Physical Parameters Influencing the Rate of Subretinal Injection: A Microfluidic Analysis.
4 affiliations
- 1Vision Center, Department of Surgery, Children's Hospital Los Angeles, Los Angeles, CA, USA.
- 2Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
- 3Dipartimento di Scienze Matematiche, Politecnico di Torino, Torino, Italy.
- 4Italian Institute of Nuclear Physics, Sezione di Torino, Torino, Italy.
Abstract
Purpose
Subretinal injection during vitrectomy has become an important technique owing to the growing number of cell and gene therapy trials for retinal disease. Reducing the injection rate can mitigate trauma or shear forces on the retinal pigment epithelium, yet many surgeons alter the subretinal injection system in ways that could influence this rate.Methods
We created a theoretical model of a standard subretinal injection system by applying the Hagen-Poiseuille equation, assuming steady, incompressible, laminar flow of a water-like Newtonian fluid. The system consisted of the vitrectomy console, plastic tubing, the MedOne Microdose kit, and the MedOne 38G/41G subretinal cannula set.Results
This model generated an open-access web app allowing user modification of parameters including cannula length and diameter, beveling, viscosity, console injection pressure, and intraocular pressure. The internal diameter of the cannula had the most prominent effect on flow, with small increases producing large increases in flow. Increasing console pressure linearly increased tip flow. Trimming the tip by 3 mm modestly increased flow by 18%, whereas beveling the tip or altering intraocular pressure produced negligible changes.Conclusions
With this theoretical model, we were able to identify key parameters that influence the rate of subretinal injection, thus providing important guidance for surgeons.Translational relevance
This open-access web application enables vitreoretinal surgeons and gene- and cell-therapy trialists to assess how modifications to the subretinal injection system alter flow at the cannula tip, supporting standardized and reproducible delivery that minimizes flow-related trauma to the outer retina.
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BibTeX
@article{nagiel2026physical,
title = {{Physical Parameters Influencing the Rate of Subretinal Injection: A Microfluidic Analysis.}},
author = {Aaron Nagiel and Lamberto Rondoni},
journal = {Translational vision science \& technology},
year = {2026},
month = oct,
doi = {10.1167/tvst.15.10.20},
url = {https://europepmc.org/article/MED/42878568},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Physical Parameters Influencing the Rate of Subretinal Injection: A Microfluidic Analysis.
AU - Aaron Nagiel
AU - Lamberto Rondoni
PY - 2026
DA - 2026/10/01
JO - Translational vision science & technology
DO - 10.1167/tvst.15.10.20
UR - https://europepmc.org/article/MED/42878568
AB - Purpose Subretinal injection during vitrectomy has become an important technique owing to the growing number of cell and gene therapy trials for retinal disease. Reducing the injection rate can mitigate trauma or shear forces on the retinal pigment epithelium, yet many surgeons alter the subretinal injection system in ways that could influence this rate.Methods We created a theoretical model of a standard subretinal injection system by applying the Hagen-Poiseuille equation, assuming steady, incompressible, laminar flow of a water-like Newtonian fluid. The system consisted of the vitrectomy console, plastic tubing, the MedOne Microdose kit, and the MedOne 38G/41G subretinal cannula set.Results This model generated an open-access web app allowing user modification of parameters including cannula length and diameter, beveling, viscosity, console injection pressure, and intraocular pressure. The internal diameter of the cannula had the most prominent effect on flow, with small increases producing large increases in flow. Increasing console pressure linearly increased tip flow. Trimming the tip by 3 mm modestly increased flow by 18%, whereas beveling the tip or altering intraocular pressure produced negligible changes.Conclusions With this theoretical model, we were able to identify key parameters that influence the rate of subretinal injection, thus providing important guidance for surgeons.Translational relevance This open-access web application enables vitreoretinal surgeons and gene- and cell-therapy trialists to assess how modifications to the subretinal injection system alter flow at the cannula tip, supporting standardized and reproducible delivery that minimizes flow-related trauma to the outer retina.
SN - 2164-2591
ER -