Electrophysiological assessment of visual pathways in glaucoma.

PURPOSE: To assess nerve conduction in visual pathways in patients with open-angle glaucoma. METHODS: Pattern-electroretinograms (PERG) and visual-evoked potentials (VEP) were simultaneously recorded in 16 patients with open-angle glaucoma (POAG) and 15 age-matched controls. The visual stimuli were checker-board patterns (the check edges subtend 15'; the contrast was 70% and reversed at the rate of 2 reversals/s). RESULTS: POAG patients showed significantly higher PERG and VEP latencies (ANOVA: P < 0.01) and significantly lower amplitudes than controls; the retinocortical time (RCT: difference between VEP P100 latency and PERG P50 latency) was longer (P < 0.01) in POAG than controls and the longer RCT was correlated with the reduced PERG amplitude (r:0.798, P < 0.01). CONCLUSIONS: This suggests that POAG patients have an involvement of the innermost retinal layers and impaired nerve conduction in their visual pathways.

Multiple ocular impairment in a patient affected by Waldenström's macroglobulinaemia.

BACKGROUND: We studied a bilateral tumefaction of the lacrimal gland in a female patient. METHOD: Ocular and general clinical examinations were carried out. RESULT: Computerized tomography (CT) of the cranial orbit showed a tumefaction of solid density in the lacrimal gland. Histological examination of material removed by needle aspiration revealed the presence of elements of a lymphoplasmacytoid nature. Fluorescein angiography showed dilatation of the veins, intraretinal flame haemorrhages and small ischaemic areas. Chest CT showed an increase in the size of the middle and upper mediastinal lymph nodes, and examination of a specimen of bone marrow from the chest revealed the presence of small lymphocytes with a plasmacytoid tendency. CONCLUSION: On the basis of the findings, we diagnosed Waldenström's disease with rare multiple ocular impairment (lacrimal gland and retina) in an early stage.

Pattern of anesthetic diffusion during peribulbar infiltration: a CT evaluation.

PURPOSE: The aim of this study was to evaluate the changes undergone by orbital structures during peribulbar anesthesia. METHODS: CT-thin slices were acquired and 8-9 ml of anesthetic, with a small part of low-density non-ionic water-soluble contrast medium were injected under CT guide once to follow extraconal spreading and diffusion to intraconal structures and above all, the surgically important structures such as recti muscles, orbicular and optic nerve sheath. Conjunctival sack involvement was assessed and conjunctival chemosis was rated. Induced ptosis was evaluated, verifying change before and after eyepressure. RESULTS: The results help in optimizing anesthetic technique, above all concerning the site, materials and quantity, and suggest the amount of anesthesia could be reduced. CONCLUSIONS: The peribulbar anesthetic technique proved effective and safe for patients.

Electrophysiological assessment of visual function in newly-diagnosed IDDM patients.

Electrophysiological tests (electroretinogram, oscillatory potentials, visual evoked potentials, in the basal condition and after photostress) reveal an abnormal function of the visual system in insulin-dependent diabetic (IDDM) patients. The aim of our work was to assess whether electrophysiological abnormalities in visual function exist in newly-diagnosed diabetic patients free of any fluorangiographic signs of retinopathy. Ten control subjects (age 28.7 +/- 2.44 years) and then IDDM patients (age 25.2 +/- 6.78 years; disease duration 5.3 +/- 3.5 months) in stable metabolic control (HbA1C 7.5 +/- 1.1%) were evaluated. Flash-electroretinograms and oscillatory potentials were similar in both groups. Visual evoked potentials (VEP) recorded under basal conditions showed that P100 latency was significantly increased in the diabetic patients compared to control subjects (p < 0.01), while N75-P100 amplitude was similar in both groups. The recovery time of VEP after photostress was equivalent in diabetic patients and control subjects. The impaired basal VEPs suggest an early involvement of the nervous conduction in the optic nerve. However, the preserved flash-electroretinogram and the normal recovery time after photostress indicate that a short disease duration does not induce physiopathological changes in the outer retinal layers or in the macular function.

Anterior segment surgery with use of a new type of sodium hyaluronate preparation IAL.

Over a period of 1 year, a new sodium hyaluronate preparation (IAL) has been studied in eye surgery. The study included 18 cases of extracapsular cataract extraction with intraocular lens (IOL) implantation and 19 cases of penetrating keratoplasty. The trial has shown that this substance presents all the advantages described for use of viscoelastic substances in ocular surgery. The use of this sodium hyaluronate preparation appeared to decrease the risk of the postsurgical ocular hypertension described for analogous substances with different physicochemical characteristics.