Single Vision Research Articles

Evaluation of an Optical Defocus Treatment for Myopia Progression Among Schoolchildren During the COVID-19 Pandemic

Myopia progression has been found to be worsening during the COVID-19 pandemic. It is important to control the rapid myopia progression in this period. To analyze the association of COVID-19-related lockdown measures with myopia progression in schoolchildren and to compare the performance of defocus incorporated multiple segments (DIMS) lens with that of single vision lens (SVL) treatment in reducing myopia progression. This cohort study involved an exploratory, prespecified, comparison of 2 independent longitudinal studies performed at the same institute beginning in 2019. Data from Hong Kong schoolchildren (aged 7-13 years) were gathered and analyzed. Data analysis was performed from June to July 2021. Schoolchildren in study 1 wore a DIMS lens for 18 months, and those in study 2 wore a SVL for 24 months. Cycloplegic spherical equivalent refraction and axial length were measured. Studies 1 and 2 started before the start of lockdown measures and continued throughout the lockdown. In both studies, periods of fewer and more COVID-19-related lockdown measures were identified. Because COVID-19 lockdown caused deviations from the visit schedule, myopia progression was normalized to 12-month change, which were compared between DIMS and SVL groups, also during the periods with less and more lockdown time. There were 115 participants (58 girls [50.4%]; mean [SD] age, 10.3 [1.5] years) in the DIMS group; their mean (SD) baseline refraction was -4.02 (1.46) D. There were 56 participants (29 girls [51.8%]; mean [SD] age, 10.8 [1.5] years) in the SVL group; their mean (SD) baseline refraction was -2.99 (1.06) D. After controlling for the covariates, DIMS treatment was significantly associated with 34% less axial elongation (0.19 mm [95% CI, 0.16 to 0.22 mm] vs 0.30 mm [95% CI, 0.25 to 0.35 mm]; P < .001) and 46% less myopic progression after 12 months (-0.31 D [95% CI, -0.39 to -0.23 D] vs -0.57 D [95% CI, -0.69 to -0.45 D]; P = .001) compared with SVL treatment. In both the DIMS and SVL groups, more lockdown time was associated with significantly more spherical equivalent refraction (-0.54 D [95% CI, -0.64 to 0.44 D] vs -0.34 D [95% CI, -0.44 to -0.25 D]; P = .01) and axial length (0.29 mm [95% CI, 0.25 to 0.32 mm] vs 0.20 mm [95% CI, 0.16 to 0.24 mm]; P = .001) compared with less lockdown time. No significant interaction between treatment type and lockdown time was observed. In this exploratory analysis, myopia progressed more rapidly in schoolchildren during the period when there were more COVID-19-related lockdown measures. However, optical treatment with DIMS was significantly associated with slower myopia progression compared with SVL treatment during the lockdown period.

Pinhole amniotic membrane for peripheral corneal defects in patients with a single eye or low vision.

To describe the efficacy of a new pinhole amniotic membrane placement technique in cases of peripheral epithelial defects in patients with a single eye or low vision in the contrye. This technique is based on a small central hole done with a dermatological 3 to 4mm punch (according to pupillary diameter in mesoscopic conditions) and a continuous suture in the perilimbal cornea to fix the amniotic membrane. We performed this technique in 6 patients. Patients were followed clinical and photographically. No changes in the visual acuity before and after the surgery were observed. During follow-up, a complete re-epithelialization was observed with no need for reinterventions. Amniotic membrane transplantation is a very useful option in patients with persistent epithelial defects; however, its use is limited by the subsequent visual acuity. The use of the pinhole amniotic membrane technique allows us to treat peripheral persistent corneal lesions without modifying patients' visual acuity. This new technique may become especially useful in patients with functional single eye of low vision in the contralateral eye.

Alfred Wilhelm Volkmann on stereoscopic vision

ABSTRACT Wheatstone’s demonstration of binocular single vision and depth with stimulation of non-corresponding points reverberated throughout mid-nineteenth century German visual science. It challenged the received view that single vision was a consequence of retinal correspondence otherwise objects were seen double. Wheatstone also argued that stimulation of corresponding points could yield double vision. He interpreted his experimental observations in psychological rather than physiological terms, as did Helmholtz later. Volkmann addressed both of these challenges in a long article on stereoscopic vision published in 1859. While he accepted the first of the questions Wheatstone posed Volkmann was more cautious with regard to the second. Volkmann was an experimentalist who applied psychophysical methods to determine thresholds for stereoscopic depth perception. In line with many of his colleagues in Germany, he took issue implicitly with Wheatstone’s approach: how can the detailed quantitative experiments supporting Vieth and Müller’s interpretation of binocular single vision be derailed by simple observations with a stereoscope? Unlike most of his colleagues, Volkmann was swayed in Wheatstone’s favor through his own experiments: both physiological and psychological processes are involved in stereoscopic depth perception.

Internet.org and the rhetoric of connectivity

ABSTRACT This article analyzes the discursive construction of Facebook’s goal to build Internet connectivity in India through its “internet.org” project. I argue that the rhetoric of connectivity emergent in this project uses the language of empowerment and innovation to operationalize a mode of entrepreneurial philanthropy amenable to millennial development that in reality reflects notions of progress reminiscent of colonial modernization practices. I also contend that this case demonstrates the need to understand the particular technopolitics of everyday encounters with infrastructures that cannot be reduced to any single vision of connectivity or singular understanding of digital contexts.

A Clinical Study of the Impact of Soft Contact Lenses on the Progression of Myopia in Young Patients.

PurposeTo assess the impact of soft contact lenses on the progression of myopia in young patients.Patients and MethodsThe observational study included 102 patients divided into 3 groups: MFCL (multifocal contact lenses) group: 15 girls and 9 boys, aged 8–20 (nbar x n= 14.12 ± 2.863) with soft multifocal contact lenses with myopia: nbar x n = −3.12 D ± 1.776 D and mean myopia progression −0.23 ± 0.233D after 2 years; SVCL (single vision contact lenses) group: 30 girls and 5 boys, 11–20 years old (nbar x n=15.5 ± 2.24) with myopia nbar x n = −2.88 ± 2.122 D at admission and mean myopia progression −0.54 ± 0.464 D after 2 years; the spectacle (single vision glasses) group: 25 girls and 18 boys, aged 8–18 years (nbar x n = 13.65 ± 2.448) with single vision glasses with myopia: nbar x n = −1.74 ± 1.412 D at admission and mean myopia progression −0.86 ± 0.489D after 2 years. Medical history and physical examination were performed every 6, 12, 18 and 24 months. Refractive error was examined using the autorefractometry after cycloplegia.ResultsThe analysis of myopia correction after 2 years showed differences between MFCL and spectacle correction. The change in myopia progression after 2 years was statistically significant for MFCL vs SVCL and MFCL vs spectacle correction when the myopia occured before the period of intensive growth. When myopia occurred during the period of intensive growth, difference was noted for MFCL vs spectacle correction and SVCL vs spectacle correction. When myopia occurred after a period of intensive growth, no significant differences between the groups were observed.Conclusion1) Multifocal contact lenses and some single vision contact lenses (Biofinity) may be useful in the control of myopia in younger patients, slowing the progression of nearsightedness; therefore, they can be a therapeutic option in inhibiting the progression of myopia. 2) The best effects of using multifocal contact lenses occur if myopia is diagnosed before the period of intensive growth.

Towards a single European strategic research and innovation agenda on materials for all reactor generations through dedicated projects

The goal of the ORIENT-NM action is to produce a single European strategic vision on research and innovation concerning nuclear materials in the EU, serving all reactor generations and nuclear systems. The key in this endeavour is to focus on advanced materials science practices that, combined with digital techniques, will enable acceleration in materials development, manufacturing, supply, qualification, and monitoring, in support of nuclear energy safety, efficiency, economy and sustainability. The research agenda will be rooted in existing virtuous examples of nuclear materials science projects. Here the results of three of them are summarised, thereby covering different reactor applications and families of materials, as well as a range of advanced material research approaches. GEMMA addressed a number of key areas concerning the development and qualification of metallic structural materials for GenIV reactor conditions, focusing on austenitic steels and their compatibility with several non-aqueous coolants, their welds and the modelling of their stability under irradiation. INSPYRE was an integrated project applying a basic science approach to (U,Pu)O2fuels, to develop physics-based models for the behaviour of nuclear fuels under irradiation and improve fuel performance codes. Modelling was also the focus of the M4F project, which brought together the fission and fusion materials communities to study the effects of localised deformation under irradiation in ferritic/martensitic steels and to develop good practices to use ion irradiation as a tool to evaluate radiation effects on materials.

Effect of vision therapy on fusional vergences in intermittent exotropia

Significance: Intermittent exotropia is intermittently manifest squint at distance and latent exophoria at near. Most of the time, the eyes seems to be aligned with normal binocular single vision is maintained because its exodeviation is intermittently controlled by fusional mechanisms. Purpose: To evaluate the effect of vision therapy on fusional vergences in intermittent exotropia. Methods: This hospital-based, Quasi-Experimental study was carried out at the Orthoptics clinic of Al-Ibrahim Eye Hospital from August 2020 to July 2021. Non- probability, purposive sampling was used. This study involved the 40 subjects who were diagnosed with Intermittent Exotropia of age ranges 10 to 25 years, of both genders. A detailed history was evaluated. Orthoptics assessment included visual acuity, cover test, near the point of accommodation and convergence at a distance, and near and fusional vergences of positive and negative with prisms were measured. All subjects underwent vision therapies for 2 months. SPSS version 20.0 was used to analyze the data. Results: A total of 40 subjects with a mean age of 16.53±2.96 were included in this study. Out of 40 subjects, 22 subjects were females and 18 subjects were males. Subjects who received dot card therapy and executives bifocals therapy showed a significant change in the angle of deviation at distance and near (P=.001), followed by reduced the near point of convergence (P=.001), and increased the positive fusional vergences at distance and near (P=.001). There was no significant improvement seen in near point of accommodation (P=.16) with both therapies. Negative fusional vergences showed non-significant as (near: P=.14, distance: P=.05) with executives bifocals and (P=.26) with dot cards. Conclusions: This study showed that vision therapies with dot card and executive bifocals therapy have significantly improved the angle of deviation, positive fusional vergences, and near point of convergence in intermittent exotropia subjects.

Changes in subfoveal choroidal thickness in myopic children who wear bifocal soft contact lenses

To study the changes in subfoveal choroidal thickness in children with progressive myopia who have been wearing bifocal soft contact lenses (BSCL) with an ADD power of +4.0 D for 3 months. The study included 40 patients (80 eyes) with progressive myopia of low and moderate degrees. The main group consisted of 23 patients aged 10.04±1.5 years with an average myopia of -3.06±1.17 D, they were examined before and 3 months after vision correction with bifocal soft contact lenses Prima BIO Bi-focal («OkVision Retail», Russia). The control group consisted of 17 patients (34 eyes) aged 9.29±0.92 years with an average myopia of -3.05±1.5 D using single vision spectacle lenses. Cycloplegic refraction, choroidal thickness and axial length were measured in all patients before and after 3 months. Choroidal thickness was measured using the semi-automatic method on the optical coherent tomography system RS-3000 Advance 2 («Nidek», Japan). Axial length was measured using the optical biometer IOL Master 500 («Carl Zeiss», Germany). In the main group, subfoveolar choroidal thickness increased on average by 15.3±24.3 μm after 3 months of wearing BSCL, and in the control group it decreased on average by 9.03±28.65 μm. Comparison of changes in choroidal thickness between the main and the control groups revealed a significant difference (p<0.001). Increase in axial length of the eye in the main group was significantly less than in the control group (0.005±0.08 mm vs 0.07±0.06 mm; p<0.001). A strong negative correlation was found between changes in the axial length and subfoveolar choroidal thickness in the main group (r= -0.67), but no similar relationship was found in the control group (r= -0.13). Subfoveolar choroidal thickness increases in children wearing bifocal soft contact lenses for myopia correction.

The Myopia Control in Real Clinical Practice: The Results of an Expert Study

The article presents expert study results about myopia control. The study was conducted by Russian eye care practitioners in 2019.Purpose. to summarize the views of eye care practitioners on the problem of myopia control in Russia.Methods. The study was conducted by mailing (sending) questionnaires to practitioners. The questionnaire contained 9 questions. Base questionnaire was developed by British Contact Lens Association (BCLA) for global study, translated into Russian and updated with items of interest to Russian practitioners.Results. 356 questionnaires were received and processed. Concern increasing frequency of pediatric myopia was highest (9.0 ± 0.08 on a 10 point scale). Orthokeratology was perceived to be the most effective method of myopia control, followed by myopia control soft contact lenses and increased time outdoors. Perceived effectiveness rated as percentage was 50.7 ± 1.6 %, 44.9 ± 1.8 % и 42.9 ± 1.7 % respectively. Perifocal spectacles correction was perceived to be the most effective method in the Southern area of Russia (56.8 ± 11.1 %), atropine — in the Northwestern Federal District (39.5 ± 7.1 %), scleroplasty — in the Far East (55.1 ± 7.6 %). Under-correction was perceived to be the least effective method in all areas (11.6 ± 1.0 %). Increased time outdoors was a priority for most practitioners (on average 94.0 ± 7.8 prescriptions per month by one practitioner). Practitioners prescribed single vision spectacles as the primary mode of correction for myopic patients (47.2 ± 3.6 prescriptions per month by one practitioner). Phenylephrine instillation was used often (49.4 ± 3.6 prescriptions per month by one practitioner). This trend was in most areas. Vision therapy was used most frequent in Siberia and the Urals and in the Far East (70.4 ± 11.5 и 20.0 ± 5.2 prescriptions per month by one practitioner respectively). The most common reasons practitioners gave for not adopting myopia control strategies were: they were felt to be uneconomical (42.1 %); they considered there to be inadequate information about the modalities (22.2 %). 45 % practitioners from the Far East called the last reason the main one. 42.9 % practitioners from Northwestern Federal District did not believe that these are any more effective methods then single vision correction.Conclusion. The active promotion and introduction into everyday clinical practice of myopia control methods that have proven to be highly effective could help reduce the frequency of progressive and degenerative myopia

Призматическая коррекция при остро приобретенной эзотропии с диплопией

Purpose. To analyze changes in binocular vision functions in patients with acutely acquired esotropia after preoperative correction by prisms. Material and methods. The study included 16 patients with acutely acquired esotropia with diplopia. Depending on the tactics of preoperative case management, two groups were distinguished. Eight patients with acutely acquired esotropia of the Bielshowsky type at the age from 12 to 35 years old (mean age, M±sd – 17.5±1.9 years). This group underwent preoperative prismatic correction of diplopia and the deviation angle, as well as eight patients with acutely acquired esotropia of the Bielshowsky type at the age from 12 to 35 years (18.5±1.9 years). Patients in this group underwent surgery without prior prismatic correction. Fresnel prisms were used to select and assign prismatic correction. The patients were monitored dynamically. Results. In the course of treatment 1 group (prismatic correction followed by surgical correction) according to the indicator of Worth's four-dot test color test, revealed a statistically significant increase in the frequency of value of the binocular single vision (p=0.041), the frequency of the presence of stereovision according to the Fly-test (p=0.013), fusion amplitude in the distance by 1.11 times (p=0.033) and near fusion amplitude by 1.15 times (p=0.003). Significant differences between the groups were observed only in the frequency of stereovision presence according to the Fly-test after treatment, which was 2.0 times higher in group 1 (p=0.041). Conclusion. Prismatic correction in combination with surgical treatment had better curative benefits than surgery itself in improving both binocular and stereoscopic visual functions. Key words: acutely acquired esotropia, diplopia, binocular vision, stereoscopic vision, Fresnel prisms

Optical inspection of single vision soft contact lenses based on an active adaptive wavefront sensor.

We present an experimental configuration for optical inspection of single vision soft contact lenses based on an active adaptive wavefront sensor. At first, the soft lenses were immersed in a saline filled wet cell to prevent surface deformation during measurements. Thereafter, refractive powers and aberrations were accurately measured before and after correcting illumination laser beam aberrations and wet cell-induced aberrations. The results reveal that there is a significant difference between the measured aberrations and refractive powers before and after aberration compensation. Accordingly, the proposed system is recommended as an optical inspection tool for precise assessment of commercially available contact lenses.

God in a Single Vision: Integrating Philosophy and Theology. By David Brown. Edited by Christopher R. Brewer and Robert Mac Swain

Few can compare to David Brown in depth and range of learning, and this collection of essays is strong testimony to his contribution to British theology. The earliest piece published here first saw the light of day in 1985—the same year as his landmark work in philosophical theology The Divine Trinity—and the essays, individually and collectively, demonstrate Brown’s overall concern for the doctrinal well-being and the spiritual health of the Christian community. Some of the essays had their first outing in learned journals, others in a variety of church settings. Readers already familiar with Brown’s work will find retractations and modifications of earlier positions in this collection, and it would make a very good introduction to his work, too. The book is divided into four parts, with three or four essays per part: ‘The Created Order’, ‘Experience and Revelation’, ‘Incarnation, Trinity, and Redemption’, and ‘Heaven and our Communal Destiny’....

Visions: The Dance Most of All: Envisioning an Embodied Eighteenth-Century Studies

The editors introduce this special issue of ABO, highlighting the work of the authors included in the issue. The introduction draws on recent scholarship re-visioning the work of the long, “undisciplined” eighteenth century, arguing for an eighteenth-century studies that embodies our intersectional identities and honors the experiences of bodyminds surrounding texts and authors, as well as the bodyminds that interact with those texts in the present. Throughout the years, scholars have demonstrated that there is no single vision of what eighteenth-century scholarship is or should be, but rather multiple visions. This introduction urges scholars to consider how an eighteenth-century studies that focuses on embodied experience can and should respond to present-day issues of racial inequity, sexism, ableism, heteronormativity, and other forms of systemic oppression which remain deeply rooted in the structures of power of the long eighteenth century. Revising our ideas of what is possible, what is visible, what is required of us as teacher-scholars remains our foremost task.

Full-aperture diopter distribution measurement method for single vision and progressive addition lenses

Hartmann testing method is still widely used for measuring the diopter of spectacle lens. However, its aperture measurement and resolution are limited by diffraction. This paper proposes a method to obtain full-aperture diopter distribution of spectacle lenses, including progressive addition lenses (PAL). The method uses a specially designed Hartmann testing plate for generating testing rays. The plate is rotated during measurement to overcome the diffraction limitation. Both simulation and experiment are carried out for verifying this method. The diopter measurement error of spherical power lens, cylindrical power lens, and PAL are less than 1% compared to the theoretical value in simulation. In the experiment, the deviation error is less than 2% for signal vision lens, when compared with the results obtained by an automated focimeter. The result shows that the proposed method can measure the full-aperture of diopter distribution for PAL.

Randomised controlled trial of an accommodative support lens designed for computer users.

Accommodative support (AS) lenses are a low add progressive addition spectacle lens designed to ease symptoms in computer vision syndrome (CVS). The study aims to investigate if (1) AS lenses improve CVS symptoms; (2) binocular/accommodative functions predict a benefit from AS lenses and (3) wearing AS lenses for six months impacts on binocular/accommodative functions. Pre-presbyopic adults with symptoms of CVS (Computer Vision Syndrome Questionnaire, CVS-Q© , score≥6) were randomly allocated to wear AS lenses or control single vision (SV) lenses. The CVS-Q© and a battery of optometric tests were applied at baseline and after three and six months. Participants and researchers were masked to participant group. After six months, the SV group were unmasked and changed to AS lenses and one week later asked to choose which they preferred. The change in CVS-Q© scores from baseline to six months did not differ significantly in the two groups. At the end of the one week period, when the control group wore the AS lenses, control group participants were significantly more likely to prefer AS lenses to SV lenses. No optometric functions correlated with the benefit from AS lenses. AS lenses did not have any adverse effects on binocular or accommodative function. In pre-presbyopic adults, there was no greater improvement in CVS-Q© scores in the group wearing AS lenses than in the control group. No adverse effects on optometric function (including accommodation) are associated with wearing AS lenses.

Surgical management of Helveston syndrome (Triad exotropia)

PurposeTo evaluate and compare different surgical approaches for the treatment of Helveston syndrome and provide further information for preoperative planning.MethodsFrom February 2008 to December 2018, data of 52 patients with Helveston syndrome were retrospectively reviewed. Different surgical approaches were selected based on the extent of A-pattern exotropia, dissociated vertical deviation (DVD), and both superior oblique muscle overaction (SOOA) with fundus photograph intorsion. Eye position, A-pattern, DVD, superior oblique muscle function, and binocular vision function were evaluated pre- and postoperatively. The average follow-up duration was 20.5 months.ResultsNine cases underwent simultaneous horizontal deviation correction with bilateral superior rectus recession, 24 underwent simultaneous horizontal deviation correction with bilateral superior oblique muscle lengthening, and 19 underwent two stages of horizontal deviation correction with superior oblique muscle lengthening, and later bilateral superior rectus recession. A-pattern, DVD, SOOA, and fundus intorsion were all collapsed in all patients postoperatively. Forty-five patients had an orthophoric eye position with considerably aligned ocular movements postoperatively. The total success rate was 86.5%. Postoperatively, eight of the 10 patients with diplopia experienced a recovery of binocular single vision and three had a recovery of rudimentary stereopsis (Titmus 3000–400 s of arc). The compensatory head posture of patients improved significantly postoperatively.ConclusionsThe surgical planning of Helveston syndrome should be designed based on the degree of the A-pattern, SOOA, DVD, and the intorsion in fundus photographs, and the appropriate approach should be selected to improve patient satisfaction.

Orthokeratology reshapes eyes to be less prolate and more symmetric

PurposeThis prospective study assessed the influence of wearing and then discontinuing orthokeratology (OK) lenses on retinal shape and peripheral refraction in myopic children. MethodsFifty-eight myopic children (age 8–12 years) were equally divided into an OK group and a single vision spectacles (SVS) group. After 12 months of OK, it was discontinued for 1 month. Peripheral eye length (PEL), relative peripheral refraction (RPR), and corneal parameters were measured in the right eye on the nasal and temporal retinal sides at baseline, 6 months, and 12 months (13 months in OK group) visits. ResultsIn the SVS group, faster elongation of the temporal side PEL made the eyes more asymmetric and prolate, developing a temporal pointed shape. In the OK group, the nasal retinal side PEL grew faster, the nasal RPR developed less hyperopic defocus, and the eye shape became more symmetric and less prolate. The central cornea became thinner and flattened, while the peripheral cornea became steeper. Changes in corneal thickness, relative peripheral corneal power, and K-values were no significant differences for the OK and SVS groups at 12 months. ConclusionsThe cornea reverted to be no difference with myopic children with SVS after 1 month discontinuation of OK. The retinal shape of SVS eyes became more asymmetric and prolate with myopia progression. OK remodelled retinal shape to be less asymmetric and less prolate.

Retinal defocus in myopes wearing dual-focus zonal contact lenses.

PurposeTo evaluate the refractive impact of dual‐focus (DF) myopia control contact lenses (CLs) on accommodating young myopic adults.MethodsPhase 1: accommodative accuracy was assessed in 40 myopic participants. Phase 2: a subset of four subjects who demonstrated accurate accommodation and six who chronically underaccommodated were fitted with single vision (SV, Proclear 1 day) and centre‐distance DF myopia control CLs (MiSight 1 day) with approximately +2.00 D of additional power in two surrounding annular zones. While binocularly viewing high contrast characters at 4.00, 1.00, 0.50, 0.33, 0.25 and 0.20 m, aberrometry data were captured across the central ±30° of the horizontal retina. Local refractive errors were pooled for each area of the pupil covered by the central distance or first annular defocus zone of the DF CLs.ResultsIn the “good” accommodator group fitted with SV CLs, accommodative lags were generally absent except at the closest viewing distance (mean errors: −0.09 ± 0.22 D, −0.12 ± 0.26 D, −0.05 ± 0.37 D and +0.38 ± 0.54 D for −2.00, −3.00, −4.00 and −5.00 D target vergences, respectively) but significantly larger in the “poor” accommodating participants (+0.81 ± 0.21 D, +0.97 ± 0.27 D, +1.18 ± 0.39 D, +1.47 ± 0.55 D). For most viewing distances, hyperopic defocus observed in the region of the pupil covered by the first annular zone was replaced with myopic defocus when fitted with the DF CLs. Myopic defocus created by the first annular region was present across the central 30° of the retina.ConclusionsSome young adult myopes chronically experience high levels of hyperopic defocus when viewing near targets, which was replaced by myopic defocus in the annular part of the pupil covered by the treatment zones when fitted with a centre‐distance myopia control DF CL.

Surgical Outcomes of Transposition Surgery for the Correction of Large-Angle Strabismus.

Many potential surgical options exist to address large-angle deviations and head turns that result from various forms of paralytic strabismus. Muscle transposition surgeries serve as suitable alternatives to simple resection-recessions. Here, we report outcomes of augmented Hummelsheim and X-type transpositions for the correction of large-angle strabismus and provide insights for surgical planning. We performed a retrospective chart review of 40 consecutive patients with strabismus who were treated with an augmented Hummelsheim or X-type transposition surgery at a single academic medical center. Etiologies included cranial nerve palsies (n = 26), monocular elevation palsy (n = 3), Duane syndrome (n = 1), traumatic extraocular muscle damage (n = 8), and chronic progressive external ophthalmoplegia (n = 2). All patients were followed for a minimum of 2 months postsurgery. Logistic regression analyses were performed to assess for predictors of surgical outcome. Forty consecutive patients were enrolled in our series. The median preoperative deviation was 46.5Δ (interquartile range [IQR] 35-70). The median postoperative deviation 2 months after surgery was 0.5Δ (IQR 0-9.5), which represented a significant improvement (P < 0.001). Thirty-three patients (82.5%) experienced an improvement in range and/or centration of binocular single vision (BSV). More patients who underwent an augmented Hummelsheim procedure and had a small overcorrection at postoperative day 3 had a favorable result on postoperative month 2 (79%) compared with those that were initially under-corrected (38%). Multiple logistic regressions found larger preoperative deviation (P < 0.005) and esotropia (P < 0.021) to be predictors of a less favorable surgical outcome (C-statistic = 0.83). Subgroup analysis revealed that less, favorable outcome after X-type transposition occurred most frequently in patients undergoing correction of an esodeviation. Augmented Hummelsheim transposition techniques offer effective treatment options for paralytic strabismus with esotropic deviations, whereas X-type transpositions are effective for exotropic deviations and deviations from severe inferior rectus damage. In addition to potentially providing a wider field of BSV, improved centration is often achieved.

Accuracy and Repeatability of Internet-ordered Spectacle Lenses.

Both consumers and eye care practitioners need to know how well online optical vendors conform with the accepted standards for quality and safety. We found that almost 1 in 10 prescriptions failed to meet national standards, which is a significant improvement over previous studies. The purpose of this study was to assess the accuracy and repeatability of spectacle lens prescriptions ordered from a sample of online vendors. Spectacle lens prescriptions were ordered by paid participants with no optical training who were masked to the study objectives. The prescription powers ordered (sphere, cylinder, and axis) were statistically sampled from 1000 previously filled prescriptions. A total of 100 orders were placed with each of three online vendors that included a range of high- and low-powered single vision lenses and progressive addition lenses, and duplicate orders to assess repeatability. An independent certified testing laboratory was contracted to assess conformance with voluntary consensus standards (ANSI Z80.1-2015) and Food and Drug Administration drop-ball safety testing. Lenses not meeting these standards were counted as failures. The overall failure rates for the three vendors were 11.2 ± 3.2% (vendor A), 8.0 ± 2.7% (vendor B), and 8.2 ± 2.8% (vendor C). The repeatability for 20 prescriptions ordered five times from each vendor was high, with correlation coefficients greater than 90%. There were no observed lens impact failures. Almost 1 in 10 spectacle lens prescriptions ordered from three online vendors failed to meet national standards for optical quality. Additional studies are needed to assess eyewear ordered online for other important patient-specific variables that can influence visual performance and ultimate acceptability of prescription eyewear, such as lens placement relative to the visual axis, frame fit, and cosmetic acceptability.