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Leber optic atrophy (LOA) is a familial disorder primarily affecting males. We report the case of a 44-year-old male for whom the prescription of low vision aids was an important rehabilitative factor.
It is reported on 71 visually handicapped pupils. The visual acuity of 48 of these children could be tested with low-vision aids and the electronic television reading apparatus (Reinecker). With telescopic glasses (Zeiss, Keeler) 31 children had an average improvement of their visual acuity of two lines on a test board for near vision (Birkhäuser). With the reading apparatus 43 children showed an improvement of the visual acuity of 5 more lines. Only 3 to 21 pupils, who had been offered a regular use of the telescopic glasses, decided to have one. Finally our own experiences are compared with those of other authors.
Decreased vision in older adults is extremely common and carries a wide range of functional and emotional implications. Primary care physicians play an important part in helping patients realize that low vision or even total vision loss does not mean an end to most of life's activities. You can recommend magnifiers and other devices that enhance vision as well as nonoptical devices that help patients rely on other senses. Your role also includes providing emotional support and making referrals to a rehabilitation clinic or support group when appropriate.
1. There is a growing population of persons suffering from visual impairments, and their needs must be addressed as their numbers increase. 2. Professionals in the field of ophthalmology have an obligation to meet the challenge of an increasing population of visually impaired persons by offering comprehensive service delivery to their patients. 3. The development of the low-vision consultant has yielded very positive results in the physical, psychological, and social rehabilitation of visually impaired patients.
Proliferative diabetic retinopathy (PDR) is a leading cause of visual loss in adults in industrialized countries. PDR patients with light perception (LP) or hand movement (HM) acuity due to severe vitreous hemorrhage require vitreous surgery. The purpose of this study was to determine whether the visual acuity of PDR patients with LP or HM can be graded into finer steps with the Low Vision Evaluator (LoVE). In addition, we determined whether the LoVE results are correlated with the amplitude of the electroretinogram (ERG), the presence of retinal detachment (RD), or postoperative visual prognosis. The LoVE instrument is a subjective device that measures the thresholds for light stimulus and is equipped with a pair of goggles with white light-emitting diodes as the stimulus. We measured the LoVE thresholds of 19 PDR patients, whose fundi could not be observed due to vitreous hemorrhage and whose visual acuity was LP or HM. The 13 patients with HM vision had LoVE thresholds that ranged from 25.0 and 40.0 dB, and the 6 patients with LP vision had LoVE thresholds that ranged from 20.0 and 40.0 dB. The LoVE thresholds of 9 patients with RD were significantly lower than those of 10 patients without RD (p < 0.001). The LoVE thresholds were correlated with the amplitude of the a- and b-waves of the ERG and the postoperative best-corrected visual acuity (BCVA) (a-wave: r = 0.70, p < 0.001; b-wave: r = 0.71, p < 0.001; postoperative BCVA: r = 0.46, p < 0.05). These results indicate that the LoVE is capable of grading the visual function of PDR patients with conventional LP and HM vision into finer steps. Thus, the LoVE is an invaluable device in predicting the postoperative visual acuity of patients with vitreous hemorrhage.
BACKGROUND: Surveys and empirical studies of visually impaired (VI) persons suggest that avoidance of objects while walking may depend on type of vision loss and be influenced by light level, object contrast, and object type. METHODS: Mobility performance in 88 VI adults was assessed on an indoor obstacle course under photopic and mesopic lighting conditions. Subjects were divided into three categories: primarily an acuity loss, primarily a peripheral field restriction, and a combination of the two. Performance measures were time to walk the course and total number of contacts with objects in the course. RESULTS: Decreasing light level from photopic to mesopic resulted in a significant increase (roughly double) in the time required to complete the course and in the total number of contacts, regardless of type of vision loss. Under photopic illumination, subjects with acuity loss took less time on average to complete the course and contacted fewer objects than the other two groups. At mesopic levels, acuity loss subjects performed better than those in the other categories. Low contrast obstacles were contacted more frequently than high contrast ones at both light levels. Finally, floor level walk-around objects were contacted significantly less often than either step-over or head level objects, regardless of type of vision loss and light level. CONCLUSIONS: The ability of VI persons to avoid obstacles is significantly impaired under mesopic illumination. Object contrast and location are significant factors in determining the success of VI persons in avoiding obstacles in the travel path.
This study evaluates functional vision in visually impaired children with stage IV to V cicatricial retinopathy of prematurity (CROP) by comparing results derived from the Teller acuity cards and a battery of behavioral tasks, the visual function battery (VFB). Vision was evaluated in 26 eyes of 15 children ages 6 months to 14 years, who underwent retinal reattachment procedures for active stage IV and stage V retinopathy of prematurity. Results showed that 10 of 26 eyes (38%) had a recordable grating acuity to Teller acuity card assessment. Twenty-five of 26 eyes (96%) showed a response to the VFB. Sixteen of 26 eyes (62%) showed recordable scores with the VFB but no corresponding scores with the Teller acuity cards. The VFB may be more reliable than the Teller acuity cards in measuring visual function in the very low acuity range.
Angular magnification, resolving power, astigmatism, field of view, eye relief, and light transmittance of 157 low power telescopes comprising 25 models from seven manufacturers were measured. Roof-prism Keplerian telescopes provided about one-half the resolution, 30% lower transmittance, and more objectionable image flare than Galilean designs. The roof-prism was responsible for producing overlapping doubled images that appeared astigmatic-like. The prism further compromised rotational symmetry by deviating the image in a direction along the roof edge. The Keplerian telescopes, however, had about twice the field of view of the Galilean telescopes. Notably, several Keplerian telescope models from different suppliers were found to be optically identical, although they varied 50-100% in price.
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To aid the partially sighted in writing on small areas, such as bank drafts, a clip-on eyeglass loupe (11 diopters, 3.5 inches, Bausch and Lomb) attached to a finepoint felt pen provides adequate vision.
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