Bio

Professional Education


  • Bachelor of Science, University Of Peshawar (2005)
  • B of Medicine and B of Surgery, University Of Peshawar (2012)

Stanford Advisors


Publications

All Publications


  • Multimodal Imaging in Retinal Vasculitis. Ocular immunology and inflammation Agarwal, A., Afridi, R., Agrawal, R., Do, D. V., Gupta, V., Nguyen, Q. D. 2017; 25 (3): 424?33

    Abstract

    Retinal vasculitis presents with inflammation involving the retinal vasculature as an isolated disease or in combination with other ocular or systemic conditions. This entity may be associated with a wide variety of clinical manifestations such as vascular sheathing, cotton-wool spots, retinal ischemia, and neovascularization. Often, retinal vasculitis and its complications lead to diagnostic challenges in identifying the exact etiology of the inflammation. Ancillary investigations such as fundus photography, fluorescein angiography, and more recently, adaptive optics imaging and optical coherence tomography angiography, may provide valuable information that help in establishing the exact diagnosis and initiation of appropriate therapy. In the index review, multimodal imaging features of retinal vasculitis are described. In addition, detection of vascular inflammation using novel noncontact imaging techniques has been highlighted.

    View details for PubMedID 28696172

  • New therapies in development for the management of non-infectious uveitis: a review. Clinical & experimental ophthalmology Hassan, M., Karkhur, S., Bae, J., Halim, M. S., Ormaechea, M. S., Nguyen, N. V., Afridi, R., Sepah, Y. J., Do, D. V., Nguyen, Q. D. 2019

    Abstract

    Uveitis is a spectrum of inflammatory disorders characterised by ocular inflammation and is one of the leading causes of preventable visual loss. The main aim of the treatment of uveitis is to control the inflammation, prevent recurrences of the disease, and preserve vision while minimizing the adverse effects associated with the therapeutic agents. Initial management of uveitis relies heavily on the use of corticosteroids. However, monotherapy with hi-dose corticosteroids is associated with side effects and cannot be maintained long term. Therefore, steroid-sparing agents are needed to decrease the burden of steroid therapy. Currently, the therapeutic approach for non-infectious uveitis (NIU) consists of a step-ladder strategy with the first line option being corticosteroids in various formulations followed by the use of first, second, and third line agents in cases with suboptimal steroid response. Unfortunately, the agents currently at our disposal have limitations such as having a narrow therapeutic window along with their own individual potential side-effect profiles. Therefore, research has been targeted to identify newer drugs as well as new uses for older drugs that target specific pathways in the inflammatory response. Such efforts are made in order to provide targeted and safer therapy with reduced side effects and greater efficacy. Several specially designed molecular antibodies are currently in various phases of investigations that can potentially halt the inflammation in patients with NIU. In the review, we have provided a comprehensive overview of the current and upcoming therapeutic options for patients with NIU.

    View details for PubMedID 30938012

  • New therapies in development for the management of non-infectious uveitis: A review CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY Hassan, M., Karkhur, S., Bae, J. H., Halim, M. S., Ormaechea, M. S., Onghanseng, N., Nguyen, N. V., Afridi, R., Sepah, Y. J., Do, D. V., Nguyen, Q. D. 2019; 47 (3): 396?417

    View details for DOI 10.1111/ceo.13511

    View details for Web of Science ID 000466807900009

  • Blue light versus green light fundus autofluorescence in normal subjects and in patients with retinochoroidopathy secondary to retinal and uveitic diseases. Journal of ophthalmic inflammation and infection Bittencourt, M. G., Hassan, M., Halim, M. S., Afridi, R., Nguyen, N. V., Plaza, C., Tran, A. N., Ahmed, M. I., Nguyen, Q. D., Sepah, Y. J. 2019; 9 (1): 1

    Abstract

    PURPOSE: The aim of this study is to evaluate the differences in the fundus autofluorescence (FAF) signal between the blue light autofluorescence (BAF) from Spectralis (Heidelberg, CA) and green light autofluorescence (GAF) 200TxTM (OPTOS, UK, in normal subjects and in patients with retinochoroidopathies (RC).METHODS: In this prospective study, FAF was performed using BL (lambda=488nm) and GL (lambda=532nm) on normal subjects and patients with RC. The corresponding pairs of BAF and GAF images from both groups were analyzed using Photoshop. The strength of the FAF signal was measured on a gray scale, where optic disc was a standard to indicate absence of AF. In addition, gray values obtained from three identical points (foveal center, and points of hypo and hyper autofluorescence) in the corresponding BAF and GAF images of normal and RC subjects were divided by the optic disc value to calculate autofluorescence signal ratio (R). The R values at fovea (R1), hypoautofluorescent point (R2), and hyperautofluorescent point (R3) were compared between BAF and GAF modalities, in normal and in RC subjects separately.RESULTS: One hundred six pairs (106 eyes) of FAF images analyzed (37 pairs: normal and 69 pairs: RC subjects). In normal subjects, the mean R1, R2, and R3 values for BAF were (1.5±0.88, 1.23±0.58, and 4.73±2.85, respectively) and for GAF were (0.78±0.20, 0.78±0.20, and 1.62±0.39, respectively). Similarly, in subjects with RC, the mean R1, R2, and R3 values for BAF were (1.68±1.02, 1.66±1.15, and 7.75±6.82, respectively) and for GAF were (0.95±0.59, 0.79±0.45, and 2.50±1.65, respectively). The mean difference in the R1, R2, and R3 ratios between BAF and GAF in normal and in RC subjects was statistically significant (p<0.001). The strength of the correlation (r) between ratios for BAF and GAF was weak or not statistically significant in both normal and RC subjects (p>0.05).CONCLUSION: The distribution and intensity of the AF signal differ in BAF and GAF and cannot be used interchangeably. In BAF, optic disc signal is always weaker than in other areas, which was not true for GAF where optic disc signal was stronger than fovea and hypoautofluorescent point in both groups.

    View details for PubMedID 30617430

  • Effects of Vitreomacular Adhesion on Treatment Outcomes in the Study of Safety and Bioactivity of TOcilizumab in Patients with Non-Infectious UVEITIS: The STOP-UVEITIS Study Nguyen, N. V., Hassan, M., Halim, M., Afridi, R., Baluyot, S., Sepah, Y. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2018
  • Posterior Segment Inflammatory Outcomes (Month-6) in the STOP-Uveitis Study: Evaluating the Safety, Tolerability, and Efficacy of Tocilizumab in Patients with Non-Infectious Uveitis Sadiq, M., Hassan, M., Halim, M., Afridi, R., Do, D. V., Quan Dong Nguyen, Sepah, Y. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2018
  • Scleral Vessel Density Using Novel Optical Coherence Tomography Angiography Methodology Halim, M., Hassan, M., Afridi, R., Nguyen, N. V., Maleki, A., Baluyot, S., Sepah, Y. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2018
  • Can Fundus Photograph Montage Replace the Standard 7-Field Stereo Images for Diabetic Retinopathy Severity Scale Assessments? Baluyot, S., Hassan, M., Halim, M., Afridi, R., Nguyen, N. V., Sepah, Y. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2018
  • Diurnal variation of choriocapillaris vessel flow density in normal subjects measured using optical coherence tomography angiography. International journal of retina and vitreous Sarwar, S., Hassan, M., Soliman, M. K., Halim, M. S., Sadiq, M. A., Afridi, R., Agarwal, A., Do, D. V., Nguyen, Q. D., Sepah, Y. J. 2018; 4: 37

    Abstract

    Background: Vessel flow density (VFD) may provide important information regarding perfusion status. Diurnal variation in VFD of choriocapillaris has not been reported in literature. In the index study, optical coherence tomography angiography (OCTA) was used to assess the diurnal variation of the VFD in the choriocapillaris of subjects with no known ocular disease.Methods: Fifty eyes with no known ocular disease (25 subjects) were included. OCTA images were acquired using AngioVue (Optovue, Fremont, CA, USA) at two different time points on a single day: 9:00 AM and 6:00 PM. Macular cube scan protocol (3*3mm) centered on the fovea was used. Automatic segmentation of the retinal layers and choriocapillaris was performed using ReVue software, which was also used to measure the choriocapillaris VFD. Horizontal line scan passing through fovea was obtained by the device at both time points to measure the subfoveal choroidal thickness (CT). Linear measurement tool of software was used to measure subfoveal CT according to a standardized reproducible method. Wilcoxon signed-rank test was used to assess the differences in choriocapillaris VFD and subfoveal CT at the two time points. Correlation between change in choriocapillaris VFD and subfoveal CT at the two time points was assessed using the Pearson correlation coefficient (r).Results: The mean age of the subjects was 31.96±11.23years. Choriocapillaris VFD was significantly higher at 9:00 AM compared to 6:00 PM (P<0.0001) with mean choriocapillaris VFD of 68.74±4.80% at 9:00 AM and 67.57±5.41% at 6:00 PM, with a mean diurnal amplitude of 1.17%. Mean subfoveal CT was 287.74±61.51m at 9:00 AM and 270.06±60.73m at 6:00 PM. Subfoveal CT was also significantly higher at 9:00 AM compared to 6:00 PM (P<0.0001) with a mean diurnal amplitude of 17.68m. Change in choriocapillaris VFD correlated with change in subfoveal CT (r=0.87, P<0.001).Conclusion: OCTA demonstrated significant diurnal change in choriocapillaris VFD in subjects without any ocular disease with VFD being higher in the morning and lower in the evening. Decrease in choriocapillaris VFD in the evening correlated with a reduction in subfoveal CT.

    View details for PubMedID 30338130

  • Short-Term Effects of Ranibizumab on Diabetic Retinopathy Severity and Progression. Ophthalmology. Retina Hassan, M., Sadiq, M. A., Halim, M. S., Afridi, R., Nguyen, N. V., Sepah, Y. J. 2018; 2 (7): 749?51

    View details for PubMedID 31047386

  • Primary (Month-6) Outcomes of the STOP-Uveitis Study: Evaluating the Safety, Tolerability, and Efficacy of Tocilizumab in Patients With Noninfectious Uveitis AMERICAN JOURNAL OF OPHTHALMOLOGY Sepah, Y., Sadiq, M., Chu, D. S., Dacey, M., Gallemore, R., Dayani, P., Hanout, M., Hassan, M., Afridi, R., Agarwal, A., Halim, M., Do, D. V., Quan Dong Nguyen 2017; 183: 71?80

    Abstract

    To report the primary endpoint analyses of the safety and efficacy of 2 different doses of intravenous (IV) infusions of tocilizumab (TCZ), an IL-6 inhibitor, in eyes with noninfectious intermediate uveitis, posterior uveitis, or panuveitis.Randomized, controlled, multicenter clinical trial.STOP-Uveitis is a randomized, open-label safety, efficacy, and bioactivity clinical trial conducted at 5 clinical centers across the United States. The study evaluated the role of TCZ in patients with noninfectious uveitis (NIU). Thirty-seven patients with NIU were randomized into one of 2 treatment groups in a ratio of 1:1. Group 1 received IV infusions of 4 mg/kg TCZ and group 2 received IV infusions of 8 mg/kg TCZ. Infusions were given every 4 weeks in both groups until month 6 (primary endpoint). Primary outcome measure was incidence and severity of systemic and ocular adverse events through month 6. Secondary outcome measures included mean change in visual acuity (VA), vitreous haze (VH), and central macular thickness (CMT) at month 6.A total of 37 patients were randomized in the study. At month 6, 43.5% of patients who had the potential for a 2-step decrease in VH demonstrated a 2-step decrease (40% in Group 1 and 46.1% in Group 2). Mean change in CMT was -83.88 ± 136.1 ?m at month 6 (-131.5 ± 41.56 ?m in Group 1 and -38.92 ± 13.7 ?m in Group 2). Mean change in VA was +8.22 ± 11.83 ETDRS letters at month 6 (10.9 ± 14.6 in Group 1 and 5.5 ± 7.8 in Group 2). Repeated infusions of TCZ were well tolerated.Repeated IV administrations of TCZ are well tolerated. TCZ (both 4 and 8 mg/kg) is effective in improving VA and reducing VH and CMT in eyes with noninfectious intermediate uveitis, posterior uveitis, and panuveitis.

    View details for PubMedID 28887113

  • Evaluation of macular and peripapillary vessel flow density in eyes with no known pathology using optical coherence tomography angiography. International journal of retina and vitreous Hassan, M., Sadiq, M. A., Halim, M. S., Afridi, R., Soliman, M. K., Sarwar, S., Agarwal, A., Do, D. V., Nguyen, Q. D., Sepah, Y. J. 2017; 3: 27

    Abstract

    To assess normal vessel flow density (VFD) in macular and peripapillary regions of eyes with no known ocular pathology using optical coherence tomography angiography (OCTA).AngioVue (Optovue, Fremont, CA, USA) was used to capture OCTA images. A 3 × 3 mm grid and a 4.5 × 4.5 mm grid was used to scan parafoveal and peripapillary regions, respectively. ReVue software was utilized to measure VFD in five sectors within the inner two circles of ETDRS grid in macular region and correlated to retinal thickness of same sectors. At optic disc, VFD was calculated in six sectors based on Garway-Heath map. Area and morphology of foveal avascular zone (FAZ) was correlated with VFD in central 1 mm. The influence of myopia on mean VFD was also assessed.Twenty-four eyes (mean age: 30 years) were analyzed. Mean VFD in macular sectors was 43.5 (±4.5) and 45.8 (±5.0) % in superficial and deep retinal plexuses, respectively. Mean VFD was significantly higher in deep retinal plexus compared to superficial retinal plexus in all sectors except central 1 mm (p < 0.05). Mean VFD in central 1 mm increases with an increase in central retinal thickness in both superficial and deep retinal plexuses (p < 0.001). Mean parafoveal VFD at level of both superficial and deep retinal plexuses decrease with an increase in spherical equivalent in myopics (p < 0.05). Mean VFD in myopics was found to be significantly lower in parafoveal region of deep retinal plexus (p < 0.05). Mean area of FAZ was 0.33 (±0.15) and 0.47 mm2 (±0.15) in superficial and deep retinal plexuses, respectively. Area of FAZ decreases with an increase in central 1 mm thickness and foveal VFD (p < 0.001).OCTA may be used to measure VFD in macular and peripapillary regions. Vessels in the parafoveal region are more densely packed in the deep retinal plexus leading to higher VFD compared to superficial plexus. Thicker retina in fovea translates into higher foveal VFD due to more compact arrangement of retinal layers and continuity of inner nuclear layer (INL). Myopia is associated with lower VFD in parafoveal region at level of deep retinal plexuses which may explain thinning of INL in myopics.

    View details for PubMedID 28781889

    View details for PubMedCentralID PMC5535290

  • Effects of Two Different Doses of Ranibizumab on Diabetic Retinopathy Severity. Ophthalmology. Retina Sadiq, M. A., Hassan, M., Soliman, M. K., Afridi, R., Do, D. V., Nguyen, Q. D., Sepah, Y. J. 2017; 1 (6): 566?67

    View details for PubMedID 31047459

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