Objectives: To determine the effects of diabetic eye disease (DED) on multiple aspects of visual function and self-reported visual ability. To conduct a randomised controlled trial (RCT) determining the effectiveness of low vision rehabilitation in those with DED. Methods: 100 participants with DED completed a comprehensive visual function assessment and completed the Activity Inventory (AI). The AI, scored using Rasch analysis, provided a measure of visual ability (logits). Univariate and multivariate regression examined the relationship between disease severity, visual function and visual ability. Participants were randomised to immediate (within 2 weeks of enrolment) or delayed (3 months after enrolment) intervention. The intervention was a hospital based low vision clinic appointment. The AI was repeated 3 and 6 months after enrolment. Primary outcome was the difference in visual ability between those receiving immediate intervention and those on a waiting list (no intervention control) 3 months after enrolment. Secondary outcomes were the difference in visual ability between those receiving immediate intervention and those receiving delayed intervention 6 months after enrolment and 3 months after intervention (delayed intervention control). Subgroup analyses examined whether severity, visual acuity or scotoma size influenced intervention outcome. Results: Disease severity and visual function were significantly associated with visual ability. Severity was not independently related to visual ability following adjustment for visual function. Stepwise regression revealed that a single measure of acuity explained 38% of the variance in visual ability (p < 0.001). No significant difference between intervention groups existed 3 or 6 months after enrolment or 3 months after intervention. Those with reduced acuity or central scotoma receiving delayed intervention improved between 0.42 and 0.56 logits more than those receiving immediate intervention 6 months after intervention (p = 0.02). Conclusions: Although explaining less than half the variance, a measure of acuity provided the best prediction of visual ability in DED. No overall effect of low vision rehabilitation was found. Exploratory subgroup analyses revealed visual ability improvements equivalent to between a 3 - 4 line acuity increase in those with reduced acuity or central scotoma receiving delayed intervention, indicating the need for further investigation of the effectiveness of low vision intervention in these patients.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:587786 |
| Date | January 2013 |
| Creators | Dunbar, H. M. P. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1393954/ |
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