The prevalence and expression of diabetes in a sample of optometric patients

The clinical characteristics of 100 consecutively presenting diabetic patients of an optometrist were investigated. This sample was drawn from 3798 patient first visits and represented 2.6% of the practice population sample. Diabetic retinopathy was present in 26% of the diabetic patients; this prevalence is similar to that found in diabetics examined in community based surveys. The ocular complications of diabetics observed in this study appeared to be similar to those of diabetics in the general community. The mean random blood glucose levels of the diabetics having retinopathy was not significantly different from those not having retinopathy. A first degree family history of diabetes was admitted by 46% of the diabetic subjects and was the most common associated clinical feature surveyed; a control group of non-diabetic subjects had a first degree family history of diabetes in 10% of cases. In seven patients, the diabetes was diagnosed as a result of signs detected at the optometric examination; these signs are listed. No newly diagnosed diabetic had diabetic retinopathy as a presenting sign. Ocular and systemic signs, other than diabetic retinopathy, were sought and a high prevalence of cardiovascular disease was detected in these diabetic patients. The vision of the diabetic patients was compared to that of 100 randomly selected age and sex matched controls; there was no significant difference in the visual acuity of the two groups. The implications of this finding are discussed. Guidelines for the detection and management of diabetic patients of optometrists are suggested.     

Effect of morphological abnormalities on blood retinal barrier permeability in diabetic retinopathy

The morphological base for the impaired function of the blood retinal barrier was studied in 50 eyes of 10 insulin dependent and 21 non-insulin dependent patients with various levels of diabetic retinopathy. The permeability of the blood retinal barrier (P_BRB) was determined by vitreous fluorophotometry with correction for autofluorescence, lenstransmission and non-protein bound plasma fluorescein concentration. Morphological abnormalities of diabetic retinopathy assessed by fundus photography and fluorescein angiography were individually scored on a decimal scale and related to the P_BRB by multiple regression analysis. The P_brb was not correlated to morphological abnormalities of non-proliferative retinopathy [(1) microaneurysms, (2) hard exudates, (3) soft exudates, (4) intraretinal hemorrhages, (5) fluorescein leakage, and (6) capillary closure, p > 0.3]. The P_BRB was correlated to morphological abnormalities of (pre)proliferative retinopathy [(1) intraretinal microvascular abnormalities (S_irma) and (2) new vessels (S_neo): p_brb = A – B.S_IRMA – C.S_neo with P_BRB in nm/sec, A = 1.5 ± 0.5, B = 0.9 ± 0.2 and C = 1.7 ± 0.4, R² = 0.65, p < 0.0001]. It can be concluded that the increased blood retinal barrier permeability in diabetic patients is mainly due to (pre)proliferative abnormalities and not to non-proliferative abnormalities.     

A review of the effects of external pressure on skin blood flow

The human foot is a complex mechanical structure consisting of bones, ligaments and joints. They act together to provide a robust system capable of absorbing and dissipating the intermitted pressure that is subjected to its plantar surface during walking to prevent soft tissue breakdown. Current studies suggest that plantar foot pressure may lead to soft tissue breakdown (e.g. neuropathic ulceration) and hence research has so far concentrated on investigating the mechanical effects of plantar foot pressure on the foot’s integrity. This has been possible through the widely available pressure and force platforms as well as in-shoe pressure systems. However, to understand how plantar foot pressure causes soft tissue breakdown it is vital to investigate both the physiological–mechanical interactions between the skin and plantar foot pressure. This review suggests that with the current advances in technology, the physiological response of skin blood flow to mechanical plantar foot pressure should be investigated and correlated further, both during static and dynamic loading, by developing a new system capable of either measuring both variables simultaneously or by synchronising two systems in real time.     

Activity and distribution of phosphoinositidase C in rat sciatic nerve.

The hydrolysis of phosphatidylinositol-4,5-bisphosphate (PIP2) by rat sciatic nerve cytosolic phosphoinositidase C [phosphoinositide-specific phospholipase C (PIC)] was studied at neutral pH and at ionic concentrations that approximate intracellular conditions. The principal water-soluble product formed was shown to be inositol trisphosphate by anion exchange chromatography. The maximum hydrolysis rate (2.5 nmol/min/mg protein) was achieved at less than 100 nM Ca2+. Hydrolysis was markedly increased to 15 nmol/min/mg protein by inclusion of K+ in the reaction mixture. In the presence of 200 mM K+, the optimum Ca2+ was increased to approximately 600 nM. Higher Ca2+ concentrations progressively inhibited PIP2 hydrolysis. Mg2+ also inhibited the reaction, but the presence of equimolar amounts of ATP and Mg2+ had no effect. Appreciable degradation of phosphatidylinositol-4-phosphate (PIP) also occurred in the nanomolar Ca2+ range, whereas breakdown of phosphatidylinositol (PI) required millimolar Ca2+. The presence of PIP but not PI inhibited PIP2 hydrolysis. Upon subcellular fractionation of nerve, more than 50% of recovered PIC activity was in the cytosol and about 20% was located in a myelin-enriched fraction. Using PIP2 as substrate, PIC activities in nerves from normal and streptozotocin-induced diabetic animals were not different. However, the myelin-associated enzyme from diabetic animals was more labile to freezing and thawing.     

Neuropathy in children and adolescents with diabetes mellitus

Nerve conduction velocities were studied in the median, posterior tibial, radial and sural nerves of 50 juvenile diabetics, average age 13 +/- 1.3 years and mean duration of diabetes 2.3 +/- 1.4 years. Motor conduction velocity (MCV) in the median nerve was reduced in 10% of the subjects, and in the posterior tibial in 32%. Sensory conduction velocity (SCV) in the radial nerve was reduced in 30% of the subjects, and in the sural in 44%. No relationship was found between the reduction in conduction velocity and the duration of diabetes; nevertheless, a correlation was observed between this reduction and the degree of glycaemic control represented by the glycosylated haemoglobin concentration. The authors emphasize the importance of good glycaemic control for the prevention of diabetic neuropathy.     

Peripheral Foot Blockade Versus Popliteal Fossa Nerve Block: A Prospective Randomized Trial in 51 Patients

The majority of foot and ankle operations are performed on an outpatient basis and often under some form of regional anesthesia. In this prospective, randomized study of 51 patients undergoing elective unilateral forefoot procedures, we compared 2 different anesthetic techniques: the peripheral foot blockade and the popliteal sciatic nerve block. Variables assessed included the quality of surgical anesthesia, postoperative analgesia, and the incidence of postoperative complications. The anesthesia was classified as effective if it was the sole anesthetic technique for the forefoot surgery. We found successful results in both groups: 92% in the foot block group and 96% in the popliteal block group. Analysis of time required to perform the anesthetic procedure showed a significant difference between the 2 groups, with foot block being considerably faster (14.3 minutes vs 19.2 minutes for popliteal block) (P = .0078). Foot block patients demonstrated 10.96 hours of analgesia, whereas popliteal block patients exhibited 14.32 hours (P = .132). With a mean follow-up of 5.7 months, we did not find anesthesia-related complications in any of the patients. Both techniques showed a high level of safety and efficacy, with no significant difference detected between them. Our patients showed a high rate of satisfaction with both procedures (96% for foot block patients and 96.1% for popliteal block patients) and reported a good discharge disposition. These data show that both procedures are safe and effective anesthetic techniques and well suited to forefoot ambulatory surgery.     

The Distally Based Sural Artery Flap for Ankle and Foot Coverage

The sural artery flap is a distally based fasciocutaneous flap that has many advantages to offer for coverage in the foot and ankle area. It has the largest arc of rotation of all the regional flaps and does not require sacrifice of any major artery, and moderate-to-large-sized defects can be covered adequately. The dissection technique is simple, and donor site morbidity is minimal. We report our experience with 17 cases. Age range was from 13 to 56 years. Ten (59%) defects were posttraumatic, 3 (17%) were related to reconstructive surgery of the foot or tendon Achilles', 2 (11%) resulted from tumor resection, and 1 each were from infection and gunshot wound. The smallest flap was 6 x 4 cm and the largest was 15 x 12 cm, with the average size being 11 x 7.5 cm. In 5 cases, the donor site was closed primarily, and in other cases, split-thickness skin graft was needed. The short saphenous vein was included in the pedicle in all cases. There was no incidence of complete flap necrosis. Follow-up ranged from 3 to 30 months. Two cases (12%) developed partial superficial necrosis. In 1 case, there was partial wound dehiscence that needed debridement and repair. Another case had postoperative discharge, which subsided after removal of the calcaneal plate. None of the patients complained of any functional problem related to loss of sensation along the lateral border of the foot. The sural island flap is a reliable, safe, and easy method of providing soft tissue coverage in the area of the foot and ankle.