[Is fundus photography useful in screening for diabetic retinopathy in patients with type II diabetes mellitus?]. / Is fundusfotografie zinvol bij de screening op diabetische retinopathie bij patiënten met diabetes mellitus type II?

OBJECTIVE: To determine the value of a screening programme with fundus photography for diabetic retinopathy in diabetes mellitus type II patients. DESIGN: Prospective. SETTING: General practices in the region Zwolle, The Netherlands. METHOD: 650 Patients from 50 general practices were photographed after dilating both eyes. Of these 215 were examined by an ophthalmologist. Data of patients who did not join the study were analysed in 13 general practices. Any symptom of retinopathy and/or photographs of poor quality implied referral to an ophthalmologist. RESULTS: Of a total of 1300 photographs 208 (16%) could hardly or not at all be assessed. The agreement in the group of 215 patients between photography and ophthalmoscopy was statistically significant at classification level (Cohen's kappa 0.41). The advice given to patients after photography did not differ from that after ophthalmoscopy (kappa: 0.50); photography did not miss any high-risk characteristics, it yielded more warnings, and underestimated the level of retinopathy in 8 out of 215 cases. With current ophthalmologic rates in the Netherlands fundus photography was not financially advantageous as 71 (33%) out of 215 patients needed to be referred to an ophthalmologist. However, in the other 144 (67%) patients photography sufficed. This may offer a solution where ophthalmic care is in short supply. Of 168/420 patients who did not apply for photography 116 (69%) were either under ophthalmic supervision already or too disabled to be screened. CONCLUSION: The use of a fundus camera is equivalent to funduscopy by an ophthalmologist in screening for retinopathy of type II diabetic patients. There are no financial benefits, but it reduces the work load of ophthalmologists.

Circulating immune complexes in uveitis patients.

Immune complexes have been implicated in the pathogenesis of several types of uveitis. This has been substantiated in experimental models such as serum sickness, and in the analysis of the sera and aqueous of uveitis patients. The mechanisms influencing the deposition of the complexes in the eye are described. Furthermore a prospective study is presented, dealing with the presence of serum immune complexes and complement in 104 uveitis patients. A role for circulating immune complexes in the pathogenesis of uveitis could not be substantiated by this study.

Treatment of ptosis by levator resection with adjustable sutures via the anterior approach.

The authors describe a one-step anterior approach levator resection technique with intraoperative adjustable sutures. Forty-four ptotic eyes were divided into five groups, and the results of this technique were evaluated for each of these five types of ptosis. Our results show that it is not possible to predict the extent of a levator resection preoperatively from the assessment of the levator function and degree of ptosis. We therefore propose this flexible method as the operation of choice for the correction of senile, traumatic and congenital ptosis.

The role of the immune system in uveitis induced in animals.

The etiological diagnosis in many cases of uveitis is hampered by the lack of insight into the pathogenesis of the disease. Animal models might provide clues for the understanding of the ocular and systemic processes leading to this invalidating disease. The immune system seems to play an important role in the pathogenesis of uveitis. Four main topics i.e. autoimmune phenomena, circulating immune complexes, effects of systemic endotoxin and bacterial or viral uveitis are reviewed. Autoimmune phenomena might cause the recurrence of uveitis after presentation of slightly altered self-antigens to the immune system. The endotoxin induced uveitis might be the initial event of recurrent episodes of uveitis caused by the deposition of immune complexes. Endotoxin might play a role in the so called HLA-B27 positive uveitis, mediated through tumour necrosis factor and interleukin-1. In this paper the characteristics of these animal models are described. Attention has been paid to those situations where several of these mechanisms combine in the pathogenesis of ocular diseases.

In vivo and in vitro deposition of immunoglobulin aggregates in the mouse eye.

The possible role of specific mechanisms involved in the adherence process of immune aggregates to tissue components of the mouse eye was investigated in an experimental animal model. Passive intravenous administration of immunoglobulin aggregates to mice, resulted in the localisation of these aggregates in various organs, including the eye. In the eye a strong localisation was seen in the episcleral capillary plexus, whereas only a weak deposition was seen in the iris, ciliary body and choroid. No deposits were seen in the retina. To investigate the role of specific receptors for immune complexes in the eye, in vitro experiments were performed, whereby immunoglobulin aggregates were layered on cryostat sections of the mouse eye. These in vitro studies also showed an adherence of immune aggregates to the episcleral capillary region, but furthermore a deposition on mast cells scattered throughout the extra-ocular muscles. The in vitro binding of immunoglobulin aggregates to the episcleral capillary plexus could be inhibited by high concentrations of Fc fragments and monomeric IgG, but not with Fab fragments or 0.5 M NaCl. The in vitro adherence of aggregates to mast cells could not be blocked by the inhibitors employed in our study and could therefore be distinguished from the interaction of aggregates with the episcleral capillary plexus. These results indicate that the ocular deposition of immunoglobulin aggregates in the episcleral capillary plexus of the mouse eye is (immune) specific and mediated by Fc receptors.

Deposition of immune complexes in the mouse eye.

The ocular deposition of circulating immune complexes was studied in mice using passive and active immune complex models. In the passive model, immune complexes were made at different antigen-to-antibody ratios and subsequently injected intravenously. In the active model, antigen alone was injected intravenously into immune mice. Ocular localization was studied by immunofluorescence microscopy. In both experimental models a marked deposition of antigen, antibody and mouse C3 could be observed in the scleral capillary area, whereas a weaker deposition could also be observed in the ciliary body, iris and choroid. With the immune complex doses used, only a short (1-2 hr) ocular deposition was observed and no inflammatory signs were seen upon histological examination. The deposition of complexes in the episcleral capillary area could provide a suitable experimental model to analyse the role of circulating immune complexes in the pathogenesis of scleral phenomena associated with rheumatoid arthritis.