A catheter technique in ophthalmic regional anaesthesia. Cadaver experiments.

BACKGROUND: Regional anaesthesia for ophthalmic surgery is generally accomplished by peri- or retrobulbar techniques. Depending on the duration of ophthalmic surgery, reblock might become necessary. Our goal was to invent a catheter technique for ophthalmic regional anaesthesia that enables the user to administer local anaesthetics intraoperatively into the peri- or retrobulbar space continuously. METHODS: Twenty-five adult cadaver orbits of normal size and anatomy were used for the experiments. A flexible catheter was introduced transcutaneously or transconjunctivally into the extra- or intraconal space. Methylene blue solution was injected through the catheter. RESULTS: Using the same transcutaneous retro- and peribulbar technique, it was possible to introduce flexible catheters into a proper position of the cadaver orbits. The injected dye was found intra- or extraconally. CONCLUSION: Examining the spread of the dye in the orbit, we concluded that it is possible to provide ophthalmic anaesthesia for surgery through an indwelling catheter. We proved that continuous or intermittent administration of a local anaesthetic agent into the extra- or inraconal space can be achieved and this technique may allow us to maintain anaesthesia as long as it is necessary.

A catheter technique in ophthalmic regional anaesthesia. Clinical investigations.

BACKGROUND: Usually general anaesthesia is chosen if ophthalmic surgery of longer duration is expected. Our goal was to introduce a flexible catheter preoperatively into the extra- or intraconal space and to provide sufficient anaesthesia by continuous administration of a local anaesthetic via the catheter. METHODS: The continuous anaesthetic technique was applied in 28 patients undergoing vitreoretinal surgery. An indwelling catheter was introduced in 20 patients into the intraconal and in 8 patients into the extraconal space. In 6 patients, the position of the catheter was controlled by ultrasound examination prior to the injection of the local anaesthetic agent. RESULTS: For all patients adequate anaesthesia could be achieved and maintained with continuous retrobulbar administration (CRA) of a local anaesthetic by catheter. There were two patients who experienced moderate pain intraoperatively during continuous peribulbar administration (CPA). No complications occurred with the placement of the catheters. The catheter did not disturb the surgeon or the process of the ophthalmic surgery. CONCLUSIONS: Continuous administration of a local anaesthetic agent via an indwelling catheter into the intraconal space allowed ophthalmic anaesthesia without time restriction. Thus, CRA is a good alternative to general anaesthesia for patients undergoing long-lasting ophthalmic surgery.

[Growth inhibition of intraocular proliferative explants under in vitro conditions by verapamil]. / Wachstumshemmung intraokularer proliferativer Explantate unter in-vitro-Bedingungen durch Verapamil.

BACKGROUND: For the treatment of non neoplastic proliferations in the fundus, a nontoxic, proliferation-inhibiting long-term therapy would be desirable in addition to vitreoretinal surgery. In theory, the use of calcium channel blockers as a means of prevention appears promising. METHODS: In order to test the action of Verapamil in the above application, 42 preretinal, epiretinal and subretinal membranes were removed during pars plana vitrectomy between May, 1991 and June, 1992. Following crushing, these were cultured under cell culture conditions. RESULTS: Cell division outside the membranes was seen in 27 cases. In 13 cases the minimum cell count was approximately 1000 per primary culture. Subcultures were prepared from each of the latter, the cells having been divided into four portions. Two of the samples were diluted with Verapamil in a concentration of 0.25 microgram/ml. When cell fusion began, the number of intact cells in each sample was determined. Verapamil inhibited growth significantly (significance level of 0.93, P < 0.01). CONCLUSIONS: A larger number of cases would have to be studied to permit more comprehensive conclusions.

[Isolated leukemic iritis in childhood]. / Isolierte leukämische Iritis im Kindesalter.

Case report on a child with acute lymphogenous leukemia. Although there was constant hematological remission she developed an isolated leukemic iritis and secondary glaucoma. The clinical picture showed a characteristic stratification of the hyphema. After the patient had remained seated for a prolonged period of time the leukemic cells settled above the erythrocytes, forming a so-called pseudohypopyon, which diagnostically important. Cytologic examination after anterior chamber paracentesis is indispensable in order to establish the etiology of the disease. Isolated leukemic iritis may be the first sign of a relapse and therefore indicate a need to reinstitute induction therapy.

Controlled trial of D-penicillamine to prevent retinopathy of prematurity.

204 infants with birthweights between 751 and 2000 g and 26-35 weeks gestational age (100 treated and 104 control subjects) were enrolled in a prospective controlled trial of the effectiveness of D-penicillamine (DPA) in the prevention of retinopathy of prematurity (ROP). The two groups did not differ significantly in gestational age, birth weight, Apgar scores, the time of exposure to oxygen and in the incidence of PDA or in the number of exchange transfusions and RBTs. Of the treated infants 29, and of the control infants 34 died before the tenth week of life. These cases were not included in further analysis. Patients were subsequently examined and assessed by two ophthalmologists independently, who did not know which babies were receiving DPA. Six of the 70 surviving control infants and none of the 71 surviving treated infants had ROP stage II or graver. The results suggested that ROP may effectively be prevented with DPA in very low-birth-weight-infants, and that the drug has no serious adverse effects during the neonatal period.

Age-related difference in radioprotective effect of D-penicillamine.

D-Penicillamine, previously suspected to have a beneficial effect on the occurrence of severe retrolental fibroplasia among very low birth weight infants, was tested to determine the extent to which this drug modifies acute radiosensitivity on 3- to 4-day-old mice in comparison with adult animals. It was found that the radioprotective effect of penicillamine, given in doses of 3,000 mg/kg i.p. 60 min before whole-body exposure to 6-10 Gy of 60Co gamma rays, was greater in 3- to 4-day-old mice than in adult animals. These data seem to be compatible with the view that D-penicillamine, by virtue of its antioxidant action, may reduce the toxic effects associated with exposure of the newborn infant to hyperoxia, specifically retrolental fibroplasia and bronchopulmonary dysplasia.

Chemotactic response of polymorphonuclear leukocytes to corneal tissue extracts.

The chemotactic response of polymorphonuclear leukocytes of normal subject, to corneal extracts of 0.2 and 0.4 mg/dl protein concentration were studied in blind-well type chemotactic chambers. E. coli endotoxin served for the positive, Rindex-5 fluid for the negative controls. The chemotactic response to corneal tissue extracts, as compared to random migration in the Rindex-5 medium, proved significant. It is suggested that chemotactic factors may be released from corneal grafts in vivo too, in consequence of diverse noxae. These factors are supposed to elicit a granulocytic invasion and to lead to an opacification of the graft as a result of a cellular reaction.

Local lymphokine production in ocular inflammatory diseases.

We took samples of the aqueous humour and subretinal fluid from 12 patients suffering from various types of ocular inflammation. The presence of leucocyte migration inhibition factor in these fluids was determined using the leucocyte migration inhibition test. Our results indicated that this test differentiated ocular inflammatory reactions due to cell mediated immunity from those due to other mechanisms.

[Conjunctivitis caused by fly larvae (author's transl)]. / Durch Fliegenlarven verursachte Konjunktivitis.

The author presents a case of ophthalmomyiasis externa which caused conjunctivitis. The larvae which were visible in photomicrographs were immobilised in paraffin oil.

Lymphokine activity in the aqueous humour and in the subretinal fluid in various ophthalmic diseases.

The aqueous humour and the subretinal fluid were studied for migration-inhibition factor (MIF) activity by the capillary migration technique. The retrospective conclusions are based on the results obtained with 15-fold dilutions of aqueous humour and subretinal fluid of 12 patients. Under the conditions of the experiment a MIF activity over 30% was regarded as indicative of an active cell-mediated immune reaction. In case of a lower activity, the process was in general amenable to local treatment. In the light of further clinical observations, study of MIF activity is likely to prove a useful indicator of the local immune status and to provide therapeutic guidelines in various syndromes. In retinal detachment due to inflammatory uveitis it may furnish clues to the optimum time for surgery.