1. Department of Ophthalmology, B. N. Bose SD Hospital, Barrackpore, West Bengal, India
2. Department of Medicine, Burdwan Medical College and Hospital, Purba Burdwan West Bengal, India
3. Department of Ophthalmology, Gouri Devi Institute of Medical Sciences and Hospital, Durgapur, West Bengal, India
4. Department of Medicine, N. R. S. Medical College and Hospital, Kolkata, West Bengal, India