Michael D. Sanders

Ophthalmologic findings in 70 patients with evidence of retinal embolism.

Seventy cases of retinal embolism showed cholesterol and platelet-fibrin emboli, usually from a carotid source, and calcific emboli, usually from a cardiac source, in that order of frequency. A marked preference for the temporal circulation, and particularly for the posterior pole, was observed with all the types of emboli. Only patients with cholesterol embolism complained of amaurosis fugax, whereas all the patients with calcific or stationary platelet-fibrin emboli experienced permanent visual loss. Visual field defects were characteristic of those seen with degeneration of the retinal axons. Collateral vessels usually developed with emboli to the arterioles of the disc and peripapillary region. Periarteriolar sheathing, as well as late fluorescein leakage from the impacted site, seemed to follow the cases of more severe endothelial damage due to cholesterol embolism. Subtotal nonprogressive ischemia ensued in relationship to post-embolic sheathing, which eventually disappeared, leaving a narrowed arteriole.

ANTI-RETINAL AUTOIMMUNITY AND CIRCULATING IMMUNE COMPLEXES IN PATIENTS WITH RETINAL VASCULITIS

Sera from 44 patients with isolated retinal vasculitis (RV), 38 patients with retinal vasculitis accompanying systemic inflammatory diseases (RV + SID), and 33 patients with a similar range of systemic inflammatory diseases without eye involvement (SID alone) were assayed for circulating immune complexes (CIC) and for anti-retinal autoantibodies. CIC were present in 41% of patients with isolated RV and 55% of patients with RV + SID, whilst anti-retinal antibodies were present in about 70% of all patients with RV. 42% of those with SID alone had CIC and 30% of those with SID alone had retinal autoantibodies. Titres of anti-retinal antibodies were higher in patients with RV than in those with SID alone. In isolated RV there was an inverse relation between pronounced retinal autoimmunity and the occurrence of CIC--i.e., the more severe autoimmune retinal disease occurred in CIC-negative patients. Most patients with RV + SID tended to have mild or moderate retinal disease accompanied by both retinal autoantibodies and CIC, but severe retinal disease occurred in CIC-positive patients who did not have circulating anti-retinal antibodies. Patients with SID alone had high titres of retinal antibodies only when they were CIC-positive. It is suggested that the formation of CIC, possibly of an idiotype/anti-idiotype nature, may be a compensatory mechanism accompanying anti-retinal autoimmunity and that an imbalance between autoimmunity and immune complex formation may be an important predisposing factor in the development of retinal inflammatory disease.

A point prevalence study of 150 patients with idiopathic retinal vasculitis: 2. Clinical relevance of antiretinal autoimmunity and circulating immune complexes.

This study describes the occurrence of antiretinal antibodies and circulating immune complexes in the sera of a large series of patients with idiopathic retinal vasculitis whose ophthalmological and clinical features are presented in Part 1. Antiretinal antibodies were measured by indirect immunofluorescence and passive haemagglutination, and circulating immune complexes were measured by polyethylene glycol precipitation and Clq binding. The occurrence of antiretinal antibodies and that of circulating immune complexes were analysed in relation to each other, to severity of retinal disease, to the type of associated systemic inflammatory disease, and to the presence of individual features of retinal inflammation. In patients with retinal vasculitis together with systemic inflammatory disease circulating immune complexes were usually accompanied by antiretinal antibodies. However, those patients with antiretinal antibodies in the absence of circulating immune complexes tended to have more severe retinal vasculitis, a feature particularly evident in Behçets disease (p = 0.028). In patients with isolated retinal vasculitis, severity of disease was associated with antiretinal antibody (p = 0.013), as well as with the occurrence of both antiretinal antibody and circulating immune complexes together (p = 0.010). In the series as a whole there was a tendency for individual features of retinal vasculitis to be associated with antiretinal antibodies unaccompanied by circulating immune complexes; especially in macular oedema (p = 0.028). In isolated retinal vasculitis there was also an additive effect of antiretinal antibodies and circulating immune complexes in relation to disease severity; in contrast, in patients with systemic inflammatory disease, the coexistence of antiretinal antibodies and concluded that both antiretinal autoimmunity and circulating immune complexes may act as immunopathogenetic factors in idiopathic retinal vasculitis but that, in certain patients, circulating immune complex formation seems to protect against the more severe forms of autoimmune retinal inflammatory disease.

Antibody Affinity to Retinal S-antigen in Patients with Retinal Vasculitis

Using a modified enzyme-linked immunosorbent antibody method that included dissociation of antigen antibody complexes with sodium thiocyanate, we examined the functional affinity of antibody to retinal S-antigen in 48 patients with retinal vasculitis and 46 age-matched healthy control subjects. Antibody affinity was markedly lower in patients with retinal vasculitis than in healthy subjects. Low-affinity antibody was more prevalent in acute retinal vasculitis and in patients with normal levels of circulating immune complexes. We found distinct differences between the antiretinal antibodies found in patients with retinal vasculitis and those in control subjects. The association of low-affinity antibody with normal levels of circulating immune complexes may suggest defective regulation of antiretinal autoimmunity and have important pathogenic implications.

Relationship of the distal optic nerve sheath to the circle of Zinn

Abstract · Background: This study was designed to determine the relationship of the vascular circle of Zinn (CZ) and its branches to the termination of the subarachnoid space surrounding the optic nerve sheath, with particular reference to optic disc size. · Methods: Serial sections of 29 normal human optic nerves were performed at 6-µm intervals. The position of the CZ and subarachnoid space were measured with WILD Heerbrugg objective graticules. The results were analysed with reference to the optic disc size. · Results: The position of the CZ was variable but two major types were recognised. In type 1 the circle was located anterior to the distal sheath, and in type 2 posterior to the sheath. There were more small optic discs observed in type 2. · Conclusion: In this study the CZ was more posteriorly located in small optic discs. This location may induce risk factors contributing to the development of ischaemic optic neuropathy. The combination of small discs, posterior placement of the CZ, and anatomical variations in the vascular pattern may predispose to ischaemic events.

GRAVES' DISEASE PRESENTING WITH BILATERAL ACUTE PAINFUL PROPTOSIS, PTOSIS, OPHTHALMOPLEGIA, AND VISUAL LOSS

Two middle-aged women presented with bilateral acute painful proptosis, ptosis, ophthalmoplegia, and visual loss. In both an initial diagnosis of orbital cellulitis was made, but they did not respond to systemic antibiotics. Orbital computerised tomographic (CT) scans were thus done within 36 h of admission and they showed grossly enlarged extraocular muscles in each case suggestive of dysthyroid eye disease. Clinical examination was otherwise normal. When high doses of systemic steroids were substituted for the antibiotics the physical signs resolved rapidly, accompanied by a dramatic reduction in the size of extraocular muscles on CT scanning. One patient subsequently became clinically hypothyroid, while the other showed clinical and biochemical evidence of thyroid overactivity. These case-reports suggest that patients with bilateral acute painful proptosis should have an early CT scan to exclude atypical dysthyroid disease. Delay in giving systemic steroids may allow the development of unnecessary visual loss due to optic nerve damage.

Ciclosporin (CyA) in the Treatment of Retinal Vasculitis

Seventeen patients with severe posterior uveitis and retinal vasculitis were treated with CyA. An initial improvement occurred in all cases and persisted until the dose was reduced or the drug withdrawn, when a rapid recurrence of symptoms was noted.