The Parameters Governing the Anti-Myopia Efficacy of Chromatically Simulated Myopic Defocus in Tree Shrews.

Purpose: We previously showed that exposing tree shrews (Tupaia belangeri, small diurnal mammals closely related to primates) to chromatically simulated myopic defocus (CSMD) counteracted small-cage myopia and instead induced hyperopia (approximately +4 diopters [D]). Here, we explored the parameters of this effect. Methods: Tree shrews were exposed to the following interventions for 11 days: (1) rearing in closed (n = 7) or open (n = 6) small cages; (2) exposed to a video display of Maltese cross images with CSMD combined with overhead lighting (n = 4); (3) exposed to a video display of Maltese cross images with zero blue contrast ("flat blue," n = 8); and (4) exposed to a video display of black and white grayscale tree images with different spatial filtering (blue pixels lowpass <1 and <2 cycles per degree [CPD]) for the CSMD. Results: (1) Tree shrews kept in closed cages, but not open cages, developed myopia. (2) Overhead illumination reduced the hyperopia induced by CSMD. (3) Zero-blue contrast produced hyperopia but slightly less than the CSMD. (4) Both of the CSMD tree images counteracted small cage myopia, but the one low pass filtering blue <1 CPD was more effective at inducing hyperopia. Conclusions: Any pattern with reduced blue contrast at and below approximately 1 CPD counteracts myopia/promotes hyperopia, but maximal effectiveness may require that the video display be the brightest object in the environment. Translational Relevance: Chromatically simulated myopic blur might be a powerful anti-myopia therapy in children, but the parameter selection could be critical. Issues for translation to humans are discussed.

Nonsurgical Consecutive Exotropia Following Childhood Esotropia: A Multicentered Study.

PURPOSE: Nonsurgical consecutive exotropia (NCX) occurs when an esotropia (ET) spontaneously converts to exotropia (XT) without surgical intervention. Although NCX is considered to occur in early-onset accommodative ET with high hyperopia, consensus on causation is lacking. We report the clinical characteristics of NCX and assess the response to conservative management. DESIGN: Retrospective, multicenter, observational case series. METHODS: Patients aged 6 months and older with an initial diagnosis of ET who converted to XT without surgical intervention. Sensory strabismus was excluded. Age, visual acuity, cycloplegic refraction, glasses prescriptions, deviation, and binocular vision were collected. RESULTS: Forty-nine children were included with a mean age of 3.5 ± 1.6 years and 8.4 ± 3.6 years at the time of ET and NCX, respectively. Mean refractive error was +4.40 ± 2.13 diopters (D) and +4.05 ± 2.74 D at the time of ET and NCX, respectively. Accommodative ET occurred in 60% of cases, and only 35.7% were high hyperopes. All but 1 patient presented with XT at distance. In response to the XT, a mean decrease in hyperopic prescription of 1.55 ± 0.48 D was given (N = 17); only 1 case reverted to ET. Eventually, 43% underwent XT surgery, with similar rates between those who had refractive management and those who did not. CONCLUSIONS: NCX occurs in both accommodative and nonaccommodative ET; high hyperopia is present in only one-third of cases. On average, drift to XT occurs within 5 years. Refractive management has a modest result. No predictive risk factors were identified. Our findings challenge hyperopia-linked theories of causation. Nonrefractive explanations, such as the role of the vergence system, deserve further study.

Resolution of cyclic esotropia with 5-year follow-up after brief Fresnel prism treatment.

Cyclic esotropia is a rare form of strabismus that is characterized by a recurring esotropic deviation, usually with a 48-hour cycle. On esotropic days, the patient has a constant deviation with suppression, followed by a day with straight eyes and good binocular function. We report a case of cyclic esotropia in which the cycling resolved with 2 months of Fresnel prism for the amount of the distance deviation on her "straight" days. Five years later, with low plus hyperopic correction, she remains with a stable esophoria and normal stereopsis.

Effects of Spectacle Lenses With Aspherical Lenslets on Peripheral Eye Length and Peripheral Refraction in Myopic Children: A 2-Year Randomized Clinical Trial.

Purpose: To investigate changes in peripheral eye length (PEL) and peripheral refraction (PR) in myopic children after wearing spectacle lenses with highly or slightly aspherical lenslets (HAL or SAL) for 2 years. Methods: We recruited 170 children aged 8 to 13 years with myopia between -0.75 diopters (D) and -4.75 D. Participants were randomized to wear HAL, SAL, or single vision spectacle lenses (SVL). PEL and PR were measured at 0° central and 15° and 30° in the nasal and temporal retina every 6 months for 2 years. The relative PR (RPR) was calculated by subtracting central from peripheral values. Results: PELs significantly increased with time (all P < 0.001), with the greatest elongation in the SVL group and the least in the HAL group. In the SVL and SAL groups, axial length elongated faster than the periphery. Whereas in the HAL group, N30 elongated faster than other PELs, axial length elongated less than the periphery. With time, the PR became more negative (all P < 0.001), with the most negative changes in the SVL group and the least negative changes in the HAL group. RPR became more hyperopic in the SVL and SAL groups, but less hyperopic in the HAL group (all P < 0.001). Conclusions: Over the 2-year myopia progression, steeper retina and greater peripheral hyperopic defocus were found in the SVL group. In the SAL group, changes were attenuated. In the HAL group, the retina flattened and peripheral defocus became less hyperopic. Translational Relevance: HAL and SAL lenses had little impact on PEL elongation.

Factors affecting the total occlusion time in eyes with hyperopic anisometropic amblyopia.

BACKGROUND: Amblyopia treatment by occluding the healthy eye is known to be effective during a sensitive critical period. This study aims to clarify the factors for the total occlusion time (TOT) required for the amblyopic eye to achieve a normal visual acuity (VA) level of 1.0 (0.0 logMAR equivalent). This could contribute to an efficient treatment plan for eyes with hyperopic anisometropic amblyopia. METHODS: Subjects were 58 patients (26 boys and 32 girls; age range, 3.6-9.2, average, 5.8 ± 1.3 years) with hyperopic anisometropic amblyopia. All the subjects had initially visited and completed occlusion therapy with improved VA of 1.0 or better in the amblyopic eye at Kindai University Hospital between January 2007 and March 2017. Using the subjects' medical records, we retrospectively investigated five factors for the TOT: the age at treatment, the initial VA of the amblyopic eye, refraction of the amblyopic eye, anisometropic disparity, and the presence of microstrabismus. Patient's VA improvement at one month after treatment was also evaluated to confirm the effect of the occlusion therapy. RESULTS: The initial VA of the amblyopic eye ranged from 0.1 to 0.9 (median, 0.4). The TOT ranged from 140 to 1795 (median, 598) hours with an average daily occlusion time of 7 hours. The initial VA of the amblyopic eye and presence of microstrabismus were the significant factors for the TOT (p < 0.01). To achieve VA of 1.0 or better, patients with an initial VA of ≤ 0.3 in the amblyopic eye required a longer TOT. Moreover, patients with concomitant microstrabismus required a 1.7-fold longer TOT compared to those without microstrabismus. CONCLUSION: Longer daily occlusion hours and early start of the treatment will be necessary for patients with poor initial VA or microstrabismus to complete occlusion therapy within the sensitive critical period.

Effect of peripheral defocus on axial growth and modulation of refractive error in children with anisohyperopia.

PURPOSE: To establish whether axial growth and refractive error can be modulated in anisohyperopic children by imposing relative peripheral hyperopic defocus (RPHD) using multifocal soft contact lenses. METHODS: This study is a prospective, controlled paired-eye study with anisohyperopic children. Axial growth and refractive error were observed without intervention for the first 6 months of the 3-year trial with participants wearing single vision spectacles. Then, participants wore a centre-near, multifocal, soft contact lens (+2.00 D add) in their more hyperopic eye for 2 years, with a single vision contact lens worn in the fellow eye if required. The 'centre-near' portion of the contact lens in the more hyperopic eye corrected distance refractive error while the 'distance' portion imposed hyperopic defocus in the peripheral retina. Participants reverted to single vision spectacles for the final 6 months. RESULTS: Eleven participants, mean age of 10.56 years (SD 1.43; range 8.25-13.42), completed the trial. No increase in axial length (AL) was found during the first 6 months in either eye (p > 0.99). Axial growth across the 2-year intervention period was 0.11 mm (SEM 0.03; p = 0.06) in the test eye versus 0.15 mm (SEM 0.03; p = 0.003) in the control eye. AL was invariant during the final 6 months in both eyes (p > 0.99). Refractive error was stable during the first 6 months in both eyes (p = 0.71). Refractive error change across the 2-year intervention period was -0.23 D (SEM 0.14; p = 0.32) in the test eye versus -0.30 D (SEM 0.14; p = 0.61) in the control eye. Neither eye demonstrated a change in refractive error during the final 6 months (p > 0.99). CONCLUSIONS: Imposing RPHD using the centre-near, multifocal, contact lens specified here did not accelerate axial growth nor reduce refractive error in anisohyperopic children.

Effects of Morning or Evening Narrow-band Blue Light on the Compensation to Lens-induced Hyperopic Defocus in Chicks.

SIGNIFICANCE: Exposure to blue light before bedtime is purported to be deleterious to various aspects of human health. In chicks, blue evening light stimulated ocular growth, suggesting a role in myopia development. To further investigate this hypothesis, we asked if brief blue light altered the compensatory responses to hyperopic defocus. PURPOSE: Previous work showed that several hours' evening exposure to blue light stimulated ocular growth in chicks, but morning exposure was only effective at a lower illuminance. By contrast, rearing in blue light has inhibited ocular growth in untreated eyes and eyes exposed to form deprivation or defocus. We studied the effects of brief exposures to blue light on the compensation to hyperopic defocus. METHODS: Chicks wore monocular negative lenses (-10 D) starting at age 10 days. They were subsequently exposed to blue light (460 nm) for 4 hours in the morning or evening for 8 to 9 days ("dim," 200 lux[morning, n = 9; evening, n = 11]; "bright," 600 lux[morning, n = 8; evening, n = 20]); controls wore lenses in white light (n = 14). Ultrasonography was done on days 1, 5, 8, and 9 for "evening" groups and days 1, 6, and 8 for "morning." All data are reported as interocular differences (experimental minus fellow eyes). Refractions were measured on the last day. RESULTS: For evening exposure, dim blue light enhanced the axial compensation at all times (change in axial length: day 6: 465 vs. 329 µm/9 days, analysis of variance P < .001, P = .03; day 9: 603 vs. 416 µm/9 days, analysis of variance P < .001; P < .05). Bright blue light had a transient inhibitory effect (day 5: 160 vs. 329 µm; P < .005). Refractive errors were consistent with axial growth, with dim causing more myopia than bright (-9.4 vs. -4.7 D; P < .05). Morning blue light had no significant effect. CONCLUSIONS: We speculate that these findings reflect a complex interaction between illuminance, defocus, and time of day.

Temporal properties of positive and negative defocus on emmetropization.

Studying the temporal integration of visual signals is crucial to understand how time spent on different visual tasks can affect emmetropization and refractive error development. In this study we assessed the effect of interrupting positive and negative lens-imposed defocus with brief periods of unrestricted vision or darkness. A total of forty-six marmosets were treated monocularly with soft contact lenses for 4 weeks from 10 weeks of age (OD: + 5D or - 5D; OS: plano). Two control groups wore + 5D (n = 5) or - 5D (n = 13) lenses continuously for 9 h/day. Two experimental groups had lens-wear interrupted for 30 min twice/day at noon and mid-afternoon by removing lenses and monitoring vision while marmosets sat at the center of a viewing cylinder (normal vision interruption, + 5D: n = 7; - 5D: n = 8) or while they were in the dark (dark interruption, + 5D: n = 7; - 5D: n = 6). The interruption period (30 min/day) represented approx. 10% of the total stimulation time (9 h/day). On-axis refractive error (RE) and vitreous chamber depth (VCD) were measured using an autorefractor and high frequency A-scan ultrasound at baseline and after treatment. Wearing + 5D lenses continuously 9 h/day for 4 weeks induced slowed eye growth and hyperopic shifts in RE in treated relative to contralateral control eyes (relative change, VCD: - 25 ± 11 µm, p > 0.05; RE: + 1.24 ± 0.58 D, p > 0.05), whereas - 5D lens wear resulted in larger and myopic eyes (relative change, VCD: + 109 ± 24 µm, p < 0.001; RE: - 2.03 ± 0.56 D, p < 0.05), significantly different from those in the + 5D lens-treated animals (p < 0.01 for both). Interrupting lens induced defocus with periods of normal vision or darkness for approx. 10% of the treatment time affected the resulting compensation differently for myopic and hyperopic defocus. Interrupting defocus with unrestricted vision reduced - 5D defocus compensation but enhanced + 5D defocus compensation (- 5D, VCD: + 18 ± 33 µm; RE: - 0.93 ± 0.50 D, both p > 0.05; + 5D, VCD: - 86 ± 30 µm; RE: + 1.93 ± 0.50 D, both p < 0.05). Interrupting defocus with darkness also decreased - 5D defocus compensation, but had little effect on + 5D defocus compensation (- 5D, VCD: + 73 ± 34 µm, RE: - 1.13 ± 0.77 D, p > 0.05 for both; + 5D, VCD: - 10 ± 28 µm, RE: + 1.22 ± 0.50 D, p > 0.05 for both). These findings in a non-human primate model of emmetropization are similar to those described in other species and confirm a non-linear model of visual signal integration over time. This suggests a mechanism that is conserved across species and may have clinical implications for myopia management in school-aged children.

The effect of peripheral defocus on axial growth and modulation of refractive error in hyperopes.

PURPOSE: To establish whether axial growth and refractive error can be modulated in hyperopic children by imposing relative peripheral hyperopic defocus using multifocal soft contact lenses. METHODS: A prospective controlled study with hyperopic participants allocated to a control or test group. Control group participants were corrected with single vision spectacles and changes to axial length and refractive error were followed for 3 years. For the test group, axial growth and post-cycloplegic refractive error were observed with participants wearing single vision spectacles for the first 6 months of the trial and then corrected with centre-near multifocal soft contact lenses with a 2.00 D add for 2 years. The central 'near' portion of the contact lens corrected distance refractive error while the 'distance' portion imposed hyperopic defocus. Participants reverted to single vision spectacles for the final 6 months of the study. RESULTS: Twenty-two participants, mean age 11.13 years (SD 1.72) (range 8.33-13.92), completed the trial. Axial length did not change during the first 6 months in either group (p = 1.00). Axial growth across the 2-year intervention period was 0.17 mm (SEM 0.04) (p < 0.0005) in the test group versus 0.06 mm (SEM 0.07) (p = 0.68) in the control group. Axial length was invariant during the final 6 months in either group (p = 1.00). Refractive error was stable during the first 6 months in both groups (p = 1.00). Refractive error change across the 2-year intervention period was -0.26 D (SEM 0.14) (p = 0.38) in the test group versus -0.01 D (SEM 0.09) (p = 1.00) in the control group. Neither the test (p = 1.00) nor control (p = 0.63) group demonstrated a change in refractive error during the final 6 months. CONCLUSIONS: The rate of axial growth can be accelerated in children with hyperopia using centre-near multifocal soft contact lenses.

Comparison of Long-term Stereoacuity Improvement Between Patients With Initial Subnormal Stereopsis and Nil Stereopsis in Refractive Accommodative Esotropia.

PURPOSE: To compare improvement in long-term stereoacuity between patients with refractive accommodative esotropia (RAET) with initial subnormal stereopsis (between 120 and 1,980 arcsec of stereoacuity) and nil stereopsis. METHODS: The medical records of patients 4 years and older who had RAET with initial subnormal stereopsis and nil stereopsis and a minimum follow-up period of 5 years were retrospectively reviewed. Improvement in stereoacuity at the last follow-up visit and the factors that could influence it were compared between the initial subnormal stereopsis and the nil stereopsis groups. RESULTS: A total of 79 patients (mean age: 6.3 ± 1.9 years) were included: 31 patients with initial subnormal stereopsis and 48 patients with nil stereopsis. The mean follow-up time was 11.7 ± 1.8 years (range: 5 to 21 years). At the last follow-up visit, a statistically significantly greater number of patients with initial subnormal stereopsis demonstrated improvement in stereoacuity and also achieved 60 arcsec of stereoacuity compared with those with nil stereopsis. Age at onset, duration of esodeviation, mean hyperopia, amblyopia, anisometropia, and follow-up duration were not significantly different between the initial subnormal stereopsis and the nil stereopsis groups. The initial mean near and distance deviations with hyperopic correction were significantly smaller in patients with initial subnormal stereopsis. A significantly greater number of patients with initial sub-normal stereopsis had fusion at distance. CONCLUSIONS: Patients with RAET with initial subnormal stereopsis have greater chances of stereoacuity improvement and recovery of 60 arcsec of stereoacuity than those with nil stereopsis. Patients who initially have nil stereopsis may develop normal stereoacuity. Smaller initial deviations with hyperopic correction and fusion at distance indicate a favorable prognosis for stereoacuity improvement. [J Pediatr Ophthalmol Strabismus. 2022;59(4):248-253.].

The Impact of Hyperopia on Academic Performance Among Children: A Systematic Review.

PURPOSE: To assess the impact of uncorrected hyperopia and hyperopic spectacle correction on children's academic performance. DESIGN: Systematic review and meta-analysis. METHODS: We searched 9 electronic databases from inception to July 26, 2021, for studies assessing associations between hyperopia and academic performance. There were no restrictions on language, publication date, or geographic location. A quality checklist was applied. Random-effects models estimated pooled effect size as a standardized mean difference (SMD) in 4 outcome domains: cognitive skills, educational performance, reading skills, and reading speed. (PROSPERO registration: CRD-42021268972). RESULTS: Twenty-five studies (21 observational and 4 interventional) out of 3415 met the inclusion criteria. No full-scale randomized trials were identified. Meta-analyses of the 5 studies revealed a small but significant adverse effect on educational performance in uncorrected hyperopic compared to emmetropic children {SMD -0.18 [95% confidence interval (CI), -0.27 to -0.09]; P < 0.001, 4 studies} and a moderate negative effect on reading skills in uncorrected hyperopic compared to emmetropic children [SMD -0.46 (95% CI, -0.90 to -0.03); P = 0.036, 3 studies]. Reading skills were significantly worse in hyperopic than myopic children [SMD -0.29 (95% CI, -0.43 to -0.15); P < 0.001, 1 study]. Qualitative analysis on 10 (52.6%) of 19 studies excluded from meta-analysis found a significant (P < 0.05) association between uncorrected hyperopia and impaired academic performance. Two interventional studies found hyperopic spectacle correction significantly improved reading speed (P < 0.05). CONCLUSIONS: Evidence indicates that uncorrected hyperopia is associated with poor academic performance. Given the limitations of current methodologies, further research is needed to evaluate the impact on academic performance of providing hyperopic correction.

Contrast Sensitivity and Stereoacuity in Successfully Treated Refractive Amblyopia.

Purpose: To assess whether monocular contrast sensitivity and stereoacuity impairments remain when visual acuity is fully recovered in children with refractive amblyopia. Methods: A retrospective review of 487 patients diagnosed with refractive amblyopia whose visual acuity improved to 0.08 logMAR or better in both eyes following optical treatment was conducted. Measurements of monocular contrast sensitivity and stereoacuity had been made when visual acuity normalized. All patients had been treated with refractive correction for approximately 2 years following diagnosis. No other treatments were provided. Monocular contrast sensitivity was measured using the CSV-1000E chart for children 6 years of age or younger and a psychophysical technique called the quick contrast sensitivity function in older children. Stereoacuity was measured using the Random Dot Test that includes monocular cues and the Randot Stereoacuity Test that does not have monocular cues. Results: Statistically significant interocular differences in contrast sensitivity were observed. These differences tended to occur at higher spatial frequencies (12 and 18 cycles per degree). Stereoacuity within the age-specific normal range was achieved by 47.4% of patients for the Random Dot Test and only 23.1% of patients for the Randot Stereoacuity Test. Conclusions: Full recovery of visual acuity following treatment for refractive amblyopia does not equalize interocular contrast sensitivity or restore normal stereopsis. Alternative therapeutic approaches that target contrast sensitivity and/or binocular vision are required.

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.

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.

Amber light treatment produces hyperopia in tree shrews.

PURPOSE: Exposure to narrow-band red light, which stimulates only the long-wavelength sensitive (LWS) cones, slows axial eye growth and produces hyperopia in tree shrews and macaque monkeys. We asked whether exposure to amber light, which also stimulates only the LWS cones but with a greater effective illuminance than red light, has a similar hyperopia-inducing effect in tree shrews. METHODS: Starting at 24 ± 1 days of visual experience, 15 tree shrews (dichromatic mammals closely related to primates) received light treatment through amber filters (BPI 500/550 dyed acrylic) either atop the cage (Filter group, n = 8, 300-400 human lux) or fitted into goggles in front of both eyes (Goggle group, n = 7). Non-cycloplegic refractive error and axial ocular dimensions were measured daily. Treatment groups were compared with age-matched animals (Colony group, n = 7) raised in standard colony fluorescent lighting (100-300 lux). RESULTS: At the start of treatment, mean refractive errors were well-matched across the three groups (p = 0.35). During treatment, the Filter group became progressively more hyperopic with age (p < 0.001). By contrast, the Goggle and Colony groups showed continued normal emmetropization. When the treatment ended, the Filter group exhibited significantly greater hyperopia (mean [SE] = 3.5 [0.6] D) compared with the Goggle (0.2 [0.8] D, p = 0.01) and Colony groups (1.0 [0.2] D, p = 0.01). However, the refractive error in the Goggle group was not different from that in the Colony group (p = 0.35). Changes in the vitreous chamber were consistent with the refractive error changes. CONCLUSIONS: Exposure to ambient amber light produced substantial hyperopia in the Filter group but had no effect on refractive error in the Goggle group. The lack of effect in the Goggle group could be due to the simultaneous activation of the short-wavelength sensitive (SWS) and LWS cones caused by the scattering of the broad-band light from the periphery of the goggles.

[Optical correction principles of accommodative esotropia].

Accommodative esotropia is the most common type of esotropia in children. The patients often need to wear hyperopic glasses to correct eye positions and improve vision and binocular function. However, the course of accommodative esotropia is usually long, so it is necessary to monitor the refractive changes for a long time. Maintaining full hyperopic correction will interfere with the emmetropia development of the eyeball, and undercorrection of hyperopia will lead to the risk of esotropia decompensation. These often bring confusion when clinicians prescribe glasses. The benefits of accommodative esotropia with a high accommodation convergence/accommodation ratio from fitting bifocal lenses and the effect of prisms on residual esotropia have also been controversial topics in this field. In this article, we combine the research status and clinical practice to present some points of view for the peer reference. (Chin J Ophthalmol, 2021, 57: 331-335).

Correction of Low-Moderate Hyperopia Improves Accommodative Function for Some Hyperopic Children During Sustained Near Work.

Purpose: This study investigated whether refractive correction improved accommodative function of hyperopic children while engaged in two sustained near activities. Methods: Sustained accommodative function of 63 participants (aged 5-10 years) with varying levels of uncorrected hyperopia (>/= +1.00 D and < + 5.00 D spherical equivalent in the least hyperopic eye) was measured using eccentric infrared photorefraction (PowerRef 3; PlusOptix, Germany). Binocular accommodation measures were recorded while participants engaged in 2 tasks at 25 cm for 15 minutes each: an "active" task (reading small print on an Amazon Kindle), and a "passive" task (watching an animated movie on liquid crystal display [LCD] screen). Participants also underwent a comprehensive visual assessment, including measurement of presenting visual acuity, prism cover test, and stereoacuity. Reading speed was assessed with and without hyperopic correction. Refractive error was determined by cycloplegic retinoscopy. Results: Hyperopic refractive correction significantly improved accuracy of accommodative responses in both task (pairwise comparisons: t = -3.70, P = 0.001, and t = -4.93, P < 0.001 for reading and movie tasks, respectively). Accommodative microfluctuations increased with refractive correction in the reading task (F(1,61) = 25.77, P < 0.001) but decreased in the movie task (F(1,59) = 4.44, P = 0.04). Reading speed also significantly increased with refractive correction (F(1,48) = 66.32, P < 0.001). Conclusions: Correcting low-moderate levels of hyperopia has a positive impact on accommodative performance during sustained near activity in some schoolchildren. For these children, prescribing hyperopic correction may benefit performance in near vision tasks.

Effectiveness of vergence/accommodative therapy for accommodative dysfunction in children with convergence insufficiency.

PURPOSE: To determine the effectiveness of office-based vergence/accommodative therapy for improving accommodative amplitude and accommodative facility in children with symptomatic convergence insufficiency and accommodative dysfunction. METHODS: We report changes in accommodative function following therapy among participants in the Convergence Insufficiency Treatment Trial - Attention and Reading Trial with decreased accommodative amplitude (115 participants in vergence/accommodative therapy; 65 in placebo therapy) or decreased accommodative facility (71 participants in vergence/accommodative therapy; 37 in placebo therapy) at baseline. The primary analysis compared mean change in amplitude and facility between the vergence/accommodative and placebo therapy groups using analyses of variance models after 4, 8, 12 and 16 weeks of treatment. The proportions of participants with normal amplitude and facility at each time point were calculated. The average rate of change in amplitude and facility from baseline to week 4, and from weeks 4 to 16, were determined in the vergence/accommodative therapy group. RESULTS: From baseline to 16 weeks, the mean improvement in amplitude was 8.6 dioptres (D) and 5.2 D in the vergence/accommodative and placebo therapy groups, respectively (mean difference = 3.5 D, 95% confidence interval (CI): 1.5 to 5.5 D; p = 0.01). The mean improvement in facility was 13.5 cycles per minute (cpm) and 7.6 cpm in the vergence/accommodative and placebo therapy groups, respectively (mean difference = 5.8 cpm, 95% CI: 3.8 to 7.9 cpm; p < 0.0001). Significantly greater proportions of participants treated with vergence/accommodative therapy achieved a normal amplitude (69% vs. 32%, difference = 37%, 95% CI: 22 to 51%; p < 0.0001) and facility (85% vs. 49%, difference = 36%, 95% CI: 18 to 55%; p < 0.0001) than those who received placebo therapy. In the vergence/accommodative therapy group, amplitude increased at an average rate of 1.5 D per week during the first 4 weeks (p < 0.0001), then slowed to 0.2 D per week (p = 0.002) from weeks 4 to 16. Similarly, facility increased at an average rate of 1.5 cpm per week during the first 4 weeks (p < 0.0001), then slowed to 0.6 cpm per week from weeks 4 to 16 (p < 0.0001). CONCLUSION: Office-based vergence/accommodative therapy is effective for improving accommodative function in children with symptomatic convergence insufficiency and coexisting accommodative dysfunction.

Power profiles of centre-distance multifocal soft contact lenses.

PURPOSE: Centre-distance multifocal contact lenses (MFCLs) for myopia control are thought to slow myopia progression by providing both clear foveal vision and myopic defocus. Characterising the power profile of lenses is important to understanding their possible effects on retinal defocus when worn. The power profiles of three commercially available MFCLs were determined. METHODS: Three centre-distance MFCL designs were studied: Biofinity Multifocal D +2.50 add (comfilcon A), Proclear Multifocal D +2.50 add (omafilcon A), and NaturalVue Multifocal (etafilcon A). Two lenses each in power from -1.00D to -6.00D in 1D steps were stored in ISO 18369-3:2017 standard phosphate buffered saline for 24 h. Optical power profiles were measured in a wet cell with the SHSOphthalmic profiler accounting for centre thickness and manufacturer-reported material refractive index. Sagittal power maps from the SHSOphthalmic were exported, and custom MATLAB code was used to generate power profiles by averaging along the vertical and horizontal meridians. One-way anova with Tukey's HSD post-hoc t-tests were used to analyse maximum add power by lens design. RESULTS: Plus power increased out from the lens centre for all three MFCLs. Power profiles of Biofinity D and Proclear D MFCLs show three distinct areas within the optic zone; the distance zone (from lens centre to about 1.6 mm radius), intermediate zone (about 1.6 mm radius to 2.1 mm) and near zone (about 2 mm radius to 4 mm). For NaturalVue MFCLs, plus power starts increasing almost immediately from the lens centre, reaching maximum measured mean plus power at a radius of 2.7 mm. From 2.7 mm to 3.0 mm, there was a decrease in plus power, which was then generally maintained out to the optic zone edge. Across all lens powers, maximum add power was highest with the NaturalVue MFCL (+3.32 ± 0.44D), then Proclear D (+1.84 ± 0.28D) and Biofinity D (+1.47 ± 0.34D) MFCLs (all p < 0.04). Add power peaked at different locations for different lens powers and designs. CONCLUSIONS: Power profiles of MFCLs vary based on lens design and power. These power profiles are consistent with reported myopic and hyperopic changes in peripheral refraction with MFCLs and provide some explanation for reported differences in peripheral refraction with these MFCLs. Further work is needed to determine whether these power profile differences influence myopia progression.

Lower sensitivity to peripheral hypermetropic defocus due to higher order ocular aberrations.

PURPOSE: Many myopia control interventions are designed to induce myopic relative peripheral refraction. However, myopes tend to show asymmetries in their sensitivity to defocus, seeing better with hypermetropic rather than myopic defocus. This study aims to determine the influence of chromatic aberrations (CA) and higher-order monochromatic aberrations (HOA) in the peripheral asymmetry to defocus. METHODS: Peripheral (20° nasal visual field) low-contrast (10%) resolution acuity of nine subjects (four myopes, four emmetropes, one hypermetrope) was evaluated under induced myopic and hypermetropic defocus between ±5 D, under four conditions: (a) Peripheral Best Sphere and Cylinder (BSC) correction in white light; (b) Peripheral BSC correction + CA elimination (green light); (c) Peripheral BSC correction + HOA correction in white light; and (d) Peripheral BSC correction + CA elimination + HOA correction. No cycloplegia was used, and all measurements were repeated three times. RESULTS: The slopes of the peripheral acuity as a function of positive and negative defocus differed, especially when the natural HOA and CA were present. This asymmetry was quantified as the average of the absolute sum of positive and negative defocus slopes for all subjects (AVS). The AVS was 0.081 and 0.063 logMAR/D for white and green light respectively, when the ocular HOA were present. With adaptive optics correction for HOA, the asymmetry reduced to 0.021 logMAR/D for white and 0.031 logMAR/D for green light, mainly because the sensitivity to hypermetropic defocus increased when HOA were corrected. CONCLUSION: The asymmetry was only slightly affected by the elimination of the CA of the eye, whereas adaptive optics correction for HOA reduced the asymmetry. The HOA mainly affected the sensitivity to hypermetropic defocus.