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Item Canonical Grading Scales of Corneal and Conjunctival Staining Based on Psychophysical and Physical Attributes(Association for Research in Vision and Ophthalmology, 2021) Simpson, Trefford; Begley, Carolyn G.; Situ, Ping; Feng, Yunwei; Nelson, J. Daniel; Caffery, Barbara; Springs, Clark; Butterworth Connell, Sara; Ophthalmology, School of MedicinePurpose: In this study, we apply psychophysical scaling principles based on physical (photometric) attributes of images to better understand the factors involved in clinician judgement of ocular surface staining and, using that knowledge, to develop photographic scales for the assessment of staining for dry eye (DE) and related conditions. Methods: Subjects with noninfectious ocular surface staining were enrolled at five clinical sites. Following instillation of fluorescein, photographs of corneal staining were taken every 30 seconds for at least 5 minutes. The same procedure was followed for conjunctival staining after instillation of 2 µl of 1% lissamine green. A subset of the best corneal and bulbar conjunctival staining images were anonymized and a spectroradiometer measured photometric attributes (luminance and chromaticity). The images were scaled psychophysically by study investigators, who participated in constructing grading scales based on physical and psychophysical analyses. The final grading scales were refined following consultation with outside DE experts. Results: Photographs were collected from 142 subjects (81% women), with an average age of 58 ± 17 years; 89% were diagnosed with DE. There was a monotonic relationship between between physical measurements and psychophysically scaled staining of both corneal (fluorescein) and bulbar (lissamine green) staining. Michelson contrast and u' (chromaticity) accounted for 66% and 64% of the variability in the psychophysically scaled images of fluorescein corneal and lissamine green conjunctival staining, respectively. Translational relevance: This paper provides examples of the first ever clinically usable ocular surface staining scales validated using psychophysical scaling and the physical attributes (luminance and chromaticity) of the staining itself. In addition, it provides a generalizable method for the development of other clinical scales of ocular appearance.Item Detection of artificial enamel caries-like lesions with a blue hydroxyapatite-binding porosity probe(Elsevier, 2023-08) Lippert, Frank; Eder, Jennifer S.; Eckert, George J.; Mangum, Jonathan; Hegarty, Kerry; Cariology, Operative Dentistry and Dental Public Health, School of DentistryObjectives This in vitro study investigated the ability of a blue protein-based hydroxyapatite porosity probe to selectively detect artificial enamel caries-like lesions of varying severities. Methods Artificial caries-like lesions were formed in enamel specimens using a hydroxyethylcellulose-containing lactic acid gel for 4/12/24/72 or 168 h. One untreated group was used as a control. The probe was applied for 2 min and unbound probe rinsed off with deionized water. Surface color changes were determined spectrophotometrically (L*a*b* color space) and with digital photography. Lesions were characterized using quantitative light-induced fluorescence (QLF), Vickers surface microhardness, and transverse microradiography (TMR). Data were analyzed using one-way ANOVA. Results Digital photography did not reveal any discoloration in unaffected enamel. However, all lesions stained blue with color intensity positively correlated with demineralization times. The color data reflected similar trends: lesions became significantly darker (L* decreased) and bluer (b* decreased), while overall color differences (ΔE) increased significantly after probe application (4-h lesion, mean±standard deviation: ΔL*=-2.6 ± 4.1/Δb*=0.1 ± 0.8/ΔE=5.5 ± 1.3 vs. 168-h lesion: ΔL*=-17.3 ± 1.1/Δb*=-6.0 ± 0.6/ΔE=18.7 ± 1.1). TMR analysis revealed distinct differences in integrated mineral loss (ΔZ) and lesion depth (L) between demineralization times (4-h lesion: ΔZ=391±190 vol%min × µm/L = 18.1 ± 10.9 µm vs. 168-h lesion: ΔZ=3606±499 vol%min × µm/L = 111.9 ± 13.9 µm). QLF and microhardness were also able to differentiate between demineralization times. L and ΔZ strongly correlated (Pearson correlation coefficient [r]) with Δb* (L vs. Δb*: r=-0.90/ΔZ vs. Δb*: r=-0.90), ΔE (r = 0.85/r = 0.81), and ΔL* (r=-0.79/r=-0.73). Conclusion Considering the limitations of this study, the blue protein-based hydroxyapatite-binding porosity probe appears to be sufficiently sensitive to distinguish between unaffected enamel and artificial caries-like lesions. Clinical significance Early detection of enamel caries lesions remains one of the most critical aspects in the diagnosis and management of dental caries. This study highlighted the potential of a novel porosity probe in detecting artificial caries-like demineralization by objective means.