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Polypoidal Choroidal Vasculopathy in Adult Chinese: The Beijing Eye Study
Reports Polypoidal Choroidal Vasculopathy in Adult Chinese: The Beijing Eye Study Polypoidal choroidal vasculopathy (PCV) is a choroidal vascular abnormality characterized by macular choroidal neovascularization, orange retinal lesions, subretinal and intraretinal hemorrhage and edema, and sudden and painless visual loss.1 Because populationbased data on the prevalence and risk factors for PCV have yet to be defined, we conducted the present investigation to assess the prevalence and associations of PCV in a general population. The Beijing Eye Study 2011 is a population-based study in Northern China.2 The study protocol was approved by the Medical Ethics Committee of the Tongren Hospital and all study participants gave informed consent. Out of 4403 eligible individuals with 50 years old, 3468 subjects (78.8%) participated in the eye examination. The study design included an ophthalmic examination with digital photography of the macula and spectral-domain optical coherence tomography (OCT) of the macula (Spectralis, Heidelberg Engineering, Heidelberg, Germany).2 We defined PCV as an elevated orange-red lesion on the fundus photographs, characterized by a double-layer sign and high dome-shaped pigment epithelial detachments on the OCT images (Fig 1). The OCT images and fundus photographs were examined repeatedly in several steps, including an assessment by a panel (Y.L., Q.S.Y., W.B.W., J.B.J.). Polypoidal choroidal vasculopathy was diagnosed in 18 eyes (prevalence rate, 0.30.1%; 95% CI, 0.1%e0.4%) of 17 subjects (0.5%; 10 men; prevalence rate, 0.50.1%; 95% CI, 0.3%e0.7%). Polypoidal choroidal vasculopathy was located in the foveal region in 15 eyes (83%) and was associated with subretinal exudations in 16 (89%). Two eyes showed subretinal scar formation. In all but 1 patient with PCV, the disease occurred unilaterally. Mean age of the subjects with PCV was 74.57.5 years (range, 59e87), and mean refractive error was 0.021.42 diopters (range, 3.00 to þ2.63). Mean best-corrected visual acuity was 0.310.42 logarithm of the minimum angle of resolution (0.650.34 Snellen), with 2 eyes having an acuity of 1/20 and altogether 4 eyes having an acuity of <20/60. Polypoidal choroidal vasculopathy was asymptomatic in 10 eyes with a best-corrected visual acuity of 0.10 logarithm of the minimum angle of resolution (0.80 Snellen acuity). The eyes with PCV, compared with the contralateral unaffected eyes, did not differ significantly in refractive error (P ¼ 0.59), axial length (P ¼ 0.48), or intraocular pressure (P ¼ 0.97). If only patients with a foveal location of PCV were included in the analysis, subfoveal choroidal thickness was significantly thicker in the affected eyes than in the contralateral eyes (27590 vs 21092 mm; P ¼ 0.02). The prevalence of PCV increased significantly with age from 0% among those 50 to 54 years old, to 1/643 (0.2%) among those 55 to 59 years old, to 1/508 (0.2%) among those 60 to 64 years old, to 1/469 (2.1%) among those 65 to 69 years old, to 5/540 (1.3%) among those 70 to 74 years old, 5/385 (1.3%) among those 75 to 79 years old, and to 4/260 (1.5%) among those 80 years old. Model building for the multivariate analysis began with all significant factors from the univariate associations (Table 1; available at www.aaojournal.org). From this full model,
nonsignificant parameters were removed in a stepwise manner, starting with the parameters with the highest P values. In the final model, presence of PCV was significantly associated with older age, thicker subfoveal choroid, and thicker central corneal thickness (Table 2; available at www.aaojournal.org). If only patients with a foveal location of PCV were included, similar results were obtained. The association between PCV and a thicker subfoveal choroid confirms previous hospital-based studies.3 As in other studies, PCV was strongly associated with older age.4 In contrast with a Japanese study with a predominance of men, our study did not show a significant association of PCV with gender.4 In contrast with previous hospital-based studies with a percentage of 14% to 32% of bilaterality of PCV, only 1 of 17 patients in our study (6%) showed bilateral PCV.5 The observation of a thicker subfoveal choroid in eyes with PCV compared with eyes with exudative age-related macular degeneration may imply that this morphologic difference between the diseases may be a surrogate for differences in the pathophysiology and may explain differences in treatment outcomes observed with PCV as opposed to exudative age-related macular degeneration. In 10 eyes (56%), PCV was asymptomatic, suggesting that it may be more prevalent than hospital-based investigations suggest. Our study has limitations. First, the diagnosis of PCV was based on fundus photographs and OCT images, rather than on indocyanine green angiography, which is the gold standard for PCV
Figure 1. Optical coherence tomographic image (upper panel) and fundus photograph (lower panel) of an eye with polypoidal choroidal vasculopathy.
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Ophthalmology Volume -, Number -, Month 2014 diagnosis.3e5 because our study was population based, we did not perform indocyanine green angiography. The PCV diagnosis in our study may, therefore, be regarded to be presumptive rather than definitive, because the sensitivity and specificity of OCT for PCV diagnosis is limited. It is difficult to estimate whether the lack of an angiographic confirmation of the diagnosis of PCV may have led to an underestimation or overestimation in the prevalence of PCV. Interestingly, PCV has usually been observed in younger patients compared with patients with exudative age-related macular degeneration, and the mean age of patients with PCV in our study was relatively old (74.57.5 years). Second, it can be difficult to differentiate between the late stage of PCV and the late stage of exudative age-related macular degeneration. Third, the limitations of the statistics owing to the small number of PCV patients identified has to be acknowledged. Although the P value from the multivariable regression was nominally significant, the odds ratio was relatively small. Fourth, a major concern in any prevalence study is nonparticipation. The Beijing Eye Study 2011 had a reasonable response rate of 78.8%; however, differences between participants and nonparticipants could have led to a selection artifact. In conclusion, in adult Chinese in Greater Beijing, PCV with a mean prevalence of 0.5% per subject was significantly associated with older age and thicker subfoveal choroid. It was not associated with blood concentrations of glucose, glycosylated hemoglobin, lipids, creatinine, arterial hypertension, diabetes mellitus, axial length, or other ocular biometric parameters. In 15 of 18 eyes (83%), PCV was located in the foveal region.
YANG LI, MD1 QI SHENG YOU, MD2 WEN BIN WEI, MD1 JIE XU, MD1
2
CHANG XI CHEN, MD2 YA XING WANG, MD2 LIANG XU, MD2 JOST B. JONAS, MD2,3 1
Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Ophthalmology and Visual Science Key Lab, Capital Medical University, Beijing, China; 2Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Beijing Ophthalmology and Visual Science Key Lab, Capital Medical University, Beijing, China; 3Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-KarlsUniversity, Heidelberg, Germany Financial Disclosures: The authors have made the following disclosures: Jost B. Jonas: Consultant e Allergan, Merck Sharp & Dohme, Alimera, Boehringer Ingelheim, Sanofi; Patent holder - CellMed AG. Supported by the State National Sciences Fund (no. 81170890) and by the National Key Technology R&D Program of the Ministry of Science and Technology (No. 2012BAH05F05 and 2013BAH19F04).
References 1. Yannuzzi LA, Sorenson J, Spaide RF, Lipson B. Idiopathic polypoidal choroidal vasculopathy (IPCV). Retina 1990;10:1–8. 2. Wei WB, Xu L, Jonas JB, et al. Subfoveal choroidal thickness: the Beijing Eye Study. Ophthalmology 2013;120:175–80. 3. Chung SE, Kang SW, Lee JH, Kim YT. Choroidal thickness in polypoidal choroidal vasculopathy and exudative age-related macular degeneration. Ophthalmology 2011;118:840–5. 4. Sho K, Takahashi K, Yamada H, et al. Polypoidal choroidal vasculopathy: incidence, demographic features, and clinical characteristics. Arch Ophthalmol 2003;121:1392–6. 5. Imamura Y, Engelbert M, Iida T, et al. Polypoidal choroidal vasculopathy: a review. Surv Ophthalmol 2010;55:501–15.
nonsignificant parameters were removed in a stepwise manner, starting with the parameters with the highest P values. In the final model, presence of PCV was significantly associated with older age, thicker subfoveal choroid, and thicker central corneal thickness (Table 2; available at www.aaojournal.org). If only patients with a foveal location of PCV were included, similar results were obtained. The association between PCV and a thicker subfoveal choroid confirms previous hospital-based studies.3 As in other studies, PCV was strongly associated with older age.4 In contrast with a Japanese study with a predominance of men, our study did not show a significant association of PCV with gender.4 In contrast with previous hospital-based studies with a percentage of 14% to 32% of bilaterality of PCV, only 1 of 17 patients in our study (6%) showed bilateral PCV.5 The observation of a thicker subfoveal choroid in eyes with PCV compared with eyes with exudative age-related macular degeneration may imply that this morphologic difference between the diseases may be a surrogate for differences in the pathophysiology and may explain differences in treatment outcomes observed with PCV as opposed to exudative age-related macular degeneration. In 10 eyes (56%), PCV was asymptomatic, suggesting that it may be more prevalent than hospital-based investigations suggest. Our study has limitations. First, the diagnosis of PCV was based on fundus photographs and OCT images, rather than on indocyanine green angiography, which is the gold standard for PCV
Figure 1. Optical coherence tomographic image (upper panel) and fundus photograph (lower panel) of an eye with polypoidal choroidal vasculopathy.
1
Ophthalmology Volume -, Number -, Month 2014 diagnosis.3e5 because our study was population based, we did not perform indocyanine green angiography. The PCV diagnosis in our study may, therefore, be regarded to be presumptive rather than definitive, because the sensitivity and specificity of OCT for PCV diagnosis is limited. It is difficult to estimate whether the lack of an angiographic confirmation of the diagnosis of PCV may have led to an underestimation or overestimation in the prevalence of PCV. Interestingly, PCV has usually been observed in younger patients compared with patients with exudative age-related macular degeneration, and the mean age of patients with PCV in our study was relatively old (74.57.5 years). Second, it can be difficult to differentiate between the late stage of PCV and the late stage of exudative age-related macular degeneration. Third, the limitations of the statistics owing to the small number of PCV patients identified has to be acknowledged. Although the P value from the multivariable regression was nominally significant, the odds ratio was relatively small. Fourth, a major concern in any prevalence study is nonparticipation. The Beijing Eye Study 2011 had a reasonable response rate of 78.8%; however, differences between participants and nonparticipants could have led to a selection artifact. In conclusion, in adult Chinese in Greater Beijing, PCV with a mean prevalence of 0.5% per subject was significantly associated with older age and thicker subfoveal choroid. It was not associated with blood concentrations of glucose, glycosylated hemoglobin, lipids, creatinine, arterial hypertension, diabetes mellitus, axial length, or other ocular biometric parameters. In 15 of 18 eyes (83%), PCV was located in the foveal region.
YANG LI, MD1 QI SHENG YOU, MD2 WEN BIN WEI, MD1 JIE XU, MD1
2
CHANG XI CHEN, MD2 YA XING WANG, MD2 LIANG XU, MD2 JOST B. JONAS, MD2,3 1
Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Ophthalmology and Visual Science Key Lab, Capital Medical University, Beijing, China; 2Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Beijing Ophthalmology and Visual Science Key Lab, Capital Medical University, Beijing, China; 3Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-KarlsUniversity, Heidelberg, Germany Financial Disclosures: The authors have made the following disclosures: Jost B. Jonas: Consultant e Allergan, Merck Sharp & Dohme, Alimera, Boehringer Ingelheim, Sanofi; Patent holder - CellMed AG. Supported by the State National Sciences Fund (no. 81170890) and by the National Key Technology R&D Program of the Ministry of Science and Technology (No. 2012BAH05F05 and 2013BAH19F04).
References 1. Yannuzzi LA, Sorenson J, Spaide RF, Lipson B. Idiopathic polypoidal choroidal vasculopathy (IPCV). Retina 1990;10:1–8. 2. Wei WB, Xu L, Jonas JB, et al. Subfoveal choroidal thickness: the Beijing Eye Study. Ophthalmology 2013;120:175–80. 3. Chung SE, Kang SW, Lee JH, Kim YT. Choroidal thickness in polypoidal choroidal vasculopathy and exudative age-related macular degeneration. Ophthalmology 2011;118:840–5. 4. Sho K, Takahashi K, Yamada H, et al. Polypoidal choroidal vasculopathy: incidence, demographic features, and clinical characteristics. Arch Ophthalmol 2003;121:1392–6. 5. Imamura Y, Engelbert M, Iida T, et al. Polypoidal choroidal vasculopathy: a review. Surv Ophthalmol 2010;55:501–15.