Faculty Bibliography

Purpose: To evaluate fractal analysis box size resolution and self-similarity breakdown in box counting method of fractal analysis of optical coherence tomography angiography (OCTA) images in eyes with primary open angle glaucoma (POAG) or normal tension glaucoma (NTG) compared to control patients. Methods: This retrospective study used OCTA images obtained on 40 eyes with POAG, 26 eyes with NTG, and 28 control eyes. OCTA images consisted of 4.5x4.5mm peripapillary scans obtained with the RTVue XR Avanti (Optovue Inc., Fremont, CA), standardized and binarized using ImageJ (NIH, Bethesda, MD). Fractal dimension by means of a box-counting algorithm used box sizes with increasing exponential factor of two with grid algorithm on Fractalyse (TheMA, Besancon Cedex, France) was plotted against linear box dimension and first maximum (first peak) that represents the smallest box size resolution before breakdown of self-similarity. Statistical analysis was performed using one-way analysis of variance with post-hoc Tukey HSD. Results: There was significant difference among control, POAG, and NTG groups (p=0.002), with POAG having larger box size (12.8+/-1.54) compared to control (8.0+/-0.0, p=0.008) and NTG groups (8.0+/-0.0, p<0.01). When further divided into early, moderate, and severe subgroups of POAG, there were significant differences between moderate POAG (16+/-5.06, p=0.03) versus control and severe POAG (16.57+/-3.19, p=0.001) versus control. There was also a significant difference between early POAG (9.2+/-1.2) versus severe POAG (p=0.006). Lastly, the NTG group showed a significant difference with moderate POAG (p=0.031) and severe POAG (p=0.001). Conclusions: The first peak box size of fractal dimension as a function of increasing box size represents the smallest box size resolution prior to loss of uniformity of the vascular pattern's fractal dimension. The differences in breakdown size among controls, POAG, and NTG suggest that this resolution is limited by and serves as an indicator for breakdown of self-similarity and reduced capillary density. Breakdown of self-similarity for POAG occurred at significantly higher resolution than that of controls or NTG, and more so for moderate to severe POAG subgroups, suggesting their increased loss of microvasculature and highlighting the potential of fractal analysis in establishing quantitative parameters for evaluation of glaucoma

PURPOSE OF THE STUDY/OBJECTIVE:The purpose of the study was to report long-term outcomes and complications of Baerveldt glaucoma implant (BGI) surgery with pars plana tube insertion in children. MATERIALS AND METHODS/METHODS:The medical records of consecutive aphakic and pseudophakic children (<16 y of age) who underwent BGI surgery with pars plana tube insertion between 1990 and 2013 were retrospectively reviewed. Main outcome measures were intraocular pressure and number of glaucoma medications. Postoperative complications were recorded. Failure was defined as an intraocular pressure <5 or ≥21 mm Hg (with or without glaucoma medications), loss of light perception, or need for additional glaucoma surgery. RESULTS:Thirty-seven children were identified with a mean age of 6.0±4.7 years (range, 4 mo to 14.5 y). Mean follow-up after pars plana BGI surgery was 6.5±3.4 years (range, 9 mo to 12.8 y) for patients who met success criteria. Mean intraocular pressure and mean number of glaucoma medications at most recent follow-up for patients with successful intraocular pressure control were 13.8±4.1 and 2.3±1.9 mm Hg, respectively. The Kaplan-Meier survival analysis revealed 1-, 3-, 5-, and 7-year success rates of 94.5%, 74.6%, 65.0%, and 45.8%, respectively. Complications included tube exposure in 1 patient (2.7%), tube obstruction in 8 patients (21.6%), and retinal detachment in 9 patients (24.3%). Seventeen patients (45.9%) failed due to inadequate intraocular pressure control, of whom 9 (24.3%) required additional glaucoma surgery. CONCLUSIONS:Although pars plana BGI surgery is a reasonable option for managing refractory glaucoma in aphakic and pseudophakic children, surgeons must be aware of the potential need for additional glaucoma surgery and/or posterior segment complications with extended follow-up.

Purpose:To compare perfused peripapillary capillary density in primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), and normal patients using optical coherence tomography angiography (OCT-A). Methods:A retrospective review of POAG, NTG, and normal patients imaged with OCT-A was performed. En face OCT angiograms identifying peripapillary vessels were obtained using a spectral-domain OCT system (Avanti RTVue-XR). A custom image analysis approach identified perfused peripapillary capillaries, quantified perfused capillary density (PCD), and generated color-coded PCD maps for 3.5- and 4.5-mm-diameter scans. We compared PCD values, PCD maps, standard automated perimetry (Humphrey visual field [HVF]) parameters, and OCT retinal nerve fiber layer (RNFL) thickness analyses across all groups. Results:Forty POAG, 26 NTG, and 26 normal patients were included. Annular PCD in POAG (34.24 ± 6.76%) and NTG (37.75 ± 3.52%) patients was significantly decreased compared to normal patients (42.99 ± 1.81%) in 4.5-mm scans (P < 0.01 and P < 0.01, respectively). Similar trends and statistical significances were seen in 3.5-mm scans. Linear regression analysis resulted in moderate correlations between annular PCD values and other glaucomatous parameters. Pearson coefficients comparing annular PCD from 4.5-mm scans in POAG and NTG groups to HVF mean deviation, HVF pattern standard deviation, and average RNFL thickness all showed statistical significance (P < 0.05). Color maps showed that POAG and NTG patients had a reduction of perfused capillaries that progressed in size when comparing early, moderate, and severe glaucoma groups. Conclusions:Optical coherence tomography angiography can uniquely identify changes in peripapillary PCD in glaucoma patients. Optical coherence tomography angiography may offer insights into the pathophysiology of glaucomatous damage and risk factors for disease progression.

PURPOSE/OBJECTIVE:To evaluate the efficacy of transconjunctival revision (TCR) with mitomycin-C (MMC) following failed trabeculectomy. MATERIALS AND METHODS/METHODS:The medical records of 27 patients (27 eyes) who underwent TCR with subconjunctival injection of MMC by a single surgeon between September 2001 and August 2013 were retrospectively reviewed. The same surgical protocol was followed for all patients. Revision was performed using a microvitreoretinal blade through a small conjunctival incision. Main outcome measures included visual acuity, intraocular pressure (IOP), and number of glaucoma medications. Failure was defined as an IOP<5 or >14 mm Hg, loss of light perception, or need for additional glaucoma surgery. RESULTS:Mean interval between trabeculectomy and TCR was 56.4±57.2 months. Mean preoperative IOP was 21.9±6.8 mm Hg using 4.0±1.2 glaucoma medications. Fifteen (55.6%) patients met success criteria. At most recent follow-up, mean IOP and number of glaucoma medications for successful patients were 9.7±3.8 mm Hg and 0.6±1.1, respectively. Kaplan-Meier analysis revealed 1-, 2-, and 3-year success rates of 62%, 58%, and 53%, respectively. Three additional patients achieved success after undergoing a second TCR, and 1 patient achieved success after a third TCR. Postoperative complications included transient choroidal effusion (n=8), shallow anterior chamber requiring reformation (n=5), 5-fluorouracil-related corneal epitheliopathy (n=10), and bleb leak (n=1). CONCLUSIONS:TCR with adjunctive MMC is a safe and effective procedure following failure of a trabeculectomy. More than 1 revision may be necessary to achieve long-term IOP reduction.

PURPOSE/OBJECTIVE:To compare the safety and efficacy of Baerveldt implantation (Abbott Medical Optics, Santa Ana, CA) and trabeculectomy with mitomycin C (MMC) in patients who have not undergone prior incisional ocular surgery. DESIGN/METHODS:Retrospective, comparative case series. PARTICIPANTS/METHODS:A total of 125 patients with low-risk glaucoma undergoing primary glaucoma surgery, including 55 patients who received a 350-mm(2) Baerveldt glaucoma implant and 70 patients who underwent trabeculectomy with MMC. METHODS:Eligible patients were identified using Current Procedural Terminology codes, and their medical records were reviewed retrospectively. MAIN OUTCOME MEASURES/METHODS:The primary outcome measure was surgical success (intraocular pressure [IOP] ≤21 mmHg and reduced ≥20% from baseline, IOP >5 mmHg, no reoperation for glaucoma, no loss of light-perception vision). Secondary outcome measures included visual acuity, IOP, number of glaucoma medications, and complications. RESULTS:The cumulative probability of success at 3 years with or without medical therapy was 87% in the Baerveldt group and 76% in the trabeculectomy group (P = 0.23). Postoperative complications occurred in 11 patients (20%) in the Baerveldt group and 20 patients (29%) in the trabeculectomy group (P = 0.27). Mean follow-up ± standard deviation was 27±19 months in the Baerveldt group and 34±20 months in the trabeculectomy group (P = 0.053). CONCLUSIONS:Similar rates of surgical success and postoperative complications were observed in patients undergoing trabeculectomy with MMC and in those undergoing Baerveldt implantation during 3 years of follow-up. Both are viable primary glaucoma procedures in patients who have not undergone prior ocular surgery.

PURPOSE OF REVIEW/OBJECTIVE:This article describes important aspects of postoperative management after trabeculectomy and glaucoma drainage implant surgery. RECENT FINDINGS/RESULTS:Postoperative management of glaucoma drainage implant surgery includes stabilization of intraocular pressure, possible ligature release, and management of complications such as corneal edema, and tube/plate exposure. Postoperative management of trabeculectomy includes evaluation of bleb encapsulation, management of hypotony, and assessment of need for adjuvant therapy. Recent advances in surgical techniques, device/tissue availability, and imaging continue to shape the postoperative course. SUMMARY/CONCLUSIONS:Careful preoperative planning and postoperative care may decrease the likelihood of complications in tube surgery or trabeculectomy.

PURPOSE/OBJECTIVE:To determine the impact of 8 multicenter randomized clinical trials (RCTs) on glaucoma practice. METHODS:An electronic survey was distributed to the members of the American Glaucoma Society (AGS). Each participant was asked 2 study-specific questions and 1 standard question common to all 8 RCTs assessing the study's impact on clinical practice. RCTs included in the survey were the Advanced Glaucoma Intervention Study (AGIS), Collaborative Initial Glaucoma Treatment Study (CIGTS), Collaborative Normal Tension Glaucoma (CNTG) Study, European Glaucoma Prevention Study (EGPS), Early Manifest Glaucoma Trial (EMGT), Glaucoma Laser Trial (GLT), Ocular Hypertension Treatment Study (OHTS), and Tube Versus Trabeculectomy (TVT) Study. A 5-point Likert scale was used for rating all responses. The practice setting and duration of glaucoma practice was determined for all AGS members who responded. RESULTS:A total of 206 (23.0%) of 894 AGS members participated in the survey. Among those who responded, 46.4% were self classified as academic practitioners and 53.6% worked in a private practice setting. Mean Likert scores for the standard question evaluating the overall impact of the RCT were OHTS 4.47, CNTG Study 4.13, AGIS 3.78, TVT Study 3.53, EMGT 3.48, CIGTS 3.44, GLT 3.39, and 2.69 EGPS. CONCLUSIONS:Substantial differences were observed in the clinical impact of several RCTs in glaucoma. The reported impact of each study likely reflects several factors including study timing, design, conduct, and interpretation of results.

PURPOSE/OBJECTIVE:To evaluate the safety and efficacy of transscleral cyclophotocoagulation (TSCPC) in patients requiring intraocular pressure (IOP) reduction despite prior Baerveldt glaucoma implant (BGI) surgery. PARTICIPANTS AND METHODS/METHODS:Twenty eyes of 20 patients who had previously undergone BGI placement and subsequently underwent TSCPC with the red (810 nm) diode laser between April 2005 and January 2010 were retrospectively reviewed. RESULTS:All patients underwent BGI placement an average of 34.7±24.2 months before TSCPC. The mean follow-up period after TSCPC was 25.6±17.4 months (range, 2.3 to 56.5 mo). IOPs were reduced from a mean of 21.8±4.6 to 10.8±3.2 mm Hg at the most recent follow-up, which represents a 50.2% reduction in mean IOP. Successful postoperative IOP control was achieved in 16 (80%) of 20 patients. The number of glaucoma medications decreased from 4.2±0.6 to 2.2±1.2. The life-table success rate was 78.6% at 12, 24, and 36 months. Postoperative complications included persistent corneal edema in 1 patient and both persistent corneal edema and cystoid macular edema in another patient. Both patients sustained a >2 line reduction in Snellen visual acuity. CONCLUSIONS:TSCPC is safe and effective in the management of patients requiring IOP reduction after BGI surgery. Although our sample size was limited, the safety profile of TSCPC after BGI seems promising.