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International Journal of Ophthalmology 2023To assess the effect of experimentally induced anisometropia on binocularity in normal adults with glasses-free three-dimensional (3D) technique.
AIM
To assess the effect of experimentally induced anisometropia on binocularity in normal adults with glasses-free three-dimensional (3D) technique.
METHODS
Totally 54 healthy medical students with normal binocularity in the cross-sectional study were enrolled. Anisometropia was induced by placing trail lenses over the right eye, in 0.5 D steps including lenses of -0.5, -1, -1.5, -2, -2.5 D (hyperopic anisometropia) and lenses of +0.5, +1, +1.5, +2, +2.5 D (myopic anisometropia). The glasses-free 3D technique was used to evaluated not only fine stereopsis, but also coarse stereopsis, dynamic stereopsis, foveal suppression, and peripheral suppression in these subjects. One-way analysis of variance was used to compare quantitative data such as fine stereopsis, coarse stereopsis. Pearson's Chi-square test was performed to compare categorical data such as dynamic stereopsis, foveal suppression and peripheral suppression.
RESULTS
The subjects showed a statistically significant decline in fine stereopsis, coarse stereopsis, and dynamic stereopsis with increasing levels of anisometropia (<0.001). Binocularity was affected when induced anisometropia was more than 1 D (<0.05). Foveal suppression and peripheral suppression were evident and increased in proportion to anisometropia (<0.001).
CONCLUSION
The relatively low degrees of anisometropia may have a potentially significant effect on high-grade binocular interaction. The mechanisms underlying the defect of binocularity seem to involve not only foveal suppression, but also peripheral suppression.
PubMed: 37077487
DOI: 10.18240/ijo.2023.04.14 -
Sisli Etfal Hastanesi Tip Bulteni 2021The purpose of the study was to evaluate the effect of different treatment modalities on refractive outcomes in patients treated with severe retinopathy of prematurity...
OBJECTIVES
The purpose of the study was to evaluate the effect of different treatment modalities on refractive outcomes in patients treated with severe retinopathy of prematurity (ROP).
METHODS
The records of children who were treated for severe ROP in our clinic between January 2015 and August 2018 were retrospectively reviewed. The children who were treated were analyzed in three subgroups as intravitreal bevacizumab (IVB), laser photocoagulation (LPC), and IVB + LPC. Spherical equivalent (SEQ), spherical and cylindrical power measurements of the cases were recorded in diopters (D). SE ≤-0.25D was accepted as myopia and SE of more than 1 D between two eyes was accepted as anisometropia.
RESULTS
A total of 160 eyes of 80 participants were eligible for inclusion: 38 eyes in the IVB group, 24 eyes in the LPC group, 16 eyes in the IVB + LPC group, 44 eyes in the spontaneously regressed group, and 38 eyes in the full-term children. Although the mean spherical power and SEQ in the IVB group were lower than in the LPC group (p=0.019 and 0.013, respectively), there was no significant difference between the IVB group and the IVB + LPC group (p=0.541 and 0.804, respectively). In terms of mean cylindrical power and prevalence of myopia and anisometropia, there was no significant difference between the treatment groups (p>0.05).
CONCLUSION
Although spherical power and SEQ can change according to the ROP treatment management, there is no difference in terms of the cylindrical power, prevalence of myopia, and anisometropia. The most important risk factor for myopia and anisometropia in premature children may be ROP severity and retinal immaturity.
PubMed: 35317380
DOI: 10.14744/SEMB.2021.34966 -
BMC Ophthalmology Jun 2023To compare the degree of myopia between the dominant and non-dominant eyes in teenagers with intermittent exotropia (IXT) in China. (Comparative Study)
Comparative Study
PURPOSE
To compare the degree of myopia between the dominant and non-dominant eyes in teenagers with intermittent exotropia (IXT) in China.
METHODS
A total of 199 IXT patients with myopia were included in this retrospective study and were divided into two groups according to the difference between near and distance exodeviation: basic IXT and convergence insufficiency (CI) IXT. Refractive errors were analyzed by spherical equivalent (SE) values. Patients were further stratified into anisometropia group and non-anisometropia group based on binocular SE values difference greater than 1.0D or not.
RESULTS
There were 127 patients in the CI IXT group, with a near deviation of 46.94 ± 20.53 prism diopters (PD) and a distance deviation of 28.36 ± 14.34 PD, and there were 72 (36.2%) patients in the basic IXT group, with a near deviation of 37.68 ± 22.21 PD and a distance deviation angle of 33.21 ± 23.96 PD. The near exodeviation was significantly larger in the CI group than in the basic IXT group(P < 0.001). In the CI IXT group, the mean SE was - 2.09 ± 1.45 diopters (D) in the dominant eye and - 2.53 ± 1.44D in the non-dominant eye, while in the basic IXT group, the mean SE was - 2.46 ± 1.56D in the dominant eye and - 2.89 ± 1.37D in the non-dominant eye. The anisometropia group included 43 patients, while non-anisometropia group included 156 patients. The near and distance exodeviation in the anisometropia group were 45.26 ± 24.41 PD and 33.53 ± 23.31 PD, respectively, and those in the non-anisometropia group were 43.42 ± 20.69 PD and 29.07 ± 16.84 PD, respectively. There were no significant differences in near and distance deviation (P = 0.78 and P = 0.73 respectively) between the two groups. The SE of the dominant eye was less myopic than of the non-dominant eyes in both the CI and anisometropia groups (P = 0.002 and P < 0.001, respectively).
CONCLUSIONS
Our study revealed that convergence insufficiency IXT is more common than the basic type in pediatric myopic population and is characterized by higher inter-eye differences of myopia. The dominant eye was found to be less myopic in IXT patients, particularly in those with convergence insufficiency and anisometropia.
Topics: Adolescent; Child; Humans; Anisometropia; China; Chronic Disease; Exotropia; Myopia; Ocular Motility Disorders; Retrospective Studies
PubMed: 37365512
DOI: 10.1186/s12886-023-03043-8 -
Frontiers in Medicine 2022This research aims to study the corneal morphological changes in adult patients with myopic anisometropia after small incision lenticule extraction (SMILE) and the...
PURPOSE
This research aims to study the corneal morphological changes in adult patients with myopic anisometropia after small incision lenticule extraction (SMILE) and the safety, efficacy, and predictability of clinical outcomes.
METHODS
This was a prospective cohort study. Patients with myopic anisometropia [refractive difference >2.0 diopters (D)] were included in this study who underwent SMILE at our hospital from September 2019 to March 2021. For the two eyes of each patient, the one with higher myopia was defined as group A, and the fellow eye was group B. The follow-up time points were set as 1 week, 1 month, 3 months, and 6 months after the surgery. The data collected were uncorrected and best-corrected distance visual acuity (UDVA and CDVA), spherical equivalent (SE), efficacy and safety indexes, posterior corneal elevation (PCE), anterior and posterior corneal radius of curvature in the 3 mm area at the center of the thinnest point of the cornea (ARC and PRC), and higher-order aberrations (HOAs).
RESULTS
The study included 36 patients (72 eyes), and the mean age was 25.2 ± 6.4 years. The preoperative SEs were -6.45 ± 1.25 D in group A and -3.76 ± 1.29 D in group B. Six months after surgery, the SEs in groups A and B were -0.09 ± 0.50 D and 0.07 ± 0.47 ( = 0.059), respectively. The efficacy indexes were 1.06 ± 0.16 in group A and 1.07 ± 0.14 in group B ( = 0.750). The safety indexes were 1.08 ± 0.14 in group A and 1.12 ± 0.15 in group B ( = 0.173). The PCE was significantly reduced at 6 months after surgery in pagebreak both groups ( < 0.05). The ARC was significantly higher than before the surgery ( < 0.05) in the two groups. The two groups showed significant increases in total HOAs, coma 90°, and spherical aberrations ( < 0.05).
CONCLUSION
SMILE is predictable, effective, and safe in correcting myopic anisometropia. The postoperative changes in HOAs are characteristic.
PubMed: 36091674
DOI: 10.3389/fmed.2022.977586 -
Ophthalmic Research 2021Amblyopia is an important public health problem and standard screening is quite necessary for early diagnosis and treatment especially for the remote areas. As the place...
INTRODUCTION
Amblyopia is an important public health problem and standard screening is quite necessary for early diagnosis and treatment especially for the remote areas. As the place of the largest Tibetan population, the Tibetan Plateau has special geographical characteristics such as high altitude, time zone, and ethnic composition, where very little information is available about the prevalence of amblyopia and other ocular diseases. The article aims to determine the prevalence of amblyopia and associated factors in grade 1 Tibetan children, living in Lhasa, Tibet Autonomous Region.
METHODS
A cross-sectional study was conducted. All the participants were scheduled for comprehensive eye examinations including visual acuity testing, ocular deviation and movement evaluation, cycloplegic refraction and examinations of the external eye, anterior segment, media, and fundus. Amblyopia was assessed in the children according to the standard definition.
RESULTS
A total of 1,856 students participated in the examinations (97.58% response rate). 1,852 students completed all the related examinations, and 34 of them were diagnosed as amblyopia with the prevalence of 1.84% (95% confidence interval [CI]: 1.22-2.45%). Unilateral amblyopia was diagnosed in 23 students (1.24%, 95% CI: 0.74-1.75%), including 16 anisometropic, 4 strabismic, 1 visual deprivational, and 2 mixed. Other 11 students were diagnosed as bilateral amblyopia (0.59%, 95% CI: 0.24-0.94%), including 9 ametropic, 1 deprivational, and 1 with nystagmus. The mean cylinder refraction and absolute value of the spherical equivalent refraction of amblyopic eyes was respectively -2.15 ± 1.52 D and 2.70 ± 2.33 D. Amblyopia was significantly associated with hyperopia (≥+2.00 D, odds ratio [OR] 8.22, 95% CI 3.42-19.72), astigmatism (≤-2.00 D, OR 6.76, 95% CI 2.56-17.85), and anisometropia (≥+0.50 to <+1.00 D, OR 3.95, 95% CI 1.44-10.79; ≥+1.00 D, OR 21.90, 95% CI 8.24-58.18).
CONCLUSIONS
The prevalence of amblyopia in grade 1 students of Lhasa is relatively higher than that of many other ethnic populations in China previously reported. Refractive errors including anisometropia, hyperopia, and astigmatism are the major risk factors of amblyopia.
Topics: Amblyopia; Child; Child, Preschool; China; Cross-Sectional Studies; Ethnicity; Female; Humans; Male; Prevalence; Refraction, Ocular; Retrospective Studies; Risk Factors; Schools; Tibet; Visual Acuity
PubMed: 33279900
DOI: 10.1159/000511264 -
Journal of Refractive Surgery... May 2022To report 6-month visual and refractive outcomes following PRESBYOND Laser Blended Vision (Carl Zeiss Meditec) treatment using non-linear aspheric micro-anisometropia...
PURPOSE
To report 6-month visual and refractive outcomes following PRESBYOND Laser Blended Vision (Carl Zeiss Meditec) treatment using non-linear aspheric micro-anisometropia laser in situ keratomileusis (LASIK) for the correction of myopic and hyperopic presbyopia.
METHODS
A retrospective, non-comparative study of 139 consecutive patients with a mean age of 53.13 ± 5.84 years (range: 42 to 70 years) treated with LASIK-induced micro-anisometropia using the MEL 90 excimer laser and VisuMax femtosecond laser (both Carl Zeiss Meditec). The target refraction was plano for distance eyes (dominant eye) and between -0.50 and -1.50 diopters (D) for near eyes. Patients were observed for 6 months.
RESULTS
A total of 278 eyes (78 myopic and 200 hyperopic) from 139 patients completed the study. Mean preoperative spherical equivalent (SE) was -3.40 ± 1.83 D (range: -0.50 to -8.25 D) for myopic eyes and +1.61 ± 0.98 D (range: -1.25 to +4.63 D) for hyperopic eyes. Mean postoperative SE refraction of distance eyes was +0.20 ± 0.35 D (range: -0.38 to +1.00 D) and -0.14 ± 0.42 D (range: -1.38 to +0.88 D) for myopic and hyperopic eyes, respectively. Mean postoperative SE refraction of near eyes was -0.90 ± 0.44 D (range: -0.13 to -2.25 D) and -1.21 ± 0.48 D (range: -0.13 to -2.25 D) for myopic and hyperopic eyes, respectively. Mean binocular uncorrected near visual acuity was 0.70 ± 0.28 logMAR (range: 0.32 to 1.00 logMAR) and 0.79 ± 0.27 logMAR (range: 0.25 to 1.00 logMAR) for myopic and hyperopic eyes, respectively. Mean binocular uncorrected distance visual acuity was 1.19 ± 0.18 logMAR (range: 0.63 to 1.25 logMAR) and 1.14 ± 0.26 logMAR (range: 0.40 to 1.25 logMAR) for myopic and hyperopic eyes, respectively. Stereoacuity was better than 100 seconds of arc in 79% of myopic eyes and 85% of hyperopic eyes and all vision quality scores were greater than 90 of 100. No eyes lost two or more lines.
CONCLUSIONS
The non-linear aspheric micro-anisometropia protocol resulted in safe and effective visual outcomes in patients with both myopic and hyperopic presbyopia. .
Topics: Anisometropia; Corneal Topography; Humans; Hyperopia; Keratomileusis, Laser In Situ; Lasers, Excimer; Middle Aged; Myopia; Presbyopia; Refraction, Ocular; Retrospective Studies; Treatment Outcome
PubMed: 35536710
DOI: 10.3928/1081597X-20220323-01 -
Journal of Ophthalmic & Vision Research 2022In this case-control study, we measured visual acuity, objective refraction, ocular biometric parameters, and strabismus in premature cases classified according to the...
PURPOSE
In this case-control study, we measured visual acuity, objective refraction, ocular biometric parameters, and strabismus in premature cases classified according to the following categories: argon laser-treated retinopathy of prematurity (ROP), untreated spontaneously regressed ROP, no ROP, and full-term controls.
METHODS
Cases with a history of prematurity at six years of age were categorized into the following groups: patients with a history of treated type 1 ROP using argon laser (group I), untreated spontaneously regressed ROP (group II), and no history of ROP (group III). Group IV included age-matched healthy full-term controls. Funduscopy was performed for all the cases and the control group.
RESULTS
In total, 24 eyes of 12 laser-treated ROP cases, 186 eyes of 93 spontaneously regressed ROP patients, 74 eyes of 37 premature cases with no history of ROP, and 286 eyes of 143 controls were included in the study. The mean spherical equivalent in the treated cases was not significantly different from that in the untreated cases and patients in group III. However, the average cylindrical power was significantly different among the groups ( 0.004). Furthermore, anisometropia ( 1.5 diopters) was diagnosed with a higher rate in the treated cases ( = 0.03). The corneal curvature of the laser-treated eyes was significantly steeper and the axial length was significantly shorter than those in the other groups ( 0.002 and 0.001, respectively, for multivariate analysis). Strabismus was found in three treated patients (25%). Additionally, there were three treated eyes (12.5%) diagnosed with macular dragging.
CONCLUSION
Premature cases including those who had a history of argon laser-treated ROP and those with untreated spontaneously regressed ROP showed acceptable long-term visual and refractive outcomes along with a fairly low rate of ocular disorders.
PubMed: 36160100
DOI: 10.18502/jovr.v17i3.11576 -
Children (Basel, Switzerland) Sep 2023The purpose of this prospective study is to show findings of OCT angiography in children with anisometropic amblyopia with a statistically significant difference,...
PURPOSE
The purpose of this prospective study is to show findings of OCT angiography in children with anisometropic amblyopia with a statistically significant difference, regardless of the type of refractive disorder, between the amblyopic and the fellow eye. This research aimed to establish whether there is a difference in vascular density [VD] and size of the foveal avascular zone [FAZ] in the superficial capillary plexus [SCP].
METHODS
All children between 9 and 18 years of age who were treated at the Outpatient Clinic for Orthoptics and Pleoptics of the Department of Ophthalmology, University Medical Centre Maribor from January 2020 to December 2022 due to unilateral anisometric amblyopia were enrolled in our study. Fourteen children met the criteria. Cirrus 5000 high-resolution OCT with AngioPlex OCT angiography was used to analyze the size of the FAZ and VD in the SCP and TCS. The paired -test or Wilcox signed-rank test [ < 0.05] was used for statistical analysis of each parameter between the amblyopic and fellow eye.
RESULTS
Mean child age was 13 years ± 2.9 and ranged from 9 to 18 years. Most of the children [85.7%] were boys. The VD of the SCP did not show statistically significant differences between the visually impaired and control eyes [ = 0.328]. The comparison of the FAZ area between the two eyes was also not statistically significant [ < 0.808]. There was also no statistically significant difference in central macular thickness [TCS] [ < 0.291].
CONCLUSIONS
Our research results show no statistically significant differences in the VD and the FAZ of the SCP, and in the TCS between the amblyopic and fellow eye in children with unilateral anisometropic amblyopia. Our research did not confirm the results of certain previous studies in which a lower density of the capillary network was present in the visually impaired eye. Further studies with more children are necessary to confirm our results.
PubMed: 37761480
DOI: 10.3390/children10091519 -
Neural Regeneration Research Nov 2023Amblyopia is the most common cause of vision loss in children and can persist into adulthood in the absence of effective intervention. Previous clinical and neuroimaging...
Amblyopia is the most common cause of vision loss in children and can persist into adulthood in the absence of effective intervention. Previous clinical and neuroimaging studies have suggested that the neural mechanisms underlying strabismic amblyopia and anisometropic amblyopia may be different. Therefore, we performed a systematic review of magnetic resonance imaging studies investigating brain alterations in patients with these two subtypes of amblyopia; this study is registered with PROSPERO (registration ID: CRD42022349191). We searched three online databases (PubMed, EMBASE, and Web of Science) from inception to April 1, 2022; 39 studies with 633 patients (324 patients with anisometropic amblyopia and 309 patients with strabismic amblyopia) and 580 healthy controls met the inclusion criteria (e.g., case-control designed, peer-reviewed articles) and were included in this review. These studies highlighted that both strabismic amblyopia and anisometropic amblyopia patients showed reduced activation and distorted topological cortical activated maps in the striate and extrastriate cortices during task-based functional magnetic resonance imaging with spatial-frequency stimulus and retinotopic representations, respectively; these may have arisen from abnormal visual experiences. Compensations for amblyopia that are reflected in enhanced spontaneous brain function have been reported in the early visual cortices in the resting state, as well as reduced functional connectivity in the dorsal pathway and structural connections in the ventral pathway in both anisometropic amblyopia and strabismic amblyopia patients. The shared dysfunction of anisometropic amblyopia and strabismic amblyopia patients, relative to controls, is also characterized by reduced spontaneous brain activity in the oculomotor cortex, mainly involving the frontal and parietal eye fields and the cerebellum; this may underlie the neural mechanisms of fixation instability and anomalous saccades in amblyopia. With regards to specific alterations of the two forms of amblyopia, anisometropic amblyopia patients suffer more microstructural impairments in the precortical pathway than strabismic amblyopia patients, as reflected by diffusion tensor imaging, and more significant dysfunction and structural loss in the ventral pathway. Strabismic amblyopia patients experience more attenuation of activation in the extrastriate cortex than in the striate cortex when compared to anisometropic amblyopia patients. Finally, brain structural magnetic resonance imaging alterations tend to be lateralized in the adult anisometropic amblyopia patients, and the patterns of brain alterations are more limited in amblyopic adults than in children. In conclusion, magnetic resonance imaging studies provide important insights into the brain alterations underlying the pathophysiology of amblyopia and demonstrate common and specific alterations in anisometropic amblyopia and strabismic amblyopia patients; these alterations may improve our understanding of the neural mechanisms underlying amblyopia.
PubMed: 37282452
DOI: 10.4103/1673-5374.371349