[Persisting lesion of the conjunctiva. A masquerade syndrome?]. / Persistierende herdförmige Bindehautläsion. Ein Maskeradesyndrom?

A 26-year-old female patient was referred because of a persisting swelling and redness of the conjunctiva for 4 months accompanied by pruritus. An ultrasound biomicroscopy showed hypoechogenic structures separated by multiple hyperechogenic septa. A biopsy was performed which revealed a marginal B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type. A generalized lymphatic disease could be excluded by positron emission tomography-computed tomography (PET-CT). In agreement with the patient an extensive excision was performed followed by a wait and see strategy including close monitoring by ophthalmological and general internist control examinations.

[Toric intraocular lenses: a valuable method for correcting corneal astigmatism]. / Torische Intraokularlinsen: Eine nützliche Methode in der Korrektur des kornealen Astigmatismus.

BACKGROUND: The aim of this stud was to assess clinical outcomes after implantation of a hydrophobic toric intraocular lens (IOL) in patients undergoing cataract surgery. PATIENTS AND METHODS: 22 eyes (16 patients) with at least 0.8 diopter (D) of corneal astigmatism having routine cataract surgery were included. After marking the final axis of the IOL, phacoemulsification, implantation and alignment of a toric IOL was performed. Uncorrected distance visual acuity (UDVA), best corrected distance visual acuity (BDVA), manifest refraction, and keratometry were measured 5 to 19 months postoperatively. Individual patient satisfaction was also recorded. The cylinder axis of the toric IOL was determined at a slitlamp examination. RESULTS: The mean UDVA postoperatively was 0.3 logMAR±0.23 (SD) and was 0.3 logMAR or better in 63.6% of eyes. The mean refractive cylinder decreased significantly postoperatively, ranging from -3.3±1.5 D to -1.3±0.7 D. The mean absolute IOL misalignment was 7.5 degrees (range 0 to 21°). The good UDVA resulted in high levels of patient satisfaction. CONCLUSIONS: Implantation of a toric IOL during cataract surgery was an effective and safe method to manage corneal astigmatism in this series of patients.

Predictability of morphological changes of the anterior chamber angle after laser iridotomy by ultrasound biomicroscopy.

BACKGROUND: Laser peripheral iridotomy is a useful method in primary angle-closure eyes to prevent angle-closure attack and development of glaucomatous optic nerve damage. The aim of this study was to quantify morphological changes after LPI and their impact on intraocular pressure, and to evaluate predictive parameters for enlarging the anterior chamber angle after laser peripheral iridotomy. PATIENTS AND METHODS: Ultrasound biomicroscopy images and intraocular pressure before and after laser peripheral iridotomy from 62 eyes of 34 patients with primary angle-closure were retrospectively analysed. Anterior chamber angle, anterior chamber depth, lens thickness, iris curvature and a newly defined parameter, the end-iris-lens vault were measured. RESULTS: In each quadrant anterior chamber angle was on average significantly larger (at 12 o'clock: from 10.1° to 15.0°; at 3 o'clock: from 13.4° to 19.8°; at 6 o'clock: from 12.2° to 18.5°; at 9 o'clock: from 12.9 to 17.9°; p<0.001) and iris curvature significantly smaller (at 12 o'clock: from 0.26 mm to 0.10 mm; at 3 o'clock: from 0.21 mm to 0.08 mm; at 6 o'clock: from 0.25 mm to 0.08 mm; at 9 o'clock: from 0.21 mm to 0.08 mm; p<0.001) after laser peripheral iridotomy. Anterior chamber depth, lens thickness and end-iris-lens-vault did not significantly change. Anterior chamber angle in each quadrant (p<0.05), and iris curvature at 3 and 6 o'clock positions (p<0.05) were highly predictive for the enlargement of the anterior chamber angle after laser peripheral iridotomy. Intraocular pressure was slightly lower after laser peripheral iridotomy (from 16.6 mmHg to 16.1 mmHg). CONCLUSION: In primary angle-closure eyes, laser peripheral iridotomy enlarges the angle and flattens the iris significantly. This study demonstrated that a small anterior chamber angle and a large iris curvature are predictive parameters for a greater enlargement of the anterior chamber angle after laser peripheral iridotomy. These new findings underline the importance of the ultrasound biomicroscopy and may help in counselling patients about laser peripheral iridotomy.

[Usability testing of the canal expander - a new implant for canaloplasty]. / Gebrauchstauglichkeitstest des Kanal-Expander - ein neues Implantat für die Kanaloplastik.

BACKGROUND: Canaloplasty is a bleb-independent glaucoma surgery in which Schlemm's canal is dilated with a microcatheter and viscoelastic material, and stretched by a tensioning suture. The suture stent has numerous drawbacks such as the technical challenging implantation, deficient knowledge of proper suture tension, late loosening of the suture, or suture extrusion into the anterior chamber. The Stegmann Canal Expander (SCE) was developed to replace the suture stent and to make canaloplasty easier and more reproducible. The aim of this test was evaluate the usability regarding effectiveness, efficacy, and satisfaction of the implanting ophthalmologist (test person). METHODS: In an experimental setting, the test persons were asked to implant the SCE in human autopsy eyes with a surgically prepared Schlemm's canal by means of surgical instruments and an operating microscope. The standardised test was performed in terms of participant observation with a subsequent opinion survey based on checklist and photographic documentation. Data for a successful handling of the task and qualitative data from the experience of the test person with the product were anonymised, collected and registered in an assessment sheet. The evaluation comprised the aspects of instructions for use, packaging, identification, handling, and implantation of the SCE. RESULTS: The implantation took 2 to 5 min (mean: 3 min). All questions in the assessment sheet regarding effectiveness, efficacy, and satisfaction (n=35) were answered by all test persons (6/6) with the best category ("completely true"; or "no, no problem"). CONCLUSIONS: The usability of the SCE under standardised and experimental conditions regarding effectiveness, efficacy, and satisfaction has been rated as very positive, especially allowing for the fact that some of the ophthalmologists did not have experience in glaucoma surgery or only little experience in ophthalmic surgery.

[Channelography and mechanism of action in canaloplasty]. / Kanalographie und Wirkmechanismus der Kanaloplastik.

BACKGROUND: Canaloplasty lowers the intraocular pressure (IOP) by restoring the natural outflow system. The success of canaloplasty depends on the function of this system. OBJECTIVES: To evaluate the natural outflow system regarding canaloplasty by two clinical tests, provocative gonioscopy and channelography and to describe the mechanism of action of canaloplasty. MATERIAL AND METHODS: Provocative gonioscopy evaluates the pattern of blood reflux which is induced by ocular hypotension as the result of a reversed pressure gradient between the episcleral venous pressure and IOP following paracentesis. In channelography the transtrabecular diffusion and the filling properties of the episcleral venous system are assessed by a microcatheter and a fluorescein tracer. RESULTS: Blood reflux varied greatly in glaucomatous eyes and showed an inverse correlation with the preoperative IOP. The higher the IOP, the poorer the blood reflux. The filling qualities of the episcleral venous system and diffusion through the trabecular meshwork were different. Poor trabecular passage and good episcleral fluorescein outflow indicates patent distal outflow pathways, poor trabecular passage and poor episcleral fluorescein outflow indicates obstructed trabecular meshwork and closed collector channels and good trabecular passage together with poor episcleral fluorescein outflow suggests that the site of impairment is mainly in the distal outflow system. CONCLUSIONS: The quality of blood reflux and the characteristics of the episcleral filling and the transtrabecular diffusion by fluorescein represent the clinical state of the outflow pathway and help in the prediction of the surgical outcome in canaloplasty. The mechanism for canaloplasty is not yet completely clarified; currently under discussion are circumferential viscodilation, permanent distension of the inner wall of Schlemm's canal using a suture and a Stegmann canal expander.

Hemorrhagic descemet membrane detachment after classic canaloplasty.

PURPOSE: Canaloplasty is a safe and effective alternative in glaucoma surgery, avoiding the risk for hypotony and bleb-related complications. Two cases of hemorrhagic Descemet membrane detachment (DMD) after canaloplasty are reported in patients who did not have previous surgery. RESULTS: Two patients with primary open-angle glaucoma underwent canaloplasty because of medically uncontrolled intraocular pressure (IOP). Canaloplasty was performed using a flexible microcatheter, viscoelastic material and a tensioning suture. The day after surgery, hemorrhagic DMD was observed in the inferior quadrants in both patients on slit-lamp biomicroscopy. THERAPY: For the size and location (occlusion of the visual axis), aspiration of blood and descemetopexy with air tamponade were performed promptly. In both cases, a small translucent scar remained. CONCLUSIONS: Circumferential cannulation and viscodilation of the Schlemm canal increases the risk for DMD, which may be aggravated by blood reflux resulting from the tensioning suture and low postoperative IOP. Surgeons should be aware of this specific and potentially sight-threatening complication in classic canaloplasty. Immediate intervention is recommended for good visual prognosis.

Detection of retinal glial cell activation in glaucoma by time domain optical coherence tomography.

BACKGROUND: Activated retinal astrocytes and Müller cells (ARAM) have been found in glaucoma patients. This study investigated whether presumed ARAM can be detected by optical coherence tomography (OCT), and assessed their relationship to the retinal nerve fiber layer (RNFL) thickness. PATIENTS AND METHODS: Single-center observational study involving 35 age-matched healthy controls and 19 patients with primary open-angle glaucoma (POAG) between 45 - 82 years of age. Presumed ARAM was defined as patchy, discrete glittering but transparent changes of the macula. The retina was documented by red-free photography to assess distribution of ARAM, and compared to the RNFL thickness measured around the fovea by OCT. A linear mixed effects model was used to detect a difference between eyes with ARAM versus eyes without ARAM. RESULTS: ARAM was not found in healthy subjects. The mean RNFL around the fovea was not significantly thicker in healthy controls (34.01 SD ± 22.24) than in POAG patients with ARAM (30.86 microns SD ± 15.09; p = 0.36) or without ARAM (33.19 microns SD ± 19.87; p = 0.46). Furthermore, the median RNFL thickness was similar to the control group (29 microns) but slightly thinner in POAG patients (each 27 microns with ARAM and without ARAM). In a subgroup analysis of POAG patients with ARAM, the within subject standard deviation of RNFL was significantly lower in areas with ARAM (SD 10.12) than in areas without ARAM (SD 17.30) (p < 0.001). CONCLUSIONS: Although the mean and median RNFL thickness was comparable between the groups, the variability of the RNFL thickness was significantly lower in areas with ARAM than in areas without ARAM suggesting that ARAM may mask RNFL loss in POAG patients.

Clinical evaluation of a novel population-based regression analysis for detecting glaucomatous visual field progression.

BACKGROUND: The distinction of real progression from test variability in visual field (VF) series may be based on clinical judgment, on trend analysis based on follow-up of test parameters over time, or on identification of a significant change related to the mean of baseline exams (event analysis). The aim of this study was to compare a new population-based method (Octopus field analysis, OFA) with classic regression analyses and clinical judgment for detecting glaucomatous VF changes. PATIENTS AND METHODS: 240 VF series of 240 patients with at least 9 consecutive examinations available were included into this study. They were independently classified by two experienced investigators. The results of such a classification served as a reference for comparison for the following statistical tests: (a) t-test global, (b) r-test global, (c) regression analysis of 10 VF clusters and (d) point-wise linear regression analysis. RESULTS: 32.5 % of the VF series were classified as progressive by the investigators. The sensitivity and specificity were 89.7 % and 92.0 % for r-test, and 73.1 % and 93.8 % for the t-test, respectively. In the point-wise linear regression analysis, the specificity was comparable (89.5 % versus 92 %), but the sensitivity was clearly lower than in the r-test (22.4 % versus 89.7 %) at a significance level of p = 0.01. A regression analysis for the 10 VF clusters showed a markedly higher sensitivity for the r-test (37.7 %) than the t-test (14.1 %) at a similar specificity (88.3 % versus 93.8 %) for a significant trend (p = 0.005). In regard to the cluster distribution, the paracentral clusters and the superior nasal hemifield progressed most frequently. CONCLUSIONS: The population-based regression analysis seems to be superior to the trend analysis in detecting VF progression in glaucoma, and may eliminate the drawbacks of the event analysis. Further, it may assist the clinician in the evaluation of VF series and may allow better visualization of the correlation between function and structure owing to VF clusters.

Comparing two tensioning suture sizes for 360 degrees viscocanalostomy (canaloplasty): a randomised controlled trial.

PURPOSE: To compare the safety and efficacy of two polypropylene (Prolene) sutures for tensioning of the inner wall of Schlemm's canal (SC) in black African patients with primary open-angle glaucoma (POAG) undergoing canaloplasty. METHODS: In a prospective randomised trial of 90 patients, canaloplasty was performed with a flexible microcatheter (iTrack-250A) and sodium hyaluronidate 1.4% (Healon GV). After complete circumferential dilatation of the SC, a Prolene suture, either 6-0 Prolene (group 1) or 10-0 Prolene (group 2), was retracted through the SC and tightened leaving tension on the canal and trabecular meshwork. Nd:YAG laser goniopuncture was not performed postoperatively. RESULTS: The mean preoperative intraocular pressure (IOP) was 42.7 mm Hg+/-12.5 (SD) in group 1 and 45.0 mm Hg+/-12.1 (SD) in group 2 (P=0.70). The mean postoperative IOP without medications was 18.4 mm Hg+/-7.1 (SD) in group 1 and 16.4 mm Hg+/-6.6 (SD) in group 2 at 1 month (P=0.10), 19.2 mm Hg+/-6.4 (SD) in group 1 and 16.4 mm Hg+/-4.9 (SD) at 15 months (P=0.04). Pressures equal or less than 21, 18, and 16 mm Hg without medications (complete success) at 12 months were 51.0% (95% confidence interval (CI) 0.35-0.73), 34.1% (95% CI 0.21-0.56), and 21.2% (95% CI 0.11-0.42) in group 1, and 76.9% (95% CI 0.62-0.96), 68.8% (95% CI 0.54-0.89), and 53.6% (95% CI 0.38-0.76) in group 2, respectively. In the Cox regression analysis, IOP<18 mm Hg without medications depended significantly on the type of Prolene (hazard ratio (HR) 2.60, 95% CI 1.24-5.46, P=0.01) and age (HR 1.3, 95% CI 1.03-1.86, P=0.03), but not on preoperative IOP (HR 1.01, 95% CI 0.99-1.04, P=0.16) and gender (HR 0.67, 95% CI 0.34-1.33, P=0.26). No filtering bleb was observed. Intra- and postoperative complications were similarly rare in the two groups and included partial 'cheese-wiring' (2), Descemet's rupture (2), and hyphaema (3). CONCLUSIONS: In this clinical trial, IOP reduction was substantial in canaloplasty and slightly greater in combination with 10-0 Prolene than 6-0 Prolene sutures at an equally low complication rate. Younger age, but not the level of IOP at surgery, had a positive effect on the amount of IOP reduction, thus suggesting that an early surgical intervention to re-establish physiological outflow offers the best prognosis.

Channelography: imaging of the aqueous outflow pathway with flexible microcatheter and fluorescein in canaloplasty.

BACKGROUND: The aim of this study is to present a new approach to visualize the aqueous outflow system during glaucoma surgery using a flexible microcatheter and fluorescein, called channelography. PATIENTS AND METHODS: Schlemm's canal was unroofed in a standard non-penetrating dissection technique in patients undergoing canaloplasty. A flexible microcatheter (iTrack 250A) was introduced into the canal and advanced 360 degrees . Fluorescein sodium tracer was injected through the microcatheter during cannulation and the aqueous outflow pathway was video-recorded and evaluated. RESULTS: In the early phases, episcleral veins which were thinner, branched and fairly straight originating from the limbus could clearly be distinguished from ciliary veins which were thicker, tortuous vessels leaving posterior to the limbus. The filling quality of the episcleral veins varied among glaucoma patients. The permeability of the trabecular meshwork/inner wall of Schlemm's canal determined by fluorescein diffusion into the anterior chamber differed in this regard as well. In the late phases, the sclera stained with fluorescein, and no details were detectable. CONCLUSIONS: This qualitative in-vivo method was simple, safe, and enabled us to visualize the details of the aqueous outflow system during canaloplasty. Filling characteristics of episcleral venous network as well as trans-trabecular diffusion may reflect the clinical status of the outflow pathway in glaucoma patients, and may be helpful in the prediction of the surgical outcome in canaloplasty.

Capsular opacification after vitreous-sparing cataract surgery in children.

BACKGROUND: The aim of this study was to evaluate different methods of intraocular lens (IOL) implantation and posterior capsule management in the absence of vitrectomy with respect to visual axis opacification (VAO) in children. PATIENTS AND METHODS: Seventy-three eyes of African children undergoing cataract extraction and IOL implantation between 1998 and 2001 were evaluated. In all eyes, the IOL haptics were placed in the bag and the vitreous was preserved. The IOL optic and posterior capsule were managed in the following 3 ways: The IOL optic was captured behind the posterior capsule in conjunction with posterior capsulotomy (PC) in 47 eyes (group 1). The IOL optic was implanted in the bag with PC in 14 eyes (group 2) and without PC in 12 eyes (group 3). Cox proportional hazard analysis and Kaplan-Meier survival curves were performed to evaluate the incidence of Elschnig pearls (EP) and VAO. RESULTS: Elschnig pearls developed in 14.9 % of the patients in group 1, in 56.8 % in group 2 and in 91.7 % in group 3. The occurrence of EP depended significantly on optic capture (p < 0.001) and child's age (p < 0.05), but not on PC (p = 0.084) and eye side (p = 0.1). The persistence of visual axis clarity depended significantly on optic capture (p < 0.001) but not on PC. CONCLUSIONS: In vitreous-sparing cataract surgery, posterior capsule opening does not effectively prevent VAO unless it is in conjunction with IOL optic capture.

Adrenaline-induced chronic ocular hypertension in adult rabbits.

BACKGROUND: The aim of this study was to develop a new animal model to enhance our understanding of the biological pathomechanisms involved in glaucoma. MATERIALS AND METHODS: Forty white giant rabbits were divided into a treated (N = 30) and a control group (N = 10). Boli of adrenaline hydrochloride (0.1 mL 0.1% solution) were repeatedly injected into the veins of the ears of the rabbits and physiological saline in the control group, respectively, for three months. Intraocular pressure (IOP) and outflow facility of the aqueous humour were measured prior to, during and after treatment (4-6 months, 7-9 months, 10-12 months). RESULTS: In comparison to the control group, the adrenaline-treated group showed a significant increase in IOP both during treatment (25%) and 12 months after treatment (57%). Comparative analysis further showed that the aqueous humour outflow facility of the treated group increased by 16.5% during the treatment, and showed a continuous decrease of 60 % after treatment. CONCLUSION: This rabbit model could be useful for further investigations of the pathomechanisms involved in glaucoma.

[Contribution to comparative ophthalmo-morphology: the eye of the brown trout]. / Beitrag zur vergleichenden Ophthalmo-Morphologie: Das Bachforellenauge.

BACKGROUND: The aim of this study was to assess similarities and differences between the trout eye and the human eye. MATERIALS AND METHODS: Gross and microscopic examinations of the formalin-fixed eyes of each five trout and human eyes (donor eyes not suitable for keratoplastic) were carried out. RESULTS: Compared to the human eye, the trout showed a flattening of the anterior-posterior axis, and cartilage-stabilized sclera. The peripheral cornea was much thicker than the central, had a multilayered thick epithelium, a distinct Bowman layer, and an implied Descement membrane. A ring-shaped ligament filled up the angle of the anterior chamber and linked the iris to the cornea. The lens showed a spherical aspect with a thick capsule and missing zonular fibres, however, a suspensory ligament of a superior part of the lens was present. Ventrally, at the end of the falciform process, a small, pigmented structure was in contact with the lens. The retina was similarly differentiated, but the choroid showed special structures like choroidal gland, falciform process and the argentea compared to the human eye. CONCLUSIONS: Great variations between the ocular anatomy of the trout and the human exist. However, the retina of the trout is fully differentiated and remarkably similar to that of human eyes.

The potential value of natural antioxidative treatment in glaucoma.

Glaucomatous optic neuropathy implies loss of retinal ganglion cells, including their axons, and a major tissue remodeling, especially in the optic nerve head. Although increased intraocular pressure is a major risk factor for glaucomatous optic neuropathy, there is little doubt that other factors such as ocular blood flow play a role as well. Mechanisms leading to glaucomatous optic neuropathy are not yet clearly understood. There is, however, increasing evidence that both an activation of glial cells and an oxidative stress in the axons play an important role. Glial cells may be activated by mechanical stress via activation of the epidermal growth-factor-receptor, or by ischemic stress via an increase in endothelin. Several factors can systemically or locally increase oxidative stress. In glaucoma, an unstable ocular blood flow leading to repeated mild reperfusion seems to be most relevant in inducing oxidative stress. The simultaneous production of nitric oxide in the astrocytes and of superoxide in the mitochondria of the axons leads to the production of the damaging peroxynitrite. Therapeutically, we need to reduce intraocular pressure, stabilize ocular blood flow, and reduce oxidative stress. Various natural compounds possess potential antioxidative value. Reduction of oxidative stress at the level of mitochondria can be achieved by gingko biloba. Polyphenolic compounds, such as tea, red wine, dark chocolate, or coffee have antioxidative properties. Coffee contains 3-methyl-1,2-cyclopentanedione (MCP), capable of scavenging peroxynitirite. Red wine-polyphenols (e.g., resveratrol), exert vasoprotective effects by inhibiting the synthesis of endothelin-1. Dark chocolate decreases blood pressure and improves endothelium-dependant vasorelaxation. Anthocyanosides (bilberries) owe their antioxidant effects to their particular chemical structure. Other antioxidants include ubiquinone and melatonin.

Detection of visual field progression in glaucoma.

BACKGROUND: The aim of this study was to compare an event analysis and a trend analysis for the detection of progression in glaucomatous visual field loss. PATIENTS AND METHODS: Excluding initial fields (Octopus, Haag-Streit AG, Köniz, Switzerland), baseline was defined as the average result of the second and third examinations. Eyes with at least 6 additional fields entered the study. The event analysis used the method of the Collaborative Normal Tension Glaucoma Study, and the trend analysis was based on a point-wise linear regression analysis. RESULTS: Of 251 glaucoma patients, 235 left eyes and 225 right eyes qualified for the study. Using the event analysis, 44 series suggested a progressive damage, while the point-wise regression approach disclosed only 14 progressing series. In 9 eyes, the two approaches were concordant. Among the latter, 1 - 5 additional fields were necessary in 7 series to disclose progression using the trend analysis. In one series, the event analysis showed progression 7 examinations later. CONCLUSIONS: The point-wise linear regression analysis classified fewer cases as progressing than the event analysis and determined progression later.

[Central corneal thickness and retrobulbar blood flow in glaucoma patients]. / Hornhautdicke und retrobulbärer Blutfluss bei Glaukompatienten.

BACKGROUND: A correlation between a thin cornea and the presence of vascular risk factors has recently been reported in normal-tension glaucoma patients. The present study intended to investigate the correlation between central corneal thickness and basal retrobulbar blood flow in glaucoma patients. PATIENTS AND METHODS: Corneal pachymetry and colour Doppler imaging (CDI) of the retrobulbar arteries (ophthalmic, central retinal and cilliary) were performed in 63 glaucoma patients. Linear mixed effect models were used to evaluate the association of central corneal thickness and retrobulbar blood flow. RESULTS: There was no significant correlation between central corneal thickness and blood flow in any of the assessed arteries (p = 0.13-0.88). CONCLUSIONS: A statistical relationship between central corneal thickness and retrobulbar blood flow could not be found in the examined sample of glaucoma patients.

[Rifabutin-associated with bilateral uveitis in an HIV negative patient]. / Bilaterale Rifabutin-assoziierte Uveitis bei einem HIV-negativen Patienten.

BACKGROUND: Rifabutin-associated uveitis has often been described in patients with HIV. We present the case of a bilateral non-granulomatous uveitis in an HIV negative patient on rifabutin therapy. HISTORY AND SIGNS: A 79-year-old man presented with acute pain and decreased vision in the left eye. He had a 2-months history of Mycobacterium avium pneumonia and was treated with rifabutin, clarithromycin and ethambutol since then. At presentation, the visual acuity was hand movement. On biomicroscopy, the anterior chamber showed inflammatory sings such as hypopyon and early posterior synechiae. Ultrasound revealed no vitreal infiltration. The fellow eye was initially without any pathology. Serological testing and blood cultures were negative. THERAPY AND OUTCOME: The next day, the fellow right eye was also affected showing signs of anterior and posterior uveitis. Following intensive topical steroidal therapy, clinical findings improved within hours. Rifabutin therapy was discontinued. Later on the visual acuity of both eyes improved to 20 / 100. CONCLUSIONS: Bilateral rifabutin-associated uveitis may also occur in an HIV negative patient. A toxic reaction due to concomitant clarithromycin therapy might be causal. Well directed history, intensive topical steroids and the cessation of rifabutin therapy are helpful in the management of such rare uveitis.

Retrobulbar blood flow in idiopathic dilated episcleral veins and glaucoma.

BACKGROUND: Dilated episcleral veins may occur in the presence of orbital tumors, carotid cavernous sinus fistula and other orbital obstructive lesions. HISTORY AND SIGNS: A 39-year-old man had a history of a red left eye for two years. The visual acuity was 20/20, episcleral and conjunctival veins were dilated, and both the intraocular (24 mmHg) and episcleral venous (18 mmHg) pressures were increased. The canal of Schlemm was filled with blood, and glaucomatous damage was pronounced in the optic nerve head and the visual field of the left eye. The retrobulbar blood flow in the left eye was normal in the ophthalmic and central retinal arteries, but markedly decreased in the central retinal vein. There were no signs of fistula or shunts. The right eye was without any pathology. MR and catheter angiography of the head and orbit were both normal. THERAPY AND OUTCOME: Following trabeculectomy, the intraocular and episcleral venous pressures dropped to 9 mmHg and 8 mmHg, respectively, at 6 months follow-up. The episcleral and conjunctival venous congestion regressed, and the blood flow in the central retinal vein increased. CONCLUSION: The reason for the observed clinical picture (Radius-Maumenee syndrome) and haemodynamic improvement after reduction of the intraocular pressure is not clear. We outline a hypothesis involving an increase of the vascular resistance in the vortex veins and the superior ophthalmic vein with a shift in local blood volume and vascular pressure due to high intraocular pressure.

Retrobulbar blood flow in patients with cataract.

OBJECTIVE: To investigate retrobulbar haemodynamics in patients with cataract. SUBJECTS AND METHODS: Colour Doppler imaging of the ophthalmic artery was carried out on the eye scheduled for surgery in 30 patients with cataract and in one randomly selected eye of 100 healthy controls. The peak systolic velocity, mean velocity, end diastolic velocity and resistivity index in the ophthalmic artery were computed and adjusted for the influence of age and mean arterial pressure. Cataract type was recorded and lens opacity was measured with an opacity lensmeter. Odds ratio (OR) for cataract was analysed in a logistic regression model, depending on the adjusted blood-flow parameters, age and smoking status. RESULTS: The mean (SD) age was 45.5 (17.7) and 67.6 (5.8) years in controls and patients with cataract, respectively (p<0.001). The female to male ratio was 54:46 and 13:17, respectively (p = 0.41). Significant predictors of cataract in a forward stepwise logistic regression analysis were age (OR = 1.194; 95% confidence interval (CI) = 1.103 to 1.292; p<0.001), smoking status (OR = 14.119; 95% CI = 2.753 to 72.398; p = 0.002) and mean blood-flow velocity in the ophthalmic artery (OR = 0.731; 95% CI = 0.607 to 0.881; p = 0.001). Adjusted mean velocity was significantly lower in patients with cataract, even when only age-matched (age >55 years) non-smokers (31 controls, 19 patients with cataract) were considered (p = 0.003). Lens opacity and the type of cataract had no influence on the present findings. CONCLUSION: High mean velocity in the ophthalmic artery may be associated with a reduced risk of cataract.