M. Kaup

Fluorescein filling defects of the optic nerve head in normal tension glaucoma, primary open-angle glaucoma, ocular hypertension and healthy controls

Background:  To evaluate fluorescein filling defects of the optic nerve head in normal tension glaucoma (NTG), primary open‐angle glaucoma (POAG), ocular hypertension (OHT) and controls.

Retrobulbar haemodynamics and morphometric optic disc analysis in primary open-angle glaucoma

Background: Previous studies confirmed reduced retrobulbar haemodynamics in primary open-angle glaucoma (POAG). Aim: To investigate a correlation between retrobulbar haemodynamics and morphometric neuroretinal rim analysis in patients with POAG. Methods: 51 patients with POAG (mean (standard deviation (SD)) age 65 (11) years) were included in this clinical study. Blood flow velocities (peak systolic velocity (PSV) and end-diastolic velocity (EDV)) of the ophthalmic artery, central retinal artery (CRA), posterior ciliary arteries (PCA) and central retinal vein were measured using colour Doppler imaging (Siemens Sonoline Sienna, Erlangen, Germany). Optic disc morphometry was carried out using scanning laser tomography (Heidelberg Retinal Tomograph II Heidelberg Egineering Heidelberg, Germany). The stereometric parameters of the neuroretinal rim (rim area, rim volume, cup shape measure and retinal nerve fibre layer (RNFL) cross-sectional area) were used for analysis. Results: The PSV of the CRA was significantly (p<0.001) correlated with rim area (r = 0.50) and rim volume (r = 0.51). The minimum velocities of the central retinal vein were significantly (p<0.001) correlated with rim volume (r = 0.56) and RNFL cross-sectional area (r = 0.49). No correlations were found for the flow velocities of the ophthalmic artery and PCAs. Conclusion: Retrobulbar haemodynamics of the central retinal artery and vein are correlated with the neuroretinal rim damage in POAG.

Effects of brinzolamide on ocular haemodynamics in healthy volunteers.

Aim: A prospective, randomised study to evaluate effects of brinzolamide on ocular haemodynamics in healthy volunteers. Methods: 30 volunteers (12 men, 18 women; 28.3 (SD 7.8) years) were prospectively randomised to either brinzolamide or placebo during a 2 week double masked treatment trial. Examinations were performed at baseline and after 2 weeks of treatment. Intraocular pressure was measured and automatic static perimetry (Humphrey field analyser, 24-2) and contrast sensitivity (CSV 1000, Vector Vision) were performed. Retrobulbar blood flow velocities (peak systolic and end diastolic velocity) and resistive indices (RI) of ophthalmic artery, central retinal artery and of temporal and nasal short posterior ciliary arteries were measured by colour Doppler imaging (Sonoline Sienna Siemens). In video fluorescein angiograms (scanning laser ophthalmoscope, Rodenstock) arteriovenous passage time (AVP, dilution curves) and peripapillary diameters of retinal arterioles and venules were measured by means of digital image analysis. Results: Intraocular pressure was significantly decreased by brinzolamide (p<0.0001). Neither brinzolamide nor placebo changed visual field global indices after treatment. Contrast sensitivity at 3 cycles per degree was significantly higher in the placebo group (p<0.05). Apart from an increase of RI in ophthalmic artery under placebo treatment (p<0.05) there was no effect in retrobulbar haemodynamics in both groups. Brinzolamide therapy alone resulted in a significant reduction of AVP compared to baseline (p<0.05), while peripapillary retinal vessels diameters remained unaffected. Conclusions: Apart from the expected decrease of intraocular pressure brinzolamide showed no significant change in retrobulbar haemodynamics, but a significant shortening of AVP. Since in glaucoma AVP is prolonged indicating vascular dysfunction this effect might be beneficial in glaucoma therapy.

Retrobulbar haemodynamics in non-arteritic anterior ischaemic optic neuropathy

Aim: To compare retrobulbar haemodynamics in patients with acute non-arteritic anterior ischaemic optic neuropathy (NAION) and age-matched controls by colour Doppler imaging (CDI). Methods: 25 patients with acute NAION and 35 age-matched controls participated in this study. By means of CDI, the blood flow velocities of the ophthalmic artery, central retinal artery (CRA), and nasal and temporal short posterior ciliary arteries (PCAs) were measured. Peak-systolic velocity (PSV) and end-diastolic velocity (EDV) and Pourcelot’s resistive index were determined. Results: In the ophthalmic artery, no marked differences between patients with NAION and controls were detected. PSV and EDV of the CRA (p<0.001, p = 0.002) and PSV of the nasal PCA (p<0.05) were significantly decreased in patients with NAION compared with healthy controls. No marked differences between patients and controls were detectable for temporal PCAs. Conclusion: Blood flow velocities of the nasal PCA and the CRA are considerably reduced in patients with acute NAION compared with controls. Patients with NAION in part showed markedly different retrobulbar haemodynamics.

Performance of colour Doppler imaging discriminating normal tension glaucoma from healthy eyes

PurposePrevious studies have shown decreased retrobulbar blood flow in normal tension glaucoma (NTG) compared to healthy controls. This study evaluates the ability of colour Doppler imaging (CDI) to identify patients with NTG.MethodsSixty-two patients with untreated NTG (mean age 57±14 years) and 40 age-matched controls (mean age 58±9 years) were included in a prospective cross-sectional institutional study. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive indices (RI=(PSV–EDV)/PSV) of the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (PCAs) were measured by means of CDI. Using receiver operating characteristic (ROC) curves, sensitivity was determined at 90% specificity.ResultsPatients with NTG showed significantly decreased PSV (P<0.0001) and EDV (P<0.0001) of the CRA, significantly decreased EDV of the nasal (P=0.004) and temporal (P=0.002) PCA, and significantly increased RI of the temporal (P=0.003) PCAs compared to healthy controls. Sensitivity values at 90% specificity were calculated: PSV of the CRA, 30.6%; EDV of the CRA, 48.4%; EDV of the nasal PCA, 43.9%; EDV of the temporal PCA, 45.9%; and RI of the temporal PCA, 39.3%.ConclusionsThe power to identify NTG using CDI reaches 48% sensitivity at 90% specificity. Further longitudinal studies are needed to determine the prognostic value of CDI in glaucoma.

Fluorescein leakage of the optic disc: time course in primary open‐angle glaucoma

Purpose:  To identify and quantify the time course of fluorescein leakage of the optic nerve head in primary open‐angle glaucoma (POAG) and controls.

Intraoperative conversion rate to a large, limbal opening in minimally invasive strabismus surgery (MISS).

BackgroundTo evaluate which factors predispose to an intraoperative conversion to the usual limbal approach in minimally invasive strabismus surgery (MISS).MethodsThis study included 451 consecutive patients operated on by one surgeon at Kantonsspital St Gallen, Switzerland, with minimally invasive rectus muscle surgery between February 2003 and December 2007. We evaluated the intraoperative conversion rate to the usual limbal approach over time, and performed a retrospective determination of date of surgery, age of patient, motility of the eye, primary or revision surgery, and the type and dose of surgery in 982 consecutive rectus muscle procedures.ResultsIn 3.6% (35/982) of MISS procedures, an intraoperative conversion to a large, limbal approach was necessary. The overall conversion rate decreased over time, from 8.4% in 2003 to 0.4% in 2007. The multivariate regression analysis showed a significant negative influence between the date of surgery and the conversion rate (p < 0.005). Muscle resections were associated with a higher conversion rate (p < 0.001). The other evaluated factors had no significant influence on an intraoperative enlargement of the conjunctival opening.ConclusionsThis study confirms the reliability of the new MISS technique, and shows a low conversion rate to the usual limbal approach. The conversion rate decreased over time with increasing surgical experience. Muscle resections were associated with a higher conversion rate, while the age of the patient, the motility of the eye, revision surgery and the dose of surgery had no significant influence on an intraoperative conversion.