Ophthalmologist Interview

Applications of Artificial Intelligence in Ophthalmology have far reaching implications for healthcare through faster, non-invasive, and cost-effective solutions, making it easier to screen more people for various life altering diseases

Sahil Thakur, our next pathbreaker, is Head of Medical Affairs at Mediwhale, a Korean Software as a Medical Device (SaMD) company that develops AI algorithms using retinal images for disease prediction.

Sahil talks to Shyam Krishnamurthy from The Interview Portal about his medical background (MBBS) in Ophthalmology, and bridging clinical practice with a PhD that helps translate medical research into real world innovations that benefit patients

For students, the future is full of possibilities, and your path will be unique—so embrace every challenge, stay curious, and take that first step with confidence

Sahil, can you share your background for our young readers?

I grew up in the beautiful hills of Shimla, surrounded by books, thanks to my parents, who were both history professors. Our home was always filled with stories—both real and imaginary—and that probably sparked my love for learning early on. Later, I moved to Chandigarh with my mother when she got a job there, while my parents traveled between cities so we could all be together on weekends. I did my 11th and 12th in Chandigarh and then pursued my MBBS at GMCH Chandigarh.

From a young age, I was fascinated by science, especially biology—it just made sense to me, like solving a puzzle But my interests weren't limited to just studies. I loved reading, from Hindi comics to Enid Blyton adventures. I also had a bit of a collector's spirit, I hoarded chewing gum cards, G.I. Joe figures, stamps, and currency notes. Looking back, maybe that's why I ended up collecting degrees too The curiosity I had as a child—whether it was about how the human body works or the excitement of finding a rare stamp—never really left me. And that curiosity is what led me to where I am today

What did you do for graduation/post graduation?

After finishing my MBBS, I had many options to choose from. Some of my friends took very different paths—one became an IPS officer, another went to the US by giving the USMLE (US Medical Licensing Exam) for further training. It was exciting to see so many possibilities, but I decided to take the NEET exam and was offered an ophthalmology residency in Chandigarh. Ophthalmology is a unique field, it's all about eyes It might not be the first thing people think of when they hear "doctor," but I was always good at technical things, and the idea of performing delicate surgeries under a microscope fascinated me. It felt like a perfect fit

During my residency, I had an incredible mentor, Prof. Parul Ichhpujani, who introduced me to research. She taught me to look beyond what others were doing and think differently. That led me to take up an overseas research fellowship in Singapore.

Then came COVID-19, and like everyone else, my plans changed. But at that time, I realized I wanted to grow even more as a researcher. I was lucky to find another amazing mentor, Prof. Ching-Yu Cheng, at the Singapore Eye Research Institute, who guided me during my PhD.

I did my PhD from Duke-NUS Medical School Duke-NUS (National University of Singapore) Medical School, in Clinical and Translational Sciences

During my PhD, I got really interested in how research can be turned into real-world solutions. That's when I decided to pursue an MBA as well—to learn how to bring medical innovations to people.

I know, it sounds like I collected too many degrees But for me, every step was driven by curiosity and a love for learning. And that's the best part—when you truly enjoy something, learning never feels like a burden

What were some of the key influences that led you to such an offbeat and unconventional career in Ophthalmology?

Choosing a career is like putting together a puzzle—you find different pieces along the way that eventually fit together. For me, it wasn't one big moment but a series of experiences, people, and lessons that shaped my journey.

My Parents: They taught me the value of hard work and the importance of getting the best education before settling into a career. Growing up, I saw their dedication to learning and knew I wanted to follow that path.

Dr. Rajeev Tuli (My Uncle, an Ophthalmologist): He was the first person who introduced me to the magic of restoring sight. Ophthalmology is one of the few medical fields where you can see an instant reward for your work—like a patient who was blind due to cataracts suddenly being able to see again after surgery. That fascinated me

Prof. Parul Ichhpujani (My mentor in Medical School): She showed me how research could be done even with limited resources. She taught me to think creatively, use what I had, and never waste an opportunity.

Prof. Ching-Yu Cheng (My PhD Mentor): He introduced me to the world of high-impact research and international collaborations. From him, I learned how world-class research is crafted and the importance of strong teamwork.

Dr. Tyler Rim (My current CMO at Mediwhale): He is proof that doctors can go beyond clinics and become entrepreneurs Watching him turn research into real-world solutions that help people made me realize that I wanted to do the same.

Key events that shaped me were:

The year I lost due to an OMR Error: After Class 12, I had to take a gap year because I made a simple mistake while marking my exam sheet. That one small error cost me a whole year It was frustrating, but it taught me an important lesson—small mistakes can have big consequences. It also made me more careful and disciplined in everything I did.

Doing My PhD Abroad: Studying in Singapore opened my eyes to how research works globally. I saw how funding makes a huge difference in the quality of science, equipment, and innovation. But at the same time, my experience in India had already taught me how to work smart with limited resources and never waste any research ideas or opportunities.

Turning Points

I started as a medical student who loved surgery, but over time, I realized that I also wanted to create new solutions and innovations in healthcare. My journey—from medicine to research, from India to Singapore, and now working on turning research into real-world technology—was shaped by many mentors, experiences, and challenges. The biggest lesson? Keep learning, keep adapting, and never let setbacks stop you. Every experience, good or bad, can teach you something that helps you grow.

How did you plan the steps to get into the career you wanted? Or how did you make a transition to a new career? Tell us about your career path

My career journey has been quite unique because my first job is actually my current job Unlike most other careers where you finish studying and then start working, being a medical student means you study and work at the same time.

I earned my first salary as an intern during my MBBS in Chandigarh, where we worked in hospitals while learning. During my residency, we also received a stipend, so technically, I was earning while studying Later, when I moved to Singapore for my research fellowship, I was again working and studying at the same time.

After completing my residency (MS in Ophthalmology), I realized that I needed formal training in clinical research. While I worked on research projects during my medical studies, I often had to rely on external help, such as statisticians, for data analysis. This made me feel the need to strengthen my own research skills. During my first research fellowship at the Singapore Eye Research Institute (SERI), I attended research meetings and journal clubs, which further highlighted the gaps in my knowledge of research methodology and statistical analysis. Since self-learning could only take me so far, I decided to pursue a PhD to build a strong foundation in research methods and statistics.

Clinical work during residency

My residency in Ophthalmology (2015-2018) was primarily clinical, meaning I was involved in diagnosing and treating eye diseases. However, we also conducted research, mainly in the form of case reports and a Master's thesis. (You can access all my research here: https://scholar.google.com/citations?user=NNOOGckAAAAJ&hl=en ) My thesis focused on a new computer-based method to assess contrast sensitivity, which was useful for detecting optic nerve damage in diseases like glaucoma. (Read more here: https://pubmed.ncbi.nlm.nih.gov/29755121/ )

Clinically, I worked across various sub-specialties in ophthalmology, including corneal, lens, and retinal diseases. As residents, we handled procedures such as: Corneal perforation and ulcer management, Eye donation cornea harvesting, Cataract management and surgeries (ECCE, MICS and Phacoemulsification), Squint correction surgeries, DCR (Dacryocystorhinostomy) for tear duct blockage, Mini Monoka insertion for canalicular lid injuries and Retinal procedures like intravitreal injections. We also got exposure to more advanced procedures such as keratoplasty (corneal transplant), glaucoma surgeries (trabeculectomy), and retinal detachment surgeries under supervision.

I mainly worked in a clinical setting during my internship and residency in India (2014-2018). Afterward, in Singapore, I worked in a research clinic (2018-2024) rather than a regular hospital clinic. I was one of the ophthalmologists for the Singapore Epidemiology of Eye Diseases (SEED) study, a large-scale research project that studied eye health in Singapore's population. (More details: https://academic.oup.com/ije/article/50/1/41/6061452 ) One major difference between India and Singapore was the patient load. In India, we saw over 100 patients per session, whereas in the research clinic, we saw less than 10 per session. This meant that in Singapore, the patient interactions were much more detailed and research-focused, unlike the fast-paced consultations in India.

During my residency, I applied for international research fellowships, and I was fortunate to be selected for one at SERI (Singapore Eye Research Institute). Singapore was a great choice because:

• SERI is a world-renowned eye research center, with a strong focus on innovation in ophthalmology.
• Singapore (Duke-NUS Medical School) offers a structured PhD program with strong research training, including formal teaching in statistical methods and research methodology.
• Better work-life balance—Unlike my residency in India, where weekends were often packed with work, in Singapore, weekends were free, allowing me to explore other interests.
• Singapore is just 5.5 hours from Delhi and I wanted to stay closer to India, so I decided not to pursue some opportunities that I found in the US and Canada.

Can you tell us about your PhD work?

My PhD research focused on developing a new method for visual field (VF) testing in glaucoma patients.

Why Is This Important?

• The current method of VF testing is difficult for patients, as it requires focus and effort.
• The machines used for testing are expensive and not widely available.
• Many people, such as the elderly, children, bedridden patients, and those with neuromuscular disorders, struggle to complete the test.

I worked on an AI-based method to estimate VF from fundus photographs (pictures of the retina). Since fundus cameras are more widely available and easier to use, this method could make VF testing more accessible and efficient. (Read more about the project: https://www.singhealthdukenus.com.sg/SDC2023/Documents/00138.jpg )

I was awarded the SingHealth SERI-SNEC Learning Award, which provided $10,000 per year for two years. However, I was not eligible for many other scholarships, as most funding in Singapore is reserved for Singaporean citizens and permanent residents. There are some scholarships for foreign students as well, which usually cover tuition fees and provide a small stipend, but after careful budgeting, I realized that my salary from SERI, the partial scholarship, and some self-funding was a better financial decision.

My journey from medical school in India to a PhD in Singapore was driven by my passion for research and the need for formal training in clinical research methods. While I loved clinical work, I wanted to contribute to medical knowledge in a way that could help patients on a larger scale. My research on AI-driven visual field testing is an example of how technology can make eye care more accessible. For students reading this, if you are passionate about science, technology, and medicine, there are many paths you can take—including clinical practice, research, and even combining both

After completing my PhD, I was offered a position at Mediwhale by Dr. Tyler Rim, where I now handle Medical Affairs. In a way, I was lucky—I didn't have to struggle too much in the job market. But that doesn't mean I didn't prepare I always kept an updated CV and LinkedIn profile, and to be honest, in the last few weeks before completing my PhD, I did apply for other jobs too.

One thing that really helped me transition smoothly was that I continued working with teammates I already knew. When you work with people who understand your strengths and skills, starting a new job becomes much easier.

What helped you in your career transition?

• Learning on the Fly – Even though I didn't have direct experience in my current role, I've always been eager to learn. Every new challenge is an opportunity to grow.
• Transferable Skills – The skills I gained in medical school and my PhD—like problem-solving, critical thinking, teamwork, people management, and research skills—help in any job, not just in medicine
• Keeping my options open – I was always open to different career possibilities. Just because I was a doctor didn't mean I had to stay in a hospital forever. Exploring new fields led me to where I am today.

You don't need to have everything figured out at once. Sometimes, opportunities find you when you stay curious, keep learning, and remain open to new possibilities.

How did you get your first break?

Looking back, my career didn't have just one "big break"—it was a series of small but important steps that led me to where I am today.

• First Research Opportunity – My first real break came during my MBBS when I did an ICMR (Indian Council of Medical Research) short-term studentship (STS) with Prof. Monica Gupta at GMCH. It was my first exposure to research, and it showed me that medicine wasn't just about treating patients, it was also about discovering new knowledge.

My first research project wasn't in vision science, but in something equally eye-opening—re-hospitalization in the elderly. (https://www.researchgate.net/publication/263593094 (Factors Associated with Rehospitalisation of Elderly Medical Patients). As an MBBS student, I was drawn to the idea of understanding why some patients kept coming back to the hospital, sometimes within weeks of being discharged.

What started as a simple observational study soon turned into a deeper exploration of the fragile balance between chronic disease management, patient adherence, and healthcare system challenges. I remember sifting through patient records, uncovering patterns in comorbidities, and realizing that while some re-hospitalizations were inevitable, many were tied to factors like poor follow-up, inadequate rehabilitation, and even patients' own perceptions of their health.

This experience shaped my thinking in ways I didn't anticipate. It wasn't just about gathering numbers; it was about asking why. Why did outpatient management fail? Why did some patients not comply with treatment? Why did perceptions of health influence actual outcomes? That curiosity—driven by data but rooted in real patient experiences—became the foundation of my journey into research.

Though my first project was in internal medicine, it taught me the value of looking beyond symptoms to uncover systemic patterns. That mindset later guided me into deeper scientific inquiry, where the same investigative spirit applies—whether in medicine, public health, or vision research.

So, my first research though it wasn't in vision science certainly shaped the lens through which I see research today.

• Serious Research Career Consideration – During my residency, I had the privilege of working with Dr. Parul Ichhpujani, who helped me understand how impactful research can be. She showed me how to work with limited funding and still produce meaningful results. That was when I seriously started thinking about research as a career.
• Entry into the Business Side of Research – My journey took another interesting turn when Dr. Tyler Rim offered me the opportunity to handle Medical Affairs at Mediwhale. This was my introduction to the business and commercial side of research—how scientific discoveries can be turned into real-world solutions that help people.

Each of these experiences was a stepping-stone, helping me explore, learn, and evolve. The biggest lesson? Say yes to opportunities, even if you're not sure where they will lead—because sometimes, they open doors you never even knew existed

What were some of the challenges you faced? How did you address them?

Every journey has obstacles, and mine was no different. But the way you tackle challenges shapes your path. Here are some of the biggest hurdles I faced and what I learned from them:

Challenge 1: I had to take an extra year after Class 12 because of an OMR sheet marking error in my entrance exam. It was tough watching my friends move ahead while I had to start over. Peer pressure can be hard, but I knew my capability. Instead of feeling sorry for myself, I focused on correcting my mistakes and preparing better. That year taught me patience and resilience—qualities that helped me throughout my career.

Challenge 2: During my ophthalmology residency, I wanted to do research, but the patient load was so high that I barely had time. So, I got creative I took lots of photos and notes during clinical hours—because every interesting case can become a research paper. Case reports are like "low-hanging fruit" in high-volume clinical centers, and this approach helped me get my first few publications.

Challenge 3: Moving to Singapore for my PhD was a big adjustment. Tuition was expensive, the cost of living was high, and I was away from my family for the first time. Managing finances became a crucial skill—I had to budget carefully, limit unnecessary spending, and plan my expenses. But I also made sure to enjoy the journey. My first self-indulgence? A PlayStation in Singapore (Fun fact: Research has shown that surgeons who play video games perform better surgery. So technically, it was an investment in my skills )

Where do you work now? What problems do you solve?

I currently work as the Head of Medical Affairs at Mediwhale, a Korean Software as a Medical Device (SaMD) company that develops AI algorithms using retinal images for disease prediction.

SaMD (Software as a Medical Device) refers to software that is intended for medical purposes without being part of a hardware medical device. According to the International Medical Device Regulators Forum (IMDRF), SaMD is software that can perform functions such as diagnosing, preventing, monitoring, or treating diseases, operating independently of any physical medical device. At Mediwhale, we exemplify the concept of SaMD by developing AI-powered algorithms that analyze retinal images to predict various diseases. (www.mediwhale.com) Our software does not rely on traditional diagnostic hardware but instead processes retinal scans to provide insights into a patient's health risks, such as cardiovascular diseases or kidney conditions. This aligns perfectly with the SaMD definition, as our AI-driven solution is purely software-based and delivers medical insights without requiring additional physical diagnostic tools.

My role in the company is to bridge the gap between science, business strategy, and key stakeholders while driving the adoption of retinal imaging as a standard tool for primary healthcare diagnostics. Every day is a problem-solving day, as I work with different teams to tackle challenges—whether it's generating new clinical evidence, addressing regulatory concerns about product safety and efficacy, or ensuring that the AI works effectively in real-world settings.

What skills are needed for your role? How did you acquire the skills?

The skills needed for this job include research, statistics, AI, ophthalmology, clinical application of technology, and regulatory knowledge, but most importantly, you need to be a patient advocate—ensuring that innovations are safe, effective, and truly beneficial. I work remotely from Singapore, so my typical day involves a lot of meetings, often at odd hours due to time zone differences, as I collaborate with external teams, researchers, and regulatory bodies worldwide. I also keep a close eye on the latest AI and oculomics (Oculomics is the study of the eye to diagnose systemic diseases.) trends to ensure that we stay competitive in this rapidly evolving field. What I love about this job is that it challenges me to see the third pillar of healthcare—translation—which comes after clinical work and research. Turning research into real-world solutions is the hardest part, but it also has the biggest impact, and that's what makes it truly rewarding.

How does your work benefit society?

My work directly helps society by making disease prediction easier, faster, and more accessible. Right now, our main commercial product at Mediwhale focuses on predicting the risk of cardiovascular disease (CVD)—including heart attacks (MI) and strokes—using retinal images. Traditionally, measuring cardiovascular risk requires invasive tests like CT scans to check for calcium buildup in the arteries (which is like plumbing—if your pipes get clogged, water flow is blocked, just like how arteries get blocked by calcium deposits). This method is expensive, time-consuming, and not widely available for regular screening. But with retinal imaging, we can detect these risks in a faster, non-invasive, and cost-effective way, making it easier to screen more people, catch heart disease early, and start treatment before serious complications arise. This has the potential to save lives, reduce hospitalizations, and decrease healthcare costs by shifting the focus from late-stage treatment to early prevention. I find my work incredibly meaningful because it sits at the intersection of medicine, research, and technology—exactly what I've trained for. Seeing research turn into real-world solutions that can impact millions of lives is what drives me every day.

Tell us an example of a specific memorable work you did that is very close to you

One of the most memorable aspects of my work has been contributing to knowledge and patient care in ways that have a lasting impact. Two of my proudest achievements are my books "Smart Resources in Ophthalmology" and "Artificial Intelligence and Ophthalmology" (published by Springer Group). Writing these books took a lot of effort, and I hope they serve as valuable resources that help others learn and get inspired. Similarly, my two thesis works—one during my Master's and the other during my PhD—hold a special place in my journey. They represent years of research, problem-solving, and dedication to pushing the boundaries of what we know. Beyond academics, some of my most cherished memories come from my patient interactions. I still remember the first cataract surgery I performed, the feeling of restoring someone's vision in just minutes was unforgettable. My first eyelid repair patient, my squint surgery patients, and the glaucoma research study patients I worked with have all left a deep impact on me. These moments remind me why I chose this path—to help, heal, and make a difference. Being a part of someone's journey to better health, whether through surgery, research, or innovation, is what makes my work truly fulfilling.

Your advice to students based on your experience?

My advice to students is to stay curious and keep learning—the world is evolving fast, and the best way to grow is to ask questions, explore different subjects, and step outside your comfort zone. Mistakes are not the end; I lost a year due to an OMR marking error, but setbacks don't define you—how you bounce back does. Opportunities often come when you say yes to new challenges, even if you're unsure. Whether it was research, clinical work, or transitioning into healthcare business, I got here by being open to new experiences. Hard work always beats talent when talent doesn't work hard, so be consistent, put in effort, and keep going even on tough days. While passion is important, also learn practical skills—finance,communication, teamwork—because they help in every career. And most importantly, enjoy the journey Work hard, but don't forget to have fun along the way—whether it's through hobbies, friends, or personal growth. The future is full of possibilities, and your path will be unique—so embrace every challenge, stay curious, and take that first step with confidence

Future Plans?

For the future, my main goal is to expand the impact of our work at Mediwhale, bringing retinal imaging-based disease prediction to more people across the world. Our technology has the potential to revolutionize healthcare screening, making it faster, more accessible, and cost-effective. I want to see it integrated into primary care systems globally, helping detect diseases early and ultimately saving lives. Beyond this, I also believe in giving back—mentoring students and young researchers, sharing what I've learned, and helping others navigate their own journeys in medicine, research, and innovation. I was fortunate to have incredible mentors who guided me, and I want to do the same for the next generation. Whether it's through teaching, research collaborations, or career advice, I hope to inspire more students to explore the exciting intersections of medicine, technology, and entrepreneurship. The future is full of possibilities, and I look forward to playing a role in shaping it