Spectacle Correction Research Articles

Spectacle correction versus no spectacles for prevention of strabismus in hyperopic children.

Hyperopia in infancy requires accommodative effort to bring images into focus. Prolonged accommodative effort has been associated with an increased risk of strabismus. Strabismus may result in asthenopia and intermittent diplopia, and makes near work tasks difficult to complete. Spectacles to correct hyperopic refractive error is believed to prevent the development of strabismus. To assess the effectiveness of prescription spectacles compared with no intervention for the prevention of strabismus in infants and children with hyperopia. We searched CENTRAL (2018, Issue 12; which contains the Cochrane Eyes and Vision Trials Register); Ovid MEDLINE; Embase.com; three other databases; and two trial registries. We used no date or language restrictions in the electronic search for trials. We last searched the electronic databases on 4 December 2018. We included randomized controlled trials and quasi-randomized trials investigating spectacle intervention or no treatment for children with hyperopia. We required hyperopia to be at least greater than +2.00 diopters (D). We used standard Cochrane methodological procedures. The primary outcome was the proportion of children with manifest strabismus, as defined by study investigators. Other outcomes included the amblyopia, stereoacuity, and the effect of spectacle use of strabismus and visual acuity. We also collected information on change in refractive error as a measurement of the interference of emmetropization. We identified four randomized controlled trials (985 children enrolled who were aged six months to less than 36 months) in this review. Three trials were in the UK with follow-up periods ranging from one to 3.5 years and one in the US with three years' follow-up. Investigators reported both incidence and final status regarding strabismus. Evidence of the incidence of strabismus, measured in 804 children over three to four years in four trials was uncertain although suggestive of a benefit with spectacle use (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.41 to 1.02). We have very low confidence in these results due to high risk of bias, inconsistency, and imprecision. When assessed as the proportion of children with strabismus at the end of three years' follow-up, we found a similar level of evidence for an effect of spectacles on strabismus as reported in one study (RR 1.00, 95% CI 0.31 to 3.25; 106 children). We have very low confidence in these results because of low sample size and risk of bias. One trial reported on the risk for developing amblyopia and inadequate stereoacuity after three years in 106 children. There was unclear evidence for a decreased risk of developing amblyopia (RR 0.78, 95% CI 0.31 to 1.93), and limited evidence for a benefit of spectacles for prevention of inadequate stereoacuity (RR 0.38, 95% CI 0.16 to 0.88). We have very low confidence in these findings due to imprecision and risk of bias. The risk of not developing emmetropization is unclear. One trial reported on the proportion of children not achieving emmetropization at three years' follow-up (RR 0.75, 95% CI 0.18 to 3.19). One trial suggested spectacles impede emmetropization, and one trial reported no difference. These two trials could not be combined because the methods for assessing emmetropization were different. With the high risk of bias and inconsistency, the certainty of evidence for a risk for impeding or benefiting emmetropization is very low. Based on a meta-analysis of four trials (770 children), the risk of having visual acuity worse than 20/30 measured up to three years of age or at the end of three years of follow-up was uncertain for children with spectacle correction compared with those without correction (RR 0.87, 95% CI 0.64 to 1.18; very low confidence due to risk of bias and imprecision). The effect of spectacle correction for prevention of strabismus is still unclear. In addition, the use of spectacle on the risk of visual acuity worse than 20/30, amblyopia,and inadequate emmetropization is also unclear. There may be a benefit on prevention of inadequate stereoacuity. However, these effects may have been chance findings or due to bias.

Associations between visual-related quality of life and monocular or binocular quick contrast sensitivity function in early cataract patients

Objective To assess the association between visual-related quality of life (QOL) and the severity of quick contrast sensitivity function (qCSF) defects in patients with early cataract. Methods A cross section design was performed.Ninety-two eyes of 46 patients with early cataract were enrolled in Zhongshan Ophthalmic Center from March to June in 2017.All subjects completed the Chinese version of the National Eye Institute Visual Function Questionnaire (NEI VFQ-25). The qCSF measurements were performed monocularly and binocularly while the patients wearing full spectacle correction spectacles.Rasch analysis was performed to obtain final NEI VFQ-25 scores.Best corrected visual acuity (BCVA)(LogMAR) was measured and the eye with the better or the worse visual acuity was defined accordingly.The correlation between the Rasch calibrated QOL composite scores and the qCSF measurements of the better eye, the worse eye and binoculus, including the area under Log contrast sensitivity function (AULCSF), qCSF under cut-off frequency and 1.0, 1.5, 3.0, 6.0, 12.0, 18.0 c/d were analyzed.This study protocol was approved by the Ethic Committee of Zhongshan Ophthalmic Center.This study complied with Declaration of Helsinki. Results The Rasch calibrated QOL composite score was 64.13±4.76.Significant negative correlations were found between composite scores of QOL and the BCVA of both the better or worse eye(the better eye: r=-0.386, P=0.008; the worse eye: r=-0.413, P=0.004). Significant positive correlations were found between the composite scores of QOL and the AULCSF of binoculus, the better and worse eye (binoculus: r=0.531, P<0.001; the better eye: r=0.524, P<0.001; the worse eye: r=0.711, P<0.001); Significant positive correlations were found between the composite scores of QOL and the qCSF under cut-off of binoculus, the better and worse eye (binoculus: r=0.504; the better eye: r=0.419; the worse eye: r=0.694, P<0.01). The composite scores of QOL was positively correlated with the qCSF under 1.5, 3.0, 6.0, 12.0 c/d of binoculus, the better and worse eye (binoculus: r=0.444, 0.544, 0.545, 0.493; all at P<0.05; the better eye: r=0.374, 0.506, 0.530, 0.431; all at P<0.05; the worse eye: r=0.513, 0.679, 0.710, 0.558; all at P<0.05). The composite scores of QOL was positively correlated with the qCSF under 1.0, 18.0 c/d of binoculus and the worse eye (1.0 c/d: r=0.296, 0.292; both at P<0.05; 18.0 c/d: r=0.386, 0.321; both at P<0.05). Conclusions The qCSF measurements can reflect visual function of patients with early cataract at different spatial frequencies.The qCSF measurements of binoculus, the better eye and the worse eye show significant correlations with the composite scores of QOL.The QOL of early cataract patients shows a strong dependency on the worse eye. Key words: Quick Contrast Sensitivity Function; Quality of life; Cataract

Systemic Disease Comorbidities among Ophthalmic Patients in Nigeria: Implications for Preventive Ophthalmology

Background/Aim: Quite often patients who are refracted in our clinics have other ocular or systemic conditions that may affect the result or delay the issuance of spectacle corrections – for instance poorly controlled diabetic patients may have to wait for months to achieve better control of their condition. These associated comorbidities may require medical or surgical intervention before spectacles are ordered. The aim of this study is to determine the systemic comorbidities that exist in ophthalmic patients attending the Nigerian National Petroleum Corporation (NNPC) Eye Clinic in Port Harcourt, Nigeria.&#x0D; Methodology: This was a descriptive cross-sectional study in which adult patients who presented in the clinic for change of glasses within the stipulated period of the study were included. They were interviewed to get the relevant information and the data retrieved for each patient included baseline information such as age, gender, unaided visual acuity, visual acuity with their last correction if any as well as co-existing ocular or systemic pathology. The collected data was subsequently analysed using Predictive Analysis Software version 20.&#x0D; Results: Sixty patients participated in study; both males and females were equally represented. Of this this number, thirty-three patients (55%) had systemic comorbidities .Hypertension was present in 43.3% (n=26) while both hypertension and diabetes mellitus occurred in 10% (n=6) of the participants. Forty percent of those with refractive error had hypertension while about 30% of those with glaucoma were both hypertensive and diabetic.&#x0D; Conclusion: There is a very high level of systemic comorbidities in adult patients attending this peripheral clinic, and this is a pointer to the high prevalence of these conditions in the larger population.

Accommodative anomalies in children.

Asthenopic and related symptoms are a major problem in school-going children. With the inception of computers and other gadgets for near work, the unseen problems arising out of constant and continuous near work, are on the rise. Parents wander from pillar to post, seeking respite from their child's constant complaints from near work; but despite best spectacle correction and avoidance of excessive near work, the complaints continue. Studies have shown that the majority of these problems arise from defects in accommodation, even in a young child. Therefore, various aspects of accommodation deficiencies have to be studied clinically, detected, and treated to ameliorate the symptoms.

Prevalence of Ocular and Visual Anomalies in Students with Autism Spectrum Disorder (ASD)

Purpose: To determine the prevalence of ocular and visual anomalies in students with Autism Spectrum Disorder (ASD). Methods: This case-series in 2015-16 included students with ASD of two special schools of Bangalore, India. Comprehensive ocular and vision examination also included accommodation by dynamic retinoscopy and convergence. The amplitude of accommodation was calculated by Hofstetter minimum formula. The accommodative facility was measured by referring to the cycles of accommodative flippers, used ± 2.50D and 14 cycles/min considered as normal. Saccades were tested using Marsden ball movements. Additional eye testing at our institute was with Vision therapy system, ocular motility testing and alternate prism cover test. Result: The 120 students with ASD had a mean age of 12.9 ± 1.7 years. They included autism 58 (48.3%), ASD 27 (22.5%) and other 34 (28.3%). Spectacles correction was needed in 62 (51.7%) students. Refractive error included myopia (57; 92%), hyperopia (5; 8%), myopic astigmatism (3; 4.8%), and mixed astigmatism (2; 3.2%). The compliance of spectacle wear was 12/62 (19.4%) only. Strabismus was seen in 68 (56.7%) students. Accommodative convergence was 4 to 28 mm. Non-accommodative convergence was 4 to 37 mm. Pursuit movements were poor in 35 (29.2%), average in 39 (32.5%), good in 46 (38.3%) students. The saccadic eye movements were good in 100 (83.3%), average in 15 (12.5%) and poor in 5 (4.2%) students. Conclusion: More than half of students with ASD had at least one ocular morbidity. The commonest was refractive errors followed by strabismus. Periodic and comprehensive ocular assessment of autistic students is recommended.

Сравнительный анализ фузионных резервов у детей со слабой и средней степенью миопии на фоне очковой и ортокератологической коррекции

Сравнительный анализ фузионных резервов у детей со слабой и средней степенью миопии на фоне очковой и ортокератологической коррекции

Comparative analysis of the functional results after implantation of various diffractive trifocal intraocular lenses

To compare visual outcomes after implantation of two models of diffractive trifocal IOLs using various vision assessment systems. The study included 25 patients (25 eyes) who were implanted with AcrySof IQ PanOptix (TFN) and 25 patients (25 eyes) implanted with AT LISA tri 839 MP (TRI). Postoperative examination at 1 year included assessment of monocular visual acuity for far, intermediate and near distance using decimal scale, as well as LogMAR and an interactive computer program (ICP). Contrast sensitivity was assessed with the Optec 6500 device. A questionnaire was used to evaluate subjective quality of vision and the intensity of optical phenomena. Uncorrected visual acuity (UCVA) at distance, intermediate and near was better in the TFN group in comparison with the TRI group as measured with decimal scale, ICP and LogMAR. Under photopic and mesopic conditions with and without glare, at all spatial frequencies the contrast sensitivity function (CSF) was higher after implantation of TFN in comparison with TRI. The average VF-14 score was 97.2 after implantation of TFN and 96.7 after implantation of TRI. The amount of patients who required spectacle correction after the surgery was 5.5% less in the TFN group compared to the TRI group. High visual outcomes at all distances were observed in patients after implantation of both trifocal IOLs with TFN showing a slight advantage. Evaluation of the visual outcomes using various systems showed the benefits of the ICP assessment. The CSF had typical configuration with maximum value in the mid-range region and a decrease in the high-frequency range after implantation of both IOLs, however the indicators were better in the TFN group. The postoperative period was characterized by high levels of patient satisfaction and spectacle independence in both groups.

Canadian Opinions on Refractive Surgery and Approaches to Presbyopia Correction.

Purpose:To explore the opinions of Canadian ophthalmologists on refractive and presbyopia-correcting surgeries.Methods:We distributed an online survey to the Canadian Ophthalmological Society members, covering laser refractive surgery (LRS), femtosecond laser-assisted cataract surgery (FLACS), lenticular refractive surgery (lenRS) that includes cataract refractive surgery (CRS) with premium intraocular lens (IOL) implantation, and presbyopia correction.Results:There were 68 (7.6%) total respondents. Most respondents would not consider LRS (62.5%) nor FLACS (73.9%) for themselves. Male sex and performance of LRS or FLACS was significantly associated with consideration of these procedures for self. Most respondents (59.3%) would consider lenRS for themselves. The top method of personal presbyopia correction was spectacles, chosen by 52.5%.Conclusions:When surveying the wide body of Canadian ophthalmologists, most respondents preferred spectacle correction of presbyopia and would consider lenRS, but not LRS or FLACS for themselves. Surgeons performing these procedures were more likely to consider them for self.

Strabismus and oculomotor disorders induced by injection anesthesia for cataract surgery

To analyze diagnostic and treatment outcomes in patients with strabismus and oculomotor disorders induced by injection anesthesia for cataract surgery. The study included 11 patients (7 women and 4 men) aged 61 to 85 years (the mean age of 66±7.1 years) who complained of diplopia in the early post-op period after cataract phacoemulsification and elastic IOL implantation under retrobulbar anesthesia. Prior to further surgical treatment, all of the patients underwent functional multispiral computer tomography of the orbits. Prismatic spectacle correction was also used independently or in addition to surgical treatment. Eight out of eleven patients underwent one- or two-step surgical treatment (3 and 5 cases, respectively). In 2 patients, hypotropia did not exceed 10 prism diopters, and thus, diplopia could be compensated with prismatic spectacle correction alone. In 5 cases, binocular vision was achieved throughout the whole field of gaze. In 3 cases, surgical treatment enabled elimination of heterotropia in the primary gaze and compensation of diplopia within a radius of 40º from the center of gaze and within the entire horizontal range of eye-movement in the downward gaze. The limitation of ocular mobility decreased from 2.36 to 0.55 points leading to an associated decrease in the area of binocular diplopia - from 98% to 29%. In one case, spectacle occlusion was used. The inferior rectus restriction is the morphological substrate of anatomical and functional changes induced by retrobulbar anesthesia. As treatment options for restrictive vertical strabismus and binocular diplopia, both surgical (extraocular muscle surgery) and optical (prismatic correction, occlusion) methods should be considered.

Results of surgical treatment of complicated uveal cataract

A retrospective analysis of the results of surgical treatment of complicated uveal cataracts of different origin. The study analyzed the results of surgical treatment of uveal cataract in 30 patients (34 eyes) who were divided into three groups by uveitis etiology. The first group included 11 patients with spondyloarthritis associated with the HLA-B27 antigen; the second group included 10 patients with juvenile chronic arthritis and spondyloarthritis, negative for HLA-B27 antigen; the third group consisted of 9 patients with other systemic autoimmune diseases and uveitis of unknown etiology, also negative for the HLA-B27 antigen. The average age of the patients was 35.8±2.6; 30.8±3.8 and 34.0±2.3 years, respectively. Four patients (6 eyes) with juvenile chronic arthritis and severe ribbon-like corneal degeneration underwent standard intracapsular cataract cryoextraction with subsequent spectacle correction of aphakia. In other cases, ultrasound phacoemulsification with implantation of an intraocular lens (IOL) was used as a surgical aid. Regardless of the surgery technique and the cause of uveal cataract, a statistically significant decrease in the number of exacerbations per year (p<0.0001) and an increase in best corrected visual acuity (BCVA) were noted after its removal. In the long-term follow-up (2-24 months), 9 patients experienced persistent decompensation of the IOP level, which required various types of antiglaucoma surgery. Surgical treatment of uveal cataracts of various etiologies with adequate pre- and postoperative therapy provides an improvement in visual acuity and a reduction in the frequency of inflammation recurrence. Considering the high likelihood of IOP decompensation in the long-term postoperative period, IOP control should be given attention in such cases.

Clinical Profile on Keratoconus Presenting at A Tertiary Eye Care Centre- Tilganga Institute of Ophthalmology.

Keratoconus (KC), is a bilateral, noninflammatory degenerative disease of the cornea which is characterized by progressive corneal ectasia and loss of visual function. The onset of KC is commonly seen at puberty and affects approximately 1 in 2000 in the general population. The aim of this study was to assess the clinical profile of keratoconus in the tertiary eye centre in Nepal. It is a retrospective, hospital based, consecutive study from June 2017 to May 2018. A total of 66 patients (114 eyes) were diagnosed cases of Keratoconus presented in Cornea clinic of Tilganga institute of Ophthalmology. Parameters investigated included patients' demography, keratometric readings, visualacuity and manifest refraction. Classification of keratoconus was based on Amslern-Krumeich grading system (modified). The mean age of subjects was 18.73 (range: 10-65). Male/female distribution was 48 (72.7%) and 18 (27.3%) respectively. 48 (72.7%) had bilateral keratoconus and 18 (27.3%) were unilateral. Mean Uncorrected visual acuity (UCVA) was 0.80 (range: 0.01-1.00), mean visual acuity ( VA) with spectacle correction was 0.47 (range: 0.01-1.00). Mean spherical amount of refractive was -2.17 (range: -0.50 to -17.00D) and mean cylindrical amount of refraction was -2.85 (range: 0.00 to -6.00). Mean spherical equivalent (SE) of refraction was -4.26 (range: -0.50 to -22.50D). Mean flattest keratometric reading (K1) was 49.63 (range: 40.63-76.70D) and mean steepest keratometric reading (K2) was 53.14 (range: 41.63-73.21D). Mean average keratometric reading was 51.43 (range: 41.63-72.10D). Regarding disease severity, 35.68% of subjects were classified as mild keratoconus, 29.73% as moderate keratoconus, 9.73% as advance keratoconus, while 24.86% were found with the severestage of keratoconus. 78.9% of total eyes presented with minimum pachymetry of 401 to 500 mm. Clinical profile of Nepalese keratoconus patients looks similar to that reported earlier worldwide. The condition was found to manifest at a younger age and was more common in males.

Modern optical methods of peripheral defocus correction

Experimental animal studies proved that by manipulating with the defocus one can slow down or speed up the eye growth. The leading mechanism among modern optical strategies of myopia progression treatment is to induce myopic defocus to retinal periphery or decrease the hyperopic defocus. This review sums up the data on peripheral refraction in orthokeratological, multifocal contact, and multifocal spectacle correction. The effectiveness of these methods in myopia control in children and teenagers is shown.

A case of choroidal osteoma in a 5‐year‐old child

AbstractPurposeTo report a case of choroidal osteoma (CO) in a 5‐year‐old boy.MethodsCase reportResultsA 5‐year‐old child presented with decreased vision in both eyes. His best‐corrected visual acuity (BCVA) was 20/50 in the right eye (OD) and 20/100 in the left eye (OS). The anterior segment was normal in both eyes. Cycloplegic refraction was +2.50 ‐2.25 x 10 in the OD and +3.25 ‐2.50 x 180 in the OS. Funduscopy of the OS revealed a large subretinal, yellowish lesion in the juxta‐papillary area. B‐scan ultrasonography of the OS revealed a dense echogenic plaque with acoustic shadowing. The axial CT scan also showed a calcified lesion in the posterior pole. Optical coherence tomography (OCT) was normal at the fovea but revealed subretinal fluid (SRF) at the superior temporal vascular arcade. Spectacle correction was prescribed and alternating part‐time occlusion was performed. The patient was asked to come for regular follow‐up. Six months later his BCVA was 20/25 in both eyes, no variations of the mass were noted and the SRF disappeared.ConclusionsOC is a rare, benign ossifying tumor. It is typically found in healthy young women, mostly unilateral, in the posterior pole of the eye, near the optic disc. It is relatively rare in children. OC must be differentiated mainly from amelanotic choroidal melanoma, choroidal nevus, choroidal hemangioma, choroidal metastasis, sclerochoroidal calcification and posterior scleritis. In children it can pose a serious diagnostic challenge as it can mimic other lesions at posterior pole, such us retinoblastoma, retinochoroidal coloboma, and toxoplasmic retinochoroiditis. Asymptomatic or stable CO can be observed. For choroidal neovascular membranes photodynamic therapy and laser treatment have been used in the past. More recently, anti‐VEGF treatments have been employed with success.

Kinetic visual acuity, stereopsis, and ocular deviation with an implantable collamer lens

To compare kinetic visual acuity, stereopsis, ocular deviation, and fusion amplitude before and after implantable collamer lens (ICL) surgery. Sanno Hospital. Retrospective analysis. The charts of adult patients who underwent implantation of an ICL with a central aquaport (V4c) for emmetropia were reviewed. The mean preoperative spherical equivalent and subjective astigmatism were -7.87 diopters (D)±3.13 (SD) and -0.75±0.78 D, respectively. All measurements were obtained with full refraction before surgery and without spectacle correction after surgery. The kinetic visual acuity was measured with the AS-4D device. Stereopsis and ocular deviation were measured with the Titmus Stereotest and an alternate prism cover test, respectively. Fusion amplitude was determined from breakpoints measured using a prism. The study comprised 29 adult patients (58 eyes). One month postoperatively, the mean safety and efficacy indices were 1.13 ± 0.20 and 0.96 ± 0.25, respectively, and 57 eyes (98.7%) were within ±0.5 D of the target correction. The mean kinetic visual acuity (logarithm of the minimum angle of resolution) was 0.30 ± 0.21 preoperatively and 0.20 ± 0.15 (Snellen 20/40 versus 20/32) postoperatively and the mean stereopsis (seconds of arc), 48.5 ± 1.6 versus 41.5 ± 1.1; both improved significantly (P < .001 and P = .012, respectively). The mean distance ocular deviation (-4.0 ± 3.8 prism diopters [Δ] versus 2.8 ± 3.6 Δ; P = .002) and near ocular deviation (-6.5 ± 6.7 Δ versus 5.4 ± 6.9 Δ; P = .04) decreased significantly. The fusion amplitude increased for near vision only. ICL implantation improved kinetic visual acuity and stereopsis, decreased ocular deviation, and increased near fusion amplitude.

December consultation #5

To compare kinetic visual acuity, stereopsis, ocular deviation, and fusion amplitude before and after implantable collamer lens (ICL) surgery.Sanno Hospital.Retrospective analysis.The charts of adult patients who underwent implantation of an ICL with a central aquaport (V4c) for emmetropia were reviewed. The mean preoperative spherical equivalent and subjective astigmatism were −7.87 diopters (D) ± 3.13 (SD) and −0.75 ± 0.78 D, respectively. All measurements were obtained with full refraction before surgery and without spectacle correction after surgery. The kinetic visual acuity was measured with the AS-4D device. Stereopsis and ocular deviation were measured with the Titmus Stereotest and an alternate prism cover test, respectively. Fusion amplitude was determined from breakpoints measured using a prism.The study comprised 29 adult patients (58 eyes). One month postoperatively, the mean safety and efficacy indices were 1.13 ± 0.20 and 0.96 ± 0.25, respectively, and 57 eyes (98.7%) were within ±0.5 D of the target correction. The mean kinetic visual acuity (logarithm of the minimum angle of resolution) was 0.30 ± 0.21 preoperatively and 0.20 ± 0.15 (Snellen 20/40 versus 20/32) postoperatively and the mean stereopsis (seconds of arc), 48.5 ± 1.6 versus 41.5 ± 1.1; both improved significantly (P < .001 and P = .012, respectively). The mean distance ocular deviation (−4.0 ± 3.8 prism diopters [Δ] versus 2.8 ± 3.6 Δ; P = .002) and near ocular deviation (−6.5 ± 6.7 Δ versus 5.4 ± 6.9 Δ; P = .04) decreased significantly. The fusion amplitude increased for near vision only.ICL implantation improved kinetic visual acuity and stereopsis, decreased ocular deviation, and increased near fusion amplitude.

Patterns of Use and Knowledge about Contact Lens Wear amongst Teenagers in Rural Areas in Malaysia.

Background: Contact lenses (CLs) are more popular than spectacles for vision correction amongst the youth. Knowledge about the risks of wearing CLs is critical especially for those with poor access to public health education. This study investigates the patterns of use and level of knowledge about CL wear amongst teenagers living in rural areas in Selangor, Malaysia using a set of validated questionnaires. Methods: A total of 8500 self-administered questionnaires were distributed in eight selected secondary schools. The results were analysed using descriptive statistics. Results: A total of 2474 (29%) completed questionnaires were collected. The mean age of the respondents was 14.8 ± 1.5 years, and approximately 7.2% were CL wearers. The majority of the wearers were females (76.0%) and wore soft CLs (92.2%). Cosmetic purposes (58.1%) and comfort (24.6%) were the main reasons for wearing CLs. Many of the respondents purchased their lenses from optical shops (50.1%) and beauty accessory shops (15.6%), and approximately 10% did not disinfect their lenses properly. Regarding knowledge about CL care, approximately 56% of the respondents responded correctly. Conclusion: Half of the respondents do not have sufficient knowledge about the risks of wearing CLs. Thus, aggressive public health education aimed at teenagers is needed to prevent improper CL usage.

Effect of Primary Occlusion Therapy in Asymmetric, Bilateral Amblyopia

Many bilateral amblyopia patients have asymmetric visual acuity (VA). There is no standard treatment for these patients, and outcomes have not been well described. Our goal is to compare VA outcomes in this group based on timing of occlusion therapy. Retrospective interventional comparative case series. Setting: Institutional practice. PatientPopulation: Patients diagnosed with amblyopia at Boston Children's Hospital between 2010 and 2014. InclusionCriteria: VA ≥ 0.3 logMAR bilaterally by objective optotype-based measures, interocular difference (IOD) ≥ 0.18 logMAR, age 2-12 years. ExclusionCriteria: Loss to follow-up, managed surgically, deprivation amblyopia. Patients had either primary or secondary occlusion (primary= initiated when VA ≥ 0.3 logMAR bilaterally; secondary= initiated to correct residual IOD once VA improved to ≤0.18 logMAR in the stronger eye). ObservationProcedure: Patient demographics, VA, IOD, and stereopsis were compared between groups. OutcomeMeasures: VA improvement at 12-18months and at last visits. Of 2,200 patients reviewed, 167 (7.6%) had asymmetric, bilateral amblyopia; 98 met inclusion and exclusion criteria. Patients were equally divided between primary (n= 50) and secondary (n= 48) occlusion groups. There were no differences in demographics, baseline VA, or IOD between groups (P ≥ .22), although the primary occlusion group had a higher proportion of strabismic amblyopia (P= .007). VA in both eyes, IOD, and stereopsis improved similarly between groups, even after stratifying by amblyopia subtype (P ≥ .48). The secondary occlusion group was more likely to achieve 20/30 bilaterally and IOD ≤ 1 line at 12-18months (P ≤ .4), although this equalized by the last visit. In patients with asymmetric, bilateral amblyopia, VA improved by 4 lines in the weaker eye and 2 lines in the stronger eye, while IOD improved by 2 lines, irrespective of occlusion status. Primary occlusion thus provided no further benefit over spectacle correction alone.

Результаты использования альтернирующего предъявления различных стереостимулов для исследования способности к стереовосприятию у детей с послеоперационной остаточной микродевиацией

Purpose. To study abilities to stereo-perception in children with postoperative residual micro-deviation via alternating presentation of different stereo stimuli. Material and methods. The study included 30 children aged 8 to 16 years (average 12.5 years) with operated strabismus who have postoperative residual micro-deviation (mean 6.8±0.4 pr.D) at the time of the observation. Residual esotropia was observed in 21 children (5 of them had also a vertical micro-deviation), exotropia – 9 children. Along with the usual ophthalmic examination and evaluation of stereovision by means of classical Lang-test and Fly-test we used our own stereo-tests developed on the basis of stereo images created by J. Ninio. Our stereo-tests included stimuli: 1) with a central location of vertical or horizontal stripes with a successful fusion and an ability to stereo perception of tilt relative to the horizontal axis (vertical strip) or turn around the vertical axis (horizontal strip); 2) with a peripheral location of vertical or horizontal stripes creating respectively the effect of tilt or reversal turn; 3) randomly-point stereo-grams, creating the impression of a successful fusion of vertical or horizont al cylinder. The subject observed the images shown on the monitor screen from a distance of 50 cm from the eyes through the red-blue light filters in conditions of full prismatic compensation of the angle of strabismus and optimal spectacle or contact correction of ametropia. The stimuli were presented both in the static version and in the modes of alternation via a computer pr ogram developed by M. V. Zhmurov. Three modes of alternative presentation of stimuli were used: 1) the mode with a consecutive monocular presentation of visual stimuli corresponding to the right and left eyes 2) the mode with the presence of an empty interval between monocular phases; 3) the mode with the presence of a binocular phase between monocular phases. Results. In all patients, the results of the study of stereovision with Lang-test, Fly-test and static version of our stereo-tests used in this work were negative. In eight children of the general group, the stereo effect appears only with stereo-images with a peripheral arrangement of vertical or horizontal stripes in all three modes of the alternating presentation. In 22 children, the stereo effect appears with stimuli both with peripheral and with the central location of the stripes in all three modes of their alternating presentation. The volume effect with random-dot stereo-stimuli occurred in only nine children, with a stable bifoveal fusion, and only in the mode of alternating presentation with an empty interval between monocular phases. Thus, in this mode of alternating presentation it was possible to perceive not only linear, but also random-dot stereo-images. Comparing the maximum durations of monocular phases for different images in this mode, a significant difference was found between the mean values for stimuli with peripheral vertical stripes (57±2.3 ms) and with central vertical stripes (43.2±2.6 ms; p<0.001), as well as between the mean values for stimuli with peripheral horizontal stripes (56±2.1 ms) and central horizontal stripes (43.6±3.4 ms; p<0.002). The maximum duration of monocular phases for random-dot stereo-images producing the effect of a vertical cylinder (32.2±5.8 ms) and a horizontal cylinder (31.1±6.7 ms) was significantly lower than the maximum duration for stimuli with peripheral vertical and horizontal stripes (p<0.001). The same regularities were observed for the maximum dur ation of the empty i nterval. Conclusion. The stereo-perception is possible in children with residual postoperative micro-deviation. At the same time, the most effective of the images we used are stimuli with a peripheral arrangement of elements that create a stereo effect in condition of a successful fusion. The mode of alternating presentation of stimuli with the presence of an empty interval between monocular phases creates more favorable conditions for the appearance of a stereo effect in comparison with the mode of alternating presentation of stimuli with the presence of a binocular phase between monocular phases and in comparison with the mode of alternating monocular phases. Stereovision with random-dot stereograms causes serious difficulties in most children with postoperative microdeviation, however, it is possible in some cases in the mode of alternating presentation of stimuli with the presence of an empty i nterval between monocular phases.

Prevalence of Refractive Error, Presbyopia, and Spectacle Coverage in Bogotá, Colombia: A Rapid Assessment of Refractive Error.

Uncorrected refractive error is the leading cause of visual impairment; therefore, reducing its prevalence is important worldwide. For two decades, there has not been a comprehensive assessment of refractive error in Latin America. The purpose of this study was to determine the current prevalence of refractive error, presbyopia, spectacle coverage, barriers to uptake refractive services, and spectacle correction in people 15 years and older in Bogotá, Colombia. A cross-sectional community-based survey was conducted using 50 randomly selected clusters from 10 districts of Bogotá reflecting the socioeconomic status of the city. Respondents 15 years and older were interviewed and underwent standardized clinical eye examinations. Prevalence of uncorrected refractive error, spectacle coverage, and visual impairment were standardized to 2015 age-sex population distribution of Bogotá and further analyzed. A total of 2886 subjects (90% of 3206 eligible subjects) participated in the study; 39.1% were male and 60.9% were female in the age range of 15 to 96 years, with a median age of 46 years (interquartile range, 45 to 54 years). Age- and sex-standardized prevalence of visual impairment was 19.3% (95% confidence interval [CI], 17.8 to 20.8%). Prevalence of uncorrected refractive error was 12.5% (95% CI, 11.3 to 13.7%). Prevalence of presbyopia among participants 35 years and older was 55.2% (95% CI, 52.9 to 57.4%). Spectacle coverage was 50.9% for distance vision, and it was 33.9% for presbyopia. Main barrier to spectacle uptake was a limitation in affording spectacles because of economic factors (29.5%). This study provides a current estimate of refractive error using the Rapid Assessment of Refractive Error for Colombia and the Latin American region. The prevalence of uncorrected refractive error and presbyopia was high, and the barriers to spectacle uptake were higher in the lowest socioeconomic strata. The results obtained in the present study will help in making evidence-based decisions related to eye care service delivery in Colombia.

Post-operative analysis of pediatric esotropia associated with high hypermetropia

BackgroundTo describe clinical features, evaluation, surgical management and outcomes in children with esotropia associated with high hypermetropia.MethodsMedical records of healthy children who received strabismus surgery for accommodative esotropia with hypermetropia larger than spherical equivalence of + 4.0 diopters from 2009 to 2015, were reviewed.ResultsA total of 47 patients were identified. The average age was 2.9 years old. The average spherical equivalence of cycloplegic refraction was + 6.0 diopters (D). All patients presented with large angle esotropia with spectacle correction. Average age of esotropia onset was 1.3 years. Average time between the onset of esotropia to spectacle correction was 7.2 months. Average duration between onset of constant esotropia to strabismus surgery was 28.1 months. Average duration between spectacle correction to strabismus surgery was 21.8 months. Post-operatively, 74.5% of patients achieved ocular alignment within 10 prism diopters (PD) of orthotropia. Overall, 66.0% patients developed sensory fusion. For patients who achieved surgical success, 71.4% developed sensory fusion, compared at 50.0% for patients who were over- or under-corrected (p = 0.18). For patients who received hyperopic spectacles within 6 months of esotropia onset, 92.3% developed sensory fusion, compared with 54.5% for patients who received hyperopic spectacles at 6 month or later after esotropia onset (p = 0.02).ConclusionsStrabismus surgery for esotropia with high hypermetropia has high rate of surgical success with low rate of under- or over-correction. There is a trend toward higher rate of sensory fusion for patients with surgical success. Shorter time interval between esotropia onset and receiving hyperopic spectacles is associated with higher rate of sensory fusion development.