Laser pointer maculopathy - on the rise?

PURPOSE: To report symptoms and ocular pathology in 13 patients exposed to light from laser pointers. METHODS: We conducted a multi-centre consecutive case series from eight ophthalmology departments. RESULTS: Eleven boys aged 9-15 years and two girls aged 7 (sister of one of the aforementioned boys) and 12 years, respectively, were included. Laser wavelengths were 572 nm (green), 450 nm (blue), and red laser of unknown wavelength. Output powers were between 5 and 5000 mW. Evaluation included slit lamp examination, colour fundus photography (CFP), and optical coherence tomography (OCT). All subjects complained of unilateral vision loss. Initial visual acuities in exposed eyes ranged from 0.05 to 1.0 Snellen equivalent or better. Nine subjects showed pathology on CFP and OCT abnormalities. One subject had a macular hole, which closed after vitrectomy. Long-term visual acuity ranged from 0.3 to 1.0 Snellen equivalent or better. CONCLUSION: High-powered laser pointers have become readily available on the internet, and they have the potential to induce lasting visual loss. More than half of the published laser pointer maculopathy cases since the first incidence in 1999 have been published in 2014-2017. We suspect that incidence of exposure and subsequent visual loss is rising, and we encourage national legislators to regulate this market.

Retinal arterioles have impaired reactivity to hyperoxia in type 1 diabetes.

PURPOSE: Diabetes has adverse effects on the retinal microvasculature. The purpose of this study was to compare the effects of inhalation of hypoxic, hyperoxic and normoxic-hypercapnic gas mixtures on retinal vessel diameter in people with and without diabetes. METHODS: Sixty-one participants (aged 24-50 years) 29 with (male : female ratio 2.6 : 1) and 32 without (male : female ratio 0.7 : 1) diabetes, inhaled hypoxic, hyperoxic and normoxic-hypercapnic gas mixtures for 3-5 mins. The diameters of arterioles and venules were measured using digital retinal images taken before and after gas inhalation. RESULTS: There was no significant difference in the diameters of arterioles and venules prior to gas inhalation in people with and without diabetes. Inhalation of the hyperoxic gas mixture caused a statistically significant decrease in arteriolar and venular diameters without altering mean arterial pressure significantly. Arteriolar vasoconstriction in response to the hyperoxic gas mixture was significantly reduced in people with diabetes (3.95% versus 7.75%; p = 0.04), but venular vasoconstriction did not differ significantly. A hypoxic gas mixture caused increased arteriolar and venular diameter and a normoxic-hypercapnic gas mixture had no significant effect on vessel diameter. Responses to hypoxic and normoxic-hypercapnic gas did not differ significantly between diabetes and non-diabetes subjects. CONCLUSIONS: Type 1 diabetes impairs retinal arteriolar responses to hyperoxia. Abnormalities in retinal arteriolar reactivity in response to oxygen may play a role in the development of diabetic retinopathy and this technique may represent a simple means of identifying early abnormalities in the reactivity of retinal arterioles in diabetes.