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Chawla R, Bhattacharyya J, Moksha L, Phour A, Velpandian T, Kashyap S, Kalyanasundaram D. A novel, minimally invasive implant to assist in repeated intraocular drug delivery. Biomed Microdevices 2022; 24:17. [PMID: 35587289 DOI: 10.1007/s10544-022-00618-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2022] [Indexed: 11/29/2022]
Abstract
The standard of care for posterior segment disorders such as wet age-related macular degeneration, diabetic macular oedema and retinal vascular occlusions is pharmacotherapy by intravitreal drug delivery. Since the therapeutic effect of these drugs lasts only around 4 to 8 weeks, repeated intravitreal injections are required. Pain is experienced by the patients during injection as the needle courses through the sclera and choroid. The current work describes the design and development of a novel anodized titanium alloy implant that allows for intravitreal injections through the implant so that the needle transverses only the conjunctiva, thus minimizing discomfort to the patient. Both ex-vivo testing of the implant in enucleated goat's eye as well as in-vivo validation in rabbit eyes was carried out. The implant was placed through pars plana via a minor surgical procedure and was sutured to the sclera and covered with conjunctiva. Subsequent intravitreal injections were administered under topical anaesthesia with a 30-gauge needle through the implant thus delivering the drug into the vitreous cavity. Repeated intravitreal injections were administered every 2 weeks via the implant for 3 months in 4 rabbits. Apart from cataract in 1 rabbit, no complications were observed. There was no evidence of intra-ocular inflammation or infection at final follow-up. Histopathological analysis did not reveal any inflammation or necrosis around the area of implant. The implants were subsequently removed at 5 months and scleral wound was closed with a single suture. The sclera and overlying conjunctiva healed well and no intraocular complications were observed after removal.
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Affiliation(s)
- Rohan Chawla
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, 110029, New Delhi, India
| | - Jayanta Bhattacharyya
- Center for Biomedical Engineering, Indian Institute of Technology Delhi, 110016, New Delhi, India.,Department of Biomedical Engineering, All India Institute of Medical Sciences, 110029, New Delhi, India
| | - Laxmi Moksha
- Department of Ocular Pharmacology, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, 110029, New Delhi, India
| | - Anjali Phour
- Center for Biomedical Engineering, Indian Institute of Technology Delhi, 110016, New Delhi, India
| | - Thirumurthy Velpandian
- Department of Ocular Pharmacology, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, 110029, New Delhi, India
| | - Seema Kashyap
- Department of Ocular Pathology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, 110029, New Delhi, India
| | - Dinesh Kalyanasundaram
- Center for Biomedical Engineering, Indian Institute of Technology Delhi, 110016, New Delhi, India. .,Department of Biomedical Engineering, All India Institute of Medical Sciences, 110029, New Delhi, India.
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