Noncontact Conjunctiva: A Better Mitomycin C Application Site for Trabeculectomy.

INTRODUCTION: Bleb scarring is the most important complication of trabeculectomy. Changing the application position of mitomycin C (MMC) during trabeculectomy might affect the surgery outcome. Our aim is to compare the effectiveness and safety of intraocular pressure (IOP) lowering in two different application sites of mitomycin in trabeculectomy. METHODS: This retrospective trial compared the surgical outcomes of 177 eyes that underwent trabeculectomy with adjunctive mitomycin C. In 70 eyes, an MMC-soaked sponge was applied under the scleral flap without touching Tenon's capsule. In 107 eyes, an MMC-soaked sponge was applied under the scleral flap covered by Tenon's capsule. Outcome measures were the IOP, best-corrected visual acuity (BCVA), success rates, and incidence of complications. RESULTS: Within both groups, a highly significant IOP reduction was seen during follow-up. The effectiveness in reducing IOP and the change in best-corrected visual acuity (BCVA) were similar between the two groups. Thin-walled blebs and postoperative hypotony were seen more often when MMC-soaked sponges were applied under the scleral flap covered by Tenon's capsule (P = 0.008 and P = 0.012, respectively). There was no significant difference in BCVA or other complications in either group. CONCLUSION: Since the effectiveness of IOP reduction was similar between both groups and with a low incidence of thin-walled blebs and hypotony, the subscleral application without touching Tenon's capsule seems to be the safer application site of MMC during trabeculectomy.

Evaluation of the learning curve of laser peripheral iridectomy: the 20th case reaches the turning point.

AIM: To explore the learning curve for ophthalmologists at the start of laser peripheral iridectomy (LPI) training. METHODS: The learning curve of 4 doctor groups without previous LPI experience was studied. Three main parameters of LPI were reviewed: total energy, argon energy and neodymium-doped yttrium aluminum garnet (Nd:YAG) energy. Procedures were evaluated in cohorts of 20 cases to identify the turning points of the three variables. RESULTS: There was no significant difference in terms of age or eye among the 4 doctor groups. There were stable trends on the learning curve for the Doctor A and C groups regarding total energy and argon energy. In addition, the turning points on the learning curve were determined after the 20th procedure for the Doctor B and D groups regarding total energy and argon energy. Moreover, the Nd:YAG energy was relatively stable since the first procedure. CONCLUSION: It requires approximately 20 procedures for a beginner to reach a turning point on the learning curve regarding LPI. It can serve as a point of reference or guideline for training beginners to perform LPI.

Eye Habits Affect the Prevalence of Asthenopia in Patients with Myopia.

Purpose: This study aims to explore the risk factors of asthenopia in the myopic population. Methods: In this cross-sectional study, myopia patients were inquired about their eye habits and were requested to complete an asthenopia questionnaire and ocular examinations. Age, gender, occupation, anisometropia, eye care education, weekly outdoor activity time, duration of continuous near work, daily screen time, dry eye, near phoria, and binocular accommodative facility were calculated using the Student's test-test, Mann Whitney U test, and Pearson's chi-square test. Spherical equivalents and astigmatism were calculated using a generalized estimating equation. Binary logistic regression was performed on factors with a p-value <0.05. Results: Of the 65 myopic patients, 57% showed asthenopia, 52% experienced blurry vision, 37% felt their eyes hurt or sore, and 28% felt tired when performing close work. Asthenopia patients were older than patients without asthenopia (Z = -2.887, p=0.004). Daily screen time, continuous near-work time, eye care education, and dry eye were positively correlated with asthenopia (χ 2 = 8.64, p=0.003; χ2 = 13.873, p < 0.001, χ2 = 9.643, p=0.002; χ2 = 7.035, p=0.008). After eliminating collinearity, eye care education and continuous near-work time were identified as independent risk factors of asthenopia, with odds ratios of 0.115 and 4.227, respectively. Conclusion: This study shows that receiving eye care education from schools and hospitals and limiting near-work duration to less than 45 minutes per session could reduce the occurrence of asthenopia in myopic patients. This approach may be a more economical and convenient way for myopic people to relieve asthenopia.

Characteristics of the Ciliary Body in Healthy Chinese Subjects Evaluated by Radial and Transverse Imaging of Ultrasound Biometric Microscopy.

Background: The imaging and analysis of the ciliary body (CB) are valuable in many potential clinical applications. This study aims to demonstrate the anatomy characteristics of CB using radial and transverse imaging of ultrasound biometric microscopy (UBM) in healthy Chinese subjects, and to explore the determining factors. Methods: Fifty-four eyes of 30 healthy Chinese subjects were evaluated. Clinical data, including age, body mass index (BMI), intraocular pressure (IOP), axial length (AL), and lens thickness (LT), were collected. Radial and transverse UBM measurements of the ciliary body were performed. Anterior chamber depth (ACD), ciliary sulcus diameter (CSD), ciliary process length (CPL), ciliary process density (CPD), ciliary process area (CPA), ciliary muscle area (CMA), ciliary body area (CBA), ciliary body thickness (CBT0, CBT1, and CBTmax), anterior placement of ciliary body (APCB), and trabecular-ciliary angle (TCA) of four (superior, nasal, inferior, and temporal) quadrants were measured. Results: The average CPL was 0.513 ± 0.074 mm, and the average CPA was 0.890 ± 0.141 mm2. CPL and CPA tended to be longer and larger in the superior quadrant (p < 0.001) than in the other three quadrants. Average CPL was significantly correlated with AL (r = 0.535, p < 0.001), ACD (r = 0.511, p < 0.001), and LT (r = −0.512, p < 0.001). Intraclass correlation coefficient (ICC) scores were high for CPL (0.979), CPD (0.992), CPA (0.966), CMA (0.963), and CBA (0.951). Conclusions: In healthy Chinese subjects, CPL was greatest in the superior quadrant, followed by the inferior, temporal, and nasal quadrants, and CPA was largest in the superior quadrant, followed by the tempdoral, inferior, and nasal quadrants. Transverse UBM images can be used to measure the anatomy of the ciliary process with relatively good repeatability and reliability.

Incidence and Characteristics of Retinopathy of Prematurity Patients With Late Gestational Age and Large Birth Weight in South China.

Purpose: To investigate the incidence and characteristics of retinopathy of prematurity (ROP) premature infants with late gestational age (GA) and large birth weight (BW) and show a 7-year trend of ROP incidence in South China. Methods: This retrospective, cross-sectional study included premature infants who received ROP screening in a 7-year period (from 2010 to 2016) at the Sun Yat-sen Memorial Hospital (SYSMH), Guangzhou, South China. Infants were screened if they had GA <37 weeks or BW <2,500 g. All screened infants were divided into two groups: Group 1 (with both GA ≥ 35 weeks and BW ≥ 1,750 g) and Group 2 (others). The characteristics of ROP infants in Group 1 were analyzed and compared with those in Group 2. Results: A total of 911 premature infants were screened, with 282 infants in Group 1 and 629 in Group 2. Both the incidences of any ROP (6.7 vs. 8.3%, p = 0.50) and Type 1 ROP (1.4 vs. 1.7%, p = 0.72) in Group 1 were comparable with those in Group 2. Lower proportions of respiratory distress (15.8 vs. 71.2%, p < 0.001), blood transfusion (5.3 vs. 32.7%, p = 0.028), and oxygen administration (31.6 vs. 86.5%, p < 0.001) among ROP patients in Group 1 than those in Group 2 were revealed. Vaginal delivery [OR: 4.73 (1.83-12.26)] was identified as a factor associated with ROP among the infants in Group 1. Forty percent (6/15) of Type 1 ROP in this study would have been missed under the current screening criteria in China (GA ≤ 34 weeks and/or BW ≤ 2,000 g). Trends of increased incidence of Type 1 ROP and decreased BW were exhibited in the 7-year study period. Conclusions: These findings indicate that even the premature infants with late GA and large BW also have a high risk of developing ROP, especially for those delivered by vagina. The findings may provide a significant reference for ROP screening and neonatal care in South China and other regions with similar conditions.

Relative peripheral refraction characteristics and their relationship with retinal microvasculature in young adults: Using a novel quantitative approach.

AIM: To analyze relative peripheral refraction (RPR) characteristics in young adults and to investigate the relationship between RPR and retinal microvasculature using multispectral refractive tomography (MRT), a novel quantitative approach. METHODS: This cross-sectional study included 278 eyes of 139 young adults. All eyes underwent complete ophthalmic examinations, including MRT, optical coherence tomography angiography (OCTA) and other ocular examinations. Refraction difference values (RDVs) among different rings/sectors were compared using one-way ANOVA in bilateral eyes. Stepwise multiple linear regression analyses were performed between ∆RDV in different rings and ∆density/thickness value in OCTA. RESULTS: Among the different rings, the 30°-45°/45°-53° RDV was significantly greater than the inner rings in both eyes. Among the different sectors, RDV in the superior sector was most significantly reduced among all sectors, and RDV in the nasal sector was significantly greater than that in the temporal sector. In the stepwise multiple linear regression analyses, ∆RDV was negatively correlated with ∆radial peripapillary capillary plexus density and ∆macular thickness. CONCLUSIONS: MRT may be a useful tool in RPR quantitative assessment. RPR and some OCTA indexes might be closely correlated. Further research should be conducted to investigate the relationships among these indexes in young adults.

Global disease burden of uncorrected refractive error among adolescents from 1990 to 2019.

BACKGROUND: To estimate the global disease burden of uncorrected refractive error (URE) among adolescents and assess the contributions of various risk factors to disability-adjusted life-years (DALYs) due to URE. METHODS: Global, regional and country-level DALY numbers and rates due to URE among adolescents were acquired from the Global Burden of Disease Study 2019 database. Human Development Index (HDI), Socio-Demographic Index (SDI) and other country-level data were obtained from other open databases as potential indicators. Regression analysis was used to evaluate associations between DALY rates among adolescents and potential predictors. RESULTS: Global DALYs due to URE among adolescents rose by 8% between 1990 and 2019 but moderately decreased by 4.8% during this period after adjusting for population size. Female adolescents showed higher DALY rates. DALY rates sharply increased from 5 to 9 years of age, then rose more slowly, reaching a plateau before 20 years of age. Country-level DALY rates in 2019 were positively associated with HDI, SDI, and urbanization rates but negatively correlated with primary school dropout rates. Higher disease burden of adolescents visually impaired from URE was associated with lower primary school dropout rates (ß = - 0.257, 95% CI - 0.376 to - 0.138, P < 0.001) and higher urbanization rates (ß = 0.257, 95% CI 0.067 to 0.256, P = 0.001). CONCLUSIONS: Higher socioeconomic status, urbanization rates and education levels are associated with a heavier disease burden of URE among adolescents. The findings of this study can provide a reference for policy making on resource allocation for URE prevention and control in teenagers.

A Quantitative Comparison of Multispectral Refraction Topography and Autorefractometer in Young Adults.

Purpose: Purpose of this study is to evaluate the measuring consistency of central refraction between multispectral refraction topography (MRT) and autorefractometry. Methods: This was a descriptive cross-sectional study including subjects in Sun Yat-sen Memorial Hospital from September 1, 2020, to December 31, 2020, ages 20 to 35 years with a best corrected visual acuity of 20/20 or better. All patients underwent cycloplegia, and the refractive status was estimated with autorefractometer, experienced optometrist and MRT. We analyzed the central refraction of the autorefractometer and MRT. The repeatability and reproducibility of values measured using both devices were evaluated using intraclass correlation coefficients (ICCs). Results: A total of 145 subjects ages 20 to 35 (290 eyes) were enrolled. The mean central refraction of the autorefractometer was -4.69 ± 2.64 diopters (D) (range -9.50 to +4.75 D), while the mean central refraction of MRT was -4.49 ± 2.61 diopters (D) (range -8.79 to +5.02 D). Pearson correlation analysis revealed a high correlation between the two devices. The intraclass correlation coefficient (ICC) also showed high agreement. The intrarater and interrater ICC values of central refraction were more than 0.90 in both devices and conditions. At the same time, the mean central refraction of experienced optometrist was -4.74 ± 2.66 diopters (D) (range -9.50 to +4.75D). The intra-class correlation coefficient of central refraction measured by MRT and subjective refraction was 0.939. Conclusions: Results revealed that autorefractometry, experienced optometrist and MRT show high agreement in measuring central refraction. MRT could provide a potential objective method to assess peripheral refraction.

Predictive Equation for Angle Opening Distance at 750 µm After Laser Peripheral Iridotomy in Primary Angle Closure Suspects.

Aim: The aim of this study was to investigate the changes in anterior segment parameters as assessed by ultrasound biomicroscopy (UBM) after laser peripheral iridotomy (LPI) and to propose a prediction equation for the width of the angle after LPI. Design: This was a prospective study. Participants: The participants included 100 subjects with primary angle closure suspect (PACS). Methods: Anterior segment UBM parameters were measured, whereas AOD750 was chosen to indicate the width of the angle associated with gonioscopic angle closure, as found in a prior study. Main Outcome Measures: Angle parameters, iris parameters, anterior chamber parameters and ciliary body parameters. Results: All angle parameters increased after LPI, including the mean angle opening distance at 750 µm (AOD750), mean angle opening distance at 500 µm from the scleral spur (AOD500), mean angle opening distance at 750 µm from the scleral spur (AOD750), and mean angle recess area at 750 µm from the scleral spur (ARA750). Among iris parameters and ciliary body parameters, the iris thickness at 2,000 µm (IT2000), iris curvature (IC), and trabecular-ciliary process distance (ICPD) were reduced after LPI. The final equation consisted of four parameters: anterior chamber depth (ACD), iris thickness at 750 µm from the scleral spur (IT750), AOD750, and lens vault (LV). This equation explained 42.7% of the variability in the angle opening indicator AOD750 after LPI, whereas in the plateau iris configuration subgroup, the accuracy of the prediction equation reached the highest a maximum of 68.6%. Conclusions: There was an increase in angle opening and iris flattening after LPI. An equation involving four angle parameters was constructed, this equation which could explained 42.7% of the variability in the angle opening indicator AOD750 after LPI whereas in the plateau iris configuration subgroup, the accuracy of the prediction equation reached a maximum of 68.6%.

The Profile of Secondary Glaucoma in China: A Study of Over 10,000 Patients.

BACKGROUND: Few studies have investigated the epidemiology of secondary glaucoma (SG) in China. This study analyzed the current profile of admitted patients with SG at the largest ophthalmic center in China. METHODS: SG cases were retrieved retrospectively by International Classification of Disease-10 clinical coding data from January 2010 to December 2019. Demographic data, etiologies, and the management of SG were analyzed. The ratios of the etiologies were compared with previously reported data from other regions. The etiologies and management between the 2010 to 2014 group and the 2015 to 2019 group were compared. RESULTS: A total of 11,730 cases were enrolled. The mean age of the patients with SG was 44.45±19.45 years old. Men (66.94%) were more vulnerable than women (33.06%). The etiologies of SG in 2010 to 2019 were trauma (28%), vascular disease (18%), lens-induced (9%), inflammation (11%), drug-induced (2%), anterior segment surgery (7%), posterior segment surgery (11%), syndrome-associated (4%), and tumors (1%). Compared with other regions, our data have a higher proportion of trauma and vascular disease-associated SG. Compared with 2010 to 2014, trauma-induced SG declined, and drug-induced SG, anterior segment surgery, and syndrome-associated SG increased in 2015 to 2019 (P<0.001). Vascular disease-associated SG cases were older than trauma-induced SCs and had a higher percentage in retired patients (P<0.001), whereas trauma-induced SGs were more prevalent in pediatric patients than vascular disease-related SGs (P<0.001). In addition, the application of drainage device implantation, cataract surgery, and cyclophotocoagulation increased, whereas trabeculectomy and anterior chamber paracentesis and cyclocryotherapy decreased in 2015 to 2019 (P<0.005). CONCLUSION: Although the etiology spectrum has changed during the last 10 years, trauma and vascular disease are still common causes of SG in southern China. Traditional antiglaucoma surgery decreased gradually, and more advanced treatments emerged for its treatment. Up-to-date knowledge of SGs reflects the impact of economic development and ophthalmic service improvement on SGs and is of great value for ophthalmologists to detect SGs early and manage them in a timely manner.

The Clinical Features of Graves' Orbitopathy with Elevated Intraocular Pressure.

BACKGROUND: To investigate the clinical characteristics of Graves' orbitopathy (GO) with elevated intraocular pressure (IOP) using the European Group of Graves' Orbitopathy (EUGOGO) system. METHODS: In this retrospective study, the clinical data of GO patients with elevated IOP (≥21 mmHg) were collected in Sun Yat-sen Memorial Hospital from January 2010 to June 2016. The demographic characteristics, clinical history of thyroid disease and GO, and ocular examination data were evaluated, and the activity and severity of GO were classified. RESULTS: Data were collected from 58 eyes of 39 patients. The durations of thyroid disease and GO were 15.9 ± 18.9 months and 7.5 ± 6.2 months, respectively. The average IOP was 24.8 ± 5.3 mmHg (range: 21-55 mmHg). No significant difference in IOP was observed between active and inactive eyes. Eight eyes (13.8%), 29 eyes (50.0%), and 21 eyes (36.2%) were graded as mild, moderate-severe, and sight-threatening disease, respectively, according to the EUGOGO classification. The IOP was not significantly different among the three EUGOGO grades. No glaucomatous optic nerve damage or visual field defects were found. CONCLUSION: Increased IOP was evident for every grade of GO severity and activity of the EUGOGO system. IOP, glaucomatous optic nerve damage, and visual fields must be evaluated regularly during follow-up evaluations, regardless of the degree of activity and severity of GO.

Do microvascular changes occur preceding neural impairment in early-stage diabetic retinopathy? Evidence based on the optic nerve head using optical coherence tomography angiography.

AIMS: To evaluate the microvascular and neural differences of the optic nerve head (ONH) between type 2 diabetes mellitus (T2DM) subjects and controls. METHODS: This was a cross-sectional observational study. One hundred and eight eyes of 108 T2DM subjects with or without diabetic retinopathy (DR) (54 preclinical DR and 54 mild-to-moderate DR) were included. Fifty-two eyes of 52 healthy subjects were included as controls. The 4.5-mm Angio Disc scan mode and the ganglion cell complex scan mode were performed with all participants using AngioVue software 2.0 of the optical coherence tomography angiography (OCTA) device. RESULTS: Regarding ONH radial peripapillary capillary (RPC) density, the peripapillary region was mainly significantly reduced in the No-DR (NDR) group. Moreover, the RPC density of the peripapillary region and the inside optic disc area were significantly reduced in the non-proliferative DR (NPDR) group. When compared to the controls, significantly reduced peripapillary capillary density in six sections was observed in the NPDR group. However, reduced density was observed in only two sections in the NDR group. The NPDR group had significantly increased focal loss volume (FLV) and reduced peripapillary RNFL thickness in the inferior nasal section compared to those in the controls, but similar changes were not observed in the NDR group. A regression model identified RPCs inside the optic disc as a significant parameter in early-stage DR detection. In the NPDR group, BCVA showed a significantly negative correlation with RPCs inside the optic disc and a significantly positive correlation with FLV. CONCLUSIONS: OCTA findings of the ONH area may provide evidence that microvascular changes occur preceding neural impairment in early-stage DR. However, further researches are still needed to support the statement. Reduced ONH perfusion inside the optic disc may be one of the crucial biomarkers in early-stage DR detection and is a possible sensitive visual acuity predictor in early-stage DR subjects. With the ONH mode, OCTA may be a more promising tool in DR screening.

Comparison of efficacy between anti-vascular endothelial growth factor (VEGF) and laser treatment in Type-1 and threshold retinopathy of prematurity (ROP).

BACKGROUND: Retinopathy of Prematurity (ROP) is one of the most common causes of childhood blindness worldwide. Comparisons of anti-VEGF and laser treatments in ROP are relatively lacking, and the data are scattered and limited. The objective of this meta-analysis is to compare the efficacy of both treatments in type-1 and threshold ROP. METHODS: A comprehensive literature search on ROP treatment was conducted using PubMed and Embase up to March 2017 in all languages. Major evaluation indexes were extracted from the included studies by two authors. The fixed-effects and random-effects models were used to measure the pooled estimates. The test of heterogeneity was performed using the Q statistic. RESULTS: Ten studies were included in this meta-analysis. Retreatment incidence was significantly increased for anti-VEGF (OR 2.52; 95% CI 1.37 to 4.66; P = 0.003) compared to the laser treatment, while the incidences of eye complications (OR 0.29; 95% CI 0.10 to 0.82; P = 0.02) and myopia were significantly decreased with anti-VEGF compared to the laser treatment. However, there was no difference in the recurrence incidence (OR 1.86; 95% CI 0.37 to 9.40; P = 0.45) and time between treatment and retreatment (WMD 7.54 weeks; 95% CI 2.00 to 17.08; P = 0.12). CONCLUSION: This meta-analysis indicates that laser treatment may be more efficacious than anti-VEGF treatment. However, the results of this meta-analysis also suggest that laser treatment may cause more eye complications and increase myopia. Large-scale prospective RCTs should be performed to assess the efficacy and safety of anti-VEGF versus laser treatment in the future.

TLR7 deficiency contributes to attenuated diabetic retinopathy via inhibition of inflammatory response.

Diabetic retinopathy (DR) is a major microvascular complication of diabetes, resulting in neuronal dysfunction, retinal vascular leakage, and apoptosis within the retina. Innate immunity plays an important role in the pathogenesis of type 2 diabetes (T2D) and related complications. The toll-like receptors (TLRs), central to innate immunity, are essential participants in the progression and pathogenesis of the disease and its complications. In the study, streptozotocin (STZ) was combined with whole-body hypoxia for quicker induction of early-stage diabetic retinopathy (DR) in the wild type (WT) and TLR7-knockout (KO) C57BL/6 mice. The effects of TLR7 were also investigated in fructose-treated retinal pigment epithelial (RPE) cells. In the retinas of WT/DR mice, abnormal a-wave and b-wave activity, hyperfluorescence, and reduced retinal thickness were observed. DR development was associated with enhanced TLR7 expression, whose deletion dramatically reduced VEGF expression levels. And the secretion of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-6, IL-18 and IL-12, was highly reduced by TLR7-deficiency in DR mice. Consistently, WT/DR mice exhibited higher phosphorylation of IκB kinase α (IKKα), inhibitor of NF-κB α (IκBα) and nuclear factor κB (NF-κB), which were found to be down-regulated in KO/DR mice. Similarly, DR-induced mitogen-activated protein kinases (MAPKs) activation was blocked by TLR7-knockout. In vitro, fructose incubation-triggered inflammation was reversed by TLR7 knockdown, accompanied with inactivated NF-κB and MAPKs pathways. And reduced reactive oxygen species (ROS) generation was observed in TLR7-knockdown cells with fructose treatment. Together, inhibiting TLR7 suppressed diabetic retinopathy by reducing inflammation and suggested a potential application in clinics.

The effect of spectral property and intensity of light on natural refractive development and compensation to negative lenses in guinea pigs.

PURPOSE: To investigate the effect of spectral composition and light intensity on refractive development in guinea pigs. METHODS: One-week-old guinea pigs were randomly assigned to groups exposed to broad-spectrum Solux halogen light (BS) or spiked-spectrum fluorescent light (FL) at both high (Hi, 10,000 lux) and low (Lo, 500 lux) intensities under a 12:12 light/dark cycle. Half of the animals in each group were used as controls (n = 24, 20, 22, and 20, respectively), and half were fitted with binocular -4-diopter (D) lenses (L, lenses; n = 22, 20, 24, and 22, respectively). Refractive error, corneal curvature, and axial dimensions were determined by cycloplegic retinoscopy, photokeratometry, and A-scan ultrasonography, respectively. RESULTS: Guinea pigs exposed to FL and BS showed similar changes in refraction under both high (HiFL: 2.26 ± 0.55 D versus HiBS: 2.17 ± 0.65 D, P > 0.05)- and low-intensity lighting (LoFL: 1.39 ± 0.88 D versus LoBS: 1.40 ± 0.93 D, P > 0.05). This was also true for the groups wearing lenses (HiFL-L: -1.81 ± 0.73 D versus HiBS-L: -1.45 ± 0.99 D, P > 0.05; LoFL-L: -2.58 ± 0.65 D versus LoBS-L: -2.29 ± 0.50 D, P > 0.05). Nevertheless, animals under high-intensity lighting exhibited a significantly larger hyperopic shift compared with those under low-intensity lighting (HiFL versus LoFL: P < 0.01; HiBS versus LoBS: P < 0.05). Similarly, a significantly smaller myopic shift was observed with brighter light in the lens condition (HiFL-L versus LoFL-L: P < 0.05; HiBS-L versus LoBS-L: P < 0.05). CONCLUSIONS: In guinea pigs, spectrally spiked light and broad-spectrum light have similar effects on natural refractive development and negative lens compensation. As found in other species, effects of light intensity on refractive development were also observed in guinea pigs in both illuminants.

Treatment outcomes of myopic anisometropia with 1% atropine: a pilot study.

PURPOSE: To investigate the safety and efficacy of the treatment of myopic anisometropia with 1% atropine. METHODS: Twenty-two children with myopic anisometropia were prescribed 1% solution of atropine sulfate to the more myopic eye, one drop before sleep every 3 days. Children were visited every 3 to 4 months until the degree of anisometropia was no more than 0.5 diopters (D) ("Success") or unchanged after 9 months of treatment ("No effect"). The treatment effect was assessed by comparing the interocular imbalance in refraction and axial length before and after the treatment. A detailed questionnaire about subjective symptoms in each visit and an electroretinogram in the end were administered to evaluate the side effects of this treatment. RESULTS: The subjects were followed for 7 to 16 months. Six subjects withdrew participation on their own accord, and three were excluded because of inconstant usage of drug. Of the 13 remaining subjects, the refraction of the treated eyes decreased by 0.63 ± 0.59 D (p = 0.007), whereas that of the untreated eyes increased by -0.72 ± 0.65 D (p < 0.001). A corresponding trend was also found in the change of the axial length. Accordingly, the level of anisometropia was reduced from 1.82 ± 0.73 D to 0.47 ± 0.65 D (p < 0.001) and 10 (76.9%) of the 13 subjects were designated a "Success." One percent atropine was well tolerated by the children, and no electroretinogram abnormality was detected. CONCLUSIONS: The results from this pilot study indicate that monocular usage of a solution of 1% atropine sulfate is an effective treatment to reduce anisometropia, although with some tolerable side effects. Nevertheless, an attenuated benefit was observed after cessation of atropine treatment. Thus, participants should be informed of a possible rebound effect before the administration of atropine for myopic anisometropia.