G. Lynn Mitchell

The Repeatability of Clinical Measurements of Dry Eye

Purpose: The repeatability of individual dry eye diagnostic tests has been reported in the literature on normal samples of patients and to a lesser degree in dry eye patients. In this study, the repeatability of a battery of clinical diagnostic tests for dry eye was assessed on mild to moderate dry eye patients. Methods: A dry eye examination was performed on 75 patients on two occasions by a single examiner. The battery of dry eye tests included symptom assessment, contact lens and medical history, slit-lamp biomicroscopic evaluation of the eyelids, evaluation of Meibomian glands, assessment of tear film quality, tear meniscus height, assessment of blink quality, fluorescein tear breakup time (TBUT), fluorescein and rose bengal staining of the cornea and conjunctiva, phenol red thread test, and Schirmer test. Results: The repeatability of subjective report of dryness (κw = 0.62) and grittiness (κw = 0.73) was moderate to high. In contrast, the repeatability of Meibomian gland disease classification (κw = 0.20), presence or absence of inferior corneal fluorescein staining (κ = 0.25), and inferior conjunctival rose bengal staining (κ = 0.21) was poor. When a summed staining score of corneal and conjunctival regions was evaluated, weighted κ reliability was fair. The repeatability of tear breakup time was substantial [95% limits of agreement −5.71 to 5.83 seconds; intraclass coefficient coefficient (ICC) 0.65], and improved when the two timed readings were averaged. Repeatability of the Schirmer test is more variable as wetting scores increase. When the average Schirmer scores ≤10 mm were evaluated, moderate repeatability was demonstrated, indicating that the test performs better with more advanced disease. Conclusion: Although patient-reported symptoms are moderately repeatable from visit to visit, many of the procedures clinically used to diagnose and monitor dry eye syndromes are largely unrepeatable.

Characterization of ocular surface symptoms from optometric practices in North America.

Purpose. This study characterized ocular symptoms typical of dry eye in an unselected optometric clinical population in the United States and Canada. Methods. Self-administered dry eye questionnaires, one for non–contact lens wearers (dry eye questionnaire) and one for contact lens wearers (contact lens dry eye questionnaire), were completed at six clinical sites in North America. Both questionnaires included categoric scales to measure the prevalence, frequency, diurnal severity, and intrusiveness of nine ocular surface symptoms. The questionnaires also asked how much these ocular symptoms affected daily activities and contained questions about computer use, medications, and allergies. The examining doctors, who were masked to questionnaire responses, recorded a nondirected dry eye diagnosis for each patient, based on their own diagnostic criteria. Results. The dry eye questionnaires were completed by 1,054 patients. The most common ocular symptom was discomfort, with 64% of non–contact lens wearers and 79% of contact lens wearers reporting the symptom at least infrequently. There was a diurnal increase in the intensity of many symptoms, with symptoms such as discomfort, dryness, and visual changes reported to be more intense in the evening. The 22% percent of non–contact lens wearers and 15% of contact lens wearers diagnosed with dry eye (most in the mild to moderate categories) reported symptoms at a greater frequency than those not diagnosed with dry eye. Conclusions. Our results show that symptoms of ocular irritation and visual disturbances were relatively common in this unselected clinical population. The intensity of many ocular symptoms increased late in the day, which suggested that environmental factors played a role in the etiology of the symptoms.

Ocular component data in schoolchildren as a function of age and gender.

Purpose. To describe the refractive error and ocular components of a large group of school-aged children as a function of age and gender. Methods. In this report, we describe the refractive error and ocular components of 2583 school-aged children (49.3% girls, overall mean [±SD] age 10.0 ± 2.3). Measurement methods included cycloplegic autorefraction, autokeratometry, videophakometry, and A-scan ultrasonography. For statistical comparisons across gender and age, a critical point of &agr; = 0.005 was used to assess significance because of the large sample size and the large number of comparisons made. Results. Of these 2583 children, 10.1% were myopic (−0.75 D or more myopia in both meridians), and 8.6% were hyperopic (+1.25 D or more hyperopia in both meridians). As would be expected, there was a significant effect of age on refractive error (spherical equivalent, p < 0.0001), toward less hyperopia/more myopia. There was no significant difference in the average refractive error between girls and boys (p = 0.0192). Girls had steeper corneas than boys (0.74 D steeper in the vertical meridian and 0.63 D steeper in the horizontal meridian, p < 0.0001). There were no significant differences in corneal power with age (p = 0.16). Both older age and male gender were significantly associated with deeper anterior chambers (p < 0.0001 for both). The crystalline lens showed significant thinning with age (p < 0.0001), however, there was no significant difference in the lens thickness between girls and boys (p = 0.66). Both Gullstrand lens power and calculated lens power showed significant effects of age and gender (p < 0.0001 for both). Girls, on average, had Gullstrand lens powers that were 0.28 D steeper and calculated lens powers that were 0.80 D more powerful than boys. Axial length also showed significant effects of age and gender (p < 0.0001 for both). Girls’ eyes were, on average, 0.32 mm shorter than those of boys. Conclusions. These cross-sectional data show a general pattern of ocular growth, no change in corneal power, and crystalline lens thinning and flattening between the ages of 6 and 14 years. Girls tended to have steeper corneas, stronger crystalline lenses, and shorter eyes compared with boys.

Validity and Reliability of the Revised Convergence Insufficiency Symptom Survey in Children Aged 9 to 18 Years

Purpose. To assess the validity and reliability of the Convergence Insufficiency Symptom Survey (CISS) in children aged 9 to 18 years. The CISS is the primary outcome measure for a pilot study evaluating two different treatments for convergence insufficiency (CI). Methods. Children with CI were given the CISS twice to assess reliability. CISS scores for the first administration were also compared with scores from children with normal binocular vision to assess the validity of the CISS. Results. Forty-seven children with CI and 56 children with normal binocular vision participated in the study. Reliability was assessed using intraclass correlation and 95% limits of agreement for the children with CI. For children with CI, the intraclass correlation was 0.77 (95% confidence interval, 0.613 to 0.873), and the 95% limits of agreement were −10.2 to +12.1. The mean (±SD) CISS score was 30.8 ± 8.4 for the children with CI and 8.4 ± 6.4 for the children with normal binocular vision. These means were significantly different (p < 0.0001). Good discrimination (sensitivity, 96%; specificity, 88%) was obtained using a score of ≥16. Conclusions. Children with CI showed a significantly higher CISS symptom score than children with normal binocular vision. The results of the study indicate that the CISS is a valid and reliable instrument to use as an outcome measure for children aged 9 to 18 who are enrolled in clinical research concerning CI.

Validity and reliability of the revised convergence insufficiency symptom survey in adults

Purpose:  To assess the validity and reliability of the revised Convergence Insufficiency Symptom Survey (CISS) in adults aged 19–30 years. The CISS was developed to be the primary outcome measure for studies evaluating various treatments for convergence insufficiency (CI).

Evaluation of tear film interference patterns and measures of tear break-up time.

Purpose. The purpose of this study was to compare the agreement within and between examiners when evaluating real-time and digital photographs of TearScope Plus tear film interference patterns. We also evaluated between-examiner agreement of noninvasive digital tear break-up time (NITBUT) using the TearScope, the relation between NITBUT and tear film interference patterns, and the relation between NITBUT and tear break-up time (TBUT). Methods. Forty nondry eye patients were seen for digital imaging of the tear film using the TearScope Plus mounted on a slit-lamp with the EyeCap Ophthalmic Image Capture System. Two independent examiners first assessed the tear interference pattern in real-time and then captured the patterns and NITBUT digitally for a period of approximately 60 s. Each image series was later graded for interference pattern and NITBUT by the two independent, masked examiners. Results. Within-examiner comparisons of real-time and digital tear pattern photograph grading showed moderate to substantial agreement for experienced examiners (kappa for examiner 1 = 0.76 and kappa for examiner 2 = 0.55). Between-examiner agreement when grading tear patterns was also substantial in real-time (kappa = 0.72) and moderate when using digital photography (kappa = 0.59). The between-examiner mean NITBUT was 11.2 ± 6.8 s and the 95% limits of agreement between examiners were −19.2 to +9.2 s. The mean TBUT was 7.6 ± 10.4 s, and it was on average 3.7 ± 12.0 s shorter than NITBUT (p = 0.06). Thicker tear film interference patterns graded photographically were associated with longer NITBUTs for both examiners (p = 0.001). Conclusions. There is moderate to substantial within- and between-examiner agreement when comparing real-time and digital tear interference patterns photographs when using the TearScope. Although there is considerable between-examiner variability with the NITBUT test, the thicker lipid layer tear patterns tend to be associated with longer NITBUTs.

Relative Peripheral Refractive Error and the Risk of Onset and Progression of Myopia in Children

PURPOSE To investigate whether relative peripheral hyperopia is a risk factor for either the onset of myopia in children or the rate of myopic progression. METHODS The risk of myopia onset was assessed in 2043 nonmyopic third-grade children (mean age ± SD = 8.8 ± 0.52 years) participating in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study between 1995 and 2007, 324 of whom became myopic by the eighth grade. Progression analyses used data from 774 myopic children in grades 1 to 8. Foveal and relative peripheral refractive error 30° in the nasal visual field was measured annually by using cycloplegic autorefraction. Axial length was measured by A-scan ultrasonography. RESULTS The association between more hyperopic relative peripheral refractive error in the third grade and the risk of the onset of myopia by the eighth grade varied by ethnic group (Asian children odds ratio [OR] = 1.56, 95% confidence interval [CI] = 1.06-2.30; African-American children OR = 0.75, 95% CI = 0.58-0.96; Hispanics, Native Americans, and whites showed no significant association). Myopia progression was greater per diopter of more hyperopic relative peripheral refractive error, but only by a small amount (-0.024 D per year; P = 0.02). Axial elongation was unrelated to the average relative peripheral refractive error (P = 0.77), regardless of ethnicity. CONCLUSIONS Relative peripheral hyperopia appears to exert little consistent influence on the risk of the onset of myopic refractive error, on the rate of myopia progression, or on axial elongation.

Randomized clinical trial of treatments for symptomatic convergence insufficiency in children

OBJECTIVE To compare home-based pencil push-ups (HBPP), home-based computer vergence/accommodative therapy and pencil push-ups (HBCVAT+), office-based vergence/accommodative therapy with home reinforcement (OBVAT), and office-based placebo therapy with home reinforcement (OBPT) as treatments for symptomatic convergence insufficiency. METHODS In a randomized clinical trial, 221 children aged 9 to 17 years with symptomatic convergence insufficiency were assigned to 1 of 4 treatments. MAIN OUTCOME MEASURES Convergence Insufficiency Symptom Survey score after 12 weeks of treatment. Secondary outcomes were near point of convergence and positive fusional vergence at near. RESULTS After 12 weeks of treatment, the OBVAT groups mean Convergence Insufficiency Symptom Survey score (15.1) was statistically significantly lower than those of 21.3, 24.7, and 21.9 in the HBCVAT+, HBPP, and OBPT groups, respectively (P < .001). The OBVAT group also demonstrated a significantly improved near point of convergence and positive fusional vergence at near compared with the other groups (P <or= .005 for all comparisons). A successful or improved outcome was found in 73%, 43%, 33%, and 35% of patients in the OBVAT, HBPP, HBCVAT+, and OBPT groups, respectively. CONCLUSIONS Twelve weeks of OBVAT results in a significantly greater improvement in symptoms and clinical measures of near point of convergence and positive fusional vergence and a greater percentage of patients reaching the predetermined criteria of success compared with HBPP, HBCVAT+, and OBPT. Application to Clinical Practice Office-based vergence accommodative therapy is an effective treatment for children with symptomatic convergence insufficiency. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00338611.

A Randomized Clinical Trial of Vision Therapy/ Orthoptics versus Pencil Pushups for the Treatment of Convergence Insufficiency in Young Adults

Purpose. The purpose of this article is to compare vision therapy/orthoptics, pencil pushups, and placebo vision therapy/orthoptics as treatments for symptomatic convergence insufficiency in adults 19 to 30 years of age. Methods. In a randomized, multicenter clinical trial, 46 adults 19 to 30 years of age with symptomatic convergence insufficiency were randomly assigned to receive 12 weeks of office-based vision therapy/orthoptics, office-based placebo vision therapy/orthoptics, or home-based pencil pushups. The primary outcome measure was the symptom score on the Convergence Insufficiency Symptom Survey. Secondary outcome measures were the near point of convergence and positive fusional vergence at near. Results. Only patients in the vision therapy/orthoptics group demonstrated statistically and clinically significant changes in the near point of convergence (12.8 cm to 5.3 cm, p = 0.002) and positive fusional vergence at near (11.3&Dgr; to 29.7&Dgr;, p = 0.001). Patients in all three treatment arms demonstrated statistically significant improvement in symptoms with 42% in office-based vision therapy/orthoptics, 31% in office-based placebo vision therapy/orthoptics, and 20% in home-based pencil pushups achieving a score <21 (our predetermined criteria for elimination of symptoms) at the 12-week visit. Discussion. In this study, vision therapy/orthoptics was the only treatment that produced clinically significant improvements in the near point of convergence and positive fusional vergence. However, over half of the patients in this group (58%) were still symptomatic at the end of treatment, although their symptoms were significantly reduced. All three groups demonstrated statistically significant changes in symptoms with 42% in office-based vision therapy/orthoptics, 31% in office-based placebo vision therapy/orthoptics, and 20% in home-based pencil push-ups meeting our criteria for elimination of symptoms.

Comparison of multifocal and monovision soft contact lens corrections in patients with low-astigmatic presbyopia

Purpose. The purpose of this study was to assess visual performance and patient satisfaction with two presbyopic soft contact lens modalities. Methods. A crossover study of 38 patients with presbyopia was conducted. Patients were randomized first into either multifocal (Bausch & Lomb SofLens Multifocal) or monovision (SofLens 59) for 1 month. Visual performance was measured with high- and low-contrast visual acuity at distance and near and near stereoacuity. Patients’ satisfaction was measured by the National Eye Institute Refractive Error Quality of Life Instrument questionnaire and by recording the patient’s final lens preference. Results. Patients maintained at least 20/20 binocular vision with both multifocal (MF) and monovision (MV) contact lenses under high-contrast conditions at distance and near. Under low-contrast conditions, patients lost less than a line of vision from the best spectacle correction to either multifocal or monovision contact lens correction at distance (pMF = 0.001, pMV = 0.006). Under low-contrast conditions at near, multifocal wearers lost five to six letters and monovision wearers lost two letters of vision (pMF < 0.001, pMV = 0.03, pMF/MV = 0.005). The average stereoacuity decreased by 79 s arc with monovision vs. multifocal contact lenses (p = 0.002). On the NEI-RQL, patients reported worse clarity of vision (pMF = 0.01, pMV < 0.001), more symptoms (pMF = 0.09, pMV = 0.01), and an improvement in their appearance with contact lens wear (pMF < 0.001, pMV < 0.001). Seventy-six percent of patients reported that they preferred multifocal contact lenses, and 24% preferred monovision contact lenses (p = 0.001). Conclusion. The majority of our patients preferred multifocals to monovision, most likely because the Bausch & Lomb SofLens Multifocal provides excellent visual acuity without compromising stereoacuity to the same degree as monovision.