Kouros Nouri-Mahdavi

Evaluation of the hypertensive phase after insertion of the Ahmed Glaucoma Valve

PURPOSE To investigate the postoperative hypertensive phase (HP) in patients undergoing glaucoma drainage implant surgery. DESIGN Interventional case series. METHODS A retrospective chart review of 156 consecutive eyes (139 patients) who underwent placement of an Ahmed Glaucoma Valve (AGV) with a follow-up of >or=3 months was performed. Main outcome measures were occurrence and resolution of the HP and intraocular pressure (IOP) control. The HP was defined as IOP > 21 mm Hg during the first 3 months after surgery. Resolution of the HP was defined as an IOP < 22 mm Hg and an IOP reduction of 3 mm Hg with the same or fewer number of glaucoma medications. RESULTS An HP was observed in 88 eyes (56%). It occurred after a mean of 5.0 weeks (median, 4 weeks; range, 1-13 weeks) with an average (+/- standard deviation) peak IOP of 30.1 (+/- 7.5) mm Hg. Resolution of the HP occurred in 19 of 68 eyes (28%) with available data. Eyes with an HP had a higher mean IOP and needed more medications 6 to 12 months after surgery than eyes without an HP (17.2 +/- 5.6 vs 14.3 +/- 5.8 mm Hg; P =.012 and 1.7 +/- 1.2 vs 0.3 +/- 0.6 medications; P <.001, respectively). CONCLUSION A hypertensive phase occurs frequently after implantation of the AGV. However, it resolves in only a minority of eyes. The majority of eyes with an HP have no significant improvement of IOP control and continue to require the same number of glaucoma medications as they did during the HP.

Outcomes of Trabeculectomy for Primary Open-angle Glaucoma*

PURPOSE To determine the long-term functional and structural outcomes in patients treated with trabeculectomy for primary open-angle glaucoma. METHODS Records of 78 consecutive patients (78 eyes) who had their first trabeculectomy were studied retrospectively (duration of follow-up, 25 to 112 months). Serial automated perimetry and stereoscopic optic disc photographs were used to assess the long-term efficacy of trabeculectomy to prevent progressive glaucomatous damage. Stereoscopic optic disc photographs were available for 29 eyes (38%). Criteria for intraocular pressure control were a minimum intraocular pressure reduction of 20% and intraocular pressure at or below 20 mmHg. RESULTS There was no evidence of progression of glaucomatous damage in 81% and 65% of the eyes after 3 and 6 years, respectively. The visual field deteriorated in 16 eyes (21%) and progressive structural optic nerve damage occurred in 4 eyes (5%) during follow-up. Deterioration of the optic nerve head in the absence of visual field progression was detected in three (4%) of those eyes. In 19 eyes (25%), further glaucoma surgery was performed. The probability of successful intraocular pressure control after a single operation was 48% and 40% at 3 and 5 years, respectively. CONCLUSION Progressive glaucomatous damage occurs in about one third of eyes with moderate to severe primary open-angle glaucoma over a 6-year follow-up after trabeculectomy.

A Method to Measure and Predict Rates of Regional Visual Field Decay in Glaucoma

PURPOSE This study was conducted to measure the rate of visual field (VF) decay in glaucoma, to separate faster and slower components of decay, and to predict the rate of VF decay. METHODS Patients who had primary glaucoma and 6 or more years of follow-up were included. Thresholds at each VF location were regressed with linear, quadratic, and exponential models. The best model was used to parse the VF into slower and faster rate components. Two independent cohorts (glaucoma [n = 87] and cataract [n = 38]) were used to determine the techniques ability to distinguish areas of glaucomatous VF changes from those caused by cataract. VF forecasts, derived from the first half of follow-up, were compared with actual VF thresholds at the end of follow-up. RESULTS The mean (±SD) years of follow-up and number of VFs for the main cohort (389 eyes of 309 patients) were 8.2 (±1.1) years and 15.7 (±3.0), respectively. The proportions of best fits were linear 2%, quadratic 1%, and exponential 97%. Proportions of eyes with exponential rates of decay ≥10% for the entire visual field (VF), faster components, and slower components were 20%, 56%, and 4%, respectively. The difference in decay rates between the faster and slower components was greater in the independent glaucoma cohort (19% ± 10%) than in the cataract cohort (5% ± 5%; P < 0.001). Test location forecasts significantly correlated with measured values (r(2) = 0.67; P < 0.001). CONCLUSIONS This method isolates faster and slower components of VF decay in glaucoma, can identify patients who are fast progressors, and can predict patterns of future VF loss with appropriate confidence intervals. (ClinicalTrials.gov number, NCT00000148.).

Structure-function relationships between spectral-domain OCT and standard achromatic perimetry.

PURPOSE To explore structure-function relationships in early glaucoma with spectral-domain optical coherence tomography (SD-OCT) and standard achromatic perimetry. METHODS One hundred thirty-six eyes of 97 patients with suspected or early glaucoma were enrolled from the clinical database at UCLAs Glaucoma Division. All patients had good-quality peripapillary retinal nerve fiber layer (RNFL)/optic disc measurements and a reliable 24-2 SITA-Standard Humphrey visual field (VF) within a 6-month period. Correlations of global and sectoral RNFL thickness and rim area (RA) measurements, with corresponding global and regional VF sensitivities (both in logarithmic [dB] and 1/Lambert scales [1/L]), were investigated with components of variance models. RESULTS The average RNFL thickness, RA, and mean deviation (MD) were 85.6 ± 5.7 μ, 1.0 ± 0.3 mm(2), and -1.3 ± 1.9 dB, respectively. Global RA demonstrated a stronger correlation with MD compared to average RNFL thickness (P = 0.002). The highest correlations were observed between superonasal VF cluster (in dB scale) and inferotemporal RA (R(2) = 0.26, 95% CI: 0.15-0.40) or inferotemporal RNFL thickness (R(2) = 0.24, 95% CI: 0.13-0.37). In glaucoma suspects, the highest correlations were seen between superonasal VF cluster and inferotemporal RA (R(2) = 0.16) in dB scale or RNFL thickness (R(2) = 0.10) in 1/L scale. Correlations were slightly greater with dB scale than 1/L scale and tended to be linear with both scales. CONCLUSIONS Structure-function relationships can be detected in early glaucoma with SD-OCT. Correlations of RA with VF thresholds tended to be higher compared to those of RNFL. Structure-function relationships were well described with a linear model.

Measurement of optic disc size and rim area with spectral-domain OCT and scanning laser ophthalmoscopy.

PURPOSE To compare optic disc and neuroretinal rim area measurements from spectral-domain optical coherence tomography (SD-OCT) to those from confocal scanning laser ophthalmoscopy. METHODS Seventy-one eyes from 43 normal subjects or suspected/definite glaucoma patients were prospectively enrolled. All subjects had biometry with the IOLMaster and disc/retinal nerve fiber layer imaging with Cirrus SD-OCT (Optic Disc Cube 200×200) and Heidelberg Retina Tomograph (HRT). Uncorrected disc and rim areas and measurements corrected for eye magnification with Bennetts formula (AL-corrected measurements), along with 30° sectoral rim areas, vertical cup-to-disc ratio (VCDR), and cup volume, were compared between the two devices. RESULTS The median (range) axial length (AL) was 24.2 mm (22.4-27.7 mm). Mean keratometry-corrected HRT disc area measurements were larger than AL-corrected HRT and SD-OCT measurements (P < 0.001 for both) and the difference was a function of keratometry measurements (K-readings). The AL-corrected HRT disc area and uncorrected/corrected Cirrus disc areas were not significantly different (P > 0.481). HRT rim area was larger than Cirrus measurements (P < 0.001) and the difference decreased with decreasing rim area. HRT VCDR and cup volume were significantly smaller than Cirrus measurements (P < 0.001). The correlations for sectoral rim areas between the two devices were moderate at best (intraclass correlation coefficients = 0.12-0.65). CONCLUSIONS HRT overestimated optic disc area as compared to SD-OCT. A portion of the difference in HRT and SD-OCT disc measurements is due to HRTs magnification correction algorithm. Rim area measurements from HRT were larger than from SD-OCT, likely a result of different definitions for the reference plane and differences in disc area measurements. Disc parameters from the two devices are not interchangeable.

Detection of early glaucoma with optical coherence tomography (StratusOCT).

PurposeTo evaluate the performance of optical coherence tomography (StratusOCT) for discriminating eyes with early glaucoma from normal eyes. MethodsThirty eyes with established early glaucomatous visual field defects (EGVF group), 30 eyes with evidence of early glaucomatous optic neuropathy with normal standard achromatic perimetry [early glaucoma by disc (EGD)], and 33 age-matched normal eyes with good quality StratusOCT nerve fiber layer (NFL) images were enrolled. Average NFL thickness and NFL thickness at quadrants and sectors, areas under receiver operator characteristic curves, and sensitivities at 80% and 90% specificity were evaluated. ResultsThe average (±SD) mean deviation in the EGVF group was −3.4 (±1.7) dB. Receiver operator characteristic curves showed areas under the curve (AUC) for NFL thickness in the superior quadrant (AUC=0.75±0.07) and in the inferior quadrant (AUC=0.94±0.03) to be the best StratusOCT parameters for discrimination of normal controls from EGD and EGVF eyes, respectively. The best parameter for detection of EGD eyes at 80% and 90% specificities was NFL thickness at superior quadrant (51% and 36% sensitivities, respectively). The best parameter for detection of EGVF eyes at 80% and 90% specificities was NFL thickness in the inferior quadrant (90% and 87% sensitivities, respectively). ConclusionsOptical coherence tomography (StratusOCT) showed good sensitivity and specificity in a group of glaucoma patients with early visual field loss. In patients with normal visual fields in whom the optic disc appeared glaucomatous to glaucoma specialists, half were confirmed to have StratusOCT findings consistent with damage from glaucoma.

Measurement of the Optic Disc Vertical Tilt Angle With Spectral-Domain Optical Coherence Tomography and Influencing Factors

PURPOSE To report a novel method for measuring the vertical tilt angle of the optic nerve (ON) head and to investigate the associated factors. DESIGN Cross-sectional diagnostic study. METHODS One hundred and twelve normal, glaucomatous, and glaucoma suspect eyes (99 patients) were enrolled in this study. Subjects underwent a full eye examination, biometry, and spectral-domain optical coherence tomography (SDOCT). The vertical tilt angle was measured on high-resolution cross-sectional SDOCT images passing through the ON head and foveal centers using the inner edges of the Bruch membrane opening as the reference plane. The correlation between the vertical tilt angle with the ovality index and the potential associated factors was estimated with univariate and multivariate linear regression analyses. RESULTS The median (interquartile range, [IQR]) axial length and visual field mean deviation were 24.5 (23.8-25.3) mm and -0.9 (-2.76 to 0.26) dB. The median (IQR) tilt angle was 3.5 (1.2-11.2) degrees. There was a moderate correlation between the ovality index and tilt angle (Spearman ρ = 0.351; P < .001). In univariate analyses, axial length, spherical equivalent, and mean deviation were correlated with the tilt angle (P = .002, P = .011, and P = .013, respectively). Axial length, mean deviation, and their interaction showed a statistically significant correlation with the tilt angle in multivariate analyses (P = .044 for axial length, P = .039 for mean deviation, and P = .028 for their interaction). CONCLUSIONS We describe a new method for measuring the ON head vertical tilt angle with high-resolution SDOCT imaging. The ovality index demonstrated only a moderate correlation with the tilt angle measurements and hence is not a good proxy measure for the vertical ON head tilt angle. Axial length and visual field mean deviation are the main factors associated with the ON head vertical tilt angle. The underlying basis for the relationship of vertical tilt angle and glaucoma severity should be further explored.

Long Anterior Zonules and Pigment Dispersion

PURPOSE To describe pigment dispersion associated with long anterior zonules. DESIGN Multicenter observational case series. METHODS Fifteen patients, seven of whom were treated for glaucoma or ocular hypertension, were identified with long anterior zonules and pigment dispersion. Transmission electron microscopy was performed on one anterior capsule specimen. RESULTS All patients had anterior zonules that inserted centrally on the lens capsule. Signs of pigment dispersion included corneal endothelial pigmentation, loss of the pupillary ruff, and variable trabecular meshwork pigmentation. Ultrasound biomicroscopy verified the lack of posterior iris insertion and concavity. There was no exfoliation material. Transmission electron microscopy showed zonular lamellae with adherent pigment granules, and no exfoliation material. CONCLUSIONS Long anterior zonules inserted onto the central lens capsule may cause mechanical disruption of the pigment epithelium at the pupillary ruff and central iris leading to pigment dispersion.

Detection of visual field progression in glaucoma with standard achromatic perimetry: A review and practical implications

Detection of visual field progression remains a challenging task despite the recent advances for better handling of longitudinal visual field data, some of which are incorporated in currently available perimeters. Standard achromatic perimetry remains the gold standard for detection of visual field progression. The authors present a practical and clinically relevant review of the main issues involved in detection of early glaucoma as well as detection of visual field progression in eyes with pre-existing glaucomatous damage. After discussing some basic concepts in perimetry, the authors present evidence-based recommendations for criteria to detect earliest evidence of glaucomatous damage with perimetry. The authors will review different event- and trend-based criteria and present data with regard to comparative performance of such criteria. Relevance of using absolute versus corrected threshold data with regard to different criteria is also addressed. At the end, the authors provide practical guidelines for detection of visual field progression in a clinical setting and review issues related to clinical trials.

Effect of intravitreal bevacizumab on retrobulbar blood flow in injected and uninjected fellow eyes of patients with neovascular age-related macular degeneration.

Background: To determine the effect of intravitreal administration of bevacizumab (1.25 mg/0.05 mL) on retrobulbar circulation of the injected and the fellow (uninjected) eyes in patients with neovascular age-related macular degeneration. Methods: In this prospective study, the retrobulbar hemodynamics of 43 patients with neovascular age-related macular degeneration was examined by color Doppler ultrasonography. Peak systolic velocity, end-diastolic velocity, and resistive index values in the central retinal artery and short posterior ciliary artery in both injected and uninjected fellow eyes were measured at baseline and 7 days after a single intravitreal injection of bevacizumab. Results: At baseline, the peak systolic velocity, end-diastolic velocity, and the resistive index in the central retinal artery and short posterior ciliary artery of the injected eye were not significantly different compared with the fellow uninjected eye (P > 0.05 for all). However, intravitreal bevacizumab induced a significant reduction in the peak systolic velocity and end-diastolic velocity and a significant rise in the resistive index of the central retinal artery and short posterior ciliary artery of the injected eye (P ⩽ 0.006 for all). Peak systolic velocity and end-diastolic velocity decreased in the central retinal artery (P = 0.023 and P = 0.030) and the short posterior ciliary artery (P = 0.001 and P < 0.000) in the uninjected eye while the resistive index did not significantly change in central retinal artery (P = 0.114) and short posterior ciliary artery (P = 0.082) of the fellow eyes. Conclusion: Intravitreal injection of bevacizumab significantly affects ocular hemodynamic parameters of both the injected and the uninjected fellow eyes with neovascular age-related macular degeneration.