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Abstract #46514 Published in IGR 13-3
Pressure-cornea-vascular index (PCVI) for predicting disease progression in normal tension glaucoma
Leung DYL; Iliev ME; Chan P; Baig N; Chi SCC; Tham CCY; Lam DSCBritish Journal of Ophthalmology 2011; 95: 1106-1110
See also comment(s) by Marco Vizzeri •
Background: It has been shown that the pressure-to-cornea index (PCI), which estimates the relative effects of intraocular pressure (IOP) and central corneal thickness (CCT), may differentiate between glaucoma and non-glaucoma states. The authors investigated the utility of the pressure-cornea-vascular index (PCVI) in predicting field-progression in patientswith normal tension glaucoma(NTG). Methods: PCVI was constructed from PCI (maximum IOP/CCT (3)) extended with risk factors identified as associated with field-progression in a prospective NTG cohort. Receiver operator characteristics and area under the curve (AUC) of a range of constructs were calculated to arrive at an optimal PCVI. Results: 415 eyes from 415 NTG subjects (184 field-progressed and 231 field-stable) with 3 years of follow-up were analysed. The construct PCVI=(maximum pretreatment office IOP x age at presentation x vertical cup-to-disc ratio at presentation x (1.5 if presence of systemic hypertension; 2.5 if presence of disc haemorrhage; 3.5 if presence of both; 1.0 if none))/ (CCT(3)x100) (CCT in mm) gave the highest AUC at 0.71 (95% CI 0.66 to 0.76, p<0.001). The mean PCVI were 113.1(plus or minus)76.8 and 69.7(plus or minus)39.7 for progressed and stable NTG groups, respectively (p<0.001). Conclusion: PCVI may be useful for predicting progression in NTG with a satisfactory AUC comparable to established scoring systems in neurovascular medicine. Validation of PCVI in other NTG cohorts, preferably of different ethnicity, is necessary. Trial registration number: NCT00321386.
D.Y.L. Leung. Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong.
Classification:
6.20 Progression (Part of: 6 Clinical examination methods)
9.2.3 Open angle glaucoma with elevated IOP (Part of: 9 Clinical forms of glaucomas > 9.2 Primary open angle glaucomas)
2.2 Cornea (Part of: 2 Anatomical structures in glaucoma)
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)