Emmetropization in highly hyperopic infants: A randomized clinical trial of partial refractive correction

Highly hyperopic infants are at greater risk for not undergoing emmetropization and later developing conditions such as strabismus, amblyopia, and early literacy and reading problems. An early intervention consisting of partial hyperopic correction and encouragement of accommodation may influence the rate of emmetropization in these high-risk infants.

This study aimed to determine if moderate spectacle partial correction (3.00 D cut from cycloplegic) and visual exercises to promote accommodation enhance emmetropization (reaching ≤+3.00 D) in highly hyperopic (≥+5.00 D to ≤+7.00 D) 3-month-old infants compared with no treatment (observation).

Thirty-five highly hyperopic 3-month-old infants (57% female) were randomized to observation or treatment ( clinicaltrials.gov ; NCT03669146). Primary analysis compared the mean hyperopia at 18 months of age in treated versus untreated participants. Data were also modeled using proportional hazards survival analysis (time to reach ≤+3.00 D).

There was no significant difference in refractive error at 18 months of age between infants in the treated (+1.6 ± 0.6 D) and observation groups (+1.2 ± 0.7 D; p = 0.23) but treatment affected the rate of emmetropization depending on baseline hyperopia (p = 0.01). At 12 months of age, treated infants had similar refractive errors regardless of baseline hyperopia but untreated infants at 12 months underwent faster emmetropization if their baseline hyperopia was <+5.50 D and slower emmetropization if it was >+5.50 D.

Partial hyperopic refractive correction with accommodative exercises in highly hyperopic infants did not affect average refractive error at 18 months. However, treatment affected the rate of emmetropization and how long it took to reach ≤+3.00 D. Treatment slowed the rate of emmetropization at lower levels of initial hyperopia but may enhance emmetropization at higher levels.