Slow Binocular Reading in Amblyopic Children Is a Fellow Eye Deficit.

SIGNIFICANCE: Amblyopic children read 25% slower than their peers during binocular silent reading. PURPOSE: We compared binocular reading to fellow eye reading to determine whether slow reading in amblyopic children is due to binocular inhibition; that is, the amblyopic eye is interfering during binocular reading. METHODS: In a cross-sectional study, 38 children with amblyopia and 36 age-similar control children who completed grades 1 to 6 were enrolled. Children silently read grade-appropriate paragraphs during binocular reading and fellow eye reading while wearing ReadAlyzer eye-tracking goggles (Compevo AB, Stockholm, Sweden). Reading rate, number of forward saccades, number of regressive saccades, and fixation duration were analyzed between groups and between viewing conditions. We also examined whether sensory factors (amblyopia severity, stereoacuity, suppression) were related to slow reading. RESULTS: For amblyopic children, binocular reading versus fellow eye reading did not differ for reading rate (176 ± 60 vs. 173 ± 53 words per minute, P = .69), number of forward saccades (104 ± 35 vs. 97 ± 33 saccades/100 words, P = .18), number of regressive saccades (21 ± 15 vs. 22 ± 13 saccades/100 words, P = .75), or fixation duration (0.31 ± 0.06 vs. 0.32 ± 0.07 seconds, P = .44). As expected, amblyopic children had a slower reading rate and more forward saccades than control children during binocular reading and fellow eye reading. Slow reading was not related to any sensory factors. CONCLUSIONS: Binocular reading did not differ from fellow eye reading in amblyopic children. Thus, binocular inhibition is unlikely to play a role in slow binocular reading and is instead a fellow eye deficit that emerges from a disruption in binocular visual experience during development.

Temporal Eye-Hand Coordination During Visually Guided Reaching in 7- to 12-Year-Old Children With Strabismus.

Purpose: We recently found slow visually guided reaching in strabismic children, especially in the final approach. Here, we expand on those data by reporting saccade kinematics and temporal eye-hand coordination during visually guided reaching in children treated for strabismus compared with controls. Methods: Thirty children diagnosed with esotropia, a form of strabismus, 7 to 12 years of age and 32 age-similar control children were enrolled. Eye movements and index finger movements were recorded. While viewing binocularly, children reached out and touched a small dot that appeared randomly in one of four locations along the horizontal meridian (±5° or ±10°). Saccade kinematic measures (latency, accuracy and precision, peak velocity, and frequency of corrective and reach-related saccades) and temporal eye-hand coordination measures (saccade-to-reach planning interval, saccade-to-reach peak velocity interval) were compared. Factors associated with impaired performance were also evaluated. Results: During visually guided reaching, strabismic children had longer primary saccade latency (strabismic, 195 ± 29 ms vs. control; 175 ± 23 ms; P = 0.004), a 25% decrease in primary saccade precision (0.15 ± 0.06 vs. 0.12 ± 0.03; P = 0.007), a 45% decrease in the final saccade precision (0.16 ± 0.06 vs. 0.11 ± 0.03; P < 0.001), and more reach-related saccades (16 ± 13% of trials vs. 8 ± 6% of trials; P = 0.001) compared with a control group. No measurable stereoacuity was related to poor saccade kinematics. Conclusions: Strabismus impacts saccade kinematics during visually guided reaching in children, with poor binocularity playing a role in performance. Coupled with previous data showing slow reaching in the final approach, the current saccade data suggest that children treated for strabismus have not yet adapted or formed an efficient compensatory strategy during visually guided reaching.

Randomized clinical trial of streaming dichoptic movies versus patching for treatment of amblyopia in children aged 3 to 7 years.

Contrast-rebalanced dichoptic movies have been shown to be an effective binocular treatment for amblyopia in the laboratory. Yet, at-home therapy is a more practical approach. In a randomized clinical trial, we compared dichoptic movies, streamed at-home on a handheld 3D-enabled game console, versus patching as amblyopia treatment. Sixty-five amblyopic children (3-7 years; 20/32-125) were randomly assigned to one of two parallel arms, binocular treatment (3 movies/week) or patching (14 h/week). The primary outcome, change in best corrected visual acuity (BCVA) at the 2-week visit was completed by 28 and 30, respectively. After the primary outcome, both groups of children had the option to complete up to 6 weeks of binocular treatment. At the 2-week primary outcome visit, BCVA had improved in the movie (0.07 ± 0.02 logMAR; p < .001) and patching (0.06 ± 0.01 logMAR; p < 0.001) groups. There was no significant difference between groups (CI95%: - 0.02 to 0.04; p = .48). Visual acuity improved in both groups with binocular treatment up to 6 weeks (0.15 and 0.18 logMAR improvement, respectively). This novel, at-home, binocular movie treatment improved amblyopic eye BCVA after 2 weeks (similar to patching), with additional improvement up to 6 weeks. Repeated binocular visual experience with contrast-rebalanced binocular movies provides an additional treatment option for amblyopia.Clincaltrials.gov identifier: NCT03825107 (31/01/2019).

A randomized clinical trial of contrast increment protocols for binocular amblyopia treatment.

BACKGROUND: Most clinical trials of contrast-rebalanced binocular amblyopia treatment used a contrast increment protocol of 10% daily with successful play. Paired with a definition of success requiring only 15-30 min/day of gameplay, this increment protocol could allow children to reach 100% fellow eye contrast in 3-9 hours; however, this may not provide adequate therapeutic time with reduced fellow eye contrast. The purpose of this study was to compare the original protocol against three alternative contrast increment protocols designed to increase the number of treatment hours. METHODS: In this prospective study, 63 amblyopic children (4-10 years; amblyopic eye visual acuity, 20/40-125) were randomly assigned one of four daily contrast increment protocols for 4 weeks, all starting with 20% fellow eye contrast: 10%, 5%, 0%, or 10% for first 4 weeks then reset to 20% and repeat 10% increment for the final 4 weeks. Children played contrast-rebalanced games for 1 hour/day, 5 days/week. Best-corrected visual acuity, stereoacuity, and suppression were assessed at baseline and every 2 weeks until the 8-week outcome visit. RESULTS: At baseline, mean amblyopic eye best-corrected visual acuity was 0.47 ± 0.14 logMAR (20/60), improving overall 0.14 ± 0.08 logMAR (1.4 lines; P < 0.0001) at 8 weeks. All four protocols resulted in similar improvement in visual acuity (0.13-0.16 logMAR; all Ps < 0.0002). Stereoacuity and suppression also improved (all Ps < 0.05). CONCLUSIONS: None of the new protocols resulted in less improvement than the original 10% contrast increment protocol. Contrast-rebalanced binocular games yielded significant improvements in visual acuity, stereoacuity, and suppression with or without daily contrast increments.

Binocular reading in children following extraction of a dense congenital or infantile unilateral cataract.

BACKGROUND: Reading relies on ocular motor function, requiring sequential eye movements (forward and regressive saccades). Binocularly discordant input from a dense congenital or infantile cataract is associated with ocular motor dysfunction and may affect the development of reading ability. The purpose of this study was to assess silent, binocular reading in children treated for unilateral congenital or infantile cataract. METHODS: Twenty school-age children (age range, 7-13 years) treated for unilateral congenital (n = 9) or infantile (n = 11) cataract and 49 age-similar control children silently read a grade-appropriate paragraph during binocular viewing. Reading rate (words/min) and the number of forward and regressive saccades (per 100 words) were recorded using the ReadAlyzer. RESULTS: Reading rate in children treated for a unilateral cataract did not differ significantly from controls (174 ± 59 words/min vs 195 ± 54 words/min; P = 0.1). However, they did have significantly more forward saccades (101 ± 33 saccades/100 words vs 87 ± 21 saccades/100 words; P = 0.03) but not regressive saccades (21 ± 14 saccades/100 words vs 16 ± 8 saccades/100 words; P = 0.1) compared with controls. Reading rate was not related to cataract type (congenital vs infantile), visual acuity outcome (poor vs good), or sensory fusion (fail vs pass; all P ≥ 0.1). CONCLUSIONS: Reading rate of children treated for a dense unilateral cataract did not differ from that of controls. Increased forward saccades during reading may be due to fixation instability associated with fusion maldevelopment nystagmus prevalent in children following cataract extraction.

Impaired fine motor skills in children following extraction of a dense congenital or infantile unilateral cataract.

PURPOSE: To evaluate fine motor ability in children treated for unilateral congenital or infantile cataract. METHODS: Twenty-three children 3-13 years of age who were treated for unilateral congenital or infantile cataract and 38 age-similar control children were enrolled. Children completed five fine motor skills tasks (unimanual dexterity, bimanual dexterity, drawing trail, aiming, catching) from the Movement Assessment Battery for Children-2. Raw scores were converted into standardized scores, with higher scores indicating better performance. RESULTS: Compared with controls, children treated for unilateral cataract scored lower on drawing trail (P = 0.009), aiming (P = 0.009), and catching (P < 0.001) but not on unimanual (P = 0.77) or bimanual dexterity (P = 0.31). Poorer affected eye visual acuity was moderately related to poorer performance for unimanual dexterity (r = -0.47; P = 0.025), bimanual dexterity (r = -0.50; P = 0.014), and catching (r = -0.41; P = 0.051). Those with a poor visual outcome (>0.6 logMAR) had worse performance than those with a good visual outcome (≤0.6 logMAR) for all tasks (all P values, 0.008-0.09) except aiming. Cataract type (congenital, 9; infantile, 14) and sensory fusion by Worth 4-Dot testing at 33 cm (pass, 10; fail, 13) had no effect on fine motor performance (all P values, 0.12-0.98). CONCLUSIONS: In our study cohort, fine motor deficits were found in children treated for congenital or infantile unilateral cataract.

Binocular iPad treatment for amblyopia in preschool children.

BACKGROUND: Recent experimental evidence supports a role for binocular visual experience in the treatment of amblyopia. The purpose of this study was to determine whether repeated binocular visual experience with dichoptic iPad games could effectively treat amblyopia in preschool children. METHODS: A total of 50 consecutive amblyopic preschool children 3-6.9 years of age were assigned to play sham iPad games (first 5 children) or binocular iPad games (n = 45) for at least 4 hours per week for 4 weeks. Thirty (67%) children in the binocular iPad group and 4 (80%) in the sham iPad group were also treated with patching at a different time of day. Visual acuity and stereoacuity were assessed at baseline, at 4 weeks, and at 3 months after the cessation of game play. RESULTS: The sham iPad group had no significant improvement in visual acuity (t4 = 0.34, P = 0.75). In the binocular iPad group, mean visual acuity (plus or minus standard error) improved from 0.43 ± 0.03 at baseline to 0.34 ± 0.03 logMAR at 4 weeks (n = 45; paired t44 = 4.93; P < 0.0001). Stereoacuity did not significantly improve (t44 = 1.35, P = 0.18). Children who played the binocular iPad games for ≥8 hours (≥50% compliance) had significantly more visual acuity improvement than children who played 0-4 hours (t43 = 4.21, P = 0.0001). CONCLUSIONS: Repeated binocular experience, provided by dichoptic iPad game play, was more effective than sham iPad game play as a treatment for amblyopia in preschool children.

Postoperative glaucoma following infantile cataract surgery: an individual patient data meta-analysis.

IMPORTANCE: Infantile cataract surgery bears a significant risk for postoperative glaucoma, and no consensus exists on factors that may reduce this risk. OBJECTIVE: To assess the effect of primary intraocular lens implantation and timing of surgery on the incidence of postoperative glaucoma. DATA SOURCES: We searched multiple databases to July 14, 2013, to identify studies with eligible patients, including PubMed, MEDLINE, EMBASE, ISI Web of Science, Scopus, Central, Google Scholar, Intute, and Tripdata. We also searched abstracts of ophthalmology society meetings. STUDY SELECTION: We included studies reporting on postoperative glaucoma in infants undergoing cataract surgery with regular follow-up for at least 1 year. Infants with concurrent ocular anomalies were excluded. DATA EXTRACTION AND SYNTHESIS: Authors of eligible studies were invited to contribute individual patient data on infants who met the inclusion criteria. We also performed an aggregate data meta-analysis of published studies that did not contribute to the individual patient data. Data were pooled using a random-effects model. MAIN OUTCOMES AND MEASURES: Time to glaucoma with the effect of primary implantation, additional postoperative intraocular procedures, and age at surgery. RESULTS: Seven centers contributed individual patient data on 470 infants with a median age at surgery of 3.0 months and median follow-up of 6.0 years. Eighty patients (17.0%) developed glaucoma at a median follow-up of 4.3 years. Only 2 of these patients had a pseudophakic eye. The risk for postoperative glaucoma appeared to be lower after primary implantation (hazard ratio [HR], 0.10 [95% CI, 0.01-0.70]; P = .02; I(2) = 34%), higher after surgery at 4 weeks or younger (HR, 2.10 [95% CI, 1.14-3.84]; P = .02; I(2) = 0%), and higher after additional procedures (HR, 2.52 [95% CI, 1.11-5.72]; P = .03; I(2) = 32%). In multivariable analysis, additional procedures independently increased the risk for glaucoma (HR, 2.25 [95% CI, 1.20-4.21]; P = .01), and primary implantation independently reduced it (HR, 0.10 [95% CI, 0.01-0.76]; P = .03). Results were similar in the aggregate data meta-analysis that included data from 10 published articles. CONCLUSIONS AND RELEVANCE: Although confounding factors such as size of the eye and surgeon experience are not accounted for in this meta-analysis, the risk for postoperative glaucoma after infantile cataract surgery appears to be influenced by the timing of surgery, primary implantation, and additional intraocular surgery.

Beyond screening for risk factors: objective detection of strabismus and amblyopia.

IMPORTANCE: Commercially available automated vision screening devices assess refractive risk factors, not amblyopia or strabismus, underreferring affected children and overreferring healthy children. Nearly half of affected children are not identified until after age 5 years, when treatment is less effective. OBJECTIVES: To determine the diagnostic accuracy of the Pediatric Vision Scanner (PVS), a binocular retinal birefringence scanner, to objectively identify strabismus and amblyopia, and to compare retinal birefringence screening with a widely used automated pediatric screening device. DESIGN, SETTING, AND PARTICIPANTS: Three hundred consecutive preschool children (aged 2-6 years) were screened using the PVS and the SureSight Autorefractor at 2 pediatric ophthalmology private practices. A masked comprehensive pediatric ophthalmic examination provided the gold standard for determining sensitivity and specificity for each screening device. MAIN OUTCOMES AND MEASURES: The primary outcome was sensitivity and specificity of the PVS for detecting the targeted conditions, strabismus and amblyopia, in children aged 2 to 6 years. Secondary outcomes included the positive and negative likelihood ratios of the PVS for identifying the targeted conditions. In addition, sensitivity, specificity, and positive and negative likelihood ratios of the SureSight Autorefractor for the targeted conditions were assessed in the same cohort of children. RESULTS: Of the 300 patients, 188 had strabismus only, amblyopia only, or both, and 112 had no strabismus or amblyopia. The sensitivity of the PVS to detect strabismus and amblyopia (0.97; 95% CI, 0.94-1.00) was significantly higher than that of the SureSight Autorefractor (0.74; 95% CI, 0.66-0.83). Specificity of the PVS for strabismus and amblyopia (0.87; 95% CI, 0.80-0.95) was significantly higher than that of the SureSight Autorefractor (0.62; 95% CI, 0.50-0.73). CONCLUSIONS AND RELEVANCE: The PVS identified children with strabismus and/or amblyopia with high sensitivity, outperforming the SureSight Autorefractor. Accurate, early detection of these conditions could improve long-term vision outcomes of affected preschool children.

Visual acuity deficits in children with nystagmus and Down syndrome.

PURPOSE: To investigate the association between visual acuity deficits and fixation instability in children with Down syndrome and nystagmus. DESIGN: Prospective cross-sectional study. METHODS: setting: Institutional. study population:Sixteen children (aged 10 months-14 years) with Down syndrome and nystagmus, and a control group of 93 age-similar children with unassociated infantile nystagmus. observation procedures: Binocular Teller acuity card testing and eye-movement recordings. Fixation stability was quantified using the nystagmus optimal fixation function (NOFF). An exponential model based on results from the control group with unassociated infantile nystagmus was used to relate fixation stability to age-corrected visual acuity deficits. main outcome measures: Binocular grating visual acuity and NOFF. RESULTS: Visual acuity was 0.2-0.9 logMAR (20/30-20/174 Snellen equivalent) and corresponded to a 0.4 logMAR (4 lines) mean age-corrected visual acuity deficit. Fixation stability ranged from poor to mildly affected. Although visual acuity deficit was on average 0.17 logMAR larger (P = .005) than predicted by the model, most children had visual acuity deficit within the 95% predictive interval. CONCLUSIONS: There was a small mean difference between the measured visual acuity deficit and the prediction of the nystagmus model. Although other factors also contribute to visual acuity loss in Down syndrome, nystagmus alone could account for most of the visual acuity deficit in these children.

Unilateral lateral rectus resection for horizontal diplopia in adults with divergence insufficiency.

BACKGROUND: Divergence insufficiency (DI) is an acquired comitant strabismus in aging individuals, characterized by esotropia and diplopia at distance. Treatment options include occlusion, base-out prism glasses, and a variety of surgical procedures to the horizontal rectus extraocular muscles. Here, we present a large cohort of patients with DI who underwent unilateral resection of the lateral rectus muscle. This is a simple procedure, typically performed under regional anesthesia and on the non-dominant eye. METHODS: Clinical characteristics and complaints were collected from patients with DI who underwent unilateral lateral rectus resection over a 6.5-year period. Treatment success was evaluated in terms of post-operative symptomatic deviation and the need for prisms in order to achieve sensory fusion. RESULTS: The cohort consisted of 57 patients (age 54-89 years). The majority sought surgical care after prism glasses were no longer tolerated, or after onset of a larger symptomatic deviation (typically 10 to 18 prism diopters). After surgery (minimum 6 weeks follow-up; median 10 weeks), 86.0 % showed successful results with no further treatment; an additional 10.5 % stayed free of diplopia with a post-operative prism (horizontal or vertical), and only two patients (3.5 %) required further surgery and were considered failures. CONCLUSIONS: Mild DI is usually treated with a base-out prism. Treatment of pronounced DI with unilateral lateral rectus resection was generally successful, with 96.5 % not requiring further surgery. Unilateral lateral rectus resection appears to be a valid option for treatment of DI.

New strabismus surgical techniques.

Five new strabismus surgical procedures were developed by the authors and were presented as a workshop at the AAPOS annual meeting of the American Association for Pediatric Ophthalmology and Strabismus. They are summarized here to introduce these methods to the reader and provide surgeons with more options in approaching difficult strabismus problems. Diagnosis and correction of consecutive strabismus attributable to stretched scar is discussed. The pulley posterior fixation procedure is a unique approach to correct high accommodative convergence or to augment a maximal medial rectus recession. Diagnosis and repair of the partial avulsion (flap tear) of a rectus muscle allows correction of some restrictive strabismus following blunt trauma. The nasal myectomy of the inferior oblique muscle corrects persistent inferior oblique overaction without sacrificing the tether effect gained by a previous anterior transposition of the inferior oblique. The full advancement of the superior oblique tendon offers another option to strengthen a weak superior oblique muscle.

Fixation control and eye alignment in children treated for dense congenital or developmental cataracts.

BACKGROUND: Many children treated for cataracts develop strabismus and nystagmus; however, little is known about the critical period for adverse ocular motor outcomes with respect to age of onset and duration. METHODS: Children who had undergone extraction of dense cataracts by the age of 5 years were enrolled postoperatively. Ocular alignment was assessed regularly throughout follow-up. Fixation stability and associated ocular oscillations were determined from eye movement recordings at ≥5 years old. Multivariate logistic regression was used to evaluate whether laterality (unilateral vs bilateral), age at onset, and/or duration of visual deprivation were associated with adverse ocular motor outcomes and to determine multivariate odds ratios (ORs). RESULTS: A total of 41 children were included. Of these, 27 (66%) developed strabismus; 29 (71%) developed nystagmus. Congenital onset was associated with significant risk for strabismus (OR, 5.3; 95% CI, 1.1-34.1); infantile onset was associated with significant risk for nystagmus (OR, 13.6; 95% CI, 1.6-302). Duration >6 weeks was associated with significant risk for both strabismus (OR, 9.1; 95% CI, 1.9-54.2) and nystagmus (OR, 46.2; 95% CI, 6.0-1005). Congenital onset was associated with significant risk for interocular asymmetry in severity of nystagmus (OR, 25.0; 95% CI, 2.6-649), as was unilateral cataract (OR, 58.9; 95% CI, 5.1-2318). CONCLUSIONS: Laterality (unilateral vs bilateral) and age at onset were significant nonmodifiable risk factors for adverse ocular motor outcomes. Duration of deprivation was a significant modifiable risk factor for adverse ocular motor outcomes. The current study demonstrated that reduced risk for nystagmus and strabismus was associated with deprivation ≤6 weeks.

Cyclic exotropia in a child.

Cyclic strabismus is an uncommon disorder in which strabismus alternates with orthotropia in alternating 24-hour periods, although cycles of other lengths have also been described. Alternate-day exotropia is a rare form of cyclic strabismus which, to date, has been reported in few patients. We describe a case of alternate-day exotropia in a child who had previously undergone surgical correction of constant esotropia.

Vernier acuity cards: examination of development and screening validity.

PURPOSE: Because vernier acuity seems to be limited by the visual cortex, it possesses excellent potential as a clinical/screening tool to detect amblyopia in infants and toddlers. Thus, we developed the vernier acuity cards specifically for this age group. We compared developmental data gathered using this new test and the Teller Acuity Cards. In addition, we compared the clinical/screening validity of the two tests by testing children old enough to complete optotype acuity testing (6.2 ± 2.5 years). METHODS: Vernier acuity and grating acuity were assessed in 98 children and 18 adults with normal vision (age range = 2.8 months to 35.8 years). The developmental time course of the two visual functions was compared. In addition, vernier acuity and grating acuity were measured in 43 children with amblyopia and 30 nonamblyopic children with an amblyogenic condition. Each child's grating acuity and vernier acuity were classified as normal/abnormal based on age-appropriate norms. These classifications were compared with amblyopia diagnoses by crowded HOTV or Early Treatment Diabetic Retinopathy Study (ETDRS) testing. RESULTS: Vernier acuity and grating acuity follow different developmental time courses in normal infants and children. Vernier acuity is initially poorer than grating acuity but surpasses it by the age 5 years and is adult-like by the age 8 years. Compared with the Teller Acuity Cards, the vernier acuity cards yielded higher sensitivity (81 vs. 44%) and similar specificity (73 vs. 93%) and were more sensitive to all amblyopia subtypes/levels of severity. CONCLUSIONS: The developmental time course of vernier acuity differed from that of grating acuity, implying that it is not mediated by the retina. Also, the impressive validity of the vernier acuity cards suggests that they are an effective tool for detecting amblyopia.

Oral reading after treatment of dense congenital unilateral cataract.

BACKGROUND: Good long-term visual acuity outcomes for children with dense congenital unilateral cataracts have been reported after early surgery and good compliance with postoperative amblyopia therapy. However, treated eyes rarely achieve normal visual acuity, and there has been no formal evaluation of the utility of the treated eye for reading. METHODS: Eighteen children previously treated for dense congenital unilateral cataract were tested monocularly with the Gray Oral Reading Test, 4th edition (GORT-4) at 7 to 13 years of age with the use of 2 passages for each eye, one at grade level and one at +1 above grade level. In addition, right eyes of 55 normal children age 7 to 13 served as a control group. The GORT-4 assesses reading rate, accuracy, fluency, and comprehension. RESULTS: Visual acuity of treated eyes ranged from 0.1 to 2.0 logMAR and of fellow eyes from -0.1 to 0.3 logMAR. Treated eyes scored significantly lower than fellow and normal control eyes on all scales at grade level and at +1 above grade level. Monocular reading rate, accuracy, fluency, and comprehension were correlated with visual acuity of treated eyes (r(s) = -0.575 to -0.875, p < 0.005). Treated eyes with 0.1-0.3 logMAR visual acuity did not differ from fellow or normal control eyes in rate, accuracy, fluency, or comprehension when reading at grade level or at +1 above grade level. Fellow eyes did not differ from normal controls on any reading scale. CONCLUSIONS: Excellent visual acuity outcomes after treatment of dense congenital unilateral cataracts are associated with normal reading ability of the treated eye in school-age children.

Onset and progression of with-the-rule astigmatism in children with infantile nystagmus syndrome.

PURPOSE: The purpose of this study was to examine the onset and progression of with-the-rule (WTR) astigmatism during the first 8 years of life in children with idiopathic infantile nystagmus syndrome (INS) or INS associated with albinism and to compare their development with that of normal children. Also explored was whether early WTR astigmatism influences emmetropization in children with INS and whether there is evidence of meridional emmetropization. METHODS: Cycloplegic refractions culled from medical records were converted into power vector components: M (spherical equivalent), J(0) (positive J(0) indicates WTR astigmatism), and J(45) (oblique astigmatism). Two diagnostic groups (idiopathic, n = 106; albinism, n = 95) were evaluated and compared with a reference normal group (n = 495). Four age subgroups were evaluated: age< or =0.5 year, 0.5

Photographic assessment of changes in torsional strabismus.

The horizontal and vertical components of strabismus are measured routinely and relatively easily in the clinical setting using prism-and-cover and/or corneal light reflex tests. The third dimension of ocular alignment, ocular torsion, is more difficult to assess. Objective torsional deviation (cyclotropia) is evaluated qualitatively with fundus examination. For quantitative assessment, however, fundus photography is needed, which may not always be available during a strabismus examination and typically requires pupil dilation. We present a simple, inexpensive photographic technique to assess changes in iris torsion and evaluate its accuracy by comparison with fundus photography. Using a consumer-grade digital camera, basic photographic editing software, and a data worksheet, this technique assesses changes in objective torsion with accuracy and retest variability of both approximately 1 degrees.