Trial Outcomes & Findings for Clinical Trial of Peripheral Prism Glasses for Hemianopia (NCT NCT00494676)

NCT ID: NCT00494676

Last Updated: 2017-04-04

Results Overview

At the end of each crossover period, participants were asked a yes/no question: "If the study were to end today, would you want to continue with these prism glasses (i.e. the prism glasses worn in that period)?" The primary outcome was the overall difference, across the two periods of the crossover, between the proportion of participants saying "yes" to real prism glasses and the proportion saying "yes" to sham prism glasses.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

73 participants

Primary outcome timeframe

Evaluated after 4 weeks of wearing each type of prism glasses

Results posted on

2017-04-04

Participant Flow

Participants were recruited at 13 study sites, including Dr. Peli's lab at Schepens, 11 vision rehabilitation clinics in the US, and one in the UK. The clinics included university, hospital and private-practice clinics. Each site recruited a median of 7 participants (range 3 to 12). Data were collected in the period October 2007 to January 2010.

97 subjects were screened for eligibility of which 73 met the study criteria and were enrolled. The main reasons for not meeting the inclusion criteria were incomplete hemianopia and spatial neglect.

Participant milestones

Participant milestones
Measure
Real Prism Glasses Then Sham
Real prism glasses for 4 weeks followed by sham prism glasses for 4 weeks
Sham Prism Glasses Then Real
Sham prism glasses for 4 weeks followed by real prism glasses for 4 weeks
Allocation
STARTED
37
36
Allocation
COMPLETED
35
32
Allocation
NOT COMPLETED
2
4
First Intervention
STARTED
35
32
First Intervention
COMPLETED
34
29
First Intervention
NOT COMPLETED
1
3
Second Intervention
STARTED
34
29
Second Intervention
COMPLETED
33
28
Second Intervention
NOT COMPLETED
1
1

Reasons for withdrawal

Reasons for withdrawal
Measure
Real Prism Glasses Then Sham
Real prism glasses for 4 weeks followed by sham prism glasses for 4 weeks
Sham Prism Glasses Then Real
Sham prism glasses for 4 weeks followed by real prism glasses for 4 weeks
Allocation
Withdrawal by Subject
2
4
First Intervention
Withdrawal by Subject
1
3
Second Intervention
Withdrawal by Subject
1
1

Baseline Characteristics

Clinical Trial of Peripheral Prism Glasses for Hemianopia

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Entire Study Population
n=73 Participants
Includes groups allocated to receive real prism glasses first and sham prism glasses first
Age, Continuous
56 years
STANDARD_DEVIATION 16 • n=5 Participants
Sex: Female, Male
Female
26 Participants
n=5 Participants
Sex: Female, Male
Male
47 Participants
n=5 Participants
Duration of hemianopia
18 Months
n=5 Participants
Side of hemianopia
Right hemianopia
25 Participants
n=5 Participants
Side of hemianopia
Left hemianopia
48 Participants
n=5 Participants

PRIMARY outcome

Timeframe: Evaluated after 4 weeks of wearing each type of prism glasses

Population: Only participants who completed the crossover were included in this analysis

At the end of each crossover period, participants were asked a yes/no question: "If the study were to end today, would you want to continue with these prism glasses (i.e. the prism glasses worn in that period)?" The primary outcome was the overall difference, across the two periods of the crossover, between the proportion of participants saying "yes" to real prism glasses and the proportion saying "yes" to sham prism glasses.

Outcome measures

Outcome measures
Measure
Entire Study Population
n=61 Participants
Includes groups allocated to receive real prism glasses first and sham prism glasses first
Overall Proportion Saying "Yes" to Real Prism Glasses
Said yes to real prism glasses
39 participants
Overall Proportion Saying "Yes" to Real Prism Glasses
Said yes to sham prism glasses
22 participants

SECONDARY outcome

Timeframe: Evaluated after 4 weeks of wearing each type of prism glasses

Population: Only participants who completed the crossover were included in this analysis

Perceived difficulties with mobility were quantified using a 5-point rating scale (no difficulty to extreme difficulty) for 7 situations (items) relevant to people with hemianopia, including at home, in stores, outdoors, in unfamiliar areas, in familiar areas, in crowded areas, and noticing objects off to the side when walking. The questionnaire was administered at baseline (without prisms) and after each period of the crossover. Interval scale measures of perceived difficulty with overall mobility for each participant were estimated using Rasch analysis of the responses to all seven items (Winsteps software, version 3.70.0.226). Rasch measures were expressed as logits (log odds ratios). Mobility change scores for real and sham prisms were defined as the difference in perceived difficulty relative to baseline (in logits).

Outcome measures

Outcome measures
Measure
Entire Study Population
n=61 Participants
Includes groups allocated to receive real prism glasses first and sham prism glasses first
Mobility Change Score (All Participants Who Completed Crossover)
Mobility change score for real prisms
1.9 logits
Standard Deviation 3.3
Mobility Change Score (All Participants Who Completed Crossover)
Mobility change score for sham prisms
1.3 logits
Standard Deviation 2.5

SECONDARY outcome

Timeframe: Evaluated after 4 weeks of wearing each type of prism glasses

Population: This is a subgroup analysis of the mobility change scores for real and sham prism glasses evaluated during the crossover. The subgroup includes only those participants who completed the crossover and continued to wear prism glasses in the long term.

Perceived difficulties with mobility were quantified using a 5-point rating scale (no difficulty to extreme difficulty) for 7 situations (items) relevant to people with hemianopia, including at home, in stores, outdoors, in unfamiliar areas, in familiar areas, in crowded areas, and noticing objects off to the side when walking. The questionnaire was administered at baseline (without prisms) and after each period of the crossover. Interval scale measures of perceived difficulty with overall mobility for each participant were estimated using Rasch analysis of the responses to all seven items (Winsteps software, version 3.70.0.226). Rasch measures were expressed as logits (log odds ratios). Mobility change scores for real and sham prisms were defined as the difference in perceived difficulty relative to baseline (in logits).

Outcome measures

Outcome measures
Measure
Entire Study Population
n=25 Participants
Includes groups allocated to receive real prism glasses first and sham prism glasses first
Mobility Change Score (Only Participants Who Continued Prism Wear in the Long Term)
Mobility change score for real prisms
3.0 logits
Standard Deviation 3.2
Mobility Change Score (Only Participants Who Continued Prism Wear in the Long Term)
Mobility change score for sham prisms
1.1 logits
Standard Deviation 2.4

SECONDARY outcome

Timeframe: Evaluated after 4 weeks of wearing each type of prism glasses

Population: This is a subgroup analysis of the mobility change scores for real and sham prism glasses evaluated during the crossover. The subgroup includes only those participants who completed the crossover and then discontinued wearing prism glasses.

Perceived difficulties with mobility were quantified using a 5-point rating scale (no difficulty to extreme difficulty) for 7 situations (items) relevant to people with hemianopia, including at home, in stores, outdoors, in unfamiliar areas, in familiar areas, in crowded areas, and noticing objects off to the side when walking. The questionnaire was administered at baseline (without prisms) and after each period of the crossover. Interval scale measures of perceived difficulty with overall mobility for each participant were estimated using Rasch analysis of the responses to all seven items (Winsteps software, version 3.70.0.226). Rasch measures were expressed as logits (log odds ratios). Mobility improvement scores for real and sham prisms were defined as the difference in perceived difficulty relative to baseline (in logits).

Outcome measures

Outcome measures
Measure
Entire Study Population
n=35 Participants
Includes groups allocated to receive real prism glasses first and sham prism glasses first
Mobility Change Score (Only Participants Who Discontinued Prism Wear in the Long Term)
Mobility change score for real prisms
1.1 logits
Standard Deviation 3.3
Mobility Change Score (Only Participants Who Discontinued Prism Wear in the Long Term)
Mobility change score for sham prisms
1.6 logits
Standard Deviation 2.7

Adverse Events

Entire Study Population

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Alex Bowers

Schepens Eye Research Institute

Phone: 617-912-2512

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place