A. Rothova

Serologic and Polymerase Chain Reaction Analysis of Intraocular Fluids in the Diagnosis of Infectious Uveitis

PURPOSE Infectious uveitis entities are usually rapidly progressive blinding diseases that can be prevented by prompt administration of specific antimicrobial therapy. With the aim of improving early diagnosis in patients with infectious uveitis, intraocular fluid samples from patients with sight-threatening posterior uveitis were investigated to determine the causative agent. METHODS Thirty-eight patients with acquired immunodeficiency syndrome (AIDS) and retinitis, eight immunosuppressed patients with retinitis, 16 immunocompetent patients with acute retinal necrosis, and 22 immunocompetent patients with toxoplasmic retinochoroiditis were analyzed by polymerase chain reaction for the presence of herpesviruses and Toxoplasma gondii DNA and for local antibody production against these microorganisms. RESULTS In patients with AIDS and retinitis, polymerase chain reaction was positive for cytomegalovirus DNA in 21 (91%) of the 23 ocular fluid samples obtained during active cytomegalovirus retinitis, whereas local antibody production analysis was negative in all cases. In acute retinal necrosis, varicella-zoster virus or herpes simplex virus could be established as the inciting agent in 81% of the cases, using the combination of both techniques. Polymerase chain reaction was positive in all samples obtained within two weeks after the onset of disease. Toxoplasma gondii DNA was detected in 4 of 13 samples (31%) from immuno-competent patients with active toxoplasmic retinochoroiditis; in each case, local antibody production was also detected. In contrast, no local antibody production was observed in two of three samples from transplant recipients that were positive for T. gondii DNA. All the control samples tested were negative for the above-mentioned tests. CONCLUSIONS In patients with AIDS, polymerase chain reaction analysis is preferable above local antibody production in detecting the inciting agent of retinitis. In other cases, the combination of both techniques can make a valuable contribution to the diagnosis.

Visual loss in uveitis of childhood

Aims: To investigate the manifestations and severity of uveitis in children and to identify the risk and specific causes of blindness in this population. Methods: Retrospective study of data of 123 consecutive patients examined with active uveitis and the onset of ocular disease before the age of 16 years. Numerous variables were assessed including age and sex distribution, laboratory data, the presence of systemic diseases, onset and course of ocular inflammation, clinical features and complications, therapeutic strategies and their outcomes, final visual acuity, and characteristics associated with poor visual outcome. Results: Systemic disease was observed in 36/123 patients (29%), with juvenile idiopathic arthritis being the most frequent (25/123, 20%). Toxoplasma retinochoroiditis was diagnosed in 12/23 patients with posterior uveitis (52%; 10% of all with uveitis). Severe intraocular inflammation required systemic drugs in 57 (46%) patients. Ocular complications were observed in 93 patients (76%), of which the most common was cataract (43/123, 35%). Intraocular surgery was required in 35 patients (28%; in total 75 procedures). Three patients (2%) became legally blind and an additional 20/121 (17%) had one legally blind eye caused by uveitis. The most frequent causes of blindness were chorioretinal scars in the macular area and glaucoma in contrast with cystoid macular oedema (CMO) in adults. Conclusions: Uveitis in childhood is a potentially blinding disease, in the majority of patients characterised by a chronic course and a high complication rate.

Diagnostic anterior chamber paracentesis in uveitis: a safe procedure?

BACKGROUND Differentiation between infectious and non-infectious uveitis is of crucial value for accurate management of patients with uveitis. Tests performed on aqueous humour yield more relevant information than those done in serum. The objective of this study was to evaluate whether the aqueous humour tap for diagnostic purposes is a safe procedure to perform in uveitis patients. METHODS In this retrospective study 361 patients with uveitis, who underwent a diagnostic anterior chamber paracentesis in an outpatient clinic, were investigated. 72 of the 361 patients were examined 30 minutes after the puncture. The site of the paracentesis, the depth of the anterior chamber, and cells in the anterior chamber were examined. All 361 patients were evaluated within 2 weeks after the paracentesis was performed. The final follow up period varied from 6 months to more than 3 years. The clinical data were analysed with the emphasis on the occurrence of cataract and a history of corneal infections or endophthalmitis. RESULTS In this series no serious side effects such as cataract, keratitis, or endophthalmitis were observed. The depth of the anterior chamber of all evaluated patients was restored after 30 minutes. In five out of 72 cases (three AIDS patients with cytomegalovirus retinitis and two patients with anterior uveitis due to herpes simplex virus) a small hyphaema was observed 30 minutes after the paracentesis took place. CONCLUSION Anterior chamber paracentesis appears to be a safe procedure in the hands of an experienced ophthalmologist.

Detection of intraocular antibody production to herpesviruses in acute retinal necrosis syndrome

In order to improve the determination of the causative agent in acute retinal necrosis syndrome, we evaluated the detection of intraocular antibody production to herpesviruses in 28 patients with this disease. Intraocular antibody production was determined by calculation of the Goldmann-Witmer coefficient whereby specific antibody titers in the inflamed eye and circulation are related to the total IgG content in ocular fluid and serum. Specific antibody titers to herpesviruses and Toxoplasma were determined by the indirect immunofluorescence technique. Thirty-five patients with ocular toxoplasmosis, cataract, or proliferative vitreoretinal disorders were tested as controls. By this technique, intraocular antibody production to varicella zoster virus or herpes simplex virus could be established in 16 (57%) of the patients with the typical clinical features of acute retinal necrosis, compared to none of the controls. Of the 33 affected eyes, 21 (64%) had a visual outcome of less than 20/200. We concluded that detection of intraocular antibody production to herpesviruses may be a useful diagnostic tool in establishing the causative agents in acute retinal necrosis.

AQUEOUS-HUMOR ANALYSIS AS A DIAGNOSTIC-TOOL IN TOXOPLASMA UVEITIS

Analysis of local toxoplasma antibody production to confirm a suspected clinical diagnosis of toxoplasma chorioretinitis is a valuable diagnostic tool. Determination of toxoplasma antibodies in the blood of the patient is of limited use. When blood toxoplasma tests are negative this indicates that toxoplasma as a causative organism in the pathogenesis of uveitis is unlikely.A positive blood test is a sensitive test (100% patients positive) but not a specific test since so many healthy individuals already have undergone subclinical infection and have acquired humoral immunity against the parasite.We analysed 93 paired aqueous and serum samples for toxoplasma antibodies and total IgG and determined the Goldmann-Wittmer coefficient. In patients retrospectively diagnosed as having toxoplasma chorioretinitis 16 out of 22 had a positive coefficient, indicating local parasite antibody production. In one patient with AIDS we also found a positive toxoplasma coefficient. Three out of 15 patients with posterior uveitis of unknown origin also had a positive coefficient. None of the cataract patients tested (n=32) had a positive coefficient. Major drawbacks of aqueous humor analysis are that a false negative antibody coefficient can occur when a massive blood aqueous barrier breakdown has occurred.

Aetiology of uveitis in Sierra Leone, west Africa

BACKGROUND: In 1992, non-onchocercal uveitis caused 9% of blindness, 8% of visual impairment, and 11% of uniocular blindness among patients visiting an eye hospital in Sierra Leone, west Africa. The aim of this study was to determine the aetiology of uveitis in this population. METHODS: General and ophthalmic examination complemented by serum and aqueous humour analyses for various infectious agents was performed for 93 uveitis patients and compared with serum (n = 100) and aqueous humour (n = 9) analysis of endemic controls. RESULTS: At the initial examination, 45 patients (48%) proved to be severely visually handicapped. After clinical and laboratory analyses, an aetiological diagnosis was established for 49 patients (52%). Toxoplasma gondii was the most important cause of uveitis (40/93; 43%). Anti-toxoplasma IgM antibodies were detected in serum samples of seven of 93 patients (8%) compared with one of 100 controls (1%, p < 0.05). At least six patients (15%) with ocular toxoplasmosis had acquired the disease postnatally. Antibodies against Treponema pallidum were detected in 18 of 92 patients (20%) and in 21 controls (21%). Other causes of uveitis were varicella zoster virus (one patient), herpes simplex virus (two patients), and HLA-B27 positive acute anterior uveitis with ankylosing spondylitis (one patient), while one patient had presumed HTLV-I uveitis. CONCLUSIONS: In a hospital population in Sierra Leone, west Africa, uveitis was associated with severe visual handicap and infectious diseases. Toxoplasmosis proved to be the most important cause of the uveitis. Although the distribution of congenital versus acquired toxoplasmosis in this population could not be determined, the results indicate an important role of postnatally acquired disease. The results further suggested minor roles for HIV, tuberculosis, toxocariasis, and sarcoidosis as causes of uveitis in this population.

Risk factors for ocular sarcoidosis.

We reviewed 121 consecutive patients with biopsy-proven sarcoidosis who visited the sarcoidosis clinic of the University Hospital in Amsterdam, to determine the risk factors for the development of ocular manifestations. Of 121 patients 52 (43%) were black. Ocular disease developed in 50 (41%) patients and was more common in female and in black patients. Uveitis was the most frequent manifestation of ocular sarcoidosis (29 out of 50 or 58%). There were no differences in the extra-ocular manifestations of the sarcoidosis between patients with and without ocular disease or between uveitis and non-uveitis patients. This study covered a mixed racial population and shows that different types of uveitis are seen in white and black patients. Anterior uveitis was more frequent in black patients (P < .001), whereas posterior uveitis was more common in white patients (P < .01). Chronic posterior uveitis with complications occurred most frequently in white female patients with late onset of the systemic disease. Uveitis was an early feature of sarcoidosis (25 out of 29 or 86%); moreover in 9 out of 29 (31%) cases, uveitis preceded the non-ocular detectable signs of sarcoidosis by more than one year. This emphasizes the importance of periodic re-evaluation of uveitis patients for sarcoidosis.

Elevated serum IL-8 levels are associated with disease activity in idiopathic intermediate uveitis

AIM To find a laboratory indicator for systemic involvement in intermediate uveitis. METHODS Interleukin 8 (IL-8) and C reactive protein (CRP) serum levels were measured in patients with idiopathic intermediate uveitis (n=61), uveitis controls (n=143), and normal controls (n=29). The records of those with intermediate uveitis were reviewed with the emphasis on disease activity and severity as characterised by the presence of cystoid macular oedema, vitreous exudates or snowbank formation, papillitis, and periphlebitis. RESULTS Increased serum IL-8 (⩾20 pg/ml) was found in 27 out of 61 patients with intermediate uveitis (p< 0.01), 12 of 27 patients with sarcoid uveitis (p<0.05), in 19 of 30 patients with HLA-B27 associated acute anterior uveitis (p<0.05), and in five of 29 healthy controls. Raised IL-8 levels in intermediate uveitis were significantly associated with active disease (p<0.001) and the presence of vitreous exudates (p<0.001), papillitis, and periphlebitis (p<0.01). Elevated CRP levels were found in 12 of the 143 uveitis controls but in none of the intermediate uveitis patients or normal controls. During follow up an associated systemic disease was more frequently noticed in patients with an elevated serum IL-8 at entry into the study. CONCLUSIONS Elevated IL-8 serum levels were found in patients with active intermediate uveitis of unknown origin. An elevated IL-8 level seems to predispose the patient to a later development of associated systemic disease.

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.

Detection of locally produced antibodies to herpes viruses in the aqueous of patients with acquired immune deficiency syndrome (AIDS) or acute retinal necrosis syndrome (ARN)

Intraocular synthesis of IgG antibodies against HSV (herpes simplex virus), CMV (cytomegalovirus) and VZV (varicella zoster virus) is considered as an indirect proof of uveoretinal infection. Paired serum and aqueous samples obtained from 16 patients with retinitis associated with AIDS, 3 patients with ARN, 8 patients with posterior uveitis not related to AIDS or ARN and 5 patients with senile cataract were tested for total immunoglobulin G levels and antibodies to HSV, CMV and VZV by the fixed cell immunofluorescence technique. Since therapy must often be started before results of cultures are available, rapid detection of locally produced anti-Herpes Virus antibodies can be a precious tool in the diagnosis of ocular viral infection. Using this technique we were able to confirm the clinically suspected diagnosis in more than 50% of AIDS patients with retinitis and in two out of three patients with ARN.