Hierarchical cluster analysis of progression patterns in open-angle glaucoma patients with medical treatment.
OBJECTIVE
To classify medically treated open-angle glaucoma (OAG) by the pattern of progression using hierarchical cluster analysis, and to determine OAG progression characteristics by comparing clusters.


METHODS
Ninety-five eyes of 95 OAG patients who received medical treatment, and who had undergone visual field (VF) testing at least once per year for 5 or more years. OAG was classified into subgroups using hierarchical cluster analysis based on the following five variables: baseline mean deviation (MD), baseline visual field index (VFI), MD slope, VFI slope, and Glaucoma Progression Analysis (GPA) printout. After that, other parameters were compared between clusters.


RESULTS
Two clusters were made after a hierarchical cluster analysis. Cluster 1 showed -4.06 ± 2.43 dB baseline MD, 92.58% ± 6.27% baseline VFI, -0.28 ± 0.38 dB per year MD slope, -0.52% ± 0.81% per year VFI slope, and all "no progression" cases in GPA printout, whereas cluster 2 showed -8.68 ± 3.81 baseline MD, 77.54 ± 12.98 baseline VFI, -0.72 ± 0.55 MD slope, -2.22 ± 1.89 VFI slope, and seven "possible" and four "likely" progression cases in GPA printout. There were no significant differences in age, sex, mean IOP, central corneal thickness, and axial length between clusters. However, cluster 2 included more high-tension glaucoma patients and used a greater number of antiglaucoma eye drops significantly compared with cluster 1.


CONCLUSIONS
Hierarchical cluster analysis of progression patterns divided OAG into slow and fast progression groups, evidenced by assessing the parameters of glaucomatous progression in VF testing. In the fast progression group, the prevalence of high-tension glaucoma was greater and the number of antiglaucoma medications administered was increased versus the slow progression group.
Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
Hyoung Won
HW
Bae
Department of Ophthalmology, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
Seungsoo
S
Rho
Department of Research Affairs, Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Korea.
Hye Sun
HS
Lee
Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
Naeun
N
Lee
Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
Samin
S
Hong
Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
Gong Je
GJ
Seong
Department of Ophthalmology, College of Medicine, University of Ulsan, Asan Medical Center, Seoul, Korea.
Kyung Rim
KR
Sung
Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
Chan Yun
CY
Kim
D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D016000:Cluster Analysis; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions; D012189:Retrospective Studies; D058609:Visual Field Tests; D014794:Visual Fields
D000959:Antihypertensive Agents; D009883:Ophthalmic Solutions
hierarchical cluster analysis; open-angle glaucoma; progression