A pre-application drop containing carboxymethylcellulose can reduce multipurpose solution-induced corneal staining.

PURPOSE: Use of polyhexanide based multipurpose solutions (MPSs) for contact lens disinfection has been linked to low-grade corneal staining. In vitro data suggest that carboxymethylcellulose (CMC) may neutralize polyhexanides. The purpose of this investigation was to determine whether a pre-application drop of CMC reduces polyhexanide staining in vivo. METHODS: Thirty adapted soft contact lens (SCL) wearers participated in this investigator-masked, randomized, two-way cross-over study. Subjects wore a new Group II lens (alphafilcon A, 66% water) daily for 4 weeks and disinfected lenses using a MPS containing 0.0001% polyaminopropyl biguanide. A lens lubricant containing either CMC or povidone as the primary viscolyzer was applied to the lens each day before lens wear. Biomicroscopic signs and symptomatology were assessed. The difference in scores, 0 to 4 weeks and the difference between lubricants were analyzed. RESULTS: The cumulative fluorescein staining scores for combined eyes demonstrated a significant increase over time (e.g., cumulative staining score; p=0.004 and p<0.001 for CMC and povidone, respectively, matched pairs t-test, two-tailed), suggesting that for both lubricants the staining worsened with wear. This effect was expected and likely driven by the MPS. However, the mean cumulative staining scores for CMC and povidone were 2.8 and 2.6 out of 20 possible at baseline, increasing to 4.9 and 7.1 at 4 weeks, respectively. The increases were significantly different (p=0.003, matched pairs t-test, two-tailed) suggesting a greater increase in corneal staining for the povidone lubricant. The symptom scores were not significantly different, 0 to 4 weeks by regimen or between preinstillation drops. CONCLUSIONS: These results suggest that a CMC-containing preapplication drop can reduce corneal staining resulting from disinfection with a polyhexanide MPS. This result is consistent with a proposed mechanism for CMC to neutralize cationic disinfectants and may offer clinicians another means to reduce this type of corneal staining.

A reevaluation of the Developmental Eye Movement (DEM) test's repeatability.

PURPOSE: To investigate the repeatability of the Developmental Eye Movement (DEM) Test in a group of third grade elementary school students. METHODS: Thirty, third grade children who passed a modified clinical technique vision screening were given the DEM and then retested 2 weeks later. RESULTS: A clinically and statistically significant improvement in mean scores from test to retest was found on the vertical time, horizontal time, and ratio score. The intraclass correlation coefficient (ICC) and the 95% limits of agreement (LoA) suggest that the vertical (ICC, 0.60; LoA, -4.2 +/- 16.5 s) and corrected horizontal (ICC, 0.55; LoA, -8.3 +/- 17.4 s) times have fair to good repeatability, whereas the ratio score was found to have poor repeatability (ICC, 0.27; LoA, -0.08 +/- 0.39). Based on these results, large changes can be expected on retest, which may result in a change in diagnostic classification from pass to fail. CONCLUSIONS: These results suggest that the ratio score of the DEM had poor repeatability in the third grade children who were evaluated. Poor repeatability of the ratio score may affect the clinician's diagnostic decisions and ability to monitor the effects of saccadic treatment.

Association of symptoms and convergence and accommodative insufficiency in school-age children.

BACKGROUND: The purpose of this article was to investigate the association between convergence insufficiency (CI) and accommodative insufficiency (AI) and symptoms in a group of school-aged children. METHODS: Children ages 8 to 15 years were recruited from two public and 2 private elementary schools in Southern California. The CI Symptom Survey (CISS) was administered to all children before a Modified Clinical Technique vision screening. Children with normal visual acuity, minimal uncorrected refractive error, and no strabismus were tested for CI and Al. RESULTS: Four hundred sixty nine children were initially screened and 392 participated in testing for CI and AI. Fifty-five percent of the children (218) were classified as having normal binocular vision (NBV), 4.6% (18) had three signs of CI, 12.7% (50) had two signs of CI, 10.5% (41) were classified as AI (with no signs of CI), and 16.6% (65) were classified as other. The symptom score was 3.78 for the NBV group, 4.6 for the two-sign CI group, 6.67 for the three-sign CI group, and 6.37 for the Al group. The three-sign CI and the Al groups scored significantly higher than the NBV group on the CISS (p < or = 0.001). CONCLUSION: CI and AI are common conditions in school-age children and are associated with increased symptoms.

Reliability of binocular vision measurements used in the classification of convergence insufficiency.

PURPOSE: To evaluate the reliability of binocular vision measurements used in the classification of convergence insufficiency. METHODS: Two examiners tested 20 fifth and sixth graders in a school setting who passed a screening of visual acuity, refraction, and binocularity. The tests, conducted using a standard protocol, consisted of von Graefe near heterophoria (NH), phorometric positive fusional vergence (PFV), nearpoint of convergence (NPC), and monocular pushup accommodative amplitude (AA). Each examiner measured each child three consecutive times for each test, on two separate occasions, spaced approximately 1 week apart. Intraexaminer and interexaminer agreement was assessed using intraclass correlation coefficients (ICC), the median absolute difference (MAD), and the coefficient of repeatability (COR). RESULTS: The within-session reliability of the NH (ICC: 0.95 to 0.99), NPC (ICC: 0.94 to 0.98), and AA (ICC: 0.88 to 0.95) were good, whereas the PFV was less reliable (ICC: 0.71 to 0.94). The intraexaminer reliability between sessions was good for the NPC (ICC: 0.92 and 0.89), less reliable for NH (ICC: 0.81 and 0.81) and AA (ICC: 0.89 and 0.69), and much less reliable for PFV break (ICC: 0.59 and 0.53). Typical between-session PFV differences (MAD) were between 3 and 4 delta, whereas the COR differences were as large as 12 delta. CONCLUSIONS: Three of the four measures (NH, NPC, and AA) often used in the classification of convergence insufficiency generally have good within-session and between-session reliability. The PFV break was found to have only fair reliability with clinically significant differences between sessions. The large potential test-retest differences found could complicate clinical decision-making in regards to diagnosis and treatment.