Cell-mediated immunity against human retinal extract, S-antigen, and interphotoreceptor retinoid binding protein in onchocercal chorioretinopathy

Autoimmune mechanisms are thought to be involved in the pathogenesis of onchocercal chorioretinopathy. Cell-mediated immune responses to human retinal S-antigen, interphotoreceptor retinoid binding protein (IRBP), and crude retinal extract were investigated in patients with onchocerciasis from Sierra Leone, West Africa using a two-step migration-inhibition factor assay. Patients were subdivided into three groups: (1) without ocular involvement (n = 10), (2) with ocular onchocerciasis limited to the anterior segment (n = 19), and (3) with onchocercal chorioretinopathy (n = 21). A group of endemic controls (n = 25) from Sierra Leone were also studied. The cellular immune response to concanavalin A (Con A) was measured to assess the general capacity of lymphocytes to respond to a mitogen. Four of 50 (8%) patients with onchocerciasis and four of 25 (16%) endemic controls reacted with at least one retinal antigen. From the patients with onchocercal chorioretinopathy two of 21 (10%) showed a positive cellular response. The general mitogen response tested with Con A was positive in all these individuals. A role for an antiretinal autoimmune mechanism in the pathogenesis of onchocercal chorioretinopathy, as studied with human S-antigen, IRBP, or crude retinal extract, could not be shown because the cellular response to these antigens did not differ in patients with or without onchocercal chorioretinopathy or in endemic controls.     

Intermediate uveitis and Lyme borreliosis.

A case of chronic intermediate uveitis and associated classic snowbanking (pars planitis) with severe cystoid macular oedema probably due to Lyme borreliosis is reported. Despite a disease duration of 10 years the patient's ocular symptoms and visual acuity responded promptly to intravenous ceftriaxone treatment. This case demonstrates that periodic reevaluation of patients with intermediate uveitis is necessary to obtain a specific diagnosis which may include Lyme borreliosis.     

Blindness from uveitis in a hospital population in Sierra Leone.

A retrospective study was conducted to assess the causes of blindness and visual impairment in patients who visited an eye hospital in Sierra Leone, West Africa, in 1989 and 1992. These data were compared with figures from 1981. Throughout the years, senile cataract was the major cause of blindness, followed by uveitis (including onchocerciasis). Uveitis remained the second most important cause of blindness in this population, despite the significant decrease in blindness from onchocerciasis (from 30% in 1981 to 15% in 1992). An increasing number of patients with uveitis from non-onchocercal origin was observed: almost 10% of the blindness found in 1992 was due to uveitis of non-onchocercal origin. A reduction in visual handicap in patients with non-onchocercal uveitis could be achieved if local hospitals could obtain more accurate diagnoses in these patients.     

Ocular Manifestations and Visual Outcomes of Behçet’s Uveitis in a Thai population

Purpose: To report on ocular manifestations and visual outcomes of Thai patients with Behçet’s Uveitis (BU).

Methods: We reviewed medical records of 50 BU patients (31 males and 19 females). Ocular manifestations, treatment modalities, complications, and visual outcomes were registered.

Results: Ocular involvement was bilateral in 76% of patients, resulting in 89 affected eyes. Panuveitis and posterior uveitis were the most common types. Retinal vasculitis was noted in majority of affected eyes and specifically arteritis was noticed in 32/57(56%). Most patients received combination therapy of systemic corticosteroids and immunosuppressive agents (azathioprine 72%). At final visit, VA ≤20/200 was observed in 25 affected eyes (28%). Risk factors for poor visual outcome were poor visual acuity at presentation (p < 0.001) and development of optic atrophy (p = 0.01).

Conclusions: Typical ocular manifestations of Thai patients with BU consisted of bilateral uveitis affecting posterior eye segment with high rate of complications and frequent visual loss.     

Rhegmatogenous retinal detachment and uveitis

PURPOSE: To evaluate the frequency, high-risk factors, and visual prognosis of rhegmatogenous retinal detachment (RRD) in patients with uveitis. DESIGN: Retrospective case-control study. PARTICIPANTS: We included 1387 consecutive patients with uveitis who consulted our uveitis clinic from January 1990 through December 1997 of whom 43 patients (46 eyes) with RRD were identified. The retinal detachment (RD) controls were 212 consecutive patients with RRD (221 eyes, first occurrence of RD, not associated with uveitis) who were admitted for surgery in the period from April 1999 to April 2000. The uveitis control group consisted of 150 age-matched patients (210 eyes) selected from the entire uveitis series. INTERVENTION: Retrospective analysis of clinical data. MAIN OUTCOME MEASURES: The presence of RRD and eventual risk factors for RRD, such as myopia, retinal lattice degeneration, prior intraocular surgery, anatomic location of uveitis, its specific diagnosis, and clinical manifestations. Furthermore, the surgical and nonsurgical outcomes of RRD, as well as the results of various treatment regimens, were analyzed. RESULTS: RRD was identified in 3.1% of the patients with uveitis. RRD was most frequently associated with panuveitis (6.6%). RRD was associated more frequently with infectious (7.6%) than noninfectious uveitis (2.1%). At the onset of RRD, uveitis was active in most (46%) affected eyes. Proliferative vitreoretinopathy was present in 30% of the uveitic RRD eyes at presentation in contrast to 12% of the RRD control eyes. In uveitic RRD, the retina was reattached in 59% of eyes with a single operation; the final anatomic reattachment rate was 88%. Finally, a visual acuity of less than 20/200 was present in 71% of the uveitic RRD eyes, 10% of which had no light perception. CONCLUSIONS: We discovered a high prevalence of RRD in patients with active panuveitis and infectious uveitis and document that uveitis in itself is a risk factor for the development of RRD. The visual prognosis of RRD in uveitis was poor because of the uveitis itself and the frequent development of proliferative vitreoretinopathy.     

Uveitis masquerade syndromes

BACKGROUND: Incorrect diagnosis of the uveitic masquerade syndromes (UMS) may have severe consequences. In this study, the frequency, clinical manifestations, and informative diagnostic tests for UMS are described. DESIGN: Retrospective observational case series. PARTICIPANTS: Forty patients with UMS were identified in a cohort of 828 consecutive patients with uveitis. The mean follow-up was 4.5 years. METHODS: A review of clinical, laboratory, photographic, and angiographic records was performed. MAIN OUTCOME MEASURES: Clinical features, associated systemic diseases, diagnostic procedures and their role in the diagnostic process, and systemic and visual outcomes. RESULTS: Nineteen patients had intraocular malignancy (48% of all with UMS; 2.3% of all with uveitis), mainly intraocular lymphoma (n = 13) and leukemia (n = 3). The ophthalmologist was the first to recognize malignant disease in 11 of 19 patients (58%). Of 21 patients with nonmalignant UMS, 10 had an ocular vascular disease and 5 a hereditary ocular disorder. The patients with malignant UMS were older than those with nonmalignant UMS (average age, 50 vs 44 years, P: < 0.05). During follow-up, 9 of 19 patients with malignant UMS died. The most informative diagnostic procedure for malignant UMS was intraocular fluid analysis; for nonmalignant UMS, fluorescein angiography. The cytologic analysis of intraocular fluids yielded the best results for diagnosing intraocular malignancies (7 of 11 patients, 64%); the association of negative cytologic results with the recent administration of systemic corticosteroids was noted. Immunophenotyping of the aqueous confirmed the diagnosis of hematologic malignancy for 3 of 5 patients examined. Panuveitis was the most frequent manifestation of malignant UMS. Intraocular lymphomas presented with isolated vitreitis (n = 6), chorioretinal lesions (n = 5) and iris infiltration (n = 2). Clinical presentation of nonmalignant UMS was diverse but consisted mainly of abnormalities of the retinal vasculature. CONCLUSIONS: UMS was diagnosed in 5% of the patients with uveitis at a tertiary center. Despite the variety of underlying disorders and different clinical presentations, a high frequency of malignant and vascular diseases was found. Awareness of the clinical manifestations of UMS and application of the correct diagnostic procedures should promote timely diagnosis and treatment, which are essential not only for visual acuity but also for the life of the patient.     

Elevated serum angiotensin-converting enzyme activity in onchocerciasis

Our objective was to measure serum angiotensin-converting enzyme (ACE) activity in patients with onchocerciasis. Serum ACE activity is commonly used in the diagnosis and follow-up of patients with sarcoidosis. However, serum ACE activity can also be elevated in a number of other granulomatous disorders. In onchocerciasis, a parasitic disease affecting millions of people in Africa and Central and South America, granulomatous tissue around adult worms has been identified, yet raised serum ACE activity has not been reported so far. We measured serum ACE activity in serum samples from 42 onchocerciasis patients and 39 endemic controls previously enrolled in two studies concerning the side effects after ivermectin treatment in Sierra Leone, West Africa. The mean ACE activity in the patient group was 53.8 units/liter (S.D. 19.8) compared with 35.2 units/liter (S.D. 14.0) in the control group (p < 0.0001). Nine of 42 patients had elevated ACE activity (mean of the endemic controls ± 2 S.D.) compared with 1 of 39 controls (p = 0.01). Sensitivity and specificity of elevated ACE in serum from onchocerciasis patients from Sierra Leone was 21 and 97%, respectively. ACE activity was not related to the microfilarial skin load or development of side effects after ivermectin treatment. Serum ACE activity can be elevated in onchocerciasis. Clinicians should be aware of this phenomenon when determining serum ACE activity in persons from endemic areas. Offprint requests to: Marjolein J. H. Ronday