Frequency of Contact Lens Complications Between Contact Lens Wearers Using Multipurpose Solutions Versus Hydrogen Peroxide in the United States and Canada.

OBJECTIVES: To retrospectively compare frequency of contact lens (CL) complications in soft CL users of hydrogen peroxide (H2O2) and multipurpose solutions (MPS). METHODS: This was a multicenter, retrospective chart review of CL records from each patient's three most recent eye examinations at academic and private practices. Patients must have used the same solution type for at least 3 years. Univariate analyses were conducted using t tests, and chi-square or Fisher's exact test for categorical measures. RESULTS: There were 1,137 patients included, with 670 (59%) using MPS and 467 (41%) H2O2. In total, 706 (62%) experienced at least one complication; 409 used MPS and 297 used H2O2. There was no difference in the proportion of patients experiencing at least one complication between MPS (61%) and H2O2 (64%) (P=0.38). Multipurpose solutions users were more likely to report discomfort compared with H2O2 users (P=0.04). Presumed microbial keratitis was experienced by 16 MPS and nine H2O2 users (P=0.60). CONCLUSIONS: No significant differences were found in the frequency of CL complications between MPS and H2O2. H2O2 users were less likely to report discomfort and thus switching to a H2O2 system may be an alternative in CL users with discomfort.

Matching the LenStar optical biometer to A-Scan ultrasonography for use in small animal eyes with application to tree shrews.

We describe an analysis strategy to obtain ultrasonography-matched axial dimensions of small animal eyes using the LenStar biometer. The LenStar optical low-coherence reflectometer is an attractive device for animal research due to its high precision, non-invasiveness, and the ability to measure the axial dimensions of cornea, anterior chamber, lens, vitreous chamber, and axial length. However, this optical biometer was designed for clinical applications in human eyes and its internal analysis provides inaccurate values when used on small eyes due to species-dependent differences in refractive indices and relative axial dimensions. The LenStar uses a near infrared light source to measure optical path lengths (OPLs) that are converted by the LenStar's EyeSuite software into geometrical lengths (GLs) based on the refractive indices and axial dimensions of the human eye. We present a strategy that extracts the OPLs, determines refractive indices specific for the small animal eye of interest and then calculates corrected GLs. The refractive indices are obtained by matching the LenStar values to ultrasonography values in the same eyes. As compared to ultrasounography, we found that the internal calculations of the LenStar underestimate the axial dimensions of all ocular compartments of the tree shrew eye: anterior segment depth by 6.17±4.50%, lens thickness by 1.37±3.06%, vitreous chamber depth by 29.23±2.35%, and axial length by 10.62±1.75%. Using tree shrew-specific refractive indices, the axial dimensions closely matched those measured by ultrasonography for each compartment. Our analysis strategy can be easily translated to other species by obtaining a similar paired data set using ultrasonography and LenStar, and applying our step by step procedures.

Impact of the 2011 International Workshop on Meibomian Gland Dysfunction on clinical trial attributes for meibomian gland dysfunction.

PURPOSE: The 2011 International Workshop on Meibomian Gland Dysfunction was organized to build consensus on various disease aspects of MGD. The purpose of this review was to examine the influence of the MGD Workshop on clinical trials by examining their attributes prior to and after the Workshop. METHODS: A search for clinical trials using the terms "Meibomian Gland Dysfunction" was conducted using the "Interventional Studies" filter on ClinicalTrials.gov, and selecting studies with posting and start dates prior to (2004-2010) and after the Workshop (2012-2018). The inclusion criteria, outcome measures, and study designs and rigor were examined. RESULTS: A total of 32 post-Workshop and 5 pre-Workshop clinical trials were identified with the search. The proportion of pre-Workshop trials using generic diagnosis and systematic assessments to define MGD was similar to that of post-Workshop trials. In both pre- and post-Workshop trials, symptoms, altered gland secretions, and alteration in tear film were the most frequent clinical attributes used to define MGD. The most frequent outcome measures used for pre-Workshop and post-Workshop trials were also similar: symptoms, meibum quality/expressibility, and tear stability. CONCLUSIONS: The nature of the inclusion criteria, and the clinical attributes used to define MGD during the pre-Workshop period were similar to those of the post-Workshop period, suggesting that the MGD Workshop has had a minimal impact on the design of interventional trials for MGD.