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Abstract
The main objective of this thesis is to compare the effectiveness of low vision rehabilitation
interventions delivered in four different arms that comprised center-based rehabilitation,
community-based rehabilitation, a mix of center-based and community-based rehabilitation,
and center-based rehabilitation with non intervention visits at home.
Individuals for the trial were recruited from patients visiting the low vision services for the
first time at the L.V. Prasad Eye Institute, an advanced tertiary eye care center in
Hyderabad, India. The effectiveness of the service delivery arms was assessed 9 months
from the baseline assessment and was based on four criteria that were expected to show
positive changes if the rehabilitation was effective. These were: (a) Effectiveness of Low
Vision Rehabilitation Training (ELVRT), (b) Quality of life (WHOQOL), (c) Adaptation to
Vision Loss (AVL) and (d) Impact of Vision Impairment (IVI) that were assessed through
the administration of questionnaires at baseline and post intervention.
Four hundred and thirty-six individuals were enrolled in the study of whom 393 (90.12%)
completed the study. One-fifth of these participants were children aged 8 to 16 years. At
baseline, socio-demographic and clinical characteristics were similar between individuals
across all the four arms of the trial. Socio-demographic and clinical characteristics did not
differ significantly, except for age, between these 393 individuals who completed the trial.
Changes in pre-intervention and post-intervention were measured on ELVRT, IVI, AVL
and WHO-QOL for 347 (79.59%) adults. The mean age of the 311 subjects who completed
the pre- and post- assessments was 43.7 ± 19.7 years (range 16 to 86 years, median 42
years). Changes in pre- and post- intervention were measured on ELVRT and IVI for 89
(20.41%) children. The mean age of children who completed the pre- and post- assessments
was 11.58 ± 2.392, (range 8 to 15 years).
The pre- and post- intervention changes of the Rasch calibrated scores indicated a
statistically significant improvement in all measures: AVL (p<0.001), WHOQOL
(p<0.001), IVI-A (p<0.001), IVI C (p<0.001) and ELVRT improvement (p<0.001) post
low vision intervention. Overall improvement from the Rasch calibrated scores proved that
questionnaires such as WHOQOL, AVL, IVI and ELVRT can be used to assess low vision
intervention to identify baseline difficulties and measure changes after intervention.
Evidence from this study proved that all four methods had a significant impact on quality of
life. The greatest dropout rate was in center-based compared to other methods of service
delivery. This study finding suggests a combination of center-based and community-based
is suitable as a choice of method for low vision intervention.