Value of the Heidelberg Retinal Tomograph in Optic Nerve Hypoplasia

PURPOSE: A case of optic nerve hypoplasia (ONH) is reported to demonstrate the value of the Heidelberg Retinal Tomograph II (HRT) in assisting with the diagnosis. CASE REPORT: An 8-year-old black male was referred to our clinic for evaluation of right esotropia and presumed amblyopia. Best-corrected visual acuities were 20/60 OD (right eye) and 20/25 OS (left eye). Cover test showed constant right esotropia, measuring 10 at distance and 16 at near. A smaller optic nerve head was detected OD with absence of the double ring sign. The findings of HRT were consistent with a diagnosis of unilateral ONH, with a disc area of 1.545 mm OD vs. 2.527 mm OS. DISCUSSION: The clinical features, management, and associations of ONH are discussed. CONCLUSION: HRT is a useful tool to assist in diagnosis of ONH by physically measuring the optic nerve.