Researchers investigated the relationship between disc hemorrhages and glaucoma progression as determined by four different glaucoma testing modalities, including spectral-domain OCT (SD-OCT) optic nerve volume scans.
A total of 124 open-angle glaucoma patients who had yearly disc photography, visual fields (VFs), SD-OCT retinal nerve fiber layer (RNFL) thickness scans and optic nerve volume scans all performed on the same day over a five-year period. The minimum distance band (MDB) thickness was calculated from optic nerve volume scans.
Only 15.3% had one or more hemorrhages, but their presence was associated with localized 3D neuroretinal rim thickness progression, though not with global or inferior MDB progression, DP progression, VF progression or RNFL global, inferior or superior progression. This was in line with the authors’ previous finding that MDB thickness measurement is a sensitive modality for detecting progression in glaucoma.
In the majority of patients with MDB progression (82%), the progression was noted before or concurrently with the first instance of DH, which the authors suggest that substantial and quantifiable optic nerve damage precedes DH occurrence. Previous studies have showed the same thing.
Authors found that hemorrhages were more likely to occur in women and patients with normal tension glaucoma, which was also reported in previous studies.
“Another interesting finding of our study was that the degree of concordance between the quadrant in which [hemorrhage] occurred and where progression was detected was quite limited,” with only 31% patients with superior MDB progression also exhibiting a hemorrhage in the same (superior) quadrant, the authors explain in their study. Conversely, while inferior hemorrhages were most common (63% of patients), only 50% of those exhibited inferior MDB progression. This topographic non-correspondence between hemorrhage location and area of progression “is at first glance surprising but has been previously described,” they wrote.
The lack of agreement can be explained by two reasons: (1) many instances of glaucoma progression are not accompanied by a hemorrhage, and most do not lead to glaucoma damage and (2) since hemorrhages are transient, not all will be captured with yearly fundus photography. Thus, the observed hemorrhages and disease progression “may be two separate events.”
Margeta MA, Ratanawongphaibul K, Tsikata E, et al. Disc hemorrhages are associated with localized three-dimensional neuroretinal rim thickness progression in open-angle glaucoma. American Journal of Ophthalmology. Epub ahead of print.