J. V. Odom

Vision Rehabilitation: Recipients' Perceived Efficacy of Rehabilitation

Objective/Purpose: This survey was conducted to determine the effect on activities of daily living of persons who report that they have received vision rehabilitation. Design/Methodology: This study used a clinical sample to gather information from 417 patients. Of the 417, 105 reported receiving vision rehabilitation. The efficacy of rehabilitation was assessed by asking 20 questions about their activities of daily living prior to and after their rehabilitation. A retrospective pretest (post-then-pre) design was used. Paired t tests were conducted to evaluate the effect of rehabilitation. Results: A significant difference was found for 13 of 20 questions. Difficulty reading ordinary prints in newspapers showed a large effect size (p = 0.0005). Difficulty reading the small print in a telephone book showed a large effect size (p = 0.0005). Difficulty doing work or hobbies that require one to see up close showed a moderate effect size (p = 0.0005). Difficulty finding something on a crowded shelf showed a moderate effect size (p = 0.0005). Difficulty figuring out whether bills received are accurate showed a moderate effect size (p = 0.0005). Difficulty shaving, styling ones hair, or putting on makeup showed a small effect size (p = 0.016). Difficulties seeing and enjoying programs on television showed a moderate effect size (p = 0.0005). Conclusion: Patients with low vision who report having received vision rehabilitation show significant improvements in activities of daily living or specific types of functioning after rehabilitation. Improvement in both near and distance vision activities and in social activities indicates daily functioning was improved and that barriers to activities of daily living were removed.

Visual System Manifestations due to Systemic Exposure to Mercury

This article is a summary of the available literature on ocular symptoms due to systemic exposure to mercury. Mercury compounds are first described in terms of their different forms, industrial applications, mechanisms and routes of exposure, toxicity levels, and treatment methods. Eye symptoms are then characterized for organic and inorganic forms of mercury by using the form of various documented case studies of chronic and acute exposure to various mercury compounds.

Visual evoked potential importance in the complex mechanism of amblyopia

To compare the visual evoked potential (VEP) responses of amblyopic eyes with VEP responses of sound eyes in amblyopic children. A study of 65 amblyopic children with pattern-reversal VEPs elicited by checkerboard stimuli with large, medium and small checks. The children were classified into three groups: Group A, 22 children with anisometropic amblyopia; Group B, 16 children with exotropic strabismic amblyopia; and Group C, 27 children with esotropic strabismic amblyopia. Visual acuity (VA) was significantly worse in the amblyopic eye as compared to the sound eye. However, no statistically significant difference was found between the amblyopic and sound eye of amblyopic children in the three groups for VEP P1 amplitude and latencies for any check sizes. VEP is a very important tool in understanding the complex amblyopic mechanism. Although the sound eye has superior VA, the absence of differences in VEP P1 amplitudes and latencies demonstrate the functional abnormality of the eye considered ‘good’. More studies are necessary to explain why the sound eye in amblyopic children cannot be considered completely normal. Special attention should therefore be paid to amblyopic treatment, as patching can have a negative effect on the sound eye.

Spatial density distribution as a basis for image compensation

The paper highlights an approach to provide custom-fit, non-invasive image compensation and remapping by which to magnify and optimize central vision for humans. Medical evidence supports that the visual density lies mostly within the limited range of the central vision. The technique is, consequently, based on both practical viewing considerations as well as the spatial density distribution in human retinal cells. The perceived image is divided into three vertically distributed sections (top--center--bottom), each warped according to its respective visual significance. Optimization is also used to ensure the smooth flow and transition of the image from one region to the other. The technique is expected to serve in applications such as low-vision, surveillance, machine operation, gaming, and text-enhancement.

Ocular scanning instrumentation: Confirmation of biomarkers for anticholinesterase and cyanide exposure

The sensitivity of the eye’s reaction to a wide variety of chemicals/toxins and its role as a gauge for internal homeostasis (e.g., cardiovascular and neurophysiological imbalances) has been extensively researched via many scientific disciplines. New techniques and equipment are both harnessing and utilizing this information to define a modern approach to the field of non-invasive early detection of a vast range of physical abnormalities, injuries, and illnesses. Early detection provides an invaluable tool in the subsequent success of treating such conditions. The application of these techniques to the detection of exposure to chemical threat agents such as organophosphate nerve agents and cyanide provides an important advancement in the ability to limit the deleterious effects of these agents. The Ocular Scanning Instrumentation (OSI) technology involves the use of an automated device for the continuous or programmed monitoring of optically apparent characteristic(s) and attributes of the eye that may serve as an early-warning system for possible complications based upon generalized information obtained from ocular biomarkers. Described herein is the analysis of primary ocular biomarkers for organophosphate (miosis) and cyanide (venous blood coloration) exposure.