Screening for amblyopia in preverbal children with photoscreening photographs: IV. Interobserver variability in photograph grading: origin and method of reduction.

BACKGROUND: Earlier detection of childhood vision disorders is a prominent goal of vision screening. The Medical Technology and Innovation (MTI) PhotoScreener addresses this objective. Use of this camera does not require verbal feedback and may be administered early in a child's development. Decreasing the variability in photograph grading results will boost the utility of any photoscreening system. This report aims to understand and to decrease intra- and inter-observer variability in grading photoscreening photographs. METHODS: We dissected the photograph grading process and quantified the intra- and inter-observer agreement using intraclass plot correlation coefficients. We evaluated the outcome of a two grader verification system vs. adjudicated measurements with Receiver Operator Characteristic (ROC) curves. PARTICIPANTS: Data on 955 children under 5 years of age, normal except for refractive error, each with complete photoscreening and eye examination data, culled from two previous studies. MAIN OUTCOME MEASURES: Intra- and inter-observer agreement in measuring bright crescent dimensions and pupillary diameters. Sensitivity and specificity of detection of hyperopia. RESULTS: Measurements of bright crescents are associated with greater variability than are measurements of pupillary diameters. Recognition and omission of light "rim" measurements from photograph grading will result in superior inter-observer agreement. Photograph independent errors increase variability and may be corrected by remeasurement. A verification system in which the most discrepant 5% of measurements are redone results in ROC curves similar to adjudicated dimension. CONCLUSIONS: We conclude: 1) two novices grading photographs can do as well as one expert in most cases; 2) the proposed grading methodology has undergone statistical validation and can be used in other areas of ophthalmology and medicine; and 3) inter-observer variability, one of the limitations of photoscreening photograph grading, can be reduced. For 95% of the photographs, two novices achieve similar true positive and true negative values with or without adjudication.

Long-term study of accommodative esotropia.

PURPOSE: This study aimed, using a large sample size, to determine the long-term results of standard treatment of accommodative esotropia and identify predictors of outcome while minimizing bias in data collection and analysis. METHODS: Data from all the files of a large, long-established pediatric ophthalmology practice were collected and analyzed using a masked protocol. The study included every esotropic patient who had been prescribed glasses. Criteria for patient inclusion were designed to conform to earlier studies by the authors. RESULTS: The database totaled 1307 patients, of who 354 met inclusion criteria. A greater difference between near and distance esodeviation (AC/A relationship) correlated with a higher rate of deterioration of accommodative esotropia control (P < 0.0001). Deterioration also positively correlated with earlier age of onset (P < 0.0001), inferior oblique overaction (P = 0.0005), and amblyopia (P < 0.005). CONCLUSIONS: This study demonstrates that a high AC/A relationship increases the likelihood of deterioration of accommodative esotropia, supporting the earlier studies, as well as the accuracy of this database. It also represents a new model for the utilization of clinical trials' bias-reduction principals in the analysis of retrospective data.

The association between myopic shift and visual acuity outcome in pediatric aphakia.

PURPOSE: The advent of intraocular lens implantation after pediatric cataract surgery necessitates an increased understanding of refractive development. The significant variation in rate and amount of refractive change among eyes, both aphakic and pseudophakic, is well recognized, although the causes of such variation remain unclear. The purpose of this study was to determine if a correlation exists between the rate of refractive growth (RRG) and visual acuity outcome in pediatric aphakia. METHODS: Multicenter, retrospective observational case series. One hundred and twenty-five eyes of 85 patients with cataract surgery before 1 year of age and a minimum of 3 years of follow-up were analyzed. RRG was calculated for each eye using the logarithmic model of ocular growth and compared with final logMAR acuity using linear regression. RESULTS: The correlation of RRG with final logMAR acuity was statistically significant (r(2) = 0.10; P <.01), ie, 10% of variance in RRG is related to acuity outcome. The correlation was higher in unilaterally aphakic patients (n = 44; r(2) = 0.19; P <.01) than in bilaterally aphakic patients (n = 81; r(2) = 0.08; P <.01). Eyes with visual acuity of 20/60 or better had a significantly lower RRG than those with poorer acuity (4.1 v 5.4 diopters (D); P <.01). CONCLUSIONS: RRG in aphakia is correlated with visual acuity outcome. Eyes with poorer acuity have a greater RRG.

Long-term study of accommodative esotropia.

PURPOSE: Previous studies of accommodative esotropia have been hampered by bias-prone methods of data collection and analysis and by small sample size. The studies have conflicting conclusions, causing uncertain results. This study aims to determine long-term results of standard treatment of accommodative esotropia and identify predictors of outcome, while minimizing bias in data collection and analysis, using the largest possible sample size. METHODS: A research assistant collected data from all files of a large, long-established pediatric ophthalmology practice (M.M.P.). The assistant was given standardized collection forms that allowed inclusion of all patient data points over all visits. The assistant was masked as to study goals. She was instructed to include any patient with esotropia who had been prescribed glasses during treatment. Descriptive terms were converted to code numbers. A second, similarly masked research assistant entered data into a computerized database. Criteria for patient inclusion were designed to conform to earlier studies by I.H.L. and M.M.P. and were implemented by computer. RESULTS: The database totaled 1,307 patients (747,717 data points). Of these, 354 qualified for this analysis. A greater difference between near and distance esodeviation (AC/A relationship) correlated with a higher rate of deterioration of accommodative esotropia control (P<.0001). Deterioration also positively correlated with earlier age at onset, inferior oblique overaction, and amblyopia. CONCLUSIONS: This study agrees with our previous findings that a high AC/A relationship increases the likelihood of deterioration of accommodative esotropia, thus confirming the integrity of the database. This unique, unbiased dataset will be used for future analyses of esotropia.