Novel mobility test to assess functional vision in patients with inherited retinal dystrophies.

IMPORTANCE: This novel endpoint tracks functional vision changes in patients with inherited retinal dystrophies (IRDs) over time. BACKGROUND: The aims of the study were to determine whether a multi-luminance mobility test (MLMT) can detect functional vision changes over time in subjects with IRDs and to assess natural history and potential effects of investigational agents. DESIGN: This is a prospective, observational study. PARTICIPANTS: Sixty-two subjects were enrolled. Sixty (29 normal sighted and 31 visually impaired) were eligible; 54 (28 visually impaired and 26 normal-sighted) completed all testing visits. METHODS: Subjects navigated MLMT courses three times over 1 year. At each visit, subjects completed testing using individual eyes, and both eyes, at up to nine standardized, increasing luminance levels (range 1 to 400 lux). Accuracy and speed were evaluated and compared with visual acuity (VA), visual field (VF) and a visual function questionnaire. MAIN OUTCOME MEASURES: Accuracy and speed of normal and visually impaired subjects on MLMT, and reliability and content validity of MLMT were the main outcome measures. RESULTS: MLMT distinguished normal-sighted from visually impaired subjects. All control subjects passed all MLMT attempts at all tested light levels. Visually impaired subjects' performance varied widely; some declined over 1 year. Performance declined markedly below certain VA and VF thresholds. Concordance on performance on two baseline visits was high: correlations for accuracy were 94% and 98% for lowest common and highest common lux levels. CONCLUSIONS AND RELEVANCE: MLMT differentiated visually impaired from control populations and, in visually impaired subjects, identified a range of performances; and tracked performance declines over time, consistent with these progressive conditions.

Contact lenses for visual rehabilitation in Bilateral Nanophthalmos with Retinal Dystrophy- A case report.

BACKGROUND: Nanophthalmos is an uncommon developmental ocular disorder characterized by a small eye with short axial length, high hyperopia and high lens to eye volume ratio due to arrested development of the globe in all directions. Different types of fundus changes can rarely occur with nanophthalmos. OBSERVATIONS: This is a case report of a 17 years old female who presented with bilateral gradual progressive visual loss and photophobia at Tilganga Institute of Ophthalmology on 3rd July 2015. Her best corrected visual acuity was 20/300 with +12.00Ds/-1.00Dcyl@180 in the right eye and 20/200 with +12.00Ds/-1.50Dcyl@180 in the left eye. Axial lengths of two eyes were markedly shortened with pigmentary changes at the macula and dull foveal reflex along with retinal flecks in the mid-periphery. Full field ERG showed diminished rod and cone waves suggestive of rod and cone dysfunction. With the use of Rigid Gas Permeable (RGP) contact lenses, the acuity improved to 20/200 and 20/125 in the right and left eye respectively. CONCLUSION: This study proposes the use of contact lenses and light absorptive filters for better visual rehabilitation.

Rehabilitación visual en baja visión / Visual rehabilitation in low vision

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[What can blind patients see in daily life with the subretinal Alpha IMS implant? Current overview from the clinical trial in Tübingen]. / Was können blinde Patienten mit dem subretinalen Alpha-IMS-Implantat im Alltag sehen? Aktuelle Übersicht aus der Tübinger klinischen Studie.

The subretinal visual implant is a scientific research approach to restore partial vision in end-stage hereditary retinal diseases by replacing the function of the degenerated photoreceptors by microelectronic chips. In a clinical trial in Tübingen these implants were tested on voluntary blind patients. By using the implants in daily living the patients reported valuable visual information. The subretinal microchip mediates subjectively useful visual information in near as well as in distant vision.

Spatial resolution and perception of patterns mediated by a subretinal 16-electrode array in patients blinded by hereditary retinal dystrophies.

PURPOSE: The perception of 11 persons blinded by hereditary retinal degeneration elicited by a subretinally implanted 16-electrode array used for light-independent direct stimulation of the retina is described. This device is part of the Tübingen retina implant, which also employs a light-sensitive, multiphotodiode array (MPDA). The ability to reliably recognize complex spatial percepts was investigated. METHODS: Eleven blind volunteers received implants and participated in standardized psychophysical tests investigating the size and shape of perceptions elicited by single-electrode activation, multiple-electrode activation, and activation of compound patterns such as simplified letters. RESULTS: Visual percepts were elicited reliably in 8 of 11 patients. On single-electrode activation, percepts were generally described as round spots of light of distinguishable localization in the visual field. On activation of a pattern of electrodes, percepts matched that pattern when electrodes were activated sequentially. Patterns such as horizontal or vertical bars were identified reliably; the most recent participant was able to recognize simplified letters presented on the 16-electrode array. The smallest distance between sites of concurrent retinal stimulation still yielding discernible spots of light was assessed to be 280 µm, corresponding to a logMAR of 1.78. CONCLUSIONS: Subretinal electric stimulation can yield reliable, predictable percepts. Patterned perception is feasible, enabling blind persons to recognize shapes and discriminate different letters. Stimulation paradigms must be optimized, to further increase spatial resolution, demanding a better understanding of physical and biological effects of single versus repetitive stimulation (ClinicalTrials.gov number, NCT00515814).

Progressive cone dystrophy, nystagmus and contact lenses.

PURPOSE: To describe the contact lens fitting of a 13-year-old girl who suffers from progressive cone dystrophy with associated nystagmus and achromatopsia and a high hyperopic-astigmatic prescription. METHODS: The patient was fitted initially with partial correction contact lenses followed by lenses to the full correction some months later. RESULTS: A successful fitting of contact lenses which achieved a standard of vision favourable to that of spectacles, using small diameter soft toric lenses. CONCLUSION: An improvement in vision has been achieved in this complex case by using specialist small diameter soft toric contact lenses. Not only has an improvement in vision been achieved an improvement in quality of life has also been expressed by the patient and her family.