Vision loss following snakebite in a patient with controlled aplastic anemia

Viper venoms act mainly on blood and blood vessels. Reports of ophthalmic manifestations after snakebite include ptosis and ophthalmoplegia. In the current study, we describe a case that developed bilateral retinal and subretinal hemorrhage following snakebite. Bilateral retinal hemorrhage is a rare ocular complication of snake envenomation and has not been reported with fundus photographs in the literature so far.(AU)

The role of endoscopic retrograde pancreatography in the treatment of traumatic pancreatic duct injury.

BACKGROUND: The status of the main pancreatic duct (MPD) is the most important determinant of the morbidity and mortality associated with pancreatic trauma. Early diagnosis and optimal treatment are critical, especially when there is MPD injury. METHODS: Twenty-three patients with pancreatic trauma were studied prospectively with respect to clinical and laboratory findings, CT, and endoscopic retrograde pancreatography (ERP). Treatment modalities and clinical outcome were assessed in relation to ERP findings. RESULTS: The pancreatic duct was injured in 14 of 23 patients (11 MPD, 3 branch duct). Contrast leakage from the MPD into peritoneal cavity at ERP confirmed MPD injury in 8 patients, who underwent surgical exploration. Three patients with leakage from a branch duct into the pancreatic parenchyma recovered with conservative treatment. Three patients in whom ERP demonstrated contrast leakage from the MPD confined to the parenchyma underwent successful transpapillary stent insertion with complete resolution of the leak at 3-month follow-up. Patients who underwent ERP more than 72 hours after trauma had a significantly higher rate of pancreas-associated complications and a tendency to remain hospitalized longer than patients who underwent ERP earlier. CONCLUSION: Early ERP is one of the most useful methods for demonstrating MPD injury. ERP assists with treatment planning based on the degree of pancreatic duct injury.

Selective loss of S-cones in diabetic retinopathy.

OBJECTIVE: To determine whether selective cone loss could explain the acquired tritan-like color confusion found in diabetic retinopathy. METHODS: Terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick end labeling (TUNEL) was employed on paraffin sections of retinas from 5 donors with diabetic retinopathy. For quantitative analysis, postmortem retinas were obtained from 13 human donors; 7 from patients with various durations and stages of diabetic retinopathy (4 background, 3 proliferative) and 6 controls. Enzyme histochemical analysis for carbonic anhydrase (CA) was used to distinguish L/M-cones (positive for CA) from S-cones (negative for CA). Cone topography was determined by sampling 360 degrees from 0.1 to 1.5 mm of foveal eccentricity and along the horizontal meridians from 1.5 to 15.0 mm. RESULTS: Rare cells in both the inner and outer nuclear layers of the diabetic eyes were positively labeled with the TUNEL method. The CA staining revealed incomplete and patchy losses of S-cones that were limited to the diabetic retinas. Statistically significant reduction in the density of S-cones was found at nearly all foveal eccentricities from 0.1 mm to 15.0 mm. This was not the case for the L/M-cones. On average, for all locations, the percentage of S-cones compared with L/M-cones was decreased by 21.0% +/- 3.4% with respect to the controls. CONCLUSION: The S-cones selectively die in diabetic retinopathy. CLINICAL RELEVANCE: Selective loss of S-cones may contribute to the tritan-like color vision deficit seen in patients with diabetic retinopathy.

Protection of ganglion cells in experimental glaucoma by retinal laser photocoagulation.

OBJECTIVE: To test a hypothesis of photoreceptor involvement in retinal ganglion cell (RGC) death in chronic glaucoma. METHODS: Laser spots were applied to 6 eyes of 3 rhesus monkeys, causing focal destruction of the outer retina, including the photoreceptors. After 3 to 4 weeks, experimental glaucoma was induced in the right eyes of each monkey using argon laser trabecular destruction (ALTD). The intraocular pressures in these eyes were elevated for 3 to 7 months. As a control, 1 additional monkey underwent retinal laser photocoagulation followed by optic nerve transection instead of ALTD. Following enucleation, the retinas were embedded and sectioned for histologic evaluation. RESULTS: There was extensive loss of RGCs in the eyes with ALTD except over the large retinal laser spots, where there was an increased survival of RGCs. The RGC protection was not observed in the monkey that had undergone optic nerve transection. CONCLUSION: Photocoagulation of the outer retina that completely destroys the photoreceptors results in survival of the overlying RGCs in experimental glaucoma in monkey eyes. CLINICAL RELEVANCE: Although this is an experimental model and not a therapeutic option, these results suggest that treatments other than lowering intraocular pressure may be potential therapies for preventing RGC death in glaucomatous eyes. Arch Ophthalmol. 2000;118:1242-1250

Nasolacrimal duct obstruction treated nonsurgically with use of plastic stents.

PURPOSE: To evaluate the clinical utility of plastic stents in treatment of complete obstruction of the nasolacrimal duct. MATERIALS AND METHODS: Nineteen plastic stents were successfully placed under fluoroscopic guidance in 16 consecutive patients with epiphora due to complete obstruction of the nasolacrimal duct. After balloon dilation of the obstructed area, the stents were placed in the lacrimal system with the head portion lying in the dilated lacrimal sac and the body in the nasolacrimal duct and projecting into the inferior meatus of the nasal cavity. RESULTS: Complete resolution of epiphora was accomplished in 15 (79%) of 19 eyes and partial resolution in the remaining four (21%) eyes. CONCLUSION: These preliminary results with use of plastic nasolacrimal stents are encouraging.