G A Sutton's research while affiliated with Midland Memorial Hospital and other places

Macrocytosis is a rise in the mean cell volume of the red cells above the normal range (in adults 80-95 fl (femtolitres). It is detected with a blood count, in which the mean cell volume, as well as other red cell indices, is measured. The mean cell volume is lower in children than in adults, with a normal mean of 70 fl at age 1 year, rising by about 1 fl each year until adult volumes are reached at puberty. The causes of macrocytosis fall into two groups: (a) deficiency of vitamin B 12 (cobalamin) or folate (or rarely abnormalities of their metabolism) in which the bone marrow is megaloblastic and (b) other causes, in which the bone marrow is usually normoblastic. In this article the two groups are considered separately, and then the reader is taken through the steps to diagnose the cause of macrocytosis and its management.

Introduction Microbial keratitis is a severe complication of corneal exposure in unconscious patients. We report five cases of microbial keratitis in three patients who sustained visual loss as a result while unconscious in an intensive care unit. The devastating consequences of microbial keratitis continue to be seen despite preventive measures. Case reports Case 1 A 74 year old man underwent a coronary artery bypass graft. He subsequently had renal failure and the adult respiratory distress syndrome. He was admitted to intensive care, where he was artificially ventilated for two weeks. After a tracheostomy he contracted a respiratory tract infection with Pseudomonas aeruginosa for which no obvious source was found. Twelve days later he developed bilateral microbial keratitis secondary to corneal exposure. This rapidly deteriorated and he developed bilateral endophthalmitis and a corneal perforation in the left eye. He was treated with intravitreal and topical gentamicin, intravenous ceftazidime, and ciprofloxacin. The inflammation gradually resolved. The patient, however, was left with bilateral scarred, thinned, and vascularised corneas. Visual acuity was reduced to light perception only in each eye. Over the following six months there was little improvement in vision. The main cause of visual loss in the right eye was thought to be the result of corneal opacity and cataract. He underwent a right combined corneal transplantation, cataract extraction, and insertion of an intraocular lens. The procedure was technically difficult because of the caseous nature of the recipient corneal tissue, which tended to disintegrate. Despite some persisting …