OCT can detect subclinical RNFL loss in patients with disc hemorrhage only

Researchers used OCT to evaluate the peripapillary retinal nerve fiber layer (RNFL) in patients with disc hemorrhage (DH) and 100 healthy controls.

Eyes with DH were divided into four groups: (1) controls (2) eyes with DH but without RNFL defect according to red-free fundus photography, (3) eyes with DH and a localized RNFL defect in the same quadrant, accompanied by normal visual fields, and (4) eyes with DH and a localized RNFL defect in the same quadrant accompanied by glaucomatous visual field defect in the corresponding hemifield location.

RNFL thickness was significantly different among the four groups. The researchers observed that the average RNFL thicknesses of groups 2, 3, and 4 were decreased by 9%, 8%, and 16%, respectively, compared with normal control eyes. In addition, the 7 o'clock sector RNFL thicknesses of each group were decreased by 15%, 26%, and 35%, respectively. The authors note "Our data may support the hypothesis that structural changes precede functional changes. However, our findings did not confirm the significant relationship between structural and functional deficits because this study was not designed to produce evidences of a relationship between visual fields and RNFL thickness."

This study confirms that significant RNFL loss was already present in eyes with DH only, suggesting that these eyes are at risk for visual field loss. Subgroup analyses showed a topographic relationship between the DH location and the OCT-measured RNFL thickness.