G. Duncker

MRI of the nasal cavity, the paranasal sinuses and orbits in Wegener's granulomatosis

Abstract. The purpose of this study was to evaluate diagnostic MRI criteria in Wegeners granulomatosis of the nasal cavity, the paranasal sinuses and orbits. Between March 1991 and January 1996, 62 patients with biopsy-proven Wegeners granulomatosis were studied with T1- and T2-weighted spin-echo (SE) sequences. In 32 patients coronal postcontrast T1-weighted images were obtained. Mucosal thickening of the nasal cavity and paranasal sinuses was demonstrated as high-intensity lesions on T2-weighted SE sequences in 57 patients (92 %). Of this group, inflammatory granulomatous tissue was found on biopsy in 30 patients (48 %) in the nasal cavity and in 4 patients (6 %) in the paranasal sinuses. In 23 patients (37 %) biopsy revealed unspecific inflammatory changes without evidence of granulomatous tissue. In 14 patients (23 %) granulomas were depicted as low-signal intensity lesions on T1- and T2-weighted SE sequences in the paranasal sinuses and orbits. In 5 patients (8 %) osseous destruction was found. After gadolinium injection, 12 of 14 granulomas showed inhomogeneous signal enhancement. In two granulomas no enhancement was found. The MRI technique is helpful in the diagnosis of patients with Wegeners granulomatosis. In the initial inflammatory process of Wegeners granulomatosis, it is not possible to differentiate between mucosal inflammation and granulomatous tissue in MRI. In the later stage of granulomatous transformation, granulomas can be depicted as low-signal-intensity lesions. Therefore, Wegeners granulomatosis should be included in the differential diagnosis of patients with low-signal-intensity lesions on T1- and T2-weighted SE sequences of the nasal cavity, paranasal sinuses and orbits.

Excimer laser correction of high astigmatism after keratoplasty

Purpose: To assess the effectiveness of excimer laser correction of high astigmatism after keratoplasty. Setting: Kiel University Eye Hospital, Kiel, Germany. Methods: In a prospective study, we treated high astigmatism in 16 patients using a 193 nm excimer laser with a rotating mask system to make a toric ablation. Thirteen patients had postkeratoplasty astigmatism, 3, idiopathic natural astigmatism. Preoperative refractive cylinder ranged from 3.0 to 9.0 diopters (D). Minimum follow‐up was 6 months. Results: Mean uncorrected visual acuity increased by 3.3 lines in 13 patients. Best corrected visual acuity decreased by no more than two lines in 6 patients and improved by at least one line in 6 patients. Mean cylindrical reduction was 2.8 D. Haze was classified from 0.5 to 2.0. Conclusions: In this study, the excimer laser technique effectively reduced high corneal astigmatism. The main problems incurred were development of a hyperopic shift and, in some patients, an uncertain refractive outcome. Reasons for inadequate correction of post keratoplasty astigmatism included a slightly decentered mask and irregular astigmatism from the circular scar.

Adhesion molecules in normal human conjunctiva An immunohistological study using monoclonal antibodies

In this immunohistochemical light microscopic study we applied a panel of monoclonal antibodies to study the expression pattern of adhesion molecules in normal human conjunctiva from 15 patients. The molecules we analyzed included the VLA-family VLA-1-6, the leukocyte integrins LFA-1, Mac-1 and p150,95, the immunoglobulins LFA-3, CD2, ICAM-1 and VCAM-1 and the selectin ELAM-1. Our results show that only VLA-2, VLA-3, LFA-3, and the VLA-α 6 subunit are expressed on the epithelium. A strongly basal accentuation of the VLA-α6 subunit indicates its possible relevance in anchoring the epithelium at the substantia propria. Intraepithelial T cells were VLA-1, VLA-5, LFA-1, and CD2 positive. Endothelial cells expressed VLA-1, VLA-2, VLA-3, VLA-5, VLA-a6, ICAM-1, and LFA-3. ELAM-1 was seen only in specimens from five patients. Interestingly, mast cells were positive for VLA-3 and VLA-5, both of which are receptors for fibronectin, indicating that these integrins play an important role in mast cell function. Our study builds the basis for further investigations in adhesion molecules in conjunctival diseases.

Refractive changes after phototherapeutic keratectomy

Purpose: To evaluate refractive error changes after phototherapeutic keratectomy (PTK). Setting: University Eye Hospital, Kiel, and University Eye Hospital, Hulle, Germany. Methods: The MEL 60 excimer laser (Aesculap Meditec) was used in all cases. To even out the peaks and valleys of irregular surfaces, modulating agents were applied. The study included 45 patients with various preoperative corneal diseases: central scars, recurrent erosions, corneal dystrophies, and surface irregularities. Subjective and objective refraction, keratometry, slitlamp photography, and corneal topography were performed preoperatively and postoperatively. The follow‐up was up to 24 months. Results: Twenty‐six patients had stable postoperative refractions. Thirteen patients developed a hyperopic shift; the highest observed amount was +4.0 diopters. In seven patients, the astigmatic error increased, although no significant change in axis was measured. Three patients had a myopic shift. Conclusion: After PTK, all types of refractive change can occur. The greatest risk is that of a hyperopic shift. We saw a correlation between the degree of hyperopia and the ablation depth. Methods for preventing such changes include (1) a large treatment zone, (2) use of a polishing program involving a low viscosity fluid at the end of the laser procedure, (3) a two‐step treatment in selected cases to avoid ablations that are too deep.

Chloroquine-induced lipidosis in the rat retina: functional and morphological changes after withdrawal of the drug

Abstract• Background: The antimalarial and antirheumatic drug chloroquine is one of the most infamous amphiphilic cationic drugs in clinical ophthalmology. It is known to cause lipidosis and photoreceptor degeneration in the human and the rat retina. • Methods: We treated female albino Wistar rats (mean weight 200 g) orally with chloroquine (95 mg/kg body weight) for 12 weeks, followed by a period of 4 months with normal feed. After initial electroretinography in all rats, measurements were made after 4 and 12 weeks of treatment and 16 weeks after withdrawal. The rats were prepared for histological examination. • Results: Treatment of rats with chloroquine caused severe lipidosis in the neuroretina; photoreceptor cell degeneration was slight. After 12 weeks of treatment, the b-wave amplitude was reduced to 30% of the initial value; the awave amplitude was reduced, but remained within the range of normal values. After withdrawal of chloroquine the lipidosis remitted, but the degeneration of the photoreceptor cell layer continued to progress. Despite remission of lipidosis, electroretinography demonstrated functional disturbances, marked by reduction of the a- and b-wave amplitudes to 25% and 16% of initial values, respectively. • Conclusions: Seen from the point of view of function, it is doubtful whether lipidosis is the primary cause of changes in the electroretinogram or of receptor cell degeneration.

Expression of MHC class I and II molecules by cadaver retinal pigment epithelium cells: optimization of post‐mortem HLA typing

The objective of this study was to investigate the expression of MHC antigens by retinal pigment epithelium cells (RPE) after stimulation with interferon‐gamma (IFN‐γ) and to improve the currently practised technique of cadaver HLA typing. A concentration of 100 U/ml IFN‐γ induced expression of class I molecules up to > 90% 3 days after stimulation, whereas 50 U/ml were required for the expression of HLA‐DR to > 90%. A concentration of 750 U/ml induced 35–45% expression of HLA‐DP and <25% HLA‐DQ after 3 days. Cells were serologically typed using the standard lymphocytotoxicity assay 3 days after stimulation with 250 U/ml IFN‐γ. Typing of class I specificities was complemented by one‐dimensional isoelectric focusing (1D‐IEF). We observed high concordance between the results of the RPE typing and the lymphocytotoxicity test on the same donors. Our results show complete typing of class I and II antigens post‐mortem, which, in particular, enables graft matching and improvement of graft survival in recipients of organs removed many hours after death such as the cornea.

Chloroquine-induced Lipidosis in the Rat Retina: A Functional and Morphological Study

Chronic administration of the cationic amphiphilic anorexigenic drug chlorphentermine to rats has previously been shown to induce extraocular and ocular lipidosis: large numbers of lipidosis —related cytoplasmic inclusions can be found in the pigment epithelium and smaller numbers in the neuroretina. In the present study, female albino Wistar rats were treated orally with chlorphentermine (30–45 mg/kg body weight) for 4–16 weeks. The animals were submitted to electroretinography, and the retinae were prepared for histological investigations. Our histological findings corresponded to previous reports. The changes in electroretinographic parameters were low. The clearest change was a reduction of the b-wave amplitude of 20% after 12 and 16 weeks of treatment compared with the values before drug treatment. The a-wave amplitude did not differ from that in the control group. Lipidosis in the neuroretina may be the reason for functional influences on the b-wave amplitude. The function of the receptor cells, which is represented by the a-wave, appeared unaffected by Chlorphentermine.

Adhesion molecules in normal and pathological corneas

Abstract• Background: Adhesion molecules are cell surface receptors that are probably important in various cell-cell and cell-extracellular matrix interactions of the cornea. • Method: In this immunohistochemical light-microscopic study we analyzed the expression pattern of adhesion molecules in normal and pathological human corneas (cases of corneal inflammation and degenerative disorders). The analyzed molecules included the β1 integrin or VLA family VLA-1-6, the β2 integrins or leukocyte integrins LFA-1, Mac-1, and p150,95, the immunoglobulins LFA-3, CD2, ICAM-1 and VCAM-1 and the selectins ELAM-1 and GMP-140. • Results: Inflamed cornea (in contrast to normal cornea). On corneal epithelium, increased expression of the α2 subunit of VLA-2 was detected and ICAM-1 was induced on the basal epithelial cells. On corneal stromal keratocytes, LFA-3 was induced and expression of the α subunits of VLA-1-6 and ICAM-1 was increased. On vascular endothelium, VCAM-1 and ELAM-1 were induced and ICAM-1 and GMP-140 expression was increased. On corneal endothelium, ELAM-1 was induced and increased levels of the α1 subunit of VLA-1 and GMP-140 were expressed. Degenerative disorders (in contrast to normal cornea): In corneas with degenerative disorders we found decreased expression of adhesion molecules. • Conclusion: Inflammatory cytokines increase the expression of the adhesion molecules. Increased expression of the VLAs probably promotes cell-extracellular matrix and cell-cell interactions. ICAM-1, VCAM-1, LFA-3, ELAM-1 and GMP-140 expression was increased on vascular endothelium in inflamed corneas. Corresponding receptors on leukocytes probably enable a selective recruitment of different leukocyte populations in inflammatory corneal diseases. The decreased expression of adhesion molecules in corneal degenerative disorders is probably a sign of reduced cell-cell and cell-extracellular matrix interactions.

Complications of silicone disc intraocular lenses

Abstract Through a 4.5 mm comeoscleral incision, we implanted one of two types of foldable, silicone disc, posterior chamber intraocular lenses (IOLs) in the bag in 35 eyes of 32 patients after phacoemulsification and capsulorhexis. Five lenses were explanted in the early postoperative period because of complications. We followed 24 eyes for an average of 38 months. At the end of follow‐up, 5 of the lenses had decentered by 1 mm; 8 (33%) had developed clinically significant posterior capsule opacification (PCO). We believe the IOLs’ disc shape may not allow firm fixation, resulting in opacification. On average, there were no significant differences in long‐term results between the two silicone disc lens types.

Delayed suprachoroidal hermorrhage after penetrating keratoplasty

We report on an aphakic 30 year-old patient who underwent penetrating keratoplasty on his only functioning eye. On the first day after the operation he developed a total choroidal detachment due to suprachoroidal bleeding. The patient had no sense of orientation. Vision decreased to faulty light perception. One week postoperatively a posterior sclerotomy was performed in order to drain the suprachoroidal blood. Via a paracentesis the globe was pressurized with hyaluronic acid. The following day the suprachoroidal blood had almost disappeared. The retina had become reattached. During a follow-up period of 2 years the visual acuity remained 20/30.