Face and content validity of an artificial eye model for Ab-Interno Goniotomy

Opto-Mechanical Eye Models, a Review on Human Vision Applications and Perspectives for Use in Industry

The purpose of this review is to aggregate technical information on existent optomechanical eye models (OME) described in the literature, for image quality assessment in different applications. Several physical eye models have been reviewed from peer-reviewed papers and patent applications. A typical eye model includes an artificial cornea, an intraocular lens or other lens to simulate the crystalline lens, an aperture as the pupil, and a posterior retinal surface, which may be connected to a light sensor. The interior of the eye model may be filled with a fluid to better emulate physiological conditions. The main focus of this review is the materials and physical characteristics used and the dimensional aspects of the main components including lenses, apertures, chambers, imaging sensors and filling medium. Various devices are described with their applications and technical details, which are systematically tabulated highlighting their main characteristics and applications. The models presented are detailed and discussed individually, and the features of different models are compared when applicable, highlighting strengths and limitations. In the end there is a brief discussion about the potential use of artificial eye models for industrial applications.

Angle Examination Gonioscopy and Minimally Invasive Glaucoma Surgical Training on Human Eyes in Wet Lab

PURPOSE

To understand the feasibility, utility and efficacy of a low-cost model for performing anterior chamber angle gonioscopy and micro-surgery on human corneo-scleral tissues in wet lab on resident skill enhancement.

METHODS

Post-keratoplasty residual corneo-scleral rims and/or the expired donor corneo-scleral buttons were included for the purpose of this study. Initially, inverted rims were used to demonstrate the basic angle anatomy on a slit lamp bio-microscope. Central hazy cornea was then replaced with an artificial cornea and an artificial anterior chamber to simulate indirect gonioscopy, direct gonioscopy, goniotomy and other angle-based surgeries. Direct gonioscopy and goniotomy exercises (as a means to simulate intra-operative gonioscopy and other angle-based surgeries respectively) were evaluated quantitatively, and the rest qualitatively.

RESULTS

A total of 65 residents were included in the exercise. The mean age was 26.69±1.74 years. Amongst these, 55 ophthalmology residents performed the basic examination, that is, slit lamp mounted angle anatomy examination (n=55) and artificial chamber mounted indirect gonioscopic examination through artificial cornea (n=55). In the second exercise, 10 glaucoma fellows performed the direct gonioscopic and the goniotomy exercises on artificial chamber. The fellows demonstrated a statistically significant improvement in interpretation and surgical skill enhancement concurrent with reduction in time taken with increasing number of attempts (P<0.05). In the third simulation exercise, micro-stent placement within the Schlemm's canal, sub-conjunctival space, and the supra-choroidal space was re-produced successfully on multiple occasions.

CONCLUSIONS

The residual human corneo-scleral rims proved to be an important resource for teaching both the basic examination skills as well as those required for transitioning to advanced intraoperative gonioscopy and goniotomy skills. These low cost, easy to adapt models can be incorporated within the curriculum for improved glaucoma training of both the residents and the glaucoma fellows.