Insulinlike growth factor I affects ocular development - A study of untreated and treated patients with Laron syndrome

Objective: To evaluate the ocular dimensions in patients with primary growth hormone receptor insensitivity (Laron syndrome [LS]) and to study the effect of supplemental insulinlike growth factor I (IGF-I) on ocular growth. Design: Retrospective case series. Participants: Twelve patients with LS, 8 untreated (LS group) and 4 treated (LS-T group) with supplemental IGF-1, and 30 healthy controls. Methods: Ocular dimensions and refraction were measured, and a full ophthalmologic examination was performed. Main Outcome Measures: Differences in the average ocular dimension data among IGF-I-treated patients, untreated ones, and controls. Results: The average axial length of eyes in the LS group was 21.94 mm (standard deviation [SD], 0.81). Corresponding values for the LS-T and control group eyes were 22.53 mm (SD, 1.74) and 23.20 mm (SD, 1.35) respectively. The average anterior chamber depth of eyes in the LS group was 2.55 mm (SD, 0.26). Corresponding values for eyes in the LS-T and control groups were 3.48 mm (SD, 0.09) and 3.84 mm (SD, 0.16) respectively. The average lens thickness of eyes in the LS group was 4.56 mm (SD, 0.36). Corresponding values for the LS-T and control groups were 3.77 mm (SD, 0.23) and 3.51 mm (SD, 0.25), respectively. The average corneal curvature of eyes in the LS group was 46.9 diopters (D) (SD, 2.32). Corresponding values for the LS-T and control groups were 47.6 D (SD, 2.83) and 44.4 D (SD, 1.5), respectively. Conclusions: Insulinlike growth factor I seems to be an important regulator of ocular growth as documented in patients with primary growth hormone insensitivity. The mechanism of this observation should be investigated further.