Randomised controlled trial of the economic advantages of free near-vision glasses in working-age people with bilateral presbyopia in Kenya
Presbyopia
Trial participants will be randomised to one of the following arms: 1. Intervention arm: individuals will be given free near-vision glasses (spherical, non-astigmatic correction), appropriate for their degree of presbyopia. As they are given glasses, they will be counselled about the use and care of the glasses. 2. Control arm: Individuals will not be given free near-vision glasses at baseline. They will be given free near-vision glasses (spherical, non-astigmatic correction), appropriate for their degree of presbyopia, at the end of the trial follow-up period (2 years). However, they will be informed that they have presbyopia at baseline, so some may choose to independently purchase glasses themselves. Near vision glasses for the trial will be prescribed using a smartphone-based near-vision acuity test embedded within a validated mobile phone application. The near vision test includes an algorithm that allows an individual to prescribe near-vision (reading) glasses. This includes the following steps: (i) a rapid distance vision test to determine if a participant is eligible for potential presbyopia screening (ii) near-vision test to determine if someone may benefit from near-vision glasses (iii) use data on the participants age and uncorrected near-vision score to determine the start point for the near-vision test and (iv) guiding the data collector in terms of processes that a clinician would follow to determine the correct power for reading glasses.
1. Bilateral presbyopia (<N8) and do not currently own/use glasses for near vision. 2. Adults aged between 35 and 65 years. 3. Normally resident in the locality where the study is being conducted, defined as: lived there >6 months and intend to continue living there for the next two years. 4. Provide informed consent and agreement to be randomly allocated to one of the two study arms.
1. Presbyopia and owns near vision glasses (met need or partially met need) 2. Pinhole distance VA of worse than 6/12 in the better eye 3. Current illness or incapacity preventing the individual from working. 4. Inability to communicate. 5. Any occupation with formal guidance requiring safety glasses for near work. 6. Another member of the household has already been enrolled into the trial.