Contact

  • Academic
    gatmav@stanford.edu
    University - Faculty other teaching Department: Ophthalmology Clinic and Education Position: Adjunct Clinical Associate Professor [PAMF]

All Publications

  • Diabetic Retinopathy Preferred Practice Pattern (R) OPHTHALMOLOGY Olsen, T. W., Al-Rajhi, A., Ambrus, A., Daly, M., Lum, F. C. 2020; 127 (1): P66-P145

    View details for DOI 10.1016/j.ophtha.2019.09.025

    View details for Web of Science ID 000503224300010

    View details for PubMedID 31757498

  • Age-Related Macular Degeneration Preferred Practice Pattern (R) OPHTHALMOLOGY Olsen, T. W., Al-Rajhi, A., Ambrus, A., Daly, M., Lum, F. C. 2020; 127 (1): P1-P65

    View details for DOI 10.1016/j.ophtha.2019.09.024

    View details for Web of Science ID 000503224300009

    View details for PubMedID 31757502

  • Expanded 2-year follow-up of ranibizumab plus prompt or deferred laser or triamcinolone plus prompt laser for diabetic macular edema. Ophthalmology Elman, M. J., Bressler, N. M., Qin, H., Beck, R. W., Ferris, F. L., Friedman, S. M., Glassman, A. R., Scott, I. U., Stockdale, C. R., Sun, J. K. 2011; 118 (4): 609-14

    Abstract

    To report expanded 2-year follow-up of a previously reported randomized trial evaluating intravitreal 0.5 mg ranibizumab or 4 mg triamcinolone combined with focal/grid laser compared with focal/grid laser alone for treatment of diabetic macular edema (DME).Multicenter, randomized clinical trial.A total of 854 study eyes of 691 participants with visual acuity of 20/32 to 20/320 (approximate Snellen equivalent) and DME involving the fovea.Continuation of procedures previously reported for the randomized trial.Best-corrected visual acuity and safety at the 2-year visit.At the 2-year visit, compared with the sham + prompt laser group, the mean change in the visual acuity letter score from baseline was 3.7 letters greater in the ranibizumab + prompt laser group (95% confidence interval adjusted for multiple comparisons [aCI], -0.4 to +7.7), 5.8 letters greater in the ranibizumab + deferred laser group (95% aCI, +1.9 to +9.8), and 1.5 letters worse in the triamcinolone + prompt laser group (95% aCI, -5.5 to +2.4). After the 1- to 2-year visit in the ranibizumab + prompt or deferred laser groups, the median numbers of injections were 2 and 3 (potential maximum of 13), respectively. At the 2-year visit, the percentages of eyes with central subfield thickness ≥250 μm were 59% in the sham + prompt laser group, 43% in the ranibizumab + prompt laser group, 42% in the ranibizumab + deferred laser group, and 52% in the triamcinolone + prompt laser group. No systemic events attributable to study treatment were apparent. Three eyes in 3 (0.8%) of 375 participants had injection-related endophthalmitis in the ranibizumab groups, whereas elevated intraocular pressure and cataract surgery were more frequent in the triamcinolone + prompt laser group.The expanded 2-year results reported are similar to results published previously and reinforce the conclusions originally reported: Ranibizumab should be considered for patients with DME and characteristics similar to those of the cohort in this clinical trial, including vision impairment with DME involving the center of the macula.

    View details for DOI 10.1016/j.ophtha.2010.12.033

    View details for PubMedID 21459214

  • Effects of Medical Therapies on Retinopathy Progression in Type 2 Diabetes. NEW ENGLAND JOURNAL OF MEDICINE Chew, E. Y., Ambrosius, W. T., Davis, M. D., Danis, R. P., Gangaputra, S., Greven, C. M., Hubbard, L., Esser, B. A., Lovato, J. F., Perdue, L. H., Goff, D. C., Cushman, W. C., Ginsberg, H. N., Elam, M. B., Genuth, S., Gerstein, H. C., Schubart, U., Fine, L. J., ACCORD Study Grp, ACCORD Eye Study Grp 2010; 363 (3): 233–44

    Abstract

    We investigated whether intensive glycemic control, combination therapy for dyslipidemia, and intensive blood-pressure control would limit the progression of diabetic retinopathy in persons with type 2 diabetes. Previous data suggest that these systemic factors may be important in the development and progression of diabetic retinopathy.In a randomized trial, we enrolled 10,251 participants with type 2 diabetes who were at high risk for cardiovascular disease to receive either intensive or standard treatment for glycemia (target glycated hemoglobin level, <6.0% or 7.0 to 7.9%, respectively) and also for dyslipidemia (160 mg daily of fenofibrate plus simvastatin or placebo plus simvastatin) or for systolic blood-pressure control (target, <120 or <140 mm Hg). A subgroup of 2856 participants was evaluated for the effects of these interventions at 4 years on the progression of diabetic retinopathy by 3 or more steps on the Early Treatment Diabetic Retinopathy Study Severity Scale (as assessed from seven-field stereoscopic fundus photographs, with 17 possible steps and a higher number of steps indicating greater severity) or the development of diabetic retinopathy necessitating laser photocoagulation or vitrectomy.At 4 years, the rates of progression of diabetic retinopathy were 7.3% with intensive glycemia treatment, versus 10.4% with standard therapy (adjusted odds ratio, 0.67; 95% confidence interval [CI], 0.51 to 0.87; P=0.003); 6.5% with fenofibrate for intensive dyslipidemia therapy, versus 10.2% with placebo (adjusted odds ratio, 0.60; 95% CI, 0.42 to 0.87; P=0.006); and 10.4% with intensive blood-pressure therapy, versus 8.8% with standard therapy (adjusted odds ratio, 1.23; 95% CI, 0.84 to 1.79; P=0.29).Intensive glycemic control and intensive combination treatment of dyslipidemia, but not intensive blood-pressure control, reduced the rate of progression of diabetic retinopathy. (Funded by the National Heart, Lung, and Blood Institute and others; ClinicalTrials.gov numbers, NCT00000620 for the ACCORD study and NCT00542178 for the ACCORD Eye study.)

    View details for DOI 10.1056/NEJMoa1001288

    View details for Web of Science ID 000279864200006

    View details for PubMedID 20587587

    View details for PubMedCentralID PMC4026164

  • Randomized trial evaluating ranibizumab plus prompt or deferred laser or triamcinolone plus prompt laser for diabetic macular edema. Ophthalmology Elman, M. J., Aiello, L. P., Beck, R. W., Bressler, N. M., Bressler, S. B., Edwards, A. R., Ferris, F. L., Friedman, S. M., Glassman, A. R., Miller, K. M., Scott, I. U., Stockdale, C. R., Sun, J. K. 2010; 117 (6): 1064-1077.e35

    Abstract

    Evaluate intravitreal 0.5 mg ranibizumab or 4 mg triamcinolone combined with focal/grid laser compared with focal/grid laser alone for treatment of diabetic macular edema (DME).Multicenter, randomized clinical trial.A total of 854 study eyes of 691 participants with visual acuity (approximate Snellen equivalent) of 20/32 to 20/320 and DME involving the fovea.Eyes were randomized to sham injection + prompt laser (n=293), 0.5 mg ranibizumab + prompt laser (n=187), 0.5 mg ranibizumab + deferred (> or =24 weeks) laser (n=188), or 4 mg triamcinolone + prompt laser (n=186). Retreatment followed an algorithm facilitated by a web-based, real-time data-entry system.Best-corrected visual acuity and safety at 1 year.The 1-year mean change (+/-standard deviation) in the visual acuity letter score from baseline was significantly greater in the ranibizumab + prompt laser group (+9+/-11, P<0.001) and ranibizumab + deferred laser group (+9+/-12, P<0.001) but not in the triamcinolone + prompt laser group (+4+/-13, P=0.31) compared with the sham + prompt laser group (+3+/-13). Reduction in mean central subfield thickness in the triamcinolone + prompt laser group was similar to both ranibizumab groups and greater than in the sham + prompt laser group. In the subset of pseudophakic eyes at baseline (n=273), visual acuity improvement in the triamcinolone + prompt laser group appeared comparable to that in the ranibizumab groups. No systemic events attributable to study treatment were apparent. Three eyes (0.8%) had injection-related endophthalmitis in the ranibizumab groups, whereas elevated intraocular pressure and cataract surgery were more frequent in the triamcinolone + prompt laser group. Two-year visual acuity outcomes were similar to 1-year outcomes.Intravitreal ranibizumab with prompt or deferred laser is more effective through at least 1 year compared with prompt laser alone for the treatment of DME involving the central macula. Ranibizumab as applied in this study, although uncommonly associated with endophthalmitis, should be considered for patients with DME and characteristics similar to those in this clinical trial. In pseudophakic eyes, intravitreal triamcinolone + prompt laser seems more effective than laser alone but frequently increases the risk of intraocular pressure elevation.

    View details for DOI 10.1016/j.ophtha.2010.02.031

    View details for PubMedID 20427088

  • Retinal Vein Occlusions Preferred Practice Pattern OPHTHALMOLOGY Flaxel, C. J., Adelman, R. A., Bailey, S. T., Fawzi, A., Lim, J. I., Vemulakonda, G. A., Ying, G. 2020; 127 (2): P288-P320

    View details for DOI 10.1016/j.ophtha.2019.09.029

    View details for Web of Science ID 000508226400030

    View details for PubMedID 31757503

  • Idiopathic Macular Hole Preferred Practice Pattern OPHTHALMOLOGY Flaxel, C. J., Adelman, R. A., Bailey, S. T., Fawzi, A., Lim, J. I., Vemulakonda, G. A., Ying, G. 2020; 127 (2): P184-P222

    View details for DOI 10.1016/j.ophtha.2019.09.026

    View details for Web of Science ID 000508226400033

    View details for PubMedID 31757499

  • Posterior Vitreous Detachment, Retinal Breaks, and Lattice Degeneration Preferred Practice Pattern (R) OPHTHALMOLOGY Olsen, T. W., Al-Rajhi, A., Ambrus, A., Daly, M., Lum, F. C. 2020; 127 (1): P223-P258

    View details for DOI 10.1016/j.ophtha.2019.09.027

    View details for Web of Science ID 000503224300011

    View details for PubMedID 31757500

  • Optic Nerve Head Perfusion Before and After Intravitreal Antivascular Growth Factor Injections Using Optical Coherence Tomography-based Microangiography JOURNAL OF GLAUCOMA Wen, J. C., Chen, C., Rezaei, K. A., Chao, J. R., Vemulakonda, A., Luttrell, I., Wang, R. K., Chen, P. P. 2019; 28 (3): 188-193

    Abstract

    To use optical coherence tomography angiography (OCTA) to evaluate the changes in optic nerve head perfusion following intravitreal antivascular endothelial growth factor injections.Preinjection and postinjection intraocular pressure (IOP) and OCTA images were taken of both the injected and uninjected fellow eyes.Mean preinjection IOP was 16.6±4.7 mm Hg, which increased to a mean of 40.3±13.0 mm Hg (P<0.0001) during the first postinjection image and remained elevated at 36.1±11.5 mm Hg (P<0.0001) during the second postinjection image. Although no significant change was observed in flux, vessel area density, or normalized flux when comparing the OCTA preinjection and first postinjection images, a significant decrease at the second postinjection image was observed (P=0.03, 0.02, and 0.03, respectively). No significant change was observed in the uninjected fellow eye during the same time period (P=0.47, 0.37, and 0.38, respectively).Following an antivascular endothelial growth factor injection, mean IOP increased significantly and OCTA imaging of the optic nerve demonstrated a mild but significant decrease in optic nerve head perfusion parameters. Clinicians performing these injections should be aware of these findings and monitor the status of the optic nerve in patients undergoing injections.

    View details for DOI 10.1097/IJG.0000000000001142

    View details for Web of Science ID 000462331400007

    View details for PubMedID 30817497

  • Plasma Vascular Endothelial Growth Factor Concentrations after Intravitreous Anti-Vascular Endothelial Growth Factor Therapy for Diabetic Macular Edema. Ophthalmology Jampol, L. M., Glassman, A. R., Liu, D., Aiello, L. P., Bressler, N. M., Duh, E. J., Quaggin, S., Wells, J. A., Wykoff, C. C. 2018; 125 (7): 1054-1063

    Abstract

    To assess systemic vascular endothelial growth factor (VEGF)-A levels after treatment with intravitreous aflibercept, bevacizumab, or ranibizumab.Comparative-effectiveness trial with participants randomly assigned to 2 mg aflibercept, 1.25 mg bevacizumab, or 0.3 mg ranibizumab after a re-treatment algorithm.Participants with available plasma samples (N = 436).Plasma samples were collected before injections at baseline and 4-week, 52-week, and 104-week visits. In a preplanned secondary analysis, systemic-free VEGF levels from an enzyme-linked immunosorbent assay were compared across anti-VEGF agents and correlated with systemic side effects.Changes in the natural log (ln) of plasma VEGF levels.Baseline free VEGF levels were similar across all 3 groups. At 4 weeks, mean ln(VEGF) changes were -0.30±0.61 pg/ml, -0.31±0.54 pg/ml, and -0.02±0.44 pg/ml for the aflibercept, bevacizumab, and ranibizumab groups, respectively. The adjusted differences between treatment groups (adjusted confidence interval [CI]; P value) were -0.01 (-0.12 to +0.10; P = 0.89), -0.31 (-0.44 to -0.18; P < 0.001), and -0.30 (-0.43 to -0.18; P < 0.001) for aflibercept-bevacizumab, aflibercept-ranibizumab, and bevacizumab-ranibizumab, respectively. At 52 weeks, a difference in mean VEGF changes between bevacizumab and ranibizumab persisted (-0.23 [-0.38 to -0.09]; P < 0.001); the difference between aflibercept and ranibizumab was -0.12 (P = 0.07) and between aflibercept and bevacizumab was +0.11 (P = 0.07). Treatment group differences at 2 years were similar to 1 year. No apparent treatment differences were detected at 52 or 104 weeks in the cohort of participants not receiving injections within 1 or 2 months before plasma collection. Participants with (N = 9) and without (N = 251) a heart attack or stroke had VEGF levels that appeared similar.These data suggest that decreases in plasma free-VEGF levels are greater after treatment with aflibercept or bevacizumab compared with ranibizumab at 4 weeks. At 52 and 104 weeks, a greater decrease was observed in bevacizumab versus ranibizumab. Results from 2 subgroups of participants who did not receive injections within at least 1 month and 2 months before collection suggest similar changes in VEGF levels after stopping injections. It is unknown whether VEGF levels return to normal as the drug is cleared from the system or whether the presence of the drug affects the assay's ability to accurately measure free VEGF. No significant associations between VEGF concentration and systemic factors were noted.

    View details for DOI 10.1016/j.ophtha.2018.01.019

    View details for PubMedID 29525602

  • Assessing the Effect of Personalized Diabetes Risk Assessments During Ophthalmologic Visits on Glycemic Control: A Randomized Clinical Trial. JAMA ophthalmology Aiello, L. P., Ayala, A. R., Antoszyk, A. N., Arnold-Bush, B., Baker, C., Bressler, N. M., Elman, M. J., Glassman, A. R., Jampol, L. M., Melia, M., Nielsen, J., Wolpert, H. A. 2015; 133 (8): 888-96

    Abstract

    Optimization of glycemic control is critical to reduce the number of diabetes mellitus-related complications, but long-term success is challenging. Although vision loss is among the greatest fears of individuals with diabetes, comprehensive personalized diabetes education and risk assessments are not consistently used in ophthalmologic settings.To determine whether the point-of-care measurement of hemoglobin A(1c) (HbA(1c)) and personalized diabetes risk assessments performed during retinal ophthalmologic visits improve glycemic control as assessed by HbA(1c) level.Ophthalmologist office-based randomized, multicenter clinical trial in which investigators from 42 sites were randomly assigned to provide either a study-prescribed augmented diabetes assessment and education or the usual care. Adults with type 1 or 2 diabetes enrolled into 2 cohorts: those with a more-frequent-than-annual follow-up (502 control participants and 488 intervention participants) and those with an annual follow-up (368 control participants and 388 intervention participants). Enrollment was from April 2011 through January 2013.Point-of-care measurements of HbA1c, blood pressure, and retinopathy severity; an individualized estimate of the risk of retinopathy progression derived from the findings from ophthalmologic visits; structured comparison and review of past and current clinical findings; and structured education with immediate assessment and feedback regarding participant's understanding. These interventions were performed at enrollment and at routine ophthalmic follow-up visits scheduled at least 12 weeks apart.Mean change in HbA(1c) level from baseline to 1-year follow-up. Secondary outcomes included body mass index, blood pressure, and responses to diabetes self-management practices and attitudes surveys.In the cohort with more-frequent-than-annual follow-ups, the mean (SD) change in HbA(1c) level at 1 year was -0.1% (1.5%) in the control group and -0.3% (1.4%) in the intervention group (adjusted mean difference, -0.09% [95% CI, -0.29% to 0.12%]; P = .35). In the cohort with annual follow-ups, the mean (SD) change in HbA(1c) level was 0.0% (1.1%) in the control group and -0.1% (1.6%) in the intervention group (mean difference, -0.05% [95% CI, -0.27% to 0.18%]; P = .63). Results were similar for all secondary outcomes.Long-term optimization of glycemic control is not achieved by a majority of individuals with diabetes. The addition of personalized education and risk assessment during retinal ophthalmologic visits did not result in a reduction in HbA(1c) level compared with usual care over 1 year. These data suggest that optimizing glycemic control remains a substantive challenge requiring interventional paradigms other than those examined in our study.clinicaltrials.gov Identifier:NCT01323348.

    View details for DOI 10.1001/jamaophthalmol.2015.1312

    View details for PubMedID 25996273

    View details for PubMedCentralID PMC4924347

  • Retinal Neovascularization and Endogenous Fungal Endophthalmitis in Intravenous Drug Users Ophthalmology Vemulakonda, G. A. 2014

    View details for DOI 10.1016/j.ophtha.2014.03.037

  • Macular Edema After Cataract Surgery in Eyes Without Preoperative Central-Involved Diabetic Macular Edema JAMA OPHTHALMOLOGY Baker, C. W., Almukhtar, T., Bressler, N. M., Glassman, A. R., Grover, S., Kim, S. J., Murtha, T. J., Rauser, M. E., Stockdale, C., Diabetic Retinopathy Clinical Res 2013; 131 (7): 870-879

    Abstract

    The incidence of development or worsening of macular edema (ME) is variable in eyes without diabetic ME (DME) undergoing cataract surgery.To estimate the incidence of central-involved ME 16 weeks following cataract surgery in eyes with diabetic retinopathy without definite central-involved DME preoperatively.In a multicenter, prospective, observational study, 293 participants with diabetic retinopathy without definite central subfield thickening on optical coherence tomography (OCT) underwent cataract surgery.Cataract extraction surgery performed within 28 days of enrollment of eyes without DME in individuals with diabetes mellitus.Development of central-involved ME defined as the following: (1) OCT central subfield thickness of 250 μm or greater (time-domain OCT) or 310 μm or greater (spectral-domain OCT) with at least a 1-step increase in logOCT central subfield thickness preoperatively to the 16-week visit; (2) at least a 2-step increase in logOCT central subfield thickness preoperatively to the 16-week visit; or (3) nontopical treatment for ME received before the 16-week visit with either of the OCT criteria met at the time of treatment.The median participant age was 65 years. The median visual acuity letter score was 69 letters (Snellen equivalent 20/40). Forty-four percent of eyes had a history of treatment for DME. Sixteen weeks postoperatively, central-involved ME was noted in 0% (95% CI, 0%-20%) of 17 eyes with no preoperative DME. Of eyes with non-central-involved DME, 10% (95% CI, 5%-18%) of 97 eyes without central-involved DME and 12% (95% CI, 7%-19%) of 147 eyes with possible central-involved DME at baseline progressed to central-involved ME. History of DME treatment was significantly associated with central-involved ME development (P < .001).In eyes with diabetic retinopathy without concurrent central-involved DME, presence of non-central-involved DME immediately prior to cataract surgery or history of DME treatment may increase the risk of developing central-involved ME 16 weeks after cataract extraction.

    View details for DOI 10.1001/jamaophthalmol.2013.2313

    View details for Web of Science ID 000323553600008

    View details for PubMedID 23599174

  • Rationale for the diabetic retinopathy clinical research network treatment protocol for center-involved diabetic macular edema. Ophthalmology Aiello, L. P., Beck, R. W., Bressler, N. M., Browning, D. J., Chalam, K. V., Davis, M., Ferris, F. L., Glassman, A. R., Maturi, R. K., Stockdale, C. R., Topping, T. M. 2011; 118 (12): e5-14

    Abstract

    To describe the underlying principles used to develop a web-based algorithm that incorporated intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment for diabetic macular edema (DME) in a Diabetic Retinopathy Clinical Research Network (DRCR.net) randomized clinical trial.Discussion of treatment protocol for DME.Subjects with vision loss resulting from DME involving the center of the macula.The DRCR.net created an algorithm incorporating anti-VEGF injections in a comparative effectiveness randomized clinical trial evaluating intravitreal ranibizumab with prompt or deferred (≥24 weeks) focal/grid laser treatment in eyes with vision loss resulting from center-involved DME. Results confirmed that intravitreal ranibizumab with prompt or deferred laser provides superior visual acuity outcomes compared with prompt laser alone through at least 2 years. Duplication of this algorithm may not be practical for clinical practice. To share their opinion on how ophthalmologists might emulate the study protocol, participating DRCR.net investigators developed guidelines based on the algorithm's underlying rationale.Clinical guidelines based on a DRCR.net protocol.The treatment protocol required real-time feedback from a web-based data entry system for intravitreal injections, focal/grid laser treatment, and follow-up intervals. Guidance from this system indicated whether treatment was required or given at investigator discretion and when follow-up should be scheduled. Clinical treatment guidelines, based on the underlying clinical rationale of the DRCR.net protocol, include repeating treatment monthly as long as there is improvement in edema compared with the previous month or until the retina is no longer thickened. If thickening recurs or worsens after discontinuing treatment, treatment is resumed.Duplication of the approach used in the DRCR.net randomized clinical trial to treat DME involving the center of the macula with intravitreal ranibizumab may not be practical in clinical practice, but likely can be emulated based on an understanding of the underlying rationale for the study protocol. Inherent differences between a web-based treatment algorithm and a clinical approach may lead to differences in outcomes that are impossible to predict. The closer the clinical approach is to the algorithm used in the study, the more likely the outcomes will be similar to those published.Proprietary or commercial disclosure may be found after the references.

    View details for DOI 10.1016/j.ophtha.2011.09.058

    View details for PubMedID 22136692

  • Aqueous and vitreous concentrations following topical administration of 1% voriconazole in humans. Archives of ophthalmology (Chicago, Ill. : 1960) Vemulakonda, G. A., Hariprasad, S. M., Mieler, W. F., Prince, R. A., Shah, G. K., Van Gelder, R. N. 2008; 126 (1): 18-22

    Abstract

    To determine the penetration of 1% voriconazole solution into the aqueous and vitreous following topical administration.A prospective nonrandomized study of 13 patients scheduled for pars plana vitrectomy surgery. Aqueous and vitreous samples were obtained and analyzed after topical administration of 1% voriconazole every 2 hours for 24 hours before surgery. Drug concentration quantitation was performed using high-performance liquid chromatography.The mean (SD) sampling time after topical administration of the last voriconazole dose was 24 (14) minutes. The mean (SD) voriconazole concentrations in the aqueous and vitreous were 6.49 (3.04) microg/mL and 0.16 (0.08) microg/mL, respectively. Aqueous concentrations exceeded the minimum inhibitory concentration at which 90% of isolates are inhibited (MIC(90)) for a wide spectrum of fungi and mold, including Aspergillus, Fusarium, and Candida species. Vitreous concentrations of voriconazole exceeded the MIC(90) for Candida albicans.Topically administered voriconazole achieves therapeutic concentrations in the aqueous of the noninflamed human eye for many fungi and molds and achieves therapeutic levels in the vitreous for Candida species. Topical voriconazole may be a useful agent for the management of fungal keratitis and for prophylaxis against the development of fungal endophthalmitis.

    View details for DOI 10.1001/archophthalmol.2007.8

    View details for PubMedID 18195213