Spatial pattern of glaucomatous visual field loss obtained with regionally condensed stimulus arrangements

Abstract

Purpose: To assess the spatial distribution of glaucomatous visual field defects (VFDs) obtained with regionally condensed stimulus arrangements.

Methods: Sixty-three eyes of 63 glaucoma subjects were examined with threshold-estimating automated static perimetry (full threshold 4-2-1 dB strategy with at least three reversals) on an automatic campimeter or a full-field perimeter. Stimuli were added by the examiner to regionally enhance spatial resolution in regions that were suspicious for a glaucomatous VFD. These regions were characterized by contiguous local VFDs, attributable to the retinal nerve fiber bundle course according to the impression of the examiner. The added stimulus locations were subsets of a predefined, dense perimetric grid. All VFD locations with P < 0.05 (total deviation plots) were assessed by superimposing the visual field records of all participants.

Results: Glaucomatous VFD loss occurred more frequently in the upper than in the lower hemifield, with a typical retinal nerve fiber-related pattern and a preference of the nasal step region. More than 50% of the eyes with predominantly mild to moderate glaucomatous field loss showed defective locations in the immediate superior paracentral region within an eccentricity of 3°.

Conclusions: Conventional thresholding white-on-white perimetry with regionally enhanced spatial resolution reveals that glaucomatous visual field loss affects the immediate paracentral area, especially the upper hemifield, in many eyes with only mild to moderate glaucomatous visual field loss. Detailed knowledge about the spatial pattern and the local frequency distribution of glaucomatous VFDs is an essential prerequisite for creating regionally condensed stimulus arrangements for adequate detection and follow-up of functional glaucomatous damage.

Figure 1.

(A) Frequency distribution of the perimetric glaucoma stages of the 63 eyes of 63 patients according to the classification system of Aulhorn and Karmeyer. (B) Frequency distribution of the MD.

Figure 2.

(A) Threshold-estimating static perimetry with regional stimulus condensation in the superior paracentral visual field clearly demarcates a circumscribed paracentral small retinal nerve fiber–related scotoma corresponding to a previous splinter hemorrhage shown in the (inset) optic disc photograph (the optic disc is turned upside down). Circles: rectangular 6° × 6° grid. (B) In the corresponding Humphrey 30-2 visual field, only one pathologic location was detected within the paracentral nasal superior quadrant.

Figure 3.

Threshold-estimating static perimetry with regional stimulus condensation in the superior paracentral visual field clearly demarcates a circumscribed paracentral small retinal nerve fiber-related scotoma. Circles: 30-A grid with polar test point arrangement. Only three pathologic locations were detected without condensed stimulus arrangement (red circles).

Figure 4.

Spatial frequency distributions of all glaucomatous visual field defects with P < 0.05, according to the individual total deviation plots. This result was assessed by electronically superimposing the visual field records of all participants. Local frequency values in which more than 50% of the eyes showed P < 0.05 are shaded in light gray to highlight the pattern distribution of glaucomatous visual field loss in the upper and lower hemifields.