Abstract
Purpose :
The relationship between refractive error at age 1 and the risk of developing amblyopia or accommodative esotropia, and its protection by early glasses, is unknown, and subject of the Early Glasses Study, a population-based, prospective, randomized, controlled trial. We finalized our analysis of baseline findings.
Methods :
Children aged 12-18 mos., without known disease or eyecare, >36 weeks gestation, were recruited at Children’s Healthcare Centres. They received full orthoptic examination followed by retinoscopy in cycloplegia. Those exceeding AAPOS 2003 criteria (+3.5D, 1.5D cyl, 1D cyl (10°-80°), 1.5D aniso) were randomized into glasses or not and are followed up biannually to age 4. Children with amblyopia, strabismus, ophthalmic disease, or exceeding the criteria twofold were excluded. Visual acuity will be measured in all with logarithmic Tumbling E’s at age 4.
Results :
Parents of 888 recruited were contacted, 123 were excluded, 23 did not respond. Enrolled were 742, 131 declined participation, 10 were lost in follow-up. Examined were 601 at age 14.5±1.7 mos. Of 61 (10.1%) exceeding the criteria, 2 were excluded with esotropia, 1 of whom with amblyopia, 1 intermittent exotropia, 1 exophoria, 5 exceeded criteria twofold, 1 of whom with esotropia and amblyopia. Of 540 below the criteria, 1 was excluded for suspected amblyopia, 1 expected to develop amblyopia, 1 microstrabismus, 1 exotropia, 9 myopia, 2 ptosis, 1 congenital oculomotor apraxia and 1 Duane type 1. None of excluded prior enrollment were known to have amblyopia. Mean spherical equivalent (SE) was +1.73±1.18D (1202 eyes). Mean SE was +1.84±1.22D for the most and +1.63±1.12D for the least hyperopic eye, mean astigmatism was -0.72±0.46D, mean anisometropia was 0.21±0.34D. Randomized were 52 (age 14.2±1.5 mos.), 28 into glasses and 24 into no glasses. Of 61 exceeding the criteria, 29 had >+3.5D, 19 >1.5D cyl, 7 >1D cyl (10°-80°), 5 >1.5D aniso, 1 >+3.5D and >1.5D cyl combined (figure). At first follow-up retinoscopy after 9.3±3.6 mos. (N=43), SE had changed between -2.375D and +2.75D.
Conclusions :
10.1% of 14-months-old children of the general population exceeded AAPOS 2003 criteria. Of all 601 examined, 0.8% had strabismus and 0.3% strabismic amblyopia, all above these criteria. 2.2% had other ophthalmic disease like myopia.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.