IIT Madras Researchers Identify Enhanced Drug Delivery Method for Eye Treatments

Indian Institute of Technology Mras ( IIT Mras) Researchers have demonstrated how drugs injected in human eye can be better delivered to target region through ‘convection caused by mild laser heating’. y used simulation and modelling studies to analyse efficacy of various s of treatments on human eye, focusing on heat and mass transfer.

With nearly 11 million individuals afflicted by retinal disorders in India, indigenous original research of this nature holds promise for development and vancement of Laser-based treatments for various eye diseases.

Laser-based retinal treatments are increasingly being used to treat diseases like retinal tears, diabetic retinopathy, macular oedema and retinal vein occlusion.  Since retina is region of eye that contains blood vessels and nerves, such treatments must be performed carefully and with precision.

This Research was taken up nearly a dece ago by Prof. Arunn Narasimhan, Department of Mechanical Engineering, IIT Mras, who collaborated with Dr. Lingam Gopal of Shankar Nethralaya and initiated biormal research into effects of laser irriation on retina for first time in India.

Subsequently, team has performed computer simulations and experiments to analyse different aspects of eye treatments, within scope of bio-heat and mass transfer.

current study was taken up by Prof. Arunn Narasimhan, and IIT Mras gruate student Mr Shirinvas Vibu, who used a glass eye mimic to demonstrate how heat-induced convection reduces time taken for drugs injected into vitreous region to reach targeted region in retina.

This work will be featured in Special ICCHMT Conference Proceedings published by Springer Verlag. findings of this experimental study have been published in reputed, peer-reviewed Wiley Heat Transfer journal (https://doi.org/10.1002/htj.22899).

Highlighting need for such research, Prof. Arunn Narasimhan, Department of Mechanical Engineering, IIT Mras, said,“Inter-disciplinary research brings toger expertise from different fields like engineering and biology, to provide innovative solutions to relevant societal problems.”

Commenting on current status of research and when this research can be expected to translate to applications in field, Prof. Arunn Narasimhan said, “For engineers like us involved in medical research due to practical and ethical difficulties involved in performing experiments on live human organs, computer simulations and mimic experiments are only available research tools. Using glass-eye experiments and bioheat simulations to analyse invasive treatments in human eye, we have shown that mild targeted heating can enhance drug delivery to retina.  medical community needs to take this furr and implement it in treatment of retinal diseases.”

In patients who have undergone retinal laser surgery, most of original gel-like vitreous humour could become replaced by body secretions that are less viscous than original gel.

After surgery, drugs are often injected directly into vitreous region to treat retina. To reach retina, drug must move through liquid.Natural diffusion is a slow process, and drug may take several hours to days to reach effective levels at target location.

Prof. Arunn Narasimhan designed an experiment using a glass eye mimic geometrically similar to human eye, water and silicone oil for vitreous liquid and a heater to simulate laser heating. researchers injected a dye as a drug mimic at specific points in vitreous region of eye, and measured concentrations at different retinal locations with and without heating vitreous liquid.

Elaborating on technical aspects of research, Mr Shirinvas Vibu, Gruate Student, IIT Mras, said,“While with natural diffusion alone, drug mimic took 12 hours to achieve effective concentration at target region of retina, heating vitreous liquid reduced it to just 12 minutes.”

researchers have also shown in a separate study that required heating does not damage eye tissues. Subsequent research work in 3D human eye models earned Mr. Shirinvas Vibu an invitation to present his work at international conference ICCHMT 2023 held in Germany.