Miriam Zalish

Reduced cerebrovascular blood flow velocities and vasoreactivity in open-angle glaucoma

PURPOSE To compare cerebral blood flow velocities between open-angle glaucoma (OAG) patients and controls, at baseline and during hyperoxia. DESIGN Observational cohort study. METHODS A prospective study was conducted in a single institution. Sixteen OAG patients and 15 normal subjects, matched for age, were enrolled. Patients and controls were studied at baseline, while breathing room air, and during 100% oxygen breathing. The eye with the more severe visual field defect was chosen in glaucoma patients, while in controls, the study eye was chosen randomly. Subjects with history of diabetes, cardiovascular, or respiratory disease were excluded. Measurements included brachial arterial pressure, heart rate, intraocular pressure and transcranial Doppler (TCD). Mean and peak velocity and pulsatility index of the ipsilateral middle cerebral artery (MCA) were measured by TCD. RESULTS At baseline, MCA mean and peak systolic blood flow velocities were significantly lower in glaucoma patients compared with controls velocities were significantly lower in glaucoma patients compared with controls (mean velocity: 50.2 vs 65.3 cm/s, P <.05; peak velocity: 74.2 vs 96.8 cm/s, P <.05). Additionally, while hyperoxia significantly decreased both mean and peak systolic velocities in MCA of controls (mean velocity: 65.3 vs 57.7 cm/s, P <.05; peak velocity 96.8 vs 87.9 cm/s, P <.05), it did not cause any significant change in OAG patients. CONCLUSIONS Glaucoma patients were found to have lower MCA blood flow velocities and an absence of vasoreactivity to hyperoxia, compared with controls. The relationship of these cerebral hemodynamic abnormalities to glaucoma pathogenesis and progression remains to be explored.

The Course of Age-Related Macular Degeneration Following Bilateral Cataract Surgery

BACKGROUND AND OBJECTIVE Progression of age-related macular degeneration (AMD) following cataract surgery has been described. The aim of this study was to investigate whether an uneventful postoperative maculopathic course in one eye (the first eye) may predict a similar prognosis for the fellow eye (the second eye). PATIENTS AND METHODS Thirty-three patients with bilateral, similar, early AMD (defined by the presence of drusen and/or pigmentary abnormalities on fundal examinations and by the absence of late leakage as documented by fluorescein angiography) who had undergone unilateral cataract surgery, had had a stable postoperative maculopathic course following the first operation, and were scheduled for cataract surgery in the second eye were prospectively observed for at least 1 year after the second operation. The course of maculopathy of the second eye was compared with that of the first eye during the follow-up period of the second eye. RESULTS A total of 9 of the second eyes (27.2%) showed progression to wet AMD. Of these, 1 patient (3%) had progression in both eyes and 8 patients (24.2%) had progression in the second eye only. The conditions of 2 of the first operated on eyes (6.1%) deteriorated (P < .05). Hypertension (P < .05), soft drusen (P < .01), and Nd:YAG laser capsulotomy (P < .05) were risk factors for development of wet AMD. CONCLUSION In this study, 24.2% of the patients with early AMD who underwent bilateral cataract surgery and had an uneventful maculopathic course in the first eye had wet AMD in the second eye. Thus, patients with early AMD and soft drusen undergoing bilateral cataract surgery should be monitored for early detection of progression of maculopathy. Further prospective studies are needed to determine the course of maculopathy following cataract surgery.

Comparison of trabeculectomy with mitomycin C with or without phacoemulsification and lens implantation

PURPOSE To compare the results of combined trabeculectomy with phacoemulsification and posterior chamber intraocular lens (IOL) implantation to those of trabeculectomy alone using mitomycin C (MMC) application intraoperatively in all cases. PATIENTS AND METHODS A retrospective comparative study of consecutive patients was conducted on two groups: 102 eyes of 90 patients studied in the combined procedure group, and 33 eyes of 30 patients in the trabeculectomy alone group. RESULTS Both groups showed a significant decrease in IOP. The combined group had a change from 21.5+/-5.8 mm HG preoperative to 14.73+/-3.44 mm HG postoperative, P=0.0001; the trabeculectomy group changed from 24.2+/-7.5 mm HG preoperative to 12.46+/-3.86 mm HG postoperative, P=0.0001. This represents a 31.5% reduction in IOP in the combined group versus a 48.5% reduction in the trabeculectomy alone group (P=0.0001). The follow-up time was longer in the trabeculectomy group (trabeculectomy group, 22.6+/-13.3 months; combined group, 14.2+/-8.0 months), P=0.0014. There were 97 eyes in the combined group (95%) and 32 eyes (97%) in the trabeculectomy group that had an IOP of less than 20 mm HG at the end of follow up. Postoperatively, the two groups showed similar significant reductions in the number of antiglaucomatous medications used (combined group, 0.82+/-1.0 compared with 2.65+/-0.84 preoperatively, P=0.0001; trabeculectomy group, 0.76+/-1.2 compared with 2.7+/-0.95 preoperatively, P=0.0001). There were no cases of bleb leakage in the combined group and two cases (6%) in the trabeculectomy group. CONCLUSION The reduction of IOP is significantly larger after trabeculectomy alone than after the combined procedure; however, the functional and anatomical results of the combined procedure of phacoemulsification, posterior chamber IOL implantation, and trabeculectomy with MMC application were as good as those of trabeculectomy alone with MMC.

Development of exudative age-related macular degeneration after cataract surgery

The macular status of patients with findings consistent with early dry age-related macular degeneration (AMD) who underwent an extracapsular cataract extraction with intraocular lens implantation was evaluated by fundoscopy and fluorescent angiography pre-operatively and during the first post-operative year. Five patients who developed the exudative form of AMD, and who represent the problems arising when treating patients with AMD and cataract, are described. Patients who received laser photocoagulation responded with recurrent choroidal neovascularisation. We suggest that patients with signs of age-related changes scheduled for cataract surgery should undergo a thorough pre- and post-operative assessment of their retinal status.

Bilateral Papilledema With Retinal Hemorrhages in Association With Cerebral Venous Sinus Thrombosis and Paroxysmal Nocturnal Hemoglobinuria

PURPOSE To report a patient with paroxysmal nocturnal hemoglobinuria who complained of transient obscurations of vision and exhibited bilateral papilledema with retinal hemorrhages. METHODS Case report. Computed tomography did not demonstrate any abnormality but magnetic resonance imaging disclosed signs of cerebral venous sinus thrombosis. RESULTS The patient was treated with subcutaneous low molecular weight heparin and intravenous corticosteroids. Symptoms improved within one week and ophthalmoscopic signs resolved within four months. CONCLUSION Bilateral papilledema with extensive retinal hemorrhages may be a sign of cerebral venous sinus thrombosis, a reported devastating complication of paroxysmal nocturnal hemoglobinuria. Thus, any patient with suspected cerebral venous sinus thrombosis should undergo magnetic resonance imaging, even when results of computed tomography are normal.

Optic nerve head blood flow measurements in non-arteritic anterior ischaemic optic neuropathy

Purpose To determine whether a decrease in blood flow, measured by the Heidelberg retiinal flowmeter, can characterise a disc at risk and predict the occurrence of non-arteritic anterior ischaemic optic neuropathy (NAION).Methods Blood flow, volume and velocity were measured in the optic nerve heads of 14 unaffected fellow eyes of patients with unilateral NAION, and compared with those of the affected eyes and of the eyes of 7 age- matched healthy controls.Results The affected eyes were found to differ from the unaffected eyes in all three haemodynamic parameters. Flow (measured in arbitrary units) is the most important parameter to be taken into consideration. Blood flow was significantly lower in affected than in unaffected eyes (upper rim, p < 0.05; lower rim, p < 0.025). It was also significantly lower in the unaffected eyes than in the healthy control eyes (p < 0.005, upper and lower rims), and in the affected eyes than in the control eyes (p < 0.00005, upper and lower rims).Conclusion Decreased blood flow in the optic nerve head may indicate a risk for NAION and be considered a characteristic of the disc at risk.

Circumferential argon laser photocoagulation for prevention of retinal detachment

Circumferential argon laser photocoagulation was administered as preventive treatment for retinal detachment in 53 eyes with extensive areas of lattice degeneration and/or retinal breaks and at least one additional high-risk factor for retinal detachment. Laser burns were applied in several continuous rows 360° around the peripheral retina at the junction between the posterior border of the lesions and the unaffected retina. The retina posterior to the treated areas remained attached in 51 eyes (96.2%) during a mean follow-up period of 85.8 months (range 6 months to 18 years). The treatment did not affect visual acuity. The only complication was the appearance in 2 eyes (3.8%) of a delicate epiretinal membrane which, however, did not require surgical intervention.

Visual Loss After Transscleral Diode Laser Cyclophotocoagulation for Primary Open-Angle and Neovascular Glaucoma

BACKGROUND AND OBJECTIVE Varying incidences of visual loss after transscleral diode laser cyclophotocoagulation for uncontrolled intraocular pressure (IOP) have been reported. This study compared the treatment response in primary open-angle (POAG) and neovascular (NVG) glaucoma, particularly regarding vision loss. PATIENTS AND METHODS Case notes of consecutive patients who underwent transscleral diode laser cyclophotocoagulation between March 2001 and September 2005 were retrospectively reviewed. A diagnosis of POAG or NVG and at least 6 months of follow-up were required for inclusion. Conservative laser parameters were used. The treatment response of the POAG and NVG groups was compared. RESULTS Twenty-five eyes of23 patients with POAG and 14 eyes of 14 patients with NVG were studied. Mean follow-up was 22.4 and 12.9 months in the POAG and NVG groups, respectively. Post-treatment, both groups had significant reduction in mean IOP of 7.3 (29.2%) and 13.2 (36.6%) mm Hg, respectively (between group P = .18). One eye in each group had mild hypotony of 4 mm Hg, and no eyes became phthisical. Oral acetazolamide treatment was significantly reduced in both groups. Visual acuity post-treatment decreased in both groups; the POAG eyes had better initial visual acuity and lost more visual acuity. Nine of 25 (36%) POAG and 4 of 8 (50%) NVG eyes lost 2 or more LogMAR lines. CONCLUSIONS Transscleral diode laser cyclophotocoagulation reduced IOP and medication requirements in POAG and NVG. Patients should be warned that visual loss may occur, especially in endstage glaucoma.

Goldmann applanation tonometry and dynamic contour tonometry are not correlated with central corneal thickness in primary open angle glaucoma

PurposeTo compare intraocular pressure (IOP) measured by Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) and assess their relationship to central corneal thickness (CCT) in patients with primary open angle glaucoma (OAG). Patients and MethodsGAT, DCT, and CCT were assessed in 116 patients with OAG [mean age 65.9 (10.5); 59% female] participating in the Indianapolis Glaucoma Progression Study. GAT and DCT were measured in a randomized order followed by CCT (ultrasonic corneal pachymetry) during a single study visit. Bland-Altman plots were used to evaluate the limits of agreement between tonometery methodologies whereas multivariate regression analysis was used to evaluate the influence of CCT on GAT and DCT IOP measurements. ResultsIOP values obtained by DCT and GAT showed a strong positive correlation in patients with OAG (r=0.93; P<0.001). Mean IOP measured with DCT [18.4 (5.1) mm Hg] was significantly higher (P<0.001) than GAT IOP measurements [16.5 (4.5) mmHg]. CCT did not seem to influence either GAT or DCT measurements (r=0.1025, P=0.16; r=0.05, P=0.46), respectively. The Bland-Altman data showed that the amount of disagreement between IOP assessment techniques varied, suggesting a proportional bias. ConclusionsIn this group of patients with OAG, there was a strong correlation between GAT and DCT measurements of IOP. IOP measured with DCT was consistently higher than IOP measured with GAT. Neither GAT nor DCT measurements were correlated with CCT. This data suggests that factors other than CCT may be involved in the tendency of DCT to produce higher measures of IOP than GAT.

Outcome of consecutive trabeculectomy

Purpose: To establish a criterion for success of primary phakic trabeculectomy in the second eye of the same patient, using the first operated eye as a predictor for the surgical outcome.