Topographic Characteristics of Optic Disc Hemorrhage in Primary Open-Angle Glaucoma

Abstract

In POAG eyes, DH was larger in area and longer in length in cases of normal-baseline IOP than in cases of high-baseline IOP. This suggests the possibility that previous studies' findings of higher DH prevalence and incidence in normal-baseline IOP-POAG eyes were partially affected by these topographic characteristics, which make DH more easily detectable.

Effect of Focal Lamina Cribrosa Defect on Disc Hemorrhage Area in Glaucoma

“…14 In brief, a method of comparing pixel numbers of the disc area and DH area in SD-OCT RNFL deviation map/SDP overlay images, with ImageJ software (version 1.45s; Wayne Rasband, National Institutes of Health, Bethesda, MD, USA), was used to estimate the DH area (Fig. 2), which was calculated by the following formula: DH area ¼ DH area=disc area ratio 3 computed SD À OCT disc area:…”

“…14 The larger DH area in glaucoma eyes with normal baseline IOP was explained in two ways. First, eyes having a relatively lower IOP can produce a larger area of DH owing to the lesser tamponade effect.…”

“…For inclusion, subjects were deemed to have POAG if they met the following criteria 14 : presence of typical glaucomatous optic neuropathy with compatible visual field loss and normal anterior chamber angles. Glaucomatous visual field loss was defined as a visual field with at least three adjacent test points having a deviation of ‡5 decibels (dB) and one test point having a deviation of >10 dB; at least two adjacent test points with a deviation ‡10 dB; at least three adjacent test points with a deviation ‡5 dB abutting the nasal horizontal meridian; or a mean visual field defect of >2 dB.…”

“…14 Subjects were excluded from analyses if any of the following was true: the presence of a secondary cause of glaucomatous optic neuropathy; a history of intraocular surgery (except cataract operation) or retinal laser photocoagulation; the presence of high (<À6.0 diopters [D]) myopia; and visual field mean deviation worse than À12 dB. 14 …”

“…First, DHs are transient phenomena, usually lasting only 6-12 weeks. 14,35 Although we conducted the examinations (SDP) in regular 3-month intervals and obtained SS-OCT LC images immediately following DH detection, theoretically it is possible that the timing of DH development could have varied, from minimally just 1 day to maximally 3 months before SDP was taken. Therefore, depending on the time at which the SDP were obtained, the values of DH area could have differed, and some DHs might even have been missed.…”