CLINICAL SCIENCE

CNV subtype in first eyes predicts severity of ARM in fellow eyes

S Abugreen¹, K A Muldrew², M R Stevenson², R VanLeeuwen³, P T V M DeJong^3,4 and U Chakravarthy^1,2

¹ Royal Hospitals, Belfast, UK
² Ophthalmology and Vision Science, Queen’s University, Belfast, UK
³ Department of Epidemiology and Biostatistics, Erasmus Medical Centre, Rotterdam, Netherlands
⁴ The Netherlands Ophthalmic Research Institute, KNAW, and Department of Ophthalmology, Academic Medical Centre, Amsterdam, Netherlands

Correspondence to:
Correspondence to:
Usha Chakravarthy, FRCS, Ophthalmology and Vision Science, Queen’s University and Royal Group of Hospitals, Belfast, Northern Ireland, UK;
u.chakravarthy{at}qub.ac.uk

Aim: To examine the relation between the type of choroidal neovascularisation (CNV) in the first eye and age related maculopathy (ARM) severity in the fellow eye.

Methods: Colour fundus photographs and fluorescein angiograms from 67 subjects with a clinical diagnosis of CNV in one eye were scrutinised. CNV was classified as wholly classic, predominantly classic, minimally classic, or occult based on the proportion of classic leakage within the lesion. ARM changes in the fellow eye were assigned a severity stage using the system described by the Rotterdam Eye Study. Logistic regression analysis was employed to examine the association between CNV subtype and ARM stage.

Results: Of subjects with classic or predominantly classic CNV in the first eye 78% exhibited least no or early ARM features in the fellow eye. By contrast, 85% of subjects with minimally classic or occult CNV in the first eye exhibited more advanced ARM features in the fellow eye. Kruskall-Wallis one way ANOVA by ranks showed that this was highly significant (p = 0.002). Logistic regression analysis showed that as the proportion of occult CNV increased in the first eye, fellow eyes of subjects in this category were more likely to have been assigned to a higher ARM stage (p = 0.019). The area occupied by the CNV in the first eye also influenced severity of ARM changes in the fellow eye.

Conclusion: The type and extent of CNV in the first affected eye has a distinct relation to ARM severity in the fellow eye. Fellow eyes of subjects with minimally classic or occult CNV in the first affected eye show widespread ARM changes suggestive of retinal pigment epithelial dysfunction. These findings suggest that classic CNV may be focal disease while occult CNV is essentially a more widespread retinal pigment epithelial disorder.

Keywords: choroidal neovascularisation; age related maculopathy

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This article has been cited by other articles:

• McKay, G. J., Silvestri, G., Patterson, C. C., Hogg, R. E., Chakravarthy, U., Hughes, A. E. (2009). Further Assessment of the Complement Component 2 and Factor B Region Associated with Age-Related Macular Degeneration. IOVS 50: 533-539 [Abstract] [Full Text]  
• Tong, L (2004). CNV subtype in first eyes predicts severity of ARM in fellow eyes. Br. J. Ophthalmol. 88: 155-155 [Full Text]  

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Louis Tong

BJO Online, 21 May 2003 [Full text]