We are pleased to read that Dr Jethani values our past and ongoing efforts to investigate the effectiveness of vision therapy using rigorous scientific methodology and welcome the opportunity to respond to the issues raised in his letter.
He expressed concern that there was a great disparity in treatment time or dosage between home-based pencil push-ups and office-based vision therapy/orthoptics and calculated a difference of 60 hours between the 2 groups. His calculations are inaccurate. The home-based pencil push-ups group performed 15 minutes of treatment, 5 days per week. This yielded 75 minutes of treatment per week for 12 weeks or 15 total hours. The office-based vision therapy/orthoptics group also performed 15 hours of home therapy over the course of 12 weeks, but also received 12 hours of office-based treatment (1 hour per week) for a total of 27 hours; not the 75 hours incorrectly calculated by Dr Jethani. Thus, the office-based vision therapy/orthoptics group spent about twice as much time in treatment (rather than 5 times as much as calculated by Dr Jethani) as the home-based pencil push-ups group.
Scheiman M, Mitchell GL, Cotter S, Cooper J, Kulp M, Rouse M, Borsting E, London R, Wensveen J, Convergence Insufficiency Treatment Trial (CITT) Study Group. Convergence Insufficiency: Randomized Clinical Trial—Reply. Arch Ophthalmol. 2005;123(12):1760-1761. doi:10.1001/archopht.123.12.1760-b