Diet and diabetic retinopathy

A recent study of eating disorders in young female insulin dependent diabetics (N Engl J Med1997;336:1849–54) showed that there was a highly significant risk of developing retinopathy within 5 years which correlated with the severity of the eating disorder and was a stronger correlate of risk of retinopathy than duration of diabetes. The study comprised insulin dependent female diabetic patients who were followed up for 4–5 years. Eighteen per cent of the group suffered from an eating disorder at entry to the study which persisted for the duration of the study, and a further 15% developed an eating disorder during the study. One strategy used by the patients was to manipulate their insulin dosage downwards and this was reflected in a higher HbA_1c and poor overall control of their diabetes. A remarkable 86% of patients with severe eating disorder developed retinopathy during the study period, while 43% with moderate and 24% with mild eating disorders developed retinopathy. The authors recommend attention to possible eating disorder in young women with poor metabolic control and counselling with regard to the risk of retinopathy.

Xenografting as a solution to the problem of tissue supply

Recently in Newsdesk the problem of donor supply for corneal grafting was highlighted (see Newsdesk, BJO1998;82:8). The supply of donor material for organ transplant is a general problem and, for tissues such as heart and liver, the notion of xenotransplantation has gained popular support. There are enormous ethical as well as healthcare issues associated with xenotransplantation. Despite these, regulations in the United States are soon to be issued which would allow initial experimental studies to be undertaken in animal to human transplantation. A recent “briefing” in Nature has, however, urged considerable caution before such studies are undertaken for several reasons:

. . .the problem of xenozoonosis (for example, the transfer of viral infection from animals to humans, ominously named the Trojan pig) has not been adequately addressed

. . .the strong commercial interest in the trials is inevitable but might itself raise ethical issues

. . .previous studies reporting success in xenotransplantation—for example, by Imutran (a UK company based in Cambridge), have only reported effectivity in controlling hyperacute rejection while most of the problems associated with transplantation generally remain unsolved

. . .the specific problem of delayed xenograft rejection, mediated by macrophages and natural killer cells is still to be overcome.

 Much work still needs to be done. The debate has not yet been contributed to by significant amounts of experimental work in corneal xenotransplantation, which has several useful features to offer, not least the absence of donor MHC class II positive cells.

Weingeist asks for feedback

The January 1998 issue of EyeNet (the news magazine of the American Academy of Ophthalmologists) carried a brief editorial by Thomas Weingeist, the editor, in which he asked for opinion from ophthalmologists on the standard of care provided to a monocular patient who had a 20/25 cataract successfully removed and replaced with an intraocular lens. Apparently, the patient, whose other eye had been enucleated 7 years previously for choroidal melanoma, was found to have cataract after examination by an optometrist. He had day case surgery for which the ophthalmologist’s input amounted to a preoperative assessment, the surgery itself, and one postoperative assessment on the day following surgery, after which his remaining eye care for the cataract surgery was conducted by the optometrist. While this scenario is somewhat removed from normal clinical practice in the UK, the remarkable changes in attitudes towards cataract surgery generally could conceivably result in a similar practice occurring in the UK in the not too distant future. The case report raises many questions relating to both the current indications for cataract surgery and their application to monocular patients, and to the identification of the appropriate personnel to monitor results of surgery, particularly late complications such as capsule thickening. Dr Weingeist is keen to receive the views of the ophthalmic community. He can be contacted at EyeNet, PO Box 7424, San Francisco, CA, USA (or by email: eyenet{at}aao.org).

Glaucoma update

The 18th annual Glaucoma Society (UK and Eire) meeting (London, November 1997) was treated to a series of papers on recent research in glaucoma. Two main themes emerged: (a) surgical approaches to difficult glaucoma problems such as treatment of encapsulated trabeculectomy blebs with needling and 5-fluorouracil and the primary management of uveitis associated glaucoma with antimetabolites; and (b) the documentation of field and disc changes in different types of glaucoma using newer types of visual field analysis and image analysis techniques respectively. Pharmacological approaches to glaucoma management were notable by their low profile at the meeting. In addition, it would appear that the search for a reliable objective test of progressive glaucomatous damage is not yet quite over.

The beneficial effects of alcohol?

Much has been made of the beneficial effects of alcohol particularly in protecting against cardiovascular disease but also in terms of mortality rates overall. However, the consensus view at a recent Novertis Foundation symposium (Royal Society of Medicine, October 1997) held by cardiologists, public health experts, epidemiologists, and sociologists has tended to pour cold water over this popularly held opinion. While there is agreement that there is a general beneficial effect of alcohol for health, as evidenced by the fact that individuals who abstain from alcohol consumption have a higher rate of mortality (from all causes) than people who are light to moderate drinkers, the overall effect has been exaggerated. This is the result, apparently, of inappropriate epidemiological techniques used in gathering information which was performed mostly in the form of questionnaires. However, proper account of the types of population under study has to be taken in designing these questionnaires; apparently using non-drinkers as the baseline control group has led to significant bias in a number of studies since this group has other features which make them significantly different from the “normal” population. This is, of course, not entirely cheerful news for those who are relying on the beneficial effects of alcohol in promotion of longevity. Of importance also to ophthalmic epidemiologists are the lessons to be learned from interpreting data based on questionnaire-type research.

The BMJ appoints an ombudsman

Journal editorship continues to undergo revolution in style and practice. Several journals have in recent years appointed an ombudsman to rule on disputes between authors and the editorial board on several issues including the final decision whether or not to publish. There are many reasons why an ombudsman for every journal is a good idea, including the provision of a mechanism which allows grievances to be settled. In addition, it is likely that the editorial decision process would be improved by the presence of the ombudsman. However, an ombudsman might simply be adding another layer (and thus delay) to the refereeing process and create problems where none previously existed. In addition, it might add to the cost of the journal. The critical issue about the usefulness of the ombudsman lies in whether his remit can be effectively restricted to issues which are not simply centred around differences of opinion, but on other matters—for example, of fact or due process. If this can be achieved then the ombudsman will be a welcome addition.