| International Journal of Computer Applications |
| Foundation of Computer Science (FCS), NY, USA |
| Volume 187 - Number 149 |
| Year of Publication: 2026 |
| Authors: Tanha Asfika Jaman, Akter Mst Lovely, Iftee Shekh Iftesham, Mostafa Farzana |
10.5120/ijca8fee57096b16
|
Tanha Asfika Jaman, Akter Mst Lovely, Iftee Shekh Iftesham, Mostafa Farzana . Does Probability Calibration Survive a Change of OCT Scanner? A Leakage-Free Study of Calibration Transfer Across Manufacturers. International Journal of Computer Applications. 187, 149 ( Oct 2026), 37-44. DOI=10.5120/ijca8fee57096b16
Retinal optical coherence tomography (OCT) classifiers are usually reported with calibration measured on the same scanner on which they were trained. This study measures what happens to their predicted probabilities on a different manufacturer’s scanner. Three-class classifiers (AMD, DME, normal) are trained on 65,585 patient-disjoint Heidelberg Spectralis B-scans (Kermany) and evaluated on an unseen Optovue Avanti RTVue XR cohort (OCTDL) across eleven runs, two backbones and two resizing policies. The data audit finds two leakage channels: Kermany patient identifiers are global, being shared between class folders 501 to 2,597 times more often than chance, and in OCTDL 47 pairs of pixel-identical images carry different patient identifiers. Splits are therefore built on connected components of (same patient) OR (near-duplicate). The resizing policy matters most for accuracy: square resizing raises target balanced accuracy from 0.8821 to 0.9304 and lowers uncalibrated expected calibration error (ECE) from 0.0316 to 0.0181 relative to letterboxing, a reduction comparable to that of the best source-only calibrator. Source-only temperature scaling lowers target ECE in 10 of 11 runs (95% bootstrap interval excluding zero in 6); calibrating on source data degraded by a physically parameterised OCT acquisition model beats a generic corruption family of matched severity in only 5 of 11 runs; and input-conditioned temperature scaling loses to a single global temperature in 10 of 11 runs. A referral threshold promising 0.5% error on source data yields 1.19% to 1.59% error on the new scanner.