Search

We localised amino acids in the mid-peripheral aged human retina and a retina that had undergone radiation treatment 10 years earlier. The distribution pattern of glutamate, γ-amino butyric acid (GABA), glycine, glutamine and taurine, reflected patterns established in the primate retina. The retina that had undergone radiation exposure displayed both anatomical and neurochemical remodelling. The proximal retina comprised around 40 to 45 per cent of the total retina and neuronal kinesis and aberrant neuronal projections were also present. Amino acid neurochemistry was strikingly different with Müller cells displaying GABA loading, glycinergic neurons displaced and displaying a very high level of glycine labelling. We conclude that radiation exposure triggered these changes in the human retina and likely reflects general remodelling of structure and function following ischaemic damage to endothelial cells., (© 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.)

The history of retinal surgery in New Zealand is relatively short but covers a period of transition from caustic cautery to laser retinopexy, from scleral shortening to 25 gauge vitrectomy. The practitioners of this craft include some of the notable figures in medicine in New Zealand, and in their own way each contributed to the welfare of those patients with surgical retinal disease.

Purpose: To assess a humidity device used in vitreoretinal surgery., Methods: Infrared absorption spectroscopy analysis of absolute water content (absolute humidity) was determined for a typical vitreoretinal air infusion line with and without the humidifying device. A variety of experimental laboratory conditions were utilized and designed to mimic those found in the operating room. The effect on physical parameters, such as flow rates and resistance to flow, were also determined., Results: While large bore infusion (LBI) lines had a negligible effect on flow rate and resistance to flow (reduction in infusion pressure), the standard 20 G infusion line (SI) reduced flow rate and infusion pressure by approximately 25%. When used together, the humidifying device and SI reduced flow rate and infusion pressure by one third. The humidifying device was found to add 6.5 mg/L water content to the air infusion line system. Typical operating room (OR) air contains 9.5 mg/L water content, and 43.876 mg/L water content is required to saturate air at body temperature., Conclusion: To eliminate dehydration as a cause of intraocular morbidity, one must first saturate the infused air. If the visual field defects and other complications are eliminated, this would be good evidence for saturating infused air. As infusion pressure (flow rate) influences dehydration rate, unless saturated air is used, infusion pressure cannot be considered an independent variable in the analysis of field defects.

Thirteen young diabetic patients with peripheral capillary non perfusion who presented with symptoms of mild maculopathy were reviewed retrospectively. In this group, peripheral retinal ischaemia was often overlooked and a rapidly progressive proliferative retinopathy developed. Fluorescein angiography of the peripheral retina showed capillary closure, but with preservation of arterioles and venules. In this series, half of the eyes lost vision. In seven eyes where the peripheral ischaemia was treated by pan retinal photocoagulation, the maculopathy resolved without any specific laser treatment to the macula. In young diabetics presenting with maculopathy, the peripheral retina should be examined for ischaemia, and if present, pan retinal laser photocoagulation should be performed. Focal treatment for the macular disease can be delayed until after the peripheral photocoagulation, as the maculopathy may remit.