Diabetes mellitus: a risk factor affecting visual outcome in branch retinal vein occlusion.

PURPOSE: The prognosis of visual acuity (VA) after branch retinal vein occlusion (BRVO) in patients with diabetes mellitus is unknown compared to the VA in non-diabetic patients with BRVO. The aim of this study was to evaluate the visual outcome of BRVO in diabetic and non-diabetic patients. METHODS: A retrospective case-control study of diabetic and non-diabetic patients with BRVO was performed. VA and commonly known risk factors and complications of BRVO were compared in a follow-up period of at least 1 year. RESULTS: A total of 28 eyes of patients with diabetes and 49 eyes of non-diabetic patients with BRVO were included. One year after BRVO, the VA in the patients with diabetes decreased significantly more than that of the non-diabetic patients. During the second year after BRVO, the VA did not change significantly in either group. BRVO in patients with diabetes occurs at an earlier age. Diabetic patients needed more outpatient visits. CONCLUSIONS: The VA 1 year after BRVO in patients with diabetes is worse compared to the VA in patients without diabetes. The VA stabilizes 1 year after onset in both groups. Diabetic patients tend to need more frequent follow-up in order to treat the sequelae of BRVO.

Retinal thickness analysis(RTA): an objective method to assess and quantify the retinal thickness in healthy controls and in diabetics without diabetic retinopathy.

BACKGROUND: Since it has been shown that photocoagulation is indicated in patients with diabetic macular edema, quantitative and objective assessment of retinal thickness is of clinical importance. METHODS: A laser slit beam was projected on the retina and scanned across a 2 x 2 mm retinal area in 200 msec. Nine type 1 and 2 diabetic patients without funduscopically and photographically visible diabetic retinopathy and 10 healthy controls were scanned with the RTA. The intraindividual and interindividual variabilities of the RTA were determined. RESULTS: The intraindividual and interindividual variability was 5 microm and 15 microm, respectively. The mean value of the mean foveal thickness (MFT) and perifoveal retinal thickness (PFT) in the 10 healthy controls was 152 +/- 15 microm and 175 +/- 14 microm, respectively, and 181 +/- 26 microm and 191 +/- 27 microm, respectively, in the group of nine diabetics without signs of diabetic retinopathy. The MFT in the group of diabetic patients was significantly (P < 0.001) larger than in the control groups. CONCLUSION: Retinal thickness in diabetic patients without diabetic retinopathy was increased in all measurements in comparison with the findings in healthy subjects. Retinal thickness measurements with the RTA could possibly detect early signs of diabetic retinopathy before funduscopic and photographic signs are visible and may be helpful in guiding treatment.

Aetiological study of the presumed ocular histoplasmosis syndrome in the Netherlands.

AIM: To investigate whether presumed ocular histoplasmosis syndrome in the Netherlands is caused by Histoplasma capsulatum and whether other risk factors might play a role in the pathogenesis of this syndrome. METHODS: 23 patients were clinically diagnosed as having presumed ocular histoplasmosis syndrome based on the following criteria: peripapillary atrophy, punched out lesions, a macular disciform lesion or scar in one eye without vitritis. As controls, 66 sex and age matched healthy volunteers were used. Serum samples from both patients and controls were tested for the presence of antibodies against H capsulatum, Toxoplasma gondii, Toxocara canis et cati, Ascaris sp, and for the presence of antigens of Cryptococcus neoformans. Serum samples were also tested for the presence of autoantibodies against retinal or choroidal proteins. To investigate other risk factors, patients and controls were asked to fill in a health and travel related questionnaire. Ten patients with ocular toxoplasmosis were used as a disease control group. RESULTS: None of the patients with presumed ocular histoplasmosis syndrome or controls had circulating antibodies directed against H capsulatum. No risk factors could be identified and no indications for autoimmunity and no evidence for the role of the other infectious agents could be demonstrated. CONCLUSIONS: In a Dutch group of patients fulfilling the criteria of a disease currently named presumed ocular histoplasmosis syndrome, no risk factors or relation with the fungus H capsulatum could be detected.

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.

Recent developments in the treatment of posterior uveitis.

Uveitis is an intraocular inflammation that can be caused by infection, autoimmune disease, trauma or malignancy. It is a serious cause of visual handicap and therapy is targeted at: removal of possible infectious agents, the immunological processes that lead to or sustain the inflammation and finally to prevent or treat the destructive effects of the inflammation on the delicate ocular structures. In this review the latest developments concerning the treatment of posterior uveitis are illuminated, e. g., new approaches concerning the treatment of infectious uveitis including the therapy of herpes virus (VZV, HSV and CMV), bacterial and toxoplasma infections of the eye. Several new ways to influence the immune response and inflammation are described including the use of interferons, modulation of cytokines, soft steroids, other new immunosuppressive drugs and treatment of autoimmune uveitis by oral tolerization. An overview is given to illustrate new ways to administer drugs into eyes, such as intravitreal devices. Finally new developments in the field of the treatment of the various complications of uveitis (cystoid macular edema) are described.

Macular grid laser photocoagulation in uveitis.

AIMS/BACKGROUND: The aim of this study was to evaluate whether grid laser photocoagulation of the macula is beneficial in the treatment of cystoid macular oedema in patients with uveitis. METHODS: Six eyes of five patients with long standing cystoid macular oedema due to chronic uveitis were treated by grid laser photocoagulation of the macula. RESULTS: In the first weeks after treatment a temporary increase of oedema and paracentral scotomas were observed. At the long term follow up of more than 18 months in all patients, macular oedema had been reduced significantly or disappeared in all eyes treated. One eye had a significant increase in Snellen acuity, three eyes more or less stabilised, and two eyes deteriorated. CONCLUSION: The beneficial effect of laser treatment on visual acuity in patients with uveitis might be more favourable if performed at an earlier stage of the disease.

Long-term effects of ceftriaxone treatment on intraocular Lyme borreliosis.

Twelve patients with intraocular Lyme borreliosis suffering from vitreitis were treated with ceftriaxone intravenously. Eight patients had definitive Lyme borreliosis, and tentative diagnosis was made in four patients. After treatment with ceftriaxone, all 12 patients were followed up for more than one year. Vitreitis diminished in all patients and visual acuity improved in six patients. The best results were achieved in patients with definitive Lyme borreliosis.

Contrast sensitivity function in Graves' ophthalmopathy and dysthyroid optic neuropathy.

Contrast sensitivity function was measured by a computer automated method on 38 eyes with dysthyroid optic neuropathy and 34 eyes with Graves' ophthalmopathy only. The results were compared with 74 healthy control eyes. Disturbances of contrast sensitivity functions were found in both groups when compared with controls. The eyes affected with dysthyroid optic neuropathy showed pronounced loss of contrast sensitivity in the low frequency range, which facilitates differentiation between the two groups.

A new ultrasonographic method to detect disease activity and predict response to immunosuppressive treatment in Graves ophthalmopathy.

PURPOSE: To determine whether the internal reflectivity of the eye muscles on A-mode ultrasonography serves as indicator for disease activity in Graves ophthalmopathy, thereby predicting response to immunosuppressive treatment. METHODS: Eye muscle reflectivity, expressed as percentage of the initial scleral spike, was measured in the superior, medial, and lateral recti, and normal values were determined in 23 healthy controls. These were compared with values in 16 consecutive patients with untreated, moderately severe Graves ophthalmopathy. The accuracy of the measurement was assessed by calculating the intra- and interobserver coefficient of repeatability. Baseline eye muscle reflectivity in the 16 patients was correlated to the therapeutic outcome 24 weeks after start of immunosuppressive therapy. The response to treatment served as indicator for pretreatment disease activity. RESULTS: Eye muscle reflectivity could be measured reliably, with an intraobserver coefficient of repeatability of 8.2% in controls and 10.2% in patients. Patients had lower reflectivity than controls (54.6 +/- 17.4% versus 70.7 +/- 6.6%; P < 0.001). Reflectivity in eye muscles with the lowest echogenicity was lower in responders than in nonresponders (25.8 +/- 8.4% versus 40.6 +/- 13.6%; P = 0.02). From the individual data, a cut-off value of 40% was derived, which appeared as an accurate predictor of outcome (positive predictive value 73%; 95% confidence interval 39%-94%). CONCLUSIONS: Measuring eye muscle reflectivity in Graves ophthalmopathy appears to be a reliable new method to determine disease activity, with a promising accuracy in predicting therapeutic outcome of immunosuppressive treatment.

Birdshot chorioretinopathy and Lyme borreliosis.

Two patients in whom ocular Lyme disease was suspected and who had antibodies to Borrelia burgdorferi developed birdshot chorioretinopathy and carried the HLA-A29 antigen. In a series of 11 patients with birdshot chorioretinopathy who carried the HLA-A29 antigen, three patients had antibodies against B. burgdorferi as determined by either immunofluorescence assay, enzyme-linked immunosorbent assay, Western blot analysis, or a combination of these tests. Further studies will be necessary to evaluate whether this is a false-positive reaction or whether B. burgdorferi has a causative role in the pathogenesis of birdshot chorioretinopathy.

Induction of autoantibodies to rat corneal protein 54.

Many studies have described the presence of circulating antibodies against corneal components in patients with corneal disease or uveitis, and in patients with skin or systemic disease with or without ocular involvement. The role of such antibodies in the underlying immunopathological process remains obscure. Here we describe the induction of autoantibodies against the rat cornea. Our attempts to induce corneal autoantibodies by various forms of keratitis and corneal trauma failed. However, circulating corneal autoantibodies could be detected by Western blotting after immunization of BN rats and Lewis rats with bovine corneal protein 54 (BCP 54). Rats immunized with rat corneal extracts (RaCE) or human serum albumin (HSA) as (auto) antigen did not develop corneal autoantibodies. During the study period (greater than 4 months), it was observed that the presence of circulating corneal autoantibodies did not elicit corneal inflammation. Severe keratitis did develop when BCP 54-immunized rats were challenged intracorneally with BCP 54, but the clinical signs were not significantly different from HSA-immunized rats after an intracorneal HSA challenge. Injection of corneal autoantibodies into the corneal stroma did not provoke keratitis. To the best of our knowledge this is the first study demonstrating corneal autoantibodies in rats without actual manipulation of the eye. This model may provide further insights in the role and significance of corneal autoantibodies in disease.

The fate of antigen-antibody complexes in the rabbit cornea.

The mechanisms involved in the clearance of immune deposits in tissues are not yet clear. The cornea was chosen as a model to examine this question due to its avascularity and transparency. Bovine serum albumin (BSA) and rabbit anti BSA serum were injected at opposite sites into the corneal stroma of unsensitized rabbits. Within a day, a sharp opaque line was seen macroscopically between the two injection sites. Sections of the corneas were examined by light microscopy and electron microscopy; furthermore, immunohistochemical techniques were used. With the light microscope, a precipitation line was seen in the corneal stroma, which was identified as an antigen-antibody complex by immunofluorescence techniques. In the same area infiltrating polymorphonuclear cells and swollen keratocytes were observed. In the ultrathin sections precipitates were seen lying between the collagen fibrils without affecting the structure of the collagen. The swollen keratocytes had an activated rough endoplasmic reticulum. In certain cases the precipitates appeared to be intracellular, both in the polymorphonuclear cells, as well as in the keratocytes. These findings suggest that stromal keratocytes may play an important role in the degradation of corneal immune deposits.

Linear scleroderma associated with ptosis and motility disorders.

A case is reported in which an 11-year-old girl developed progressive ptosis and a subsequent motility disorder of the right eye. The diagnosis linear scleroderma en coup de sabre was established. Atrophy of the upper levator palpebral and superior rectus muscle could be shown on CT scan.

Contrast sensitivity and the diagnosis dysthyroid optic neuropathy.

Contrast sensitivity function (CSF) was investigated in 19 patients (34 eyes) with clinical signs and symptoms of dysthyroid optic neuropathy (DON). CSF was disturbed in 33 eyes and was shown to improve after orbital decompression. These results indicate that the CSF may be a useful supplementary test of visual function in patients with DON.

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.