Purpose To evaluate the optical and visual functional characteristics of the Osteo‐Odonto‐Keratoprosthesis (OOKP)
Methods Nine patients with implanted OOKP devices were examined. Glare effect (Low, Medium and High intensity) was measured with a brightness acuity test (BAT) and contrast sensitivity was assessed using Metropsis Visual Stimulus Generation software (Cambridge Research System) at 0.3; 0.7; 2.20; 3.50; 10.4 and 14.5 cpd. Kinetic Goldmann perimetry and wavefront aberrometry (Nidek OPD‐scan) were performed in each patient. All patients completed a Quality‐of‐Life questionnaire (NEI VFQ‐25)
Results A reduction in mean visual acuity (logMAR) with increasing glare settings was observed from 0.12 without BAT to 0.27 with BAT at High. Mean visual acuities (logMAR) measured with BAT at Medium (Mann Whitney U‐test p<0.05) and High (U‐Test p<0.01) intensity settings were found to be significantly reduced statistically when compared to VA without BAT. Contrast Sensitivity was significantly reduced when compared to age‐matched control at medium and high spatial frequencies. Several vision‐related VFQ‐25 sub‐scales correlated significantly with visual acuity at various BAT levels such as General Vision, Near Activities and Distance Activities (correlation coefficients: ‐0.71 to ‐0.86; 0.05>p>0.001). Correlation with these subscales was also observed with contrast sensitivity at medium spatial frequencies (‐0.67 to ‐0.83; 0.05>p>0.001)
Conclusion The optics of the OOKP can provide patients with excellent visual acuity that correlates well with visual function. Visual acuity is significantly reduced by glare and patients experienced a lower contrast sensitivity compared to age‐matched controls. Glare reduction and cylinder alignment could further improve function