Dosage-dependent reduction of macular pigment optical density in female breast cancer patients receiving tamoxifen adjuvant therapy.

It is now increasingly common for breast cancer patients to receive adjuvant tamoxifen therapy for a period of up to 10 years. As survival rate increases, managing tamoxifen ocular toxicities is important for patients' quality of life. Macular pigments in photoreceptor cells protect against free radical damage, which can cause macular degeneration. By reducing macular pigment concentration, tamoxifen may increase the risk of macular degeneration. Here, we compared macular pigment optical density (MPOD) and central macular thickness between breast cancer patients on tamoxifen adjuvant therapy (n = 70), and a control group (n = 72). Multiple regression analysis indicated that MPOD decreases with increasing tamoxifen dosage, up to a threshold of about 20 g, after which MPOD plateaus out. Mean MPOD in the treatment group (mean = 0.40) was significantly lower (p-value = 0.02) compared to the control group (mean = 0.47) for the left eye, and for the right eye (treatment mean = 0.39; control mean = 0.48; p-value = 0.009). No significant difference in mean central macular thickness was found between the treatment and the control group (p-values > 0.4). In the control group, MPOD and central macular thickness showed significant correlation (r∼0.30; p-values < 0.01) for both eyes. However, in the treatment group, loss of significant correlation was observed in the left eye (r = 0.21; p-value = 0.08). The present results show that MPOD decreases non-linearly as a function of tamoxifen dosage, and highlight the potential of tamoxifen to reduce macular pigment concentration through an unknown mechanism that does not depend on macular thinning solely.

Plasma, aqueous and vitreous homocysteine levels in proliferative diabetic retinopathy.

BACKGROUND/AIMS: To compare homocysteine (Hcy) concentration in the blood plasma, vitreous and aqueous of eyes with proliferative diabetic retinopathy (PDR) against control, and to investigate associations between Hcy concentration in blood plasma with that of aqueous and vitreous in these two groups. METHODS: Blood plasma, aqueous and vitreous samples were collected during combined cataract and pars plana vitrectomy from 20 eyes with PDR and 21 eyes of patients without diabetes mellitus. Hcy concentration in the samples was determined by chemiluminescent microparticle immunoassay. RESULTS: The mean Hcy concentration (± standard deviation) of blood plasma, vitreous and aqueous were 13.7± 2.2 µmol/l, 3.4±0.7 µmol/l and 1.6±0.3 µmol/l respectively in the PDR group; in the control group, they were 10.4±1.1 µmol/l, 2.6±0.9 µmol/l and 1.2±0.2 µmol/l, respectively. The estimated geometric mean of Hcy concentration of all three variables in the PDR group was about 30% higher than control. In the PDR group, Hcy concentration between the blood plasma and vitreous was significantly associated (ρ=0.71; p-value < 0.001), as was that between the blood plasma and aqueous (ρ=0.68; p-value < 0.001). In the control group, only Hcy concentration in the blood plasma and vitreous was significantly associated (ρ=0.66; p-value = 0.001). CONCLUSION: The geometric mean of Hcy concentration in the blood plasma, vitreous and aqueous of the PDR group was significantly higher than control. The Hcy levels in the blood plasma and vitreous were also significantly associated in both groups. However, the blood plasma and aqueous were significantly associated only in the PDR group.

Ocular trauma injuries: a 1-year surveillance study in the University of Malaya Medical Centre, Malaysia. 2008.

PURPOSE: To describe the epidemiology of ocular injuries presenting to the University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia. DESIGN: Prospective analysis of all ocular trauma injuries presenting to the Department of Ophthalmology in UMMC from 1 January 2008 to 31 December 2008. PARTICIPANTS: A total of 603 eyes of 546 patients were recruited for the study. METHODS: All patients presenting to the department with ocular trauma injuries were assessed by an ophthalmologist. Data on the type and source of injury, demographic profile of the patients, and clinical presentation were documented using a uniform and validated datasheet. RESULTS: Among eye injury cases, 481 patients (88.1%) were male, with a male-to-female ratio of 7.4:1. Of the patients, 412 (75.5%) were Malaysian while the remaining 134 (24.5%) were of non-Malaysian nationality. The average age was 31.5 years (range 1-81 years). A total of 238 injured eyes (43.6%) were work-related. The common sources of eye trauma include the use of high-powered tools (30.8%), motor vehicle accident (23.1%), and domestic accidents (17.7%). Only six patients (2.5%) reported to having used eye protective device (EPD) at time of their work-related injuries. CONCLUSIONS: A major cause of preventable ocular injuries in Malaysia was work-related trauma. Ocular injuries can be reduced by the use of eye protection devices and the implementation of appropriate preventive strategies to address each risk factor. Effective training is an integral part of occupational safety and health, which should be made mandatory at the workplace. In addition, there should be a continual assessment of safety and health issues at the workplace. A long-term database of all ocular injuries in Malaysia is recommended, to aid research on a larger scale and the development of new preventive strategies for ocular injuries.