Characteristics of newly-diagnosed early open-angle glaucoma patients: a comparison of structural and functional measurements

Abstract

Purpose:

Early diagnosis of glaucoma is key to effective management. However, under-diagnosis of glaucoma remains a significant problem. Therefore, we aimed to describe the structural and functional characteristics of patients with newly-diagnosed early open-angle glaucoma (OAG), and compare these with a cohort of glaucoma suspects (GS) and normal patients.

Methods:

Records of 100 and 101 randomly selected, consenting normal and GS patients respectively, and 105 patients with newly diagnosed OAG were reviewed. Demographic and clinical data (including visual field (VF) results and Cirrus optical coherence tomography (OCT) Retinal Nerve Fiber Layer and Ganglion Cell Analysis printouts) of these patients were compared. For normal and GS patients, and OAG patients with bilateral manifest OAG, one eye was randomly chosen, whilst for patients with unilateral OAG, the glaucomatous eye was used for analysis.

Results:

There was no significant difference in age, gender or ethnicity distributions between the groups. Irrespective of glaucoma type, there were significant differences in OCT and VF results, as expected, between those with and without glaucoma. One-third of eyes with OAG did not have VF loss (pre-perimetric glaucoma, PPG). Those with PPG did not exhibit any significant differences on OCT parameters to those with VF loss (perimetric glaucoma, PG). PPG patients (56.3 years) were slightly, but not significantly younger than PG patients (60.1 years), though there was no difference in the gender or glaucoma subtype distribution. Overall, linear regression analysis of structural and functional measurements showed no significant structure-function relationship in those with early OAG.

Conclusions:

Patients with PPG found in the present cohort exhibited the same amount of structural loss on OCT as those with PG. These results appear incompatible with the glaucoma continuum hypothesis and highlight the need for improved structure-function relationship in disease.