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. 2025 Apr 1;14(4):18.
doi: 10.1167/tvst.14.4.18.

A Novel Approach to Fabricate Early Keratoconus Phantom Models

Hui Tong  1   2 , Mingjue Wu  1 , Jianqiang Han  1 , Lin Li  1   2 , Haixia Zhang  1   2
Affiliations

A Novel Approach to Fabricate Early Keratoconus Phantom Models

Hui Tong et al. Transl Vis Sci Technol. .

Abstract

Purpose: To develop a method to fabricate early keratoconus phantom models and evaluate the feasibility of using corneal models for studying the dynamic response of early keratoconus under an air puff.

Methods: A corneal mold was designed, and the silicone material was poured into the mold to produce corneal phantoms. Two types of early keratoconus phantoms with reduced mechanical properties in a specific area were prepared using a two-step molding process: the central keratoconus phantom and the paracentral keratoconus phantom. Corneal Visualization Scheimpflug Technology tonometry was performed on the normal corneal phantoms and early keratoconus phantoms, and the corresponding dynamic corneal response (DCR) parameters were recorded.

Results: A majority of DCR parameters of the normal corneal phantoms, including deflection amplitude at highest concavity (HCDA), peak distance (PD), radius of curvature (HR), first and second applanation times (A1T and A2T), first and second applanation velocities (A1V and A2V), and the stiffness parameter at the first applanation (SPA1), exhibited trends in response to changes in the simulated intraocular pressure (SIOP) that aligned with experimental results based on ex vivo animal eyes. Significant differences in HCDA, PD, HR, A1V, A2V, A1T, A2T, and integrated radius (IR) were observed between the early keratoconus phantoms and the normal corneal phantoms.

Conclusions: The early keratoconus phantom models fabricated by the present novel approach are feasible for studying the dynamic response of early keratoconus under an air puff.

Translational relevance: This study demonstrated the potential of corneal phantom models for corneal biomechanical studies, which can deepen our understanding of the DCR parameters, and the results will provide valuable information for early diagnosis of keratoconus.

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Conflict of interest statement

Disclosure: H. Tong, None; M. Wu, None; J. Han, None; L. Li, None; H. Zhang, None

Figures

Figure 1.
Figure 1.
Design of the corneal mold. (a) The morphological design of the cornea phantom. (b) The corneal phantom mold, with the base on the left and the lid on the right.
Figure 2.
Figure 2.
Preparation and measurement of the softened area of early keratoconus phantoms. (a) The silicone is dropped into the central area. (b) The silicone droplet is cured in the central area. (c) Measurement of the diameter of the central softened area. (d) The silicone is dropped into the paracentral area. (e) The silicone droplet is cured in the paracentral area. (f) Measurement of the diameter of the paracentral softened area.
Figure 3.
Figure 3.
Measurement of the elastic moduli of silicone strips. (a) Stress–strain curves for silicone strips for four different silicone oil contents. (b) Elastic moduli of silicone materials with different silicone oil ratios.
Figure 4.
Figure 4.
Fabrication and mounting of the corneal phantom. (a) Cured silicone being removed from the mold. (b) A normal corneal phantom. (c) A normal corneal phantom mounted in the artificial anterior chamber.
Figure 5.
Figure 5.
The locally softened corneal phantoms and their morphological changes at different water pressures. (a) CKP. (b) CKP under water pressure. (c) PKP. (d) PKP under water pressure.
Figure 6.
Figure 6.
An example of the thickness distribution of a normal corneal phantom tested by the Pentacam.
Figure 7.
Figure 7.
Deflection amplitude with temporal evolution of a normal human cornea and a normal corneal phantom.
Figure 8.
Figure 8.
Variation trend of DCR parameters with SIOP in NCPs (elastic modulus, 0.182 MPa). (a–l) Variations in HCDA, HR, PD, HCT, A1V, A2V, A1T, A2T, A1L, A2L, IR, and SPA1 with SIOP, where r is the Spearman correlation coefficient between DCR parameters and SIOP.
Figure 9.
Figure 9.
Variation trend of DCR parameters with SIOP in normal corneal phantoms and two types of early keratoconus phantoms. (a–l) Variations in HCDA, HR, PD, HCT, A1V, A2V, A1T, A2T, A1L, A2L, IR, and SPA1 with SIOP. One-way ANOVA with the LSD post hoc test was used to compare their differences at each pressure point. CKP versus NCP: *P < 0.05, **P < 0.01; PKP versus NCP: #P < 0.05, ##P < 0.01; CKP versus PKP: +P < 0.05, ++P < 0.01.
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