A Study of the Short-Term Effect of Artificial Tears on Contrast Sensitivity in Patients With Sjogren's Syndrome
ABSTRACT Purpose: This study was designed to measure the effect of different artificial tears on the contrast sensitivity of Sjgren's syndrome patients from 5 minutes to 4 hours after instillation. Methods: Ten normal subjects and ten subjects with ocular manifestations of Sjgren's syndrome were compared at baseline, including staining scores, a dry eye questionnaire and contrast sensitivity testing. Changes in contrast sensitivity in the Sjgren's syndrome group were measured over a four hour period after instillation of a variety of artificial tears. Results: Statistically significant differences in staining, subjective questionnaire scores and contrast sensitivity were measured between the normal and Sjgren's syndrome groups. Statistically significant changes in contrast sensitivity were measured over time after artificial tear instillation, with the greatest effect at 3-6 cycles per degree. The more muco-adhesive artificial tears demonstrated a significantly greater effect. Conclusions: The effects of artificial tears on measured contrast sensitivity in dry eye patients in the post-instillation period of 5 minutes to 4 hours appear limited, but an artificial tear with more muco-adhesive properties showed more benefit than those which do not. Modest effects on contrast sensitivity, primarily at medium spatial frequencies, were observed with the more muco-adhesive formulations.
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ABSTRACT: The purpose of this study was to use factor analysis to analyze 90 clinical characteristics of a cohort of 231 patients with primary Sjogren syndrome (pSS). The records of all patients seen at the University Health Network Sjogren Syndrome Clinic from October 1992 to July 2006 were reviewed and documented. Those diagnosed as pSS by the American European Consensus Criteria of 2002 were included. The 90 clinical variables, including health history, blood analysis, symptoms of dry eye and dry mouth, salivary flow and biopsy, tear flow and staining, were analyzed by factor analysis. Two hundred thirty-one patients with pSS charts were reviewed, and 90 variables were recorded. Factor analysis resulted in three factors: factor 1: ocular surface staining, factor 2: antimicrosomal antibodies and antithyroid antibodies, and factor 3: serum anti-Ro and anti-La. Ocular surface staining accounted for the greatest variance in this population of patients with pSS.Optometry and vision science: official publication of the American Academy of Optometry 10/2010; 87(10):742-50. DOI:10.1097/OPX.0b013e3181f32196 · 2.04 Impact Factor
Article: A clinical evaluation of Systane[Show abstract] [Hide abstract]
ABSTRACT: Systane is a new artificial tear solution containing the pH dependent gelling polymer hydroxypropyl-Guar (HP-Guar). We evaluated Systane in an open trial. Patients complaining of dry feeling eyes were eligible to enroll, with inclusion criteria based on the presence of corneal staining with sodium fluorescein (NaFl) and participants' desire to use ocular lubricants. Six symptoms of ocular irritation were rated on a four-point scale. Conjunctival injection, conjunctival and corneal fluorescein staining were graded and tear break-up time (TBUT) and tear meniscus height were measured. Subjects were instructed to instill one drop of Systane into each eye four times a day for approximately four weeks. Ocular symptoms and signs were then reassessed and subjects were asked to rate eight statements concerning their satisfaction with the product. A total of 38 subjects were enrolled with 32 completing the follow-up visit. The following variables improved significantly at follow-up: all ocular irritation symptom scores, conjunctival injection, total conjunctival and total corneal staining scores, and TBUT. Tear meniscus height showed no significant change. Systane proved effective in reducing the symptoms of dry eye; however induced blur appeared to be a complication for many participants. The study represents a community based evaluation of the benefits of a novel ocular lubricant in optometric practice. The results suggest that the gelling properties of HP-Guar may be influential in promoting ocular surface recovery through improved ocular surface retention, however further randomised controlled trials are needed to confirm this. The extent and significance of induced blur also needs further investigation.Contact Lens & Anterior Eye 04/2006; 29(1):31-40. DOI:10.1016/j.clae.2005.12.003 · 2.00 Impact Factor
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ABSTRACT: Faces are perceived holistically, a phenomenon best illustrated when the processing of a face feature is affected by the other features. Here, the authors tested the hypothesis that the holistic perception of a face mainly relies on its low spatial frequencies. Holistic face perception was tested in two classical paradigms: the whole-part advantage (Experiment 1) and the composite face effect (Experiments 2-4). Holistic effects were equally large or larger for low-pass filtered faces as compared to full-spectrum faces and significantly larger than for high-pass filtered faces. The disproportionate composite effect found for low-pass filtered faces was not observed when holistic perception was disrupted by inversion (Experiment 3). Experiment 4 showed that the composite face effect was enhanced only for low spatial frequencies, but not for intermediate spatial frequencies known be critical for face recognition. These findings indicate that holistic face perception is largely supported by low spatial frequencies. They also suggest that holistic processing precedes the analysis of local features during face perception.Journal of Experimental Psychology Human Perception & Performance 09/2006; 32(4):1023-39. DOI:10.1037/0096-15188.8.131.523 · 3.11 Impact Factor