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Updated: Feb 11, 2026
03:37
Intravitreal Injections in the Ovine Eye
Published on: July 5, 2022
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A comparative study to determine the optimal intravitreal injection angle to the eye: A computational fluid-structure
Alireza Karimi1, Reza Razaghi2,3, Hasan Biglari2
1Department of Mechanical Engineering, Kyushu University, Fukuoka, Japan.
Summary
The optimal 45-degree angle for intraVitreal injections (IVI) minimizes ocular stress and potential complications. This finding suggests improved surgical outcomes and reduced patient symptoms following IVI procedures.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Computational Mechanics
Background:
- IntraVitreal injections (IVI) are crucial for treating retinal vascular diseases.
- Post-IVI complications include uveitis, retinal detachment, and elevated intraocular pressure.
- Optimal IVI angles to minimize ocular tissue damage remain under-investigated.
Purpose of the Study:
- To investigate the influence of IVI angle on ocular stresses and deformations.
- To identify the most optimal IVI angle for reducing post-injection complications.
- To propose an IVI angle based on computational stress analysis.
Main Methods:
- A Fluid-Structure Interaction (FSI) computational model was employed.
- Seven distinct IVI angles (0° to 90°) were simulated using Finite Element (FE) analysis.
- Maximal principal stress in ocular components quantified post-IVI injury.
Main Results:
- The 45° IVI angle demonstrated the lowest stress levels across most ocular components (lens, iris, vitreous, aqueous, ciliary body, sclera, retina, choroid).
- Corneal stress was similar at 45°, 60°, 75°, and 90°, with peak stress at 30°.
- Choroid experienced the least stress, while retina/sclera experienced the most, highlighting angle-dependent stress variations.
Conclusions:
- An IVI angle of 45° significantly reduces induced stresses in ocular tissues compared to other angles.
- This optimal angle is predicted to lower the incidence of post-IVI complications.
- Findings support the 45° IVI angle for enhanced surgical outcomes and patient safety.
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