Category: Peer-reviewed

Treatment Outcomes in Malignant Glaucoma

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Purpose:
To report treatment outcomes in malignant glaucoma.

Design:
Retrospective case series.

Participants:
Twenty-eight eyes of 26 patients who were treated for malignant glaucoma between 1991 and 2009.

Methods:
Malignant glaucoma was diagnosed based on the presence of a shallow or flat central and peripheral anterior chamber in the presence of patent iridotomy, with intraocular pressure (IOP) of 22 mmHg or more after any intraocular surgery. The treatment algorithm included antiglaucoma medications and cycloplegics as first-line methods; the second-line therapy in pseudophakic eyes was laser hyaloidotomy, followed by vitrectomy-hyaloidotomy-iridectomy (VHI) or transscleral cyclophotocoagulation (TSCPC).

Main Outcome Measures:
Resolution was defined as deepening of the central anterior chamber and IOP of 21 mmHg or less (on 2 successive follow-ups at least 1 week apart) with or without topical antiglaucoma medications in the absence of systemic antiglaucoma medications.

Results:
At the diagnosis of malignant glaucoma, 5 eyes were phakic and 23 were pseudophakic. The preceding surgeries were trabeculectomy (11 eyes), cataract surgery (10 eyes), and combined cataract and glaucoma surgery (7 eyes). Mean IOP decreased from 34±8.3 mmHg at presentation to 14.3±5.2 mmHg at the last visit (P<0.001). Resolution of malignant glaucoma was seen in 27 eyes (27/28; 96%), 17 eyes resolved with 1 intervention, and 10 eyes required repeat procedures. Of the 27 eyes whose disease resolved, this result was achieved in 4 eyes with medical treatment, in 7 pseudophakic eyes with laser hyaloidotomy, in 4 eyes with VHI, and in 12 eyes with TSCPC. The median duration of follow-up was 192 days (interquartile range, 35–425 days). There was no difference in the visual acuity at presentation and at the final visit in 14 eyes. Eight eyes gained 2 lines or more and 6 eyes lost 2 lines or more of visual acuity.

Conclusions:
Malignant glaucoma can be managed successfully by appropriate and timely interventions. Medical treatment was beneficial in phakic eyes, laser hyaloidotomy was beneficial in pseudophakic eyes, and vitrectomy and TSCPC were beneficial in refractory cases. A stepladder approach to treatment was successful (96%) in this series.

Financial Disclosure(s):
The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Fuchs’ Endothelial Corneal Dystrophy: Subjective Grading versus Objective Grading Based on the Central-to-Peripheral Thickness Ratio

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Purpose:
To assess interobserver agreement between 2 corneal specialists grading Fuchs’ dystrophy clinically and to determine if the corneal central-to-peripheral thickness ratio (CPTR) may be an alternative and objective metric of disease severity.

Design:
Cross-sectional study.

Participants:
Forty-five eyes (26 subjects) with mild and moderate Fuchs’ dystrophy, 73 eyes (60 subjects) with advanced Fuchs’ dystrophy, and 267 eyes (142 subjects) with normal corneas.

Methods:
Corneas with Fuchs’ dystrophy were graded by 2 corneal specialists based on the confluence and area of guttae and the presence or absence of edema. Central corneal thickness (CCT) and peripheral corneal thickness at 4 mm from the center (PCT4) were measured by using scanning-slit pachymetry. The value of CPTR4 was the quotient of CCT and PCT4.

Main Outcome Measures:
Interobserver agreement for clinical grade and CPTR4.

Results:
Interobserver agreement for clinical grading of Fuchs’ dystrophy was moderate (κ = 0.32; 95% confidence interval, 0.19–0.45). In normal corneas, CCT was not correlated with age (r = −0.10; P = 0.28; n = 267), PCT4 decreased with age (r = −0.33; P<0.001; n = 254), and CPTR4 increased with age (r = 0.59; P<0.001; n = 254). Central corneal thickness was higher in Fuchs’ dystrophy (652±61 μm; n = 118) than in normal corneas (559±31 μm; n = 267; P<0.001). Also, PCT4 was higher in Fuchs’ dystrophy (650±51 μm; n = 107) than in normal corneas (643±43 μm; n = 254; P<0.001 after adjusting thickness for age). Furthermore, CPTR4 was higher in advanced Fuchs’ dystrophy (1.03±0.07; n = 65) than in mild and moderate Fuchs’ dystrophy (0.95±0.07; n = 42; age-adjusted P<0.001), which in turn was higher than in normal corneas (0.87±0.05; n = 254; age-adjusted P<0.001). Finally, CPTR4 was highly correlated with clinical grade of Fuchs’ dystrophy (r = 0.77; P<0.001; n = 361), was repeatable (median coefficient of variation, 1.3%), and provided excellent discrimination between Fuchs’ dystrophy and normal corneas (area under the receiver operator characteristic curve, 0.93).

Conclusions:
Agreement between corneal specialists for the subjective and morphologic clinical grading of Fuchs’ dystrophy is only moderate. The corneal CPTR is an objective, repeatable, and possibly functional, metric of severity of Fuchs’ dystrophy that warrants further investigation to determine its role in monitoring disease progression and predicting the need for keratoplasty.

Financial Disclosure(s):
The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Functional Improvement after One- and Two-Eye Cataract Surgery in the Salisbury Eye Evaluation

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Purpose:
To determine the impact that cataract and cataract surgery have on clinical measurements of vision, reading speed, objective mobility performance, and subjective visual functioning.

Design:
Prospective, population-based study.

Participants:
A total of 1739 Salisbury Eye Evaluation (SEE) participants without previous cataract surgery with bilateral baseline best-corrected visual acuity (BCVA) of logarithm of the minimum angle of resolution (logMAR) ≤0.3 (≥20/40) or cataract surgery between rounds 1 and 2.

Methods:
Participants were categorized on the basis of cataract surgery by round 2 into no surgery, unilateral surgery, or bilateral surgery. Visual performance, mobility-based tasks, and the Activities of Daily Vision Scale (ADVS) were measured at baseline and 2 years. Mobility score was converted into a z score by subtracting the participant’s time from the population baseline average and then dividing by the standard deviation. Comparisons were made between the no surgery and surgery groups using multivariate linear regression.

Main Outcome Measures:
Change in bilateral BCVA in logMAR, contrast sensitivity, reading speed in words per minute (wpm), mobility score, and ADVS.

Results:
During the study period, 29 participants had cataract surgery on both eyes, 90 participants had unilateral surgery, and 1620 participants had no surgery. After adjusting for baseline value, demographics, depression, and mental status, the unilateral surgery group’s BCVA improved 0.04 logMAR (P = 0.001) and the bilateral group’s BCVA improved 0.13 compared with no surgery (P<0.001). Overall mobility declined in all groups. The unilateral group’s z score decreased 0.18 more than that of the no surgery group (P = 0.02), whereas the bilateral group showed a 0.18 z score improvement compared with no surgery (P = 0.19). Change in reading speed significantly improved in the unilateral and bilateral groups compared with no surgery (12 and 31 wpm, respectively). The bilateral surgery group showed significant positive change in ADVS compared with no surgery (5 points of relative improvement; P = 0.01), whereas the unilateral group showed a 5-point relative decline (P<0.001).

Conclusions:
Cataract negatively affects both subjective quality of life and objective performance measures. Unilateral cataract surgery improves visual functioning, but the largest gains are found in patients who undergo second-eye cataract surgery. This finding supports second-eye cataract surgery for patients with visual or functional symptoms even after successful first-eye surgery.

Financial Disclosure(s):
The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Seasonal Changes in Visual Field Sensitivity and Intraocular Pressure in the Ocular Hypertension Treatment Study

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Purpose:
Longitudinal testing plays a key role in glaucoma management. Variability between visits hampers the ability to monitor progression. It has previously been shown that average intraocular pressure (IOP) exhibits seasonal fluctuations. This study examines whether visual field sensitivity also exhibits seasonal fluctuations and seeks to determine whether such fluctuations are correlated to seasonal IOP effects.

Design:
Comparative case series.

Participants:
A total of 33 873 visits by 1636 participants enrolled in the Ocular Hypertension Treatment Study. Participants were split into 6 geographic zones according to the prevailing climate in their location.

Testing:
At each visit, standard automated perimetry was conducted on each eye, and IOP was measured.

Main Outcome Measures:
Mixed effects regression models were formed to look for sinusoidal periodic effects on the change in perimetric mean deviation since the last visit (ΔMD) and on IOP, both overall and within each zone.

Results:
When all the data were included, a significant seasonal effect on ΔMD was found with magnitude 0.06 dB, peaking in February (P < 0.001). Five of the 6 geographic zones exhibited significant seasonal effects on ΔMD, peaking between January and April, with magnitudes ranging from 0.04 dB (P = 0.049) to 0.21 dB (P < 0.001). Zones with greater climactic variation showed larger seasonal effects on ΔMD. All 6 zones exhibited a seasonal effect on IOP, peaking in January or February, with magnitudes ranging from 0.14 to 0.39 mmHg (P ≤ 0.02 in all cases). However, there was no evidence of a significant association between the magnitudes or dates of peaks of the 2 seasonal effects.

Conclusions:
The mean deviation was significantly higher in winter than in summer. There is no evidence of an association with seasonal IOP fluctuations. The cause of the seasonal effect on visual field sensitivity is unknown. These findings may help shed light on the glaucomatous disease process and aid efforts to reduce test–retest variability.

Financial Disclosure(s):
The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Progression of Intermediate Age-related Macular Degeneration with Proliferation and Inner Retinal Migration of Hyperreflective Foci

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Purpose:
Drusen and migrating retinal pigment epithelium have been associated with hyperreflective foci (HF) detected by spectral-domain optical coherence tomography (SD-OCT). This study sought to quantify the change in intraretinal HF distribution and its correlation with age-related macular degeneration (AMD) disease progression.

Design:
Prospective observational study from the multicenter Age-Related Eye Disease Study 2 (AREDS2) Ancillary SD-OCT Study.

Participants:
Patients (n=299) with 1 enrolled eye with intermediate AMD and baseline SD-OCT, followed by SD-OCT imaging at 1-year and 2-year visits.

Methods:
The number and location of HF were scored in SD-OCT scans of all 299 eyes. The change in transverse (horizontal) and axial (vertical) distribution of HF in the macula were evaluated with pairwise signed-rank tests. Two-year inner retinal HF migration was determined by the change in HF-weighted axial distribution (AxD) score calculated for each eye. The correlation of HF with SD-OCT features of AMD progression was evaluated with logistic regression analysis.

Main Outcome Measures:
The mean change in number of HF, transverse and axial distribution of HF in the macula, and AxD per eye.

Results:
In 299 study eyes, the 2-year increase in the number of HF (P<0.001) and the AxD (P<0.001) per eye represented longitudinal proliferation and shift to inner retinal layers, respectively. Eyes with geographic atrophy (GA) at 2 years were correlated with the presence of baseline HF (P<0.001; odds ratio [OR], 4.72; 95% confidence interval [CI], 2.43–9.80), greater number of baseline HF (P<0.001; OR, 1.61 per HF; 95% CI, 1.32–2.00), and greater baseline AxD (P<0.001; OR, 1.58 per AxD point; 95% CI, 1.29–1.95).

Conclusions:
Proliferation and inner retinal migration of SD-OCT HF occurred during follow-up in eyes with intermediate AMD. These characteristics were associated with greater incidence of GA at year 2; therefore, SD-OCT HF proliferation and migration may serve as biomarkers for AMD progression.

Financial Disclosure(s):
Proprietary or commercial disclosure may be found after the references.

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Spectral-Domain Optical Coherence Tomographic Assessment of Schlemm’s Canal in Chinese Subjects with Primary Open-angle Glaucoma

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Purpose:
To evaluate in vivo features of Schlemm’s canal (SC) in patients with primary open-angle glaucoma (POAG) with spectral-domain optical coherence tomography (SD-OCT) and to investigate the relationship of SC size with intraocular pressure (IOP) and glaucoma severity.

Design:
Prospective, comparative study.

Participants:
Fifty Chinese patients with newly diagnosed POAG who had not undergone surgery and 50 normal Chinese subjects from a population-based, cross-sectional study in Shanghai.

Methods:
All participants underwent SD-OCT. The diameter and area of SC were examined in the temporal and nasal sections and measured with customized software.

Main Outcome Measures:
Patient demographics, repeatability and reproducibility assessed with the coefficient of variation (CV) and the intraclass correlation coefficient (ICC), SC parameters and their correlation with IOP, and the mean deviation (MD) of the visual field were analyzed.

Results:
The percentage of sections in which SC was observable was similar between eyes with POAG and normal eyes, and ranged from 78% to 86%. For intraobserver repeatability, the CV and ICC values were 7.9% and 0.97 for diameter, and 13.8% and 0.83 for area, respectively. For interobserver repeatability, the CV and ICC values were 13.6% and 0.89 for diameter, and 13.4% and 0.80 for area, respectively. Significant differences between the 2 groups were found for the average SC area (11332±2015 μm2 vs. 13991±1357 μm2; P<0.001), but not for the SC diameter (40.2±7.1 μm vs. 45.2±4.0 μm; P = 0.195). In addition, the mean IOP values correlated well only with the SC area (ρ = −0.674, P<0.001), not with the SC diameter (ρ = −0.103, P = 248). No significant correlations were found between the MD values and the SC parameters.

Conclusions:
Eyes with POAG have a decreased SC area compared with normal eyes. A correlation between the SC area and the IOP also was observed. However, the degree of glaucoma damage was not consistently associated with the SC area. Spectral-domain OCT could be used for investigating SC changes in patients with glaucoma.

Financial Disclosure(s):
The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Use of Corneal Power-Specific Constants to Improve the Accuracy of the SRK/T Formula

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Purpose:
To evaluate the effect of average corneal power (K) and axial length (AL) in a data-adjusted A-constant for improving the refractive outcome in the Sanders–Retzlaff–Kraff (SRK)/T formula.

Design:
Retrospective, consecutive, case series.

Participants:
A total of 637 patients (637 eyes) who underwent uncomplicated phacoemulsification with implantation of the Acrysof IQ (IQ; Alcon, Fort Worth, TX; 314 eyes) or Akreos AO (AO; Bausch & Lomb, Rochester, NY; 323 eyes) intraocular lens (IOL) by a single surgeon.

Methods:
The correlation among the K, AL, and predicted refractive error in the SRK/T formula was analyzed. Patients were divided into 2 subgroups, the first to calculate the different data-adjusted A-constants based on the K and the second to compare the median absolute error (MedAE) based on different A-constants with the traditional A-constant in the SRK/T formula.

Main Outcome Measures:
The data-adjusted A-constant and the MedAE (diopters [D]).

Results:
The data-adjusted A-constant showed a decreasing trend as K increased. The data-adjusted A-constant was 119.04 in the IQ group and 118.27 in the AO group. The calculated A-constant was 119.33 in the IQ group and 118.57 in the AO group when the cornea was flatter than 43.0 D and 43.2 D, respectively. The A-constant was 118.71 in the IQ group and 117.96 in the AO group when the cornea was steeper than or equal to 44.7 D and 45.0 D, respectively. The MedAE decreased from 0.29 D to 0.23 D in the IQ group (P = 0.001) and from 0.44 D to 0.38 D in the AO group (P < 0.001) when different A-constants were used. The MedAE further decreased from 0.36 D to 0.24 D in the IQ group (P = 0.005) and from 0.58 D to 0.37 D in the AO group (P < 0.001) when subjects with K 1.00 D or more above or 1.00 D below the most accurate K in each group were compared.

Conclusions:
For a steep cornea, the calculated A-constant was smaller than that of the entire K, but for a flat cornea, a larger A-constant was calculated. Using different A-constants based on the K improved the refraction outcomes relying on the SRK/T formula.

Financial Disclosure(s):
The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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Angiographic and Optical Coherence Tomography Characteristics of Recent Myopic Choroidal Neovascularization – Corrected Proof

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Purpose: To analyze the contribution of fluorescein angiography (FA) and spectral-domain optical coherence tomography (SD OCT) to the diagnosis of recent choroidal neovascularization (CNV) associated with high myopia.Design: Retrospective, observational case series.Methods: Ninety eyes of 73 highly myopic patients (refractive error ≥−6 diopters) with CNV in 1 or both eyes were included. Epidemiologic features, refractive error, fundus examination, fluorescein angiography, and SD OCT findings at onset of CNV were analyzed.Results: Mean age at onset of CNV was 54.4 ± 14 years. CNV was bilateral in 17 of 73 cases. Mean refractive error was −13.9 ± 5.2 diopters. Myopic CNV was associated more frequently with patchy or geographic atrophy (P = .019). CNV was associated with exudative features on fluorescein angiography in 82% of cases (64/78), and on SD OCT in 48.6% of cases (36/74). There was no agreement about signs of active CNV between these 2 imaging methods (κ = 25.7 ± 10%; P = .0044). CNV area was significantly smaller in younger patients (<55 years) than in older patients (0.57 mm2 vs 1.21 mm2, respectively; P = .023).Conclusions: Exudative features of myopic CNV are more obvious on FA than on SD OCT, suggesting that fluorescein angiography should be performed when new-onset myopic CNV is suspected. Myopic CNV occurring in older patients (≥55 years) is larger than those seen in younger patients and resembles CNV associated with age-related macular degeneration. This suggests an overlap between myopic CNV in older patients and age-related macular degeneration.

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High-Resolution Imaging of Retinal Nerve Fiber Bundles in Glaucoma Using Adaptive Optics Scanning Laser Ophthalmoscopy – Corrected Proof

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Purpose: To detect pathologic changes in retinal nerve fiber bundles in glaucomatous eyes seen on images obtained by adaptive optics (AO) scanning laser ophthalmoscopy (AO SLO).Design: Prospective cross-sectional study.Methods: Twenty-eight eyes of 28 patients with open-angle glaucoma and 21 normal eyes of 21 volunteer subjects underwent a full ophthalmologic examination, visual field testing using a Humphrey Field Analyzer, fundus photography, red-free SLO imaging, spectral-domain optical coherence tomography, and imaging with an original prototype AO SLO system.Results: The AO SLO images showed many hyperreflective bundles suggesting nerve fiber bundles. In glaucomatous eyes, the nerve fiber bundles were narrower than in normal eyes, and the nerve fiber layer thickness was correlated with the nerve fiber bundle widths on AO SLO (P < .001). In the nerve fiber layer defect area on fundus photography, the nerve fiber bundles on AO SLO were narrower compared with those in normal eyes (P < .001). At 60 degrees on the inferior temporal side of the optic disc, the nerve fiber bundle width was significantly lower, even in areas without nerve fiber layer defect, in eyes with glaucomatous eyes compared with normal eyes (P = .026). The mean deviations of each cluster in visual field testing were correlated with the corresponding nerve fiber bundle widths (P = .017).Conclusions: AO SLO images showed reduced nerve fiber bundle widths both in clinically normal and abnormal areas of glaucomatous eyes, and these abnormalities were associated with visual field defects, suggesting that AO SLO may be useful for detecting early nerve fiber bundle abnormalities associated with loss of visual function.

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Comparison of Clinical Characteristics Between Korean and Western Normal-Tension Glaucoma Patients – Corrected Proof

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Purpose: To detect potential differences in the phenotypes between Western normal-tension glaucoma (NTG) and Korean NTG.Design: A retrospective, cross-sectional study.Methods: One hundred eighty-four NTG eyes of 71 patients of the Jules Stein Eye Institute, University of California, Los Angeles, and 113 patients of the Seoul National University Hospital, Seoul, Korea, were studied after reviewing medical charts retrospectively. All eligible patients from both institutions who were evaluated between July 2007 and June 2008 were included. The groups were matched for stage of glaucoma severity based on the visual field mean deviation value. All patients underwent a complete ophthalmic examination, Humphrey perimetry, Heidelberg Retina Tomography, Stratus optical coherence tomography, and pachymetry. Structural and functional parameters between the 2 groups were compared.Results: There were no statistically significant differences in the baseline intraocular pressure, disc area, frequency of disc hemorrhage, or peripapillary atrophy (P > .05). Cup-shape measure (by Heidelberg Retina Tomography), average RNFL thickness (by Stratus optical coherence tomography), and central corneal thickness were significantly different (P < .002). The eyes of Korean NTG patients showed higher values for cup-shape measure, higher average RNFL thicknesses, and thinner central corneal thicknesses than Western NTG patients. The difference was significant (P < .001) while controlling for age, sex, disc area, mean deviation, pattern standard deviation, and spherical equivalent with multivariate analysis.Conclusions: Korean NTG patients showed steeper cup shapes, thicker RNFL thickness, and thinner central corneal thickness compared with Western NTG patients with similar amounts of visual field loss. This result may help clinicians understand the clinical characteristics of NTG patients and points to the heterogeneous character of the glaucomas.

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Visualization of Blebs Using Anterior-Segment Optical Coherence Tomography after Glaucoma Drainage Implant Surgery

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Objective:
The current study investigated the internal structure of blebs using anterior-segment optical coherence tomography (AS-OCT) in patients who had undergone Ahmed glaucoma valve (AGV) (New World Medical Inc, Rancho Cucamonga, CA) implantation and compared the differences between successful and failed surgeries.

Design:
Cross-sectional, observational study.

Participants:
A total of 76 patients who had undergone AGV implantation.

Methods:
The blebs after AGV implantation were examined using AS-OCT. The relationship between intraocular pressure (IOP) or the number of glaucoma medications and intrableb parameters was evaluated. Success was defined as IOP ≤21 mmHg with a maximum of 2 glaucoma medications, and the remaining cases were assigned to the “failed surgery group.” Logistic regression was used to determine the predictive value of various bleb parameters measured by AS-OCT for bleb success.

Main Outcome Measures:
The bleb wall thickness (minimum and maximum) and the reflectivity of the bleb wall (mean, modal value, minimum, and maximum).

Results:
Blebs from 46 successful (60.5%) and 30 failed (39.5%) AGV implantation surgeries were analyzed. The AS-OCT imaging of the intrableb configuration revealed a relatively regular surface and a homogeneous and hyperreflective bleb wall. The maximum and minimum bleb wall thicknesses were significantly different between the 2 groups (P<0.001, P<0.005). No significant differences were observed between the 2 groups in mean, modal, maximum, or minimum reflectivity of the bleb wall. The maximum and minimum bleb wall thicknesses were significantly correlated with the postoperative maximum IOP (r = 0.402, P<0.001; r = 0.280, P = 0.014). The maximum and minimum bleb wall thicknesses showed a significant correlation with the number of postoperative glaucoma eye drops (r = 0.452, P<0.001; r = 0.327, P = 0.004). Maximum bleb wall thickness was significantly associated with the success of AGV surgery by multivariate analysis (P<0.001).

Conclusions:
Anterior-segment OCT can be used for bleb imaging after glaucoma valve implantation. The AS-OCT results revealed that the maximum bleb wall was significantly thinner in successful AGV implant surgeries compared with unsuccessful AGV implant surgeries. This technique may facilitate the investigation of surgical outcomes and pathogenesis in patients receiving glaucoma valve implants.

Financial Disclosure(s):
The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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