In this retrospective, case-control study, Japanese researchers sought to determine the vitreous levels of erythropoietin and vascular endothelial growth factor (VEGF) in eyes with retinopathy of prematurity (ROP) as well as to study the correlation between the two levels. They studied 40 eyes of 27 infants with stage 4 ROP (4A, 30 eyes; 4B, 10 eyes) and used five eyes of 4 patients with congenital cataract as controls.

The researchers classified the eyes with ROP by the vascular activity into three groups: highly vascular-active ROP (n=16), moderately vascular–active ROP (n=10) and mildly vascular–active ROP (n=14). They administered an intravitreal injection of 0.5 mg bevacizumab to eyes with highly vascular–active ROP initially and these eyes underwent vitrectomy approximately 1 week after the injection. The eyes in the other groups underwent vitrectomy without bevacizumab. The study researchers obtained undiluted vitreous samples at the beginning of vitrectomy, and measured the vitreous concentrations of erythropoietin and VEGF by enzyme–link immunosorbent assay. Main outcome measures were the vitreous concentrations of erythropoietin and VEGF, which were determined and compared among the four groups.

According to the researchers, the vitreous level of erythropoietin was significantly higher (p<0.05) in the highly and moderately vascular–active ROP eyes than in control eyes. They also noted that the median concentration of erythropoietin was 744.6 mIU/ml in the highly vascular–active ROP eyes, 729.9 mIU/mL in the moderately vascular–active ROP eyes, 478.0 mIU/ml in the mildly vascular–active ROP eyes and 0 mIU/ml in control eyes. The vitreous VEGF level was significantly higher (p<0.05) in the moderately vascular–active ROP eyes than in control eyes and the median concentration of VEGF was 44.7 pg/ml in the highly vascular–active ROP eyes that had received an intravitreal bevacizumab injection, 360.8 pg/ml in the moderately vascular–active ROP eyes, 0 pg/ml in the mildly vascular-active ROP eyes and 11.4 pg/ml in control eyes. Moreover, there was a significantly positive correlation (r=0.410; p=0.047) between the erythropoietin and VEGF levels in moderately and mildly vascular–active ROP eyes.

Based on the study findings, the researchers believe that the elevated level of erythropoietin and its correlation with the VEGF level in eyes with stage 4 ROP suggest that not only VEGF, but also erythropoietin may contribute to the pathogenesis of ROP.

To examine the associations between alcohol consumption and ocular diseases in the adult population of mainland China, the Beijing Eye Study, a population-base study performed in 2001, included 4,439 subjects (age 40+ years) of 5,324 individuals invited to participate (response rate 83.4%). The study was conducted in both a rural region (1,973 subjects) and an urban region of Greater Beijing (2,466 subjects).

All participants underwent an interview, including questions about alcohol consumption and a detailed ophthalmic examination that included photography of the cornea, lens and fundus. Consumption of alcohol and systemic and ophthalmic parameters served as the main outcome measures.

Information on alcohol consumption was obtained on 4,141 subjects (93.3%), of whom 549) 13.3%) reported they consumed beer or wine. In multivariate analysis, alcohol consumption was significantly associated with the systemic parameters of lower age (p=0.001), male gender (p<0.001), rural region (p<0.001), lower level of education (p=0.01) and smoking (p<0.001). Alcohol consumption was not a significant risk factor for the prevalences of age–related macular degeneration (p=0.24), open-angle glaucoma (p=0.51), angle–closure glaucoma (p=0.75), diabetic retinopathy (p=0.35), retinal vein occlusion (p=0.39), pterygium (p=0.08), trachoma (p=0.053), epiretinal membrane (p=0.09), non-glaucomatous optic nerve atrophy (p=0.55), dry eye (p=0.86), cortical cataract (p=0.67), subcapsular posterior cataract (p=0.62) or nuclear cataract (p=0.76), or with the ocular parameters of refractive error (p=0.99), IOP (p=0.19), retinal artery diameters (temporal inferior: p=0.60), retinal vein diameters (temporal inferior: p=0.41) or size of alpha zone and beta zone of parapapillary atrophy (p=0.68).

It was concluded that when adjusted for the systemic parameters of age, gender, rural/urban region, level of education and smoking, self–reported moderate consumption of alcohol does not have a significant effect on the prevalence of major ocular diseases or the physiologic parameters of IOP and refractive error.