Varun Ranganathan, MC Optom

Clinical Optometrist

An OCULAR Interface Exclusive

Keywords: Artificial Intelligence in Ophthalmology, Retinal Disease Treatments, Sustained Drug Release Implants, Anti-VEGF Intravitreal Injections, Biodegradable and Non-Biodegradable Implants

Introduction:

The treatment landscape for retinal diseases has undergone significant evolution, with intravitreal injections being a cornerstone in this domain, especially in tertiary eye-care hospitals globally. Three  prominent drugs in this category are Bevacizumab (Avastin, Genentech Inc.), Ranibizumab (Lucentis, Genentech, Inc.) and Aflibercept (Eylea, Regeneron Pharmaceuticals), known for their efficacy in treating wet macular degeneration (MD), with Eylea also being used to treat diabetic retinopathy ^(1,2)..

These drugs are broadly known as anti-vascular endothelial growth factor (VEGF) treatment and inhibit the fuctional activity of proangiogenic factors with different affinity and potency ⁽³⁾. Anti-VEGF treatments are also used in other retinal diseases such as retinal vein occlusion (RVO), retinopathy of prematurity (ROP), chronic central serous retinopathy (CSR) and even in some ocular tumours.

The intravitreal injections are administered to the patient on a regular interval over several months until the condition has stabilised. This can cause some inconvenience to the patient as MD is usually age-related and a significant number of patients are lost to follow-up due to several factors ⁽⁴⁾.

Sustained Drug Release Implants:

Recent advancements have seen the rise of both biodegradable and non-biodegradable sustained drug release implants. Biodegradable implants, made from erodible polymers, are less invasive as they negate the need for surgical removal. However, concerns over retinal toxicity due to uncontrolled drug release, especially in the final stages of these implants, have been noted ^(5).

Role of Artificial Intelligence:

Artificial Intelligence (AI) has significantly impacted various aspects of ophthalmology, offering non-invasive, rapid, and accurate diagnostics. Its application extends across a range of ocular diseases, including diabetic retinopathy, macular degeneration, and more ⁶. Optical coherence tomography (OCT) has impacted ophthalmology greatly, assisting in monitoring and treating a plethora of ocular conditions. AI can enhance the OCT’s ability in identifying subtle biomarkers, which can aid in early treatment, thus improving patients’ quality of life ⁽⁷⁾. A recent study which used deep-learning algorithm to monitor the morphological changes and the presence of subretinal fluid with in wet MD has gained approval ⁽⁸⁾.

AI and Non-Biodegradable Implants:

The integration of AI with non-biodegradable implants is a novel approach. Here, AI monitors the disease progression and adjusts the drug release accordingly. This could include a chip within the implant for data collection and analysis, potentially reducing drug toxicity.

Limitations:

Despite its potential, this method does have drawbacks, primarily the need for surgical removal of the implant post-treatment, which could lead to intraocular complications which can include endophthalmitis, pseudo-endophthalmitis, vitreous haze, hemorrhage, cataract development, and retinal detachment. Having said that, non-biodegradable implants have shown to have better control over drug release than bio-degradable ones. Such AI regulated drug implants, with enough evidence and clinical trials, can also be used to treat other ocular conditions and transform the field of ophthalmology.

References:

1. Solomon SD, Lindsley KB, Krzystolik MG, et al.. Intravitreal Bevacizumab Versus Ranibizumab for Treatment of Neovascular Age-Related Macular Degeneration: Findings from a Cochrane Systematic Review. Ophthalmology2016;123:70–7. 10.1016/j.ophtha.2015.09.002.
2. Virgili G, Parravano M, Evans JR, et al.. Anti-vascular endothelial growth factor for diabetic macular oedema: a network meta-analysis. Cochrane Database Syst Rev2017;6:Cd007419 10.1002/14651858.CD007419.pub5
3. Fogli S, Del Re M, Rofi E, Posarelli C, Figus M, Danesi R. Clinical pharmacology of intravitreal anti-VEGF drugs. Eye (Lond). 2018 Jun;32(6):1010-1020. doi: 10.1038/s41433-018-0021-7. Epub 2018 Feb 5. PMID: 29398697; PMCID: PMC5997665.
4. Jones, R., Stratton, I.M., Scanlon, P.H. et al.Disengagement and loss to follow-up in intravitreal injection clinics for neovascular age-related macular degeneration. Eye 37, 3186–3190 (2023). https://doi.org/10.1038/s41433-023-02474-3 
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