Chi Mong Christopher Or

All Publications

• The relationship between retinal vascular tortuosity and retinal vasculitis. Journal of ophthalmic inflammation and infection Zhang, X., Anover, F. A., Hung, J. H., Than, N. T., Mobasserian, A., Saengsirinavin, A. O., Yavari, N., Feky, D. E., Tram Tran, A. N., Elaraby, O., Guo, J., Karaca, I., Yoo, W. S., Akhavanrezayat, A., Or, C. M., Do, D. V., Nguyen, Q. D. 2025; 15 (1): 65

  View details for DOI 10.1186/s12348-025-00512-7

  View details for PubMedID 41028280

  View details for PubMedCentralID 7944954

• Cobalt-induced Retinopathy: Unveiling the hidden risk of knee prosthesis. American journal of ophthalmology case reports Saengsirinavin, A., Hung, J., Khatri, A., Nguyen, C. D., Seangsirinavin, P., Anover, F. A., Yavari, N., El-Feky, D., Than, N. T., Elaraby, O., Zhang, X., Tran, A. N., Yasar, C., Mobasserian, A., Karaca, I., Akhavanrezayat, A., Or, C. M., Nguyen, Q. D. 2025; 39: 102369

  Abstract

  Purpose: To report a case of cobalt-induced retinopathy from a knee prosthesis and to outline the diagnostic challenges and management approach.Observation: A 67-year-old female presented with chronic bilateral visual disturbances, including blurred vision and photopsia, which began shortly after receiving a cobalt-containing knee prosthesis (DePuy Sigma Total Knee System, recalled by FDA in 2014, Recall No. Z-0423-2014). Ophthalmic evaluation revealed bilateral chorioretinitis, cystoid macular edema, and optic disc inflammation. Removal of the cobalt-containing prosthesis, along with aggressive immunosuppressive therapy, led to significant improvement in visual acuity and retinal function, as confirmed by fluorescein angiography, electroretinography, and Goldmann visual field testing.Conclusion: This case adds to the limited literature on cobalt-induced retinopathy by demonstrating that even small prosthetic implants, such as knee prostheses, can lead to systemic cobalt toxicity with significant ocular complications. Early diagnosis, combined with prompt removal of the affected prosthesis and management of inflammation, is crucial for restoring vision and preventing further damage.

  View details for DOI 10.1016/j.ajoc.2025.102369

  View details for PubMedID 40678736

• Efficacy and safety of biologics in pediatric non-infectious retinal vasculitis. American journal of ophthalmology Karaca, I., Thng, Z. X., Bromeo, A., Mobasserian, A., Hung, J. H., Akhavanrezayat, A., Than, N. T., Yasar, C., Yavari, N., Feky, D. E., Elaraby, O., Tran, A. N., Zhang, X., Saengsirinavin, A. O., Anover, F. A., Bai, Y., Guo, J., Or, C. M., Do, D. V., Nguyen, Q. D. 2025

  Abstract

  To assess the efficacy and safety of adalimumab (ADA) injections (Group 1), infliximab (IFX) (Group 2), and tocilizumab (TCZ) (Group 3) infusions in pediatric non-infectious retinal vasculitis (RV).Retrospective interventional case series.Pediatric patients who were diagnosed with non-infectious RV and treated with biologics (ADA, IFX, TCZ) for ≥6 months were included. Chart review of 11 patients (18 eyes), 17 patients (30 eyes), and 7 patients (11 eyes) in Group 1, 2 and 3, respectively, was performed to assess clinical characteristics, central subfield thickness (CST), and fluorescein angiography (FA) score using the Angiographic Scoring for the Uveitis Working Group (ASUWOG) system.Mean age was 13.5±4.3 years in Group 1, 11.8±2.5 years in Group 2, and 13.9±4.1 years in Group 3 (p=0.332). Eight patients (72.7%, 13 eyes) in Group 1, and 14 patients (82.4%, 24 eyes) in Group 2 were biologic-naïve, whereas in Group 3 all patients were treated with ADA and/or IFX prior to TCZ. Mean FA scores were significantly reduced from 6.8±2.6, 13.4±4.8, and 12.8±4.0 at baseline to 0.9±2.3, 3.6±4.6, and 4.4±3.9 at final visit in Group 1, 2, and 3, respectively (p<0.05). Complete RV resolution was observed in 12 (66.7%), 13 (43.3%), and 1 (9.1%) eyes; mean time to complete resolution was 11.0±5.0, 13.3±5.8, and 23 months in Group 1, 2, and 3, respectively. No significant adverse events were observed in any group, except hair loss in one patient which led to discontinuation of IFX infusions after 20 cycles of therapy.ADA, IFZ, and TCZ are effective and safe treatment options for pediatric non-infectious RV as objectively shown by FA scoring. TCZ appears as an effective therapy for patients with JIA-associated RV or those who failed TNF-α inhibitors.

  View details for DOI 10.1016/j.ajo.2025.05.002

  View details for PubMedID 40374140

• Inherited retinal diseases-associated uveitis. Survey of ophthalmology Hung, J. H., Jain, T., Khatri, A., Nguyen, T. B., Nguyen, C. D., Yavari, N., Mobasserian, A., Karaca, I., Saeed Mohammadi, S., Gupta, A. S., Or, C. M., Akhavanrezayat, A., Yasar, C., Saengsirinavin, A. O., Than, N. T., Anover, F. A., Elaraby, O., El Feky, D., Yoo, W. S., Zhang, X., Thng, Z. X., Diana, V. D., Nguyen, Q. D. 2025

  Abstract

  Inherited retinal diseases (IRDs) are genetic disorders characterized by progressive photoreceptor function loss, often leading to significant visual impairment. Uveitis has been increasingly recognized in the clinical course of some IRDs. Despite advances in understanding the genetic causes and pathophysiology of IRDs, gaps remain in understanding the roles of inflammation and autoimmunity in IRD and IRD-associated uveitis. This review discusses IRD-associated uveitis, including anterior, intermediate, posterior, and panuveitis, as well as complications such as cystoid macular edema and retinal vasculitis. In patients with IRD-associated uveitis, mutations affecting protein function in cilia or photoreceptor outer segments suggest a universal autoimmunity mechanism triggered by the immunogenicity of shedding photoreceptor discs. Notably, in patients where uveitis is the initial sign, CRB1 mutations are often implicated, likely due to the compromised blood-retina barrier function or external limiting membrane. Other mechanisms leading to uveitis preceding IRD diagnosis include ALPK1 mutations, which activate the proinflammatory NF-κB pathway, CAPN5 mutations, which lead to dysfunction of the innate and adaptive immune systems, and VCAN1 mutations, which elicit immunogenicity due to irregularities in vitreous modeling. Understanding these mechanisms could enhance the development of innovative treatments that target personalized inflammation pathways in IRDs.

  View details for DOI 10.1016/j.survophthal.2025.03.011

  View details for PubMedID 40157547

• Epidemiologic study of pediatric uveitis and its ophthalmic complications using the Korean National Health Insurance Claim Database. American journal of ophthalmology Hong, E. H., Kim, J., Kang, M. H., Park, S. W., Tran, A. N., Karaca, I., Akhavanrezayat, A., Or, C. M., Thng, Z. X., Bromeo, A. J., Khatri, A., Do, D., Nguyen, Q. D., Shin, Y. U. 2025

  Abstract

  To investigate the incidence and ophthalmic complications of pediatric uveitis using the Korean National Health Insurance (NHI) Service database.Nationwide population-based longitudinal cohort study.This study used the NHI database from 2005 to 2021 and included individuals <18 years of age diagnosed with uveitis on at least three separate visits between 2010-2014, with a five-year wash-out period and a seven-year follow-up period. All uveitis cases were classified as either anterior or non-anterior on the basis of the diagnostic code. The occurrence of ophthalmic complications during the follow-up period, and the systemic and socioeconomic associations between pediatric uveitis and its ophthalmic complications were investigated. We obtained the incidence of total, anterior, and non-anterior pediatric uveitis between 2010-2014; the percentage of ophthalmic complications during the follow-up period; and hazard ratios for ophthalmic complications of anterior and non-anterior uveitis.A total of 9,495 cases of pediatric uveitis (8,734 cases with anterior and 761 with non-anterior uveitis) were identified, with an average annual incidence (per 10,000 children) of total, anterior, and non-anterior uveitis being 2.0, 1.8, and 0.2, respectively. The most common complications were glaucoma or presumed ocular hypertension, macular disease, and amblyopia. Patients with non-anterior uveitis had a significantly higher risk of ophthalmic complications including retinal detachment, cataract, amblyopia, and glaucoma or presumed ocular hypertension than those with anterior uveitis.This nationwide analysis of pediatric uveitis in South Korea revealed an average incidence of 2.0 per 10,000 children, highlighting the higher risks of ophthalmic complications associated with non-anterior uveitis.

  View details for DOI 10.1016/j.ajo.2025.03.019

  View details for PubMedID 40089173

• Trends in nationwide incidence of uveitis in South Korea using the National Health Insurance claims database from 2010 to 2021. Eye (London, England) Hong, E. H., Kim, J., Park, S., Cho, H., Kang, M. H., Bromeo, A., Tran, A. N., Akhavanrezayat, A., Or, C. M., Thng, Z. X., Shin, Y. U., Nguyen, Q. D. 2024

  Abstract

  To investigate the population-based incidence of uveitis and the differences between anterior and non-anterior uveitis using the comprehensive Korean National Health Insurance Service (NHIS) database.We extracted data of patients who visited the clinic and were diagnosed with uveitis (based on Korean Classification of Diseases) from 2010 to 2021. The incidence of uveitis, differences between the demographics, and the underlying co-morbidities of anterior uveitis, non-anterior uveitis, and control groups were investigated.We identified 919,370 cases with uveitis (anterior: 800,132; non-anterior: 119,238). The average incidences (per 10,000 persons) of anterior and non-anterior uveitis were 13.0 (95% confidence interval [CI], 12.9-13.0), and 1.9 (95% CI, 1.9-1.9), respectively. The incidence increased (2010: 13.0; 2019: 16.5) but decreased during the coronavirus disease (COVID-19) pandemic (2020: 15.5; 2021: 15.4). The non-anterior group was significantly associated with sex (female, odds ratio [OR]: 1.09, p < 0.0001), specific age range (40-69 years, p < 0.0001), high Charlson Comorbidity Index (p < 0.0001), high household income (p < 0.0001), and various immunologic diseases (antiphospholipid antibody syndrome, OR: 1.79, p < 0.0001; systemic lupus erythematosus, OR: 1.22, p < 0.0001; psoriasis, OR: 1.13, p < 0.0001; ulcerative colitis, OR: 1.11, p = 0.0013; tuberculosis, OR: 1.09, p < 0.0001; rheumatoid arthritis, OR: 1.05, p < 0.0001) compared with the anterior group.Using the NHIS database, we conducted the largest population-based epidemiological study on uveitis in South Korea to estimate its increasing incidence in the past decade (including changes during COVID-19 pandemic) as well as its anatomical distribution. Our results may be beneficial for estimating the national burden of uveitis.

  View details for DOI 10.1038/s41433-024-03500-8

  View details for PubMedID 39690300

  View details for PubMedCentralID 505625

• Efficacy and tolerability of subcutaneous repository corticotropin injection in refractory ocular inflammatory diseases. Journal of ophthalmic inflammation and infection Yavari, N., Ghoraba, H., Or, C., Thng, Z. X., Mohammadi, S. S., Karaca, I., Mobasserian, A., Akhavanrezayat, A., Le, A., Lyu, X., Khatri, A., Yoo, W. S., Feky, D. E., Than, N. T., Elaraby, O., Saengsirinavin, A. O., Zhang, X., Anover, F. A., Gupta, A. S., Halim, M. S., Jison, L. A., Nguyen, Q. D. 2024; 14 (1): 56

  Abstract

  Repository corticotropin injection (RCI) has been suggested to exert immunomodulatory and anti-inflammatory effects in ocular inflammation. The index retrospective study aimed to evaluate the efficacy and tolerability of subcutaneous RCI in patients with active scleritis or uveitis.Medical records of patients who were diagnosed with different types of active scleritis or uveitis and received RCI for more than six months at a tertiary eye center were reviewed. Patient characteristics including age, sex, comorbidities, clinical findings, treatment details, and adverse events were recorded. A total of 17 eyes of 17 patients were included. Median age was 43 years old and 53% of patients were male. Mean treatment duration was 25.4 ± 15.5 months. Indications for RCI therapy were scleritis (7 anterior and 1 posterior) (47.8%), panuveitis (17.4%), retinal vasculitis (17.4%), chronic/recurrent anterior uveitis (13%), and posterior uveitis (4.35%). RCI was initiated at a dose of 40 to 80 units 3 times weekly. Given the adequate control of inflammation, RCI was successfully discontinued in four patients (23.5%). Prior to RCI therapy, 14 (82.3%) patients were on oral prednisone at an average of 10 mg daily (range 2.5-40 mg), and two (11.7%) patients discontinued prednisone immediately before initiating RCI due to side effects. After six months of therapy, the prednisone dose was reduced in four (23.5%) patients to an average of 3 mg daily (range 1-5 mg) and was stopped in eight (53%) patients. Concomitant immunomodulatory therapies (IMTs) included mycophenolate mofetil (23.5%) and methotrexate (23.5%), and adalimumab (23.5%). Ten patients were on IMTs prior to using RCI, and during the course of treatment, IMT was stopped in two patients and reduced in one. Side effects included insomnia (23%), hypertension (11.7%), lower extremity edema (11.7%), hyperglycemia (11.7%), weight gain (11.7%), and infection (5.8%).RCI may be considered as a potential therapy with acceptable tolerability for patients with non-infectious scleritis or uveitis.

  View details for DOI 10.1186/s12348-024-00428-8

  View details for PubMedID 39448433

  View details for PubMedCentralID 7492378

• Characteristics of Patients with Adalimumab therapy that were Anti-adalimumab Antibodies Positive but Later turned Negative Or, C., Hung, J., Khatri, A., Bazojoo, V., Akhavanrezayat, A., Nguyen, Q. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2024

  View details for Web of Science ID 001312227707240

• Risk factors for development of anti-adalimumab antibodies in non-infectious uveitis. Heliyon Bromeo, A. J., Karaca, I., Ghoraba, H. H., Lyu, X., Than, N. T., Ongpalakorn, P., Shin, Y. U., Uludag, G., Tran, A. N., Thng, Z. X., Do, D. V., Or, C. M., Nguyen, Q. D. 2024; 10 (9): e29313

  Abstract

  Purpose: To evaluate risk factors associated with development of anti-adalimumab antibodies (AAA) in patients with non-infectious uveitis treated with adalimumab.Methods: A retrospective, cross-sectional, case-control study was done evaluating patients with non-infectious uveitis treated with adalimumab for at least 12 months and have undergone testing for AAA levels. Demographics, clinical characteristics, grading of ocular inflammation, and previous and concomitant immunomodulatory therapy were assessed. Univariate and multivariate analysis were done to estimate odds ratio (OR) with 95% confidence intervals for the various risk factors.Results: A total of 31 patients were included in the analysis, in which 12 patients who tested positive (Group 1) were matched with 19 patients who tested negative for AAA (Group 2). The groups differed significantly in terms of sex (female) (91.7% vs 52.6%, p=0.046), presence of systemic disease (91.7% vs 42.1%, p=0.008), and presence of anterior chamber inflammation at baseline (100% vs 63.2%, p=0.026). A history of interruption in anti-TNF therapy prior to starting or restarting adalimumab was found to have an increased odds for development of AAA (OR 16.89 [2.92, 107.11], p=0.008), as well as flare-ups (reactivation of disease) during adalimumab therapy (OR 6.77 [1.80, 61.80], p=0.027). Weekly dosing of adalimumab was shown to decrease odds of AAA development (OR 0.34 [0.02, 0.70], p=0.040), while concomitant anti-metabolite therapy was not shown to be a statistically significant protective factor (OR 2.22 [0.50, 9.96], p=0.148).Conclusions: History of interruption in anti-TNF therapy and flare during adalimumab were associated with development of AAA, while weekly dosing of adalimumab was protective against AAA. Identification of those with higher risk of developing AAA may guide in clinical decision making to optimize management for these patients.

  View details for DOI 10.1016/j.heliyon.2024.e29313

  View details for PubMedID 38694084

• Repeatability of photopic negative response parameters in normal subjects using Diopsys® NOVA™ Sendino, I., Akhavanrezayar, A., Yavari, N., Perez-Alvarez, A., Karaca, I., Park, S., Khojasteh, H., Ghoraba, H., Or, C., Bromeo, A., Yasar, C., Than, N., Bajozoo, V., Uludag, G., Do, D. V., Nguyen, Q. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2023

  View details for Web of Science ID 001053758300343

• Posterior Segment Ocular Findings in HLA-B27 Positive Patients with Uveitis: A Retrospective Analysis. Clinical ophthalmology (Auckland, N.Z.) Or, C., Lajevardi, S., Ghoraba, H., Park, J. H., Onghanseng, N., Halim, M. S., Hasanreisoglu, M., Hassan, M., Uludag, G., Akhavanrezayat, A., Nguyen, Q. D. 2023; 17: 1271-1276

  Abstract

  To describe the prevalence and characteristics of posterior segment manifestations in patients with HLA-B27-associated uveitis using wide field imaging.Medical records of patients diagnosed with HLA-B27-associated uveitis from a tertiary uveitis clinic were reviewed. Posterior segment involvements including but not limited to peripheral vasculitis, optic disc inflammation, and macula edema documented based on medical records and various imaging modalities including wide field fluorescein angiography and optical coherence tomography, were noted. Demographic characteristics, accompanied with systemic diseases as well as duration and chronicity of uveitis, were also evaluated. Patients with significant systemic and ocular comorbidities were excluded. Statistical analyses including chi-squared tests and paired t-tests were employed.Of the 44 patients with HLA-B27 associated uveitis, 22 patients (50%) were noted to demonstrate posterior segment involvement. Disc leakage and peripheral vasculitis were the most common findings of posterior involvement. Those with anterior chamber inflammation were found to have a significantly increased risk of posterior involvement. Those with posterior involvement were also noted to have a statistically significant decreased visual acuity. No significant association was found between documented duration of disease and posterior segment involvement.The prevalence of posterior segment involvement in HLA-B27 associated uveitis is higher compared to previous reports when evaluated with wide angle imaging modalities. Careful examination of the posterior segment is required in patients with HLA-B27 associated uveitis.

  View details for DOI 10.2147/OPTH.S408728

  View details for PubMedID 37152636

  View details for PubMedCentralID PMC10162386

• Electroretinographic findings in retinal vasculitis. The British journal of ophthalmology Ghoraba, H. H., Matsumiya, W., Or, C., Khojasteh, H., Patel, P., Karaca, I., Regenold, J., Zaidi, M., Hwang, J., Lajevardi, S., Yavari, N., Than, N. T., Park, S. W., Akhavanrezayat, A., Uludag, G., Yasar, C., Leung, L. B., Nguyen, Q. D. 2022

  Abstract

  To describe and correlate electroretinographic responses with clinical and angiographic findings in retinal vasculitis (RV).Medical records of patients with diagnosis of RV at a tertiary eye centre from December 2017 to May 2021 were reviewed. Cases in which fluorescein angiography (FFA) and full field electroretinography (ffERG) were done within 1 month were included. FFAs were graded according to the Angiography Scoring for Uveitis Working Group from 0 to 40, where 0 is normal. A novel ffERG grading system was implemented where individual waves were graded for timing and amplitude and general ffERG score was determined with 6 being a perfect score.20 patients (34 eyes) were included. Mean age was 43.9±19.8 years; 70% were female. Median best-corrected visual acuity was 0.8 (0.08-1). Mean FFA score was 12.6±6.5. Median general ffERG score was 5 (0-6). 68% and 91% of eyes had responses with general ffERG scores ≥5 and 4, respectively. Flicker timing was most commonly affected.FFA scores weakly correlated with delayed photopic cone b-wave and flicker timing (p=0.03 and 0.016, respectively). Vitreous haze moderately correlated with delayed cone b-wave timing (p<0.001), delayed flicker timing (p=0.002) and weakly correlated with lower flicker amplitude (p=0.03). Underlying systemic disease was associated with poor ffERG responses.In this study, RV was not frequently associated with severe global retinal dysfunction Higher FFA scores, and vitreous haze grading were weakly, but significantly, correlated with cone-generated ffERG responses.

  View details for DOI 10.1136/bjo-2022-321716

  View details for PubMedID 36130816

• Repeatability of electroretinogram measurements Or, C., Ghoraba, H., Zaidi, M., Akhavanrezayat, A., Regenold, J., Uludag, G., Yasar, C., Park, S., Than, N., Hwang, J., Nguyen, Q. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844401302074

• Efficacy of infliximab and tocilizumab in non-infectious retinal vasculitis: 12-month outcomes Karaca, I., Ghoraba, H., Hwang, J., Or, C., Matsumiya, W., Uludag, G., Zaidi, M., Regenold, J., Khojasteh, H., Mobasserian, A., Park, S., Than, N., Yavari, N., Bazojoo, V., Do, D. V., Quan Dong Nguyen ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844437002245

• Electroretinographic findings in retinal vasculitis Ghoraba, H., Matsumiya, W., Patel, P., Or, C., Karaca, I., Regenold, J., Zaidi, M., Khojasteh, H., Hwang, J., Lajevardi, S., Yavari, N., Park, S., Akhavanrezayat, A., Mobasserian, A., Nguyen, Q. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844401302086

• Novel retinopathy in pediatric retinal vasculitis: long term follow up Yasar, C., Ghoraba, H., Regenold, J., Or, C., Halim, M., Uludag, G., Hwang, J., Karaca, I., Mobasserian, A., Akhavanrezayat, A., Yasar, M., Khojasteh, H., Sepah, Y. J., Do, D. V., Quan Dong Nguyen ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844437001051

• Spectral-domain optical coherence tomography morphological characteristics in patients with cone dystrophy Khojasteh, H., Bazvand, F., Haidari, M., Mahmoudi, A., Mohammadi, S., Esfahani, H., Mirghorbani, M., Azarkish, A., Regenold, J., Akhavanrezayat, A., Karaca, I., Park, S., Uludag, G., Or, C., Ghoraba, H., Quan Dong Nguyen ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2022

  View details for Web of Science ID 000844437005174