A feasibility study of 3D printing technology for simulating rigid gas permeable contact lens fitting

To assess the feasibility of a novel method for simulating a Rigid Gas Permeable Contact Lenses (RGP-CL) fitting using 3-D printed sclero-corneal surfaces (SCSs).

The experiment involved the fabrication of two resin SCSs with biconic corneal geometry and the participation of 22 optician-optometrists as observers. Participants compared the fluorescein patterns of three RGP-CL fitted on each SCS with theoretical patterns generated through computer simulation. To standardize visualization, comparisons were conducted through a multiple-choice questionnaire composed of 6 questions. Each question presented one main fluorescein pattern (either theoretical or experimental) and four additional patterns obtained using the other technique. Optometrists were required to select the fluorescein pattern more similar to the main pattern. A statistical analysis was performed to evaluate the accuracy of the comparison between the two methods.

The surface quality of the printed SCSs was sufficient to produce consistent and interpretable fluorescein patterns. In all questions, at least 70 % of optometrists selected the correct pattern. In four questions, more than 90 % identified the correct pattern, and in one question accuracy reached 100 %. The correct option was always the most frequently chosen, with a significantly higher rate than the second most selected option (p = 0.05).

The ability of most optometrists to correctly identify patterns suggests that, even without polishing, 3-D printed SCSs can simulate fluorescein patterns closely resembling theoretical ones. This approach shows promise as a supportive tool for training in RGP-CL fitting.