Increasing compliance with protective eyewear to reduce ocular injuries in stone-quarry workers in Tamil Nadu, India: a pragmatic, cluster randomised trial of a single education session versus an enhanced education package delivered over six months.

OBJECTIVE: To evaluate the efficacy of standard education versus enhanced education in increasing compliance with protective eyewear to prevent ocular injuries in stone-quarry workers. DESIGN: Pragmatic, allocation concealed, participant and outcome assessor blinded, cluster randomised trial. SETTING: Six stone-quarries around Vellore, Tamil Nadu, South India. PARTICIPANTS: 204 consenting adult stone quarry workers. INTERVENTIONS: Protective eyewear plus enhanced education (one education session, plus 11 sessions of group education, individual discussions, and educational plays over six months) versus protective eyewear plus standard education (one education session and 5 follow up visits). OUTCOMES: The primary outcomes were observer-rated compliance with protective eyewear and reduction in incidence of ocular injuries (slit-lamp examination by an observer blinded to allocation status) at three and six months. Analysis was by intention to treat. RESULTS: Quarries and participants were similar at enrolment. All quarries; 92/103 (90%) of workers in three quarries given enhanced intervention, and 91/101 workers (89%) in three quarries given standard education, completed six months follow up. Compared to standard education, enhanced education significantly increased compliance with protective eyewear by 16% (95% CI 3-28%) at three months (OR 2.1; 95% CI 1.2-3.8); and by 25% (95% CI 11-35%) at six months (OR 2.7; 95% CI 1.5-4.8). Protective eyewear and enhanced education reduced the incidence of eye injuries at three months by 16% (95% CI 7-24%); and standard education by 13% (95% CI 4-22%), compared to the three months before interventions. The cumulative reduction over baseline in eye injuries at the six months was greater with enhanced education (12% decrease; 95% CI 3-21%) than with standard education (7% decrease; 95% CI 17% decrease to 3% increase). However, this incidence did not differ significantly between intervention arms at three months (OR 0.7% 95% CI 0.3-2.1); and at six months (OR 0.8; 95% CI 0.4-1.5). CONCLUSION: Provision of appropriate protective eyewear reduces the incidence of eye injuries in stone-quarry workers. Periodic educational and motivational sessions with individuals and groups facilitates sustained use of protective eyewear.

Measurement of forces generated during distraction of growing-rods in early onset scoliosis.

AIM: To measure the forces applied during distraction of growing-rods in early onset scoliosis (EOS), aimed at developing a motorized elongation device. METHODS: A consecutive series of measurements were carried out to analyze the forces applied by the surgeon during distraction of single growing-rods in 10 patients affected by EOS (mean age 8.3 years; range 6 to 10 years) undergoing the first distraction 6 months following implantation of the rods. For each measurement, output from the transducer of a dedicated pair of distraction calipers was recorded at zero load status and at every 1 mm of distraction, up to a maximum of 12 mm for each of the two connected rods. RESULTS: Twenty measurements were obtained showing a linear increase of the load with increasing distraction, with a mean peak force of 485 N at 12 mm distraction and a single reading over 500 N. We did not observe bone fractures or ligament disruptions during or after rod elongations. There was one case of superficial wound infection in the cohort. CONCLUSION: The safe peak force carrying capacity of a motorized device for distraction of growing-rods is 500N.