Presumed acquired ocular toxoplasmosis.

OBJECTIVE: To describe the clinical characteristics and laboratory findings of eight patients with focal chorioretinitis presumably caused by acquired toxoplasmosis. DESIGN: Case series. SETTING: Referral hospitals in the Netherlands. PATIENTS: Eight patients, aged 42 to 75 years, with unilateral focal chorioretinitis and laboratory evidence of a recently acquired infection with Toxoplasma gondii. MAIN OUTCOME MEASURES: Findings from ocular examination and analysis of both serum and aqueous humor samples for Toxoplasma and viral antibodies. RESULTS: All patients had unilateral focal chorioretinitis without associated old scars in the posterior pole. Patients treated with systemic or periocular corticosteroids not accompanied by antiparasitic medication showed a rapid increase of inflammation. All eight patients had Toxoplasma IgM antibodies in their serum samples, seven of whom had high Toxoplasma IgG titers. Five of eight patients had increased intraocular production of IgG antibodies against T gondii. CONCLUSION: Unilateral focal chorioretinitis in patients of any age should alert the clinician to consider acquired ocular toxoplasmosis in the differential diagnosis.

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.

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.

Presumed ocular histoplasmosis in The Netherlands--an area without histoplasmosis.

AIMS/BACKGROUND: The syndrome of ocular histoplasmosis is usually prefaced by "presumed' as the aetiology is not yet clear. The aim of this study was to evaluate the clinical features of a similar ocular syndrome in the Netherlands where the fungus Histoplasma capsulatum is not endemic. METHODS: A retrospective multicentre study in which all patients were included who were diagnosed with a syndrome similar to presumed ocular histoplasmosis and in whom both fluorescein angiogram and all complete patient data were available. Fluorescein angiograms were examined by three authors in a masked fashion. Eighty one patients were selected who fulfilled the ophthalmic criteria for presumed ocular histoplasmosis. Fifty one patients showed the classic clinical picture, while 30 patients had an incomplete form as they did not show numerous histospots. RESULTS: No major difference in clinical characteristics could be identified when comparing the group of patients with the classic syndrome with the one with the incomplete syndrome. Final visual outcome of patients with macular subretinal neovascularisation after laser treatment was better when compared with untreated patients (p < 0.01). CONCLUSIONS: Since the fungus Histoplasma capsulatum is absent in the Netherlands, other aetiological agents must have led to this clinical entity similar to the presumed ocular histoplasmosis syndrome seen in the USA.

[Diagnosis of systemic causes of uveitis; a matter of ophthalmologist and internist]. / Diagnostiek van systemische oorzaken van uveïtis; een zaak van oogarts en internist.

OBJECTIVE: To assess how often the aetiology is established in patients with uveitis, what systemic disease are found and what is the contribution of the internist to the diagnostic process. DESIGN: Retrospective study. SETTING: University Hospital Leiden, the Netherlands. METHOD: From January 1987 to April 1992, 342 patients presented with uveitis. All patients underwent a standard ophthalmological examination. Referral to an internist and individualised laboratory screening followed in patients with recurrent, chronic, bilateral or panuveitis. Recorded were: ophthalmological data, results of laboratory screening, results of analysis by the internist, final diagnosis and presence of systemic disease. RESULTS: 149 (44%) patients were examined by the internist, 18 (5.2%) were seen by another specialist. In 169 (49%) patients a specific diagnosis was made. 74 (22%) had a systemic disease, 74 a primary ocular disease. In 28 (8%) a systemic disease was presumed (5% were HLA-B27 positive, 3% had abnormal laboratory results); 5 (1%) patients had endophthalmitis as a complication of a septic process. CONCLUSION: In approximately 1/3 of the patients with uveitis a systemic disease was found. Examination by the internist tailored to the individual patient is essential in the evaluation of uveitis patients.

Corneal transmission in whole human eyes.

The transmission of blue-green argon laser light (lambda = 488 nm and lambda = 514.5 nm) through clear healthy corneae was measured by means of a photodiode implanted into whole human donor eyes. The mean corneal transmission in seven eyes (donor age: 32-84 y) was 93.2 +/- 3.2% S.D., range 87-98%. The time between death and measurement ranged from 3.5 to 16 hr. These results indicate that hardly any correction for light loss in a healthy cornea is required in fluorophotometric results obtained with the use of fluorescein (lambda max.exc. = 489 nm, lambda max.em. = 514 nm).

Effects of microwave-induced hyperthermia on the anterior segment of healthy rabbit eyes.

Hyperthermia was induced in nine healthy rabbit eyes by means of a microwave 2450 MHz stripline applicator. The anterior segment of each eye was heated to a fixed temperature of between 42 degrees C and 46 degrees C for 30 min. The temperature distribution in the eye was calculated using a thermal model and the actual boundary temperatures and microwave intensity were measured. The effects of treatment were evaluated by daily macroscopic examination, fluorescein angiography and fluorophotometry, as well as by histology. Histological examination of changes induced by this hyperthermic delivery system revealed a sharp transition at 44 degrees-45 degrees C from no permanent damage to the anterior chamber at lower temperatures to serious damage such as local necrosis, pigment disruption and local cataract at high temperatures. A sharp transition in the same temperature range was observed in vivo in the fluorescein leakage of the iris vessels by comparative fluorescein angiography and by anterior segment fluorophotometry.