About

Pratap Challa is a Professor of Ophthalmology and serves as the Residency Program Director in the Department of Ophthalmology at Duke University. He is based in the Wadsworth Building in Durham, North Carolina. His professional role includes overseeing residency training in ophthalmology, contributing to the education and development of future ophthalmologists within the Duke Department of Ophthalmology. His work is integral to the department's mission of providing comprehensive eye care, advancing ophthalmic education, and supporting research initiatives.

Research topics

• Medicine
• Ophthalmology
• Internal medicine
• Biology
• Chemistry
• Endocrinology
• Cell biology
• Meteorology
• Anesthesia
• Physics

Selected publications

• The Duke Baerveldt 350 Versus Ahmed ClearPath 350 Study (DBACS): A Randomized Control Trial In Adults With Medically Refractory Glaucoma

  Clinical ophthalmology · 2025-09-01 · 1 citations

  articleOpen access

  Purpose: To compare the efficacy and safety profile of two non-valved glaucoma drainage devices (GDDs). Patients & Methods: In this randomized control trial, patients with medically refractory glaucoma needing surgical intervention were randomized for placement of a Baerveldt 350 (BVT) or an Ahmed ClearPath 350 (ACP). Baseline testing included measures of visual acuity, intraocular pressure (IOP), medication, visual fields, and optical coherence tomography. IOP, medication use, and complications were assessed at post-operative day one, week one, week four, week six, month three, month six, and year one. Results: A total of 76 subjects were enrolled, 37 randomized to BVT and 39 to ACP. A total of 70 subjects underwent surgery and 61 subjects were seen to one year of follow-up. No significant differences were observed in age, sex, race, eye laterality, glaucoma type, glaucoma severity, prior surgeries, and baseline IOP (p = 0.66, 0.10, 0.70, 0.48, 0.06, 0.65, 0.50, 0.56 respectively), between the groups. At one year, both groups showed significant reductions in IOP, though the ACP group showed lower mean IOP at 12 months (11.4 vs 14.1 mmHg, p = 0.010) as well as a larger IOP decrease compared to baseline (-44.1 vs -30.7%, p = 0.038). Medication usage remained similar in both groups. Complications were infrequent and comparable between the devices. This study did not reach the number of subjects thought to be needed to power the study appropriately; despite the enrollment numbers, statistically significant differences were noted, and no type II occurred for the primary endpoint of mean IOP. Conclusion: While both GDDs demonstrated efficacy over a 1-year period, ACP showed a lower mean IOP and greater IOP percentage decrease from baseline compared to BVT. Both exhibited low complication rates. Further research over a longer follow-up is warranted to explore the IOP differences.

  PublisherOA PDFDOI

• Contemporary diversity trends among matched ophthalmology residents in the USA

  BMJ Leader · 2025-07-02

  article

  BACKGROUND: Ophthalmology remains one of the least diverse medical specialties, despite ongoing efforts to promote inclusion. To address the gap in recent literature and understand the demographic trajectory of this specialty, this study analyses current demographic trends among ophthalmology residents in the USA. METHODS: US ophthalmology residents enrolled with the Accreditation Council for Graduate Medical Education between 2008 and 2022 were included. Racial trends were analysed over the period of 2012-2022, and sex trends were analysed across 2008-2022, according to data availability. RESULTS: Over the study period, the percentage of female ophthalmology residents remained stable from 41% in 2008 to 41.8% in 2022 (compared with 54.6% of US medical students). The least represented racial group from 2012 to 2022 was American Indian/Alaskan Native (ranging 0%-0.35%) followed by black/African American (ranging 1.42%-3.01%) and Hispanic/Latin/Spanish origin (ranging 2.05%-7.50%). The year with the greatest proportion of under-represented in medicine (URiM) ophthalmology residents was 2021-2022, with 10.5% URiM residents (0% American Indian/Alaskan Native, 3.01% black/African American, 7.50% Hispanic/Latin/Spanish). The summed proportions of URiM ophthalmology residents were significantly less before 202 (5.4%) compared with after (10%) (p<0.001). CONCLUSIONS: Overall, female and URiM residents are under-represented in ophthalmology. The proportion of female residents remained constant between 2008 and 2022, highlighting a need for additional recruitment efforts. The proportion of URiM residents increased over the same period, highlighting a time period of interest for future research on recruitment strategies.

  PublisherDOI

• Reply to Correspondence Re: Gedde et al.: Reporting Clinical Endpoints in Studies of Minimally Invasive Glaucoma Surgery

  UNC Libraries · 2025-11-05

  articleOpen access
  PublisherDOI

• Adrenergic Agents

  2024-05-28

  book-chapter1st authorCorresponding

  Topical beta-blockers decrease aqueous humor formation (AHF) 1 , 2 and are used long term in the therapy of the chronic open-angle glaucomas and short term for various acute glaucomas. The introduction of the topical beta-blocker timolol in 1978 was greeted with overwhelming enthusiasm not only because of the remarkable efficacy of beta-blockers but also because of the relative low frequency of ocular side effects. Before the beta-blockers, the only topical antiglaucoma medications available were the miotics and epinephrine-like compounds, the potential side effects of which will be discussed shortly. In practice, the potential ocular side effects from these latter agents resulted in an appropriate hesitancy for clinicians to treat elevated intraocular pressure (IOP), even if substantial, unless there was obvious end-organ damage (optic nerve) or abnormalities in (preautomated perimetry) visual fields. The occurrence of these side effects also adversely affected patient compliance when aggressive therapy was required for advanced glaucomatous damage.

  PublisherDOI

• The Miotics

  2024-05-28

  book-chapter1st authorCorresponding

  Miotics, or more appropriately termed muscarinic (cho-linergic-acting) agonists, have been used in the treatment of the glaucomas for more than 100 years. This is the first class of medications used to treat glaucoma, and they remain an important glaucoma therapy for both open-angle and angle-closure glaucomas. It is noteworthy that our understanding and discrimination between open-angle and angle-closure glaucomas have been widely recognized for only the past 60 or 70 years. (Paul Chandler was an important voice in teaching this differentiation.) Cholinergic-acting agonists are miotics, but this effect on the pupil is of significance only in the acute treatment of angle-closure glaucoma due to pupillary block. For the chronic treatment of primary open-angle glaucoma (POAG), the side effects of pupillary miosis and accommodation can be bothersome for many patients and can lead to discontinuation of these medications. Some of the discussion in this chapter is of more historical than clinical relevance because the practice patterns of medical care have shifted over time. It is intrinsic, however, to understand the history of miotics as it relates to glaucoma therapy and to recognize the continuing role that this group of medications has in patient care.

  PublisherDOI

• Special Commentary: Reporting Clinical Endpoints in Studies of Minimally Invasive Glaucoma Surgery

  Ophthalmology · 2024-08-08 · 37 citations

  article
  PublisherDOI

• Performance of Polygenic Risk Scores for Primary Open-Angle Glaucoma in Populations of African Descent

  JAMA Ophthalmology · 2024-11-14 · 4 citations

  letterOpen access

  Importance: Primary open-angle glaucoma (POAG) polygenic risk scores (PRSs) continue to be evaluated in primarily European-ancestry populations despite higher prevalence and worse outcomes in African-ancestry populations. Objective: To evaluate how established POAG PRSs perform in African-ancestry samples from the Genetics in Glaucoma Patients of African Descent (GIGA), Genetics of Glaucoma in Individuals of African Descent (GGLAD), and Million Veteran Program (MVP) datasets and compare these with European-ancestry samples. Design, Setting, and Participants: This was a multicenter, cross-sectional study of POAG cases and controls from Tanzania, South Africa, Nigeria, Ghana, and the US. Included were individuals of African descent from South Africa and Tanzania from the GIGA dataset; individuals of African descent from Ghana, Nigeria, and the US from the GGLAD dataset; and individuals of African or European descent from the US in the MVP dataset. Data were analyzed from January 2022 to July 2023. Exposures: Three PRSs derived from large meta-analyses of European and Asian populations, namely Gharahkhani et al (Gharahkhani PRS), Han et al (Han PRS), and Craig et al (Craig PRS). Main Outcomes and Measures: Odds ratios (ORs) for POAG risk stratification comparing the highest and lowest quintiles; area under the receiver operating characteristic curve (AUROC), and liability coefficient of determination (R2) for the addition of PRS to a baseline of age, sex, and first 5 principal components. Results: A total of 11 673 cases and 66 432 controls were included in this study across 7 ancestral groups. Mean (SD) age of the total participants was 76.9 (8.7) years, with 74 304 males (95.1%). The following were included in each dataset: GIGA (663 cases, 476 controls), GGLAD (1471 cases, 1482 controls), and MVP (9559 cases, 64 474 controls). Increases in ORs were found for the highest POAG risk quintile ranging from an OR of 1.68 (95% CI, 1.17-2.43) in Ghanaians to 7.05 (95% CI, 2.73-19.6) in the South African multiple ancestry group (which derives from at least 5 distinct ancestral groups: Khoisan, Bantus, Europeans, Indians, and Southeast Asians) with the Gharahkhani PRS. The Han PRS showed OR increases for the highest POAG risk quintile ranging from 2.27 (95% CI, 1.49-3.47) in African American individuals in the GGLAD dataset to 7.24 (95% CI, 6.47-8.12) in Europeans. The Craig PRS predicted OR increases in the highest quintile for all groups ranging from 1.51 (95% CI, 1.05-2.18) in Ghanaians to 6.31 (95% CI, 5.67-7.04) in Europeans. However, AUROC and R2 increases above baseline were lower for all African-ancestry compared with European-ancestry groups in the 3 tested PRSs. Conclusions and Relevance: In this cross-sectional study, despite some improvements in OR-based risk stratification using the Gharahkhani PRSs, Han PRSs, and Craig PRSs, consistently lower improvements in AUROC and R2 for African-ancestry compared with European-ancestry groups highlight the need for risk prediction models tailored to diverse populations.

  PublisherOA PDFDOI

• Representation of Women at Select Academic Ophthalmology Institutions in the United States

  Journal of Academic Ophthalmology · 2024-11-07

  articleOpen access

  Purpose: To investigate the representation of women among ophthalmology faculty members at select academic institutions in the United States (US). Design: Cross-sectional study Subjects: Clinical faculty members at the top 20 academic ophthalmology institutions in the U.S. according to US News and World Report ranking Methods: Gender as reported on institutional websites either directly or via pronouns, academic rank, medical school graduation year, and subspecialty were collected about clinical faculty members with MD, MD/PhD, MBBS or DO from their respective institutional websites. The number of publications for each faculty member was collected using Scopus ® (Elsevier, Netherlands). One way z-test was used to compare proportions, and an independent t-test was used to compare means. Main Outcome Measures: Gender proportions across data points described in the Methods. Results: Women comprised 416 (38%) of the 1099 ophthalmology faculty members reviewed (z-statistic: -0.43, p Conclusion: There remain more men than women at some of the top academic ophthalmology institutions in the US and significantly fewer women at the full professor rank. This gap in representation appears to be narrowing over time. Additional efforts to reduce the challenges faced by women in academic ophthalmology may narrow this gap further.

  PublisherDOI

• Reply

  Ophthalmology · 2024-11-04

  letterOpen access
  PublisherOA PDFDOI

• Rho-Associated Protein Kinase Inhibitors and Primary Open-Angle Glaucoma

  2024-05-28

  book-chapter1st authorCorresponding

  Rho-associated protein kinase (ROCK) inhibitors have been broadly investigated over the past 15 years as potential agents for the treatment of elevated intraocular pressure (IOP) secondary to primary open-angle glaucoma (POAG). 1 , 2 Preclinical and clinical evidence has suggested that ROCK inhibitors can lower IOP through a unique mechanism of action heretofore untargeted by current ocular hypotensive drugs. 3-9 Mechanistically, ROCK inhibitors can lower IOP through their ability to induce changes in the tissue of the conventional outflow pathway of the anterior chamber, which includes: (1) disassembly of cell-cell junctions and subsequent loosening of the paracellular spaces between cells and (2) general relaxation of contractile tone. Both physiologic actions can improve outflow facility of aqueous humor from the anterior chamber. 3 , 4 , 10 Furthermore, ROCK inhibitors have been postulated to enhance blood flow to the optic nerve, which serves to ameliorate nerve destruction and potentially preserve sight. 11 The purpose of this chapter is to analyze the evolving role of ROCK inhibitors in the treatment of POAG. While the authors recognize that ROCK inhibitors have been studied for the treatment of other forms of glaucoma, the primary focus of this chapter will be their use in POAG.

  PublisherDOI

Recent grants

• NIH Grant K23EY014019

  NIH · $931k · 2009

Frequent coauthors

• R. Rand Allingham

  119 shared

• Leon W. Herndon

  Duke University

  111 shared

• David L. Epstein

  84 shared

• Paul P. Lee

  Wayne State University

  77 shared

• Sandra S. Stinnett

  Duke University

  68 shared

• Michael A. Hauser

  Duke University

  62 shared

• Sanjay Asrani

  57 shared

• Julia Song

  Southern California Eye Institute

  53 shared