0.23 to 0.09±0.09), UNVA (from 0.49±0.21 to 0.08±0.06), SE (from +7.42±3.12 to -0.75±0.79) and astigmatism (+1.95±1.04 to -0.65±0.63) postoperatively were obviously better than those before surgery. Five eyes (26.3%) gained one line of CDVA, and 3 eyes (15.8%) gained two lines of CDVA one year after surgery compared with preoperative levels. The average corneal curvature was changed from (43.19±4.37) D to (49.19±3.87) D one year after surgery. The anterior segment OCT images of corneas with lenticule inlays at each follow-up visit showed that the implanted lenticule was shaped like a crescent in the corneal stroma. The CH and CRF didn't change significantly after surgery (p = 0.189 and p = 0.107respectively). CONCLUSIONS: SMILE combined with intrastromal lenticule inlay can be used to correct high hyperopia with astigmatism with good safety, efficacy and reproducibility.

Greater higher order aberrations induced by toric orthokeratology versus soft toric multifocal contact lens wear.

PURPOSE: Spherical orthokeratology and soft multifocal contact lenses are commonly used for myopia control and correction, but have been shown to increase spherical aberration, coma and total higher order root mean square (HORMS) aberrations. There are limited myopia control contact lens options for patients with moderate to high astigmatism. The purpose of this study was to quantify changes in higher order aberrations (HOA) in myopic astigmatic eyes fitted with toric orthokeratology (TOK) and soft toric multifocal (STM) contact lenses. METHODS: Ocular wavefront aberrations were measured in both eyes of 30 adult subjects and are reported through the 6th radial order over a 5 mm, dilated pupil. All eyes met refractive criteria of myopia (-5.00 D to plano) and cylinder (-3.50 to -1.25 D). Three measurements were taken at baseline and after 10 ± 2 days of lens wear (TOK, STM). Sixteen subjects achieved logMAR high contrast visual acuity of 0.30 or better in both eyes and were included in this analysis. Repeated measures analysis of variance and post-hoc paired t-tests were used, as appropriate, with Benjamini-Hochberg correction. RESULTS: Higher order root mean square, spherical aberration (C12), and coma RMS (C7, C8) increased with TOK (0.641 [0.222], 0.409 [0.157], 0.426 [0.187] µm, respectively) and STM (0.481 [0.107], 0.223 [0.139], 0.320 [0.130] µm, respectively) from baseline (all p < 0.001). TOK was elevated compared to STM for HORMS (p = 0.03), spherical aberration (p = 0.001) and coma RMS (p = 0.04). CONCLUSIONS: Toric orthokeratology induced more HORMS, spherical aberration and coma RMS than STM in myopic astigmats; however, both lens types showed an increase in HOA compared to baseline, which placed patients outside the age and pupil size matched normative ranges. While the optical changes that accompany these modalities are helpful for myopia management, the induction of HOAs may have unintended consequences on visual performance.

The Association between Fourier Parameters and Clinical Parameters in Myopic Children Undergoing Orthokeratology.

Purpose: To explore how Fourier parameters are associated with axial length growth (ALG) and clinical parameters in children who underwent orthokeratology.Materials and Methods: A total of 267 children received orthokeratology. Baseline cycloplegic autorefraction was performed. Axial length was measured at baseline and one year after the lens dispatch, and the difference was defined as ALG. Corneal topography was performed at the same two visits. Central treatment zone (CTZ) was identified from the difference between the two tangential maps, and its center distance to corneal center was defined as decentration. A relative refractive corneal power (RCRP) map was derived by subtracting the center value from every point on the one-year axial map. It was decomposed into 3 Fourier components: a mean (F0), a single-cycle sinewave (F1), and a double-cycle sinewave (F2). Linear regressions were used to reveal the association between ALG and these parameters.Results: At baseline, the age was 10.18 ± 1.48 year, spherical equivalent (SE) was - 3.10 ± 1.15D, astigmatism was 1.17 ± 0.58D, and axial length was 24.69 ± 0.81 mm. The mean ALG was 0.181 ± 0.22 mm. In multiple regression, ALG was negatively associated with F1 (p < .001), not F0 and F2. Amplitude-wise, F0 and F1 were correlated with decentration (p < .01) and SE (p < .01), and F2 was associated with astigmatism (p < .001). Direction-wise, F1 was correlated with decentration (p < .001) and F2 was associated with astigmatism (p < .001).Conclusions: Among Fourier parameters, F0 and F1 were negatively associated with ALG in myopic children undergoing orthokeratology. Their associations to SE and CTZ decentration may partially explain the effect on ALG retardation.

Objective evaluation of static and dynamic behavior of different toric silicone-hydrogel contact lenses.

PURPOSE: The present study aimed to estimate how orientation position, recovery time, and contact lens decentration, associated with visual performance, may vary on several designs of the most recent toric silicone-hydrogel toric contact lenses in two-time different moments. METHODS: To evaluate the toric silicone-hydrogel toric contact lens position and stability, it was conducted with a prospective, observational, randomized, and single-center case series including 95 astigmatic eyes wearing four toric silicone-hydrogel toric contact lenses for two weeks. Orientation and decentration were analyzed with ImageJ software from video-frames extracted with a Python application. Recovery time was evaluated after 45 degrees of inferior-temporal misorientation. RESULTS: Evaluation of misorientation after 20 min of wear revealed the highest amount for Saphir RX, -20.41 ± 10.84 deg, and lowest for Air Optix Aqua for Astigmatism, -1.43 ± 7.48 deg. The highest horizontal misalignment was found for Air Optix Aqua for Astigmatism, -0.627 ± 0.330 mm, and lowest for Biofinity Toric, 0.004 ± 0.270 mm. Vertical misalignment presented the highest value for Acuvue Vita for Astigmatism, -0.652 ± 0.369 mm, and lowest for Air Optix Aqua for Astigmatism, -0.126 ± 0.231 mm. Recovery time showed the highest amount for Saphir RX, 80.70 ± 33.26 s, and lowest for Biofinity Toric 43.67 ± 23.70 s. Only Air Optix Aqua for Astigmatism presented significant differences after two-week of wear for misorientation (P = 0.02) and horizontal misalignment (P < 0.001). When pairwise comparisons are made between toric silicone-hydrogel toric contact lenses, significant differences (P < 0.001) are found. CONCLUSIONS: Although there was acceptable fitting, based upon decentration, orientation, and recovery with the study contact lenses, the stabilization and profile design used in the Air Optix Aqua for Astigmatism helped to minimize rotation and vertical misalignment. In addition, the peri-ballast and thickness profile of the Biofinity Toric improved rotational recovery and horizontal misalignment compared to the other contact lenses. Finally, lenses with a better fitting profile showed better visual performance.