Optometry Research Today is a free monthly online journal that collates and summarizes the latest research about Optometry, including details on myopia, optometric practice, therapy.

Corneal thinning associated with recurrent microbial keratitis resulting from 7-day extended wear of low Dk hydrogel contact lenses: A case report.

Cardona G, Saona-Santos CL

Research Group of Centre Universitari de la Visió, Optics and Optometry Department, Technical University of Catalonia, Spain.

CASE DESCRIPTION: Corneal thinning and an increased risk of corneal perforation, resulting from recurrent episodes of microbial keratitis, required a 38-year-old Caucasian female to undergo bilateral corneal grafting. Although strongly advised otherwise, the patient had been a long time user of low oxygen permeability hydrogel contact lenses in a flexible wear regime, with frequent overnight use. DISCUSSION: Microbial keratitis is a potentially severe contact lens related complication which, if not properly treated, may lead to permanent visual loss. The introduction of silicone-hydrogel materials and daily replacement modalities has not resulted in a significant decrease in the incidence of microbial keratitis, thus suggesting that the condition is mainly dependent on patient hygiene and wearing habits. Non-compliance, which is endemic in contact lens wear, may be combated by increasing patient awareness of the potential risk factors of contact lens misuse. This is accomplished through constant, rigorous information provided by contact lens practitioners.

Published 4 February 2010 in Cont Lens Anterior Eye, 33(1): 30-32.
Full-text of this article is available online (may require subscription).

Articles on Optometry published 4 February 2010:

Confocal microscopy and optical coherence tomography imaging of hereditary granular dystrophy.   Cont Lens Anterior Eye, 33(1): 33-40.

OBJECTIVES: This case report examines the clinical characteristics of hereditary granular dystrophy through the use of slit lamp digital photography, confocal microscopy (CM) and optical coherence tomography (OCT). A review of the literature describing the histopathological and genetic associations of stromal dystrophies, suggest it may be possible to differentiate dystrophies based on their clinical manifestations, and appearances of CM and OCT images, with or without the use of genetic ... [Abstract] [Full-text]

The Impact of Inoculation Parameters on the Pathogenesis of Contact Lens Related Infectious Keratitis.   Invest Ophthalmol Vis Sci.

PURPOSE. Contact lens wear predisposes to Pseudomonas aeruginosa keratitis, but the mechanisms involved remain unclear. We used an in vivo model to study lens inoculation conditions enabling disease. METHODS. Custom-made hydrogel contact lenses were fitted to rats after incubation in P. aeruginosa ~10(11) cfu/ml (3 h) or ~10(3) cfu/ml (24 h). Another group was inadvertently inoculated with a suction-pen previously used with high inocula, but ethanol-rinsed and dry-stored (6 months). Some ... [Abstract] [Full-text]

Inhibition of matrix metalloproteinase activity in the chick sclera and its effect on myopia development.   Invest Ophthalmol Vis Sci.

Purpose: To investigate the contribution of matrix degradation in the two-layer avian sclera to the process of myopia development. Methods: Tissue inhibitor of metalloproteinase-2 (TIMP-2) was used to inhibit chick scleral collagen degradation with 3H proline a marker for this effect. Ex vivo scleral culture experiments confirmed TIMP-2 doses for in vivo experimentation. Ocular growth and refractive response to exogenous TIMP-2 (11.25, 2.25 and 0.45 pmoles, plus vehicle only) was monitored in ... [Abstract] [Full-text]

The use of video-keratoscopy in predicting contact lens parameters for keratoconic fitting.   Cont Lens Anterior Eye.

PURPOSE: The purpose of this report is to demonstrate the use the video-keratoscope in determining the type and size of the cone in keratoconus and PMD patients and the final back optic zone diameter (BOZD) and total lens diameter (LD). METHODS: A retrospective review of one hundred clinical records including topographic maps, of keratoconic patients (randomly selected) was performed. Cone diameter and type and final contact lens base curve and diameter were recorded. RESULTS: The types or ... [Abstract] [Full-text]

Articles on Optometry published 3 February 2010:

The folding fingerprint of visual cortex reveals the timing of human V1 and V2.   Neuroimage, 49(3): 2494-2502.

Primate neocortex contains over 30 visual areas. Recent techniques such as functional magnetic resonance imaging (fMRI) have successfully identified many of these areas in the human brain, but have been of limited value for revealing the temporal dynamics between visual areas. The electroencephalogram (EEG) provides information with high temporal precision, but has had limited success separating out the signals from individual neighboring cortical areas. Consequently, controversies exist over ... [Abstract] [Full-text]

Early visual-evoked potential acuity and future behavioral acuity in cortical visual impairment.   Optom Vis Sci, 87(2): 80-6.

PURPOSE.: Cortical Visual Impairment (CVI) is bilateral visual impairment caused by damage to the posterior visual pathway. Both preferential looking and sweep visual-evoked potential (VEP) can be used to measure visual acuity. The purpose of this study was to determine if an early VEP measure of acuity is related to a young patient's future behavioral acuity. METHODS.: The visual acuity of 33 patients with CVI was assessed using the sweep VEP and a behavioral measure on two occasions. The ... [Abstract] [Full-text]

Use of Acular LS in the Pain Management of Keratoconus: A Pilot Study.   Optom Vis Sci, 87(2): 125-30.

PURPOSE.: The purpose of this pilot study was to determine the efficacy of ketorolac tromethamine 0.4% for pain management in conjunction with rigid gas permeable contact lenses in keratoconus. Any potential side effects and complications of this application were examined. METHODS.: A total of 12 current keratoconus patients who were presently experiencing discomfort or pain associated with their rigid gas permeables for keratoconus and/or who were contact lens-intolerant were identified from ... [Abstract] [Full-text]

Compliance with contact lens replacement in Canada and the United States.   Optom Vis Sci, 87(2): 131-9.

PURPOSE.: To assess eye care practitioners (ECPs) recommendations for replacement frequency (RF) of silicone hydrogel (SH) and daily disposable (DD) lenses in Canada and the U.S. and to compare noncompliance (NC) with manufacturer recommended RF by the ECP and patient, and the reasons given for NC. METHODS.: Invitations to participate were sent by e-mail to ECPs in Canada and the U.S. Twenty patient surveys were sent to 420 ECPs, and 2232 eligible surveys were received from 216 ECPs (26% ... [Abstract] [Full-text]

© 2005-2010 Optometry Research Today. All Rights Reserved.