Detecting disease progression in mild, moderate and severe glaucoma

Abstract

Purpose of review: The purpose of this review is to examine contemporary techniques for detecting the progression of glaucoma. We provide a general overview of detection principles and review evidence-based diagnostic strategies and specific considerations for detecting glaucomatous progression in patients with mild, moderate and severe disease.

Recent findings: Diagnostic techniques and technologies for glaucoma have dramatically evolved in recent years, affording clinicians an expansive toolkit with which to detect glaucoma progression. Each stage of glaucoma, however, presents unique diagnostic challenges. In mild disease, either structural or functional changes can develop first in disease progression. In moderate disease, structural or functional changes can occur either in tandem or in isolation. In severe disease, standard techniques may fail to detect further disease progression, but such detection can still be measured using other modalities.

Summary: Detecting disease progression is central to the management of glaucoma. Glaucomatous progression has both structural and functional elements, both of which must be carefully monitored at all disease stages to determine when interventions are warranted.

FIGURE 1.

Progression in the green in mild glaucoma. Cirrus SD-OCT scan from the same patient at baseline (a, left) and at 4-year follow-up (b, right). At follow up, average and quadrant RNFL measurements remain “green,” signalling normal-range results as compared with age-matched normative values, yet focal and asymmetric RNFL thinning is seen superiorly and inferiorly (red arrows). Furthermore, the average RNLF thickness has decreased from 103 to 95 mm. New macular ganglion cell layer and inner plexiform layer (GCL+IPL) thinning was also noted inferiorly (blue arrows), and a small new paracentral visual field defect was noted on perimetry (green arrow), all suggestive of glaucomatous progression. Adapted from original images provided by Donald Budenz, MD, MPH.

FIGURE 2.

Guided progression analysis in moderate glaucoma. Progression is detected by event-based (a) and trend-based (b) GPA output from a Humphrey Field Analyzer for a single patient. Unshaded triangles in (a) represent statistically significant deviation from a baseline test; half-shaded triangles represent statistically significant deviation from baseline on two consecutive tests. The linear regression in (b) depicts a rate of progression of −1.5% VFI per year (95% CI 4.4%/year). Adapted from original images provided by Grace Richter, MD, MPH.

FIGURE 3.

Floor effect in severe glaucoma. Series of OCT RNFL and OCT macula-ganglion cell plus inner plexiform layer (GCIPL) scans and trend-based GPA of visual fields for a patient with advanced glaucoma. As the OCT RNFL (a) approaches a measurement floor, there is minimal variability, giving the appearance of stability. Sequential visual fields (c) also demonstrated a floor effect, with high variability and without definitive progression. However, macular/GCIPL OCT (b), demonstrated progressive thinning, (red arrows) indicative of continued disease progression. Adapted from original images provided by David Greenfield, MD.