Foveal Hypoplasia Grading with Optical Coherence Tomography: Agreement and Challenges Across Experience Levels

Background/Objectives: The diagnosis and prognosis of arrested foveal development or foveal hypoplasia (FH) can be made using the Leicester grading system for FH and optical coherence tomography (OCT). In clinical practice, ophthalmologists and ophthalmic health professionals with varying experience consult patients with FH; however, to date, the FH grading system has only been validated amongst experts. We compare the inter-grader and intra-grade agreement of healthcare professionals against expert consensus across all grades of FH. Methods: Handheld and table-mounted OCT images (n = 341) were graded independently at a single centre by experts (n = 3) with over six years of experience and "novice" medical and allied health professionals (n = 5) with less than three years of experience. Sensitivity, specificity, and Cohen's kappa scores were calculated for each grader, and expert vs. novice performance was compared. Results: All graders showed high sensitivity (median 97% (IQR: 94-99)) and specificity (median 94% (IQR: 90-95)) in identifying the presence or absence of FH. No significant difference was seen in specificity between expert and novice graders, but experts had significantly greater diagnostic sensitivity (median difference = 5.3%, H = 5.00, p = 0.025). Expert graders had the highest agreement with the ground truth and novice graders showed great variability in grading uncommon grades, such as atypical FH. The proposed causes of misclassification included macular decentring in handheld OCT scans in children. Conclusions: Ophthalmologists of varying experience and allied health professionals can accurately identify FH using handheld and table-mounted OCT images. FH identification and paediatric OCT interpretation can be improved in wider ophthalmic clinical settings through the education of ophthalmic staff.