Cataract surgery and the optometrist.

PURPOSE: To determine the outcome of discharge on the first day following cataract surgery and the feedback from patients' optometrists. METHODS: Casenotes of patients who had cataract surgery between 1 April 1997 and 30 June 1998 were analysed. Patients without complications were discharged on day 1 and advised to see their optometrist at 1 month. Patients were given a form for refraction with a pre-paid envelope for their optometrist. Completed letters from the optometrists were returned to the hospital to be analysed by the principal surgeon and acted on appropriately. A questionnaire was sent out to patients whose notes did not contain any information after the first post-operative examination. RESULTS: A total of 318 eyes from 288 patients underwent cataract surgery. Completed forms from the optometrist were received in 245 (77%) cases; no optometrist's letter was found in the remaining 73 cases (23%). Of these 73 patients, 50 (68%) had other ocular pathology requiring hospital follow-up and 9 had died. There were only 6 patients about whom post-operative information could not be obtained. There were no significant differences regarding the age and sex of those who did or did not attend the optometrist. CONCLUSION: Patients without complications can be discharged to the care of their optometrist on the first day following cataract surgery. With good communication between hospital and the optometrist, better use can be made of available resources.

Effects of hypoxemia on the electroretinogram in diabetics.

PURPOSE: To identify any relationship between retinal dependence on oxygen and the presence or absence of retinopathy in a group of patients with the same duration of diabetes, based on the proposal that diabetic retinopathy results from long-term adaptation to the Crabtree effect, i.e., reduction of oxidative phosphorylation caused by increased intracellular glucose concentrations. METHODS: Electroretinograms were recorded on 17 patients with insulin-dependent diabetes (of 15 to 17 years duration) and 10 healthy controls. Recordings were made under normal conditions and then after 4 min of hypoxemia (oxygen saturation, 80%). Retinopathy status was assessed from fundus photographs. RESULTS: Electroretinogram b-wave amplitudes of seven patients without retinopathy were reduced to 69% by the hypoxemia compared to a reduction to 88% for 10 patients with retinopathy (p = 0.039). CONCLUSIONS: The relative sensitivity to hypoxemia of patients without retinopathy suggests greater dependence on oxidative phosphorylation than in patients with retinopathy. The results appear to be consistent with the Crabtree effect hypothesis. Downregulation of tissue oxygen consumption by the Crabtree effect would lead to a reduction of retinal blood flow by autoregulation and to a reduced concentration of adenosine triphosphate in the retina.