Analysis of Glaucoma Subtypes and Corresponding Demographics in a New Zealand Population

Abstract

Purpose: The aim of this paper was to determine the diagnosis distribution and demographic characteristics of glaucoma in a New Zealand population. Methods: The clinical records of all patients presenting consecutively to the Auckland District Health Board Glaucoma Service over a 6-month period were reviewed. Demographic parameters including ethnicity, age at presentation, and gender were collected along with all clinical data. Results: The case records of 857 patients were reviewed. Primary open-angle glaucoma (POAG) was the most common diagnosis (39.0%, n = 235), followed by primary-angle closure (PAC) diagnoses (24.8%, n = 149). This group was formed by the combination of narrow angle 18.1% (n = 109), narrow-angle glaucoma 0.3% (n = 2), PAC 2.1% (n = 13), and PAC glaucoma 4.2% (n = 25). Normal-tension glaucoma (NTG; 17.4%, n = 105), secondary glaucoma (SG; 11.5%, n = 69), ocular hypertension (5.0%, n = 30), and mixed mechanism (2.3%, n = 14) were also found. There was a significant difference in the ethnic distribution in the study population compared to the catchment population (p < 0.001). Caucasian and Indian ethnicities were overrepresented, whereas the Pacific Island Nation ethnicity was underrepresented in all groups except SG. The Maori ethnicity was underrepresented in all groups except PAC. The underrepresentation was most prominent in POAG (only 2 patients of Pacific origin and 1 Maori patient with POAG). Significant differences were identified in gender distribution including a higher preponderance of females in NTG and PAC. Significant differences in age at presentation were also identified between different glaucoma subtypes and ethnicities. Markers of glaucoma severity did not vary with respect to demographic characteristics. Conclusion: In a tertiary glaucoma service in New Zealand, Maori, Pacific peoples, and, to a lesser extent, Asians are underrepresented, while Caucasians and Indians are overrepresented in the glaucoma population.