Three-Dimensional Volume Calculation of Intrachoroidal Cavitation Using Deep-Learning-Based Noise Reduction of Optical Coherence Tomography

Factors associated with intrachoroidal cavitation and sinkhole formation in eyes with glaucomatous visual-field defects

PURPOSE

To investigate factors associated with intrachoroidal cavitation (ICC) and sinkhole formation in eyes with glaucomatous visual-field defects.

METHODS

This retrospective, cross-sectional study enrolled a total of 2808 eyes of 1482 patients who were diagnosed/treated for glaucoma and underwent swept-source optical coherence tomography (OCT). We first determined the prevalence of ICCs and sinkholes and their locations. Next, we selected one eye from each patient and compared the clinical characteristics of eyes with and without ICCs. Finally, in eyes with ICCs, we compared the clinical characteristics of eyes with and without sinkholes. Blood flow (BF), represented by laser speckle flowgraphy-measured tissue-area mean blur rate (MBR), was measured in the temporal optic nerve head (ONH), temporal peripapillary chorioretinal atrophy (PPA) zone, and in the ICC zone. ICC area and angle were analyzed in OCT en-face images. Mean deviation and total deviation in the central area (TD-central) were measured with Humphrey visual-field testing.

RESULTS

A total of 86 eyes (3.1%) had ICCs and 52 eyes (1.9%) had sinkholes. ICC eyes had a lower spherical equivalent and longer axial length (AL) than non-ICC eyes (P < 0.05). Patients with eyes with sinkholes were more elderly and had worse best-corrected visual acuity, worse TD-central, a larger ICC, and lower tissue-area MBR in the temporal ONH, temporal PPA zone, and ICC zone (P < 0.05).

CONCLUSION

In eyes with glaucoma, AL elongation might be linked to ICC formation. Sinkhole formation might be associated with ICC enlargement, impaired ocular BF, and impaired retinal structure and function involving the central area.

Machine Learning-Assisted Short-Wave InfraRed (SWIR) Techniques for Biomedical Applications: Towards Personalized Medicine

Personalized medicine transforms healthcare by adapting interventions to individuals' unique genetic, molecular, and clinical profiles. To maximize diagnostic and/or therapeutic efficacy, personalized medicine requires advanced imaging devices and sensors for accurate assessment and monitoring of individual patient conditions or responses to therapeutics. In the field of biomedical optics, short-wave infrared (SWIR) techniques offer an array of capabilities that hold promise to significantly enhance diagnostics, imaging, and therapeutic interventions. SWIR techniques provide in vivo information, which was previously inaccessible, by making use of its capacity to penetrate biological tissues with reduced attenuation and enable researchers and clinicians to delve deeper into anatomical structures, physiological processes, and molecular interactions. Combining SWIR techniques with machine learning (ML), which is a powerful tool for analyzing information, holds the potential to provide unprecedented accuracy for disease detection, precision in treatment guidance, and correlations of complex biological features, opening the way for the data-driven personalized medicine field. Despite numerous biomedical demonstrations that utilize cutting-edge SWIR techniques, the clinical potential of this approach has remained significantly underexplored. This paper demonstrates how the synergy between SWIR imaging and ML is reshaping biomedical research and clinical applications. As the paper showcases the growing significance of SWIR imaging techniques that are empowered by ML, it calls for continued collaboration between researchers, engineers, and clinicians to boost the translation of this technology into clinics, ultimately bridging the gap between cutting-edge technology and its potential for personalized medicine.

Understanding Posterior Staphyloma in Pathologic Myopia: Current Overview, New Input, and Perspectives

Posterior staphyloma (PS) is considered the hallmark of pathologic myopia and is defined as an outpouching of a circumscribed portion of the eyeball with a radius of curvature smaller than that of the adjacent zone. Although more common in eyes with high myopia, it can affect those without it. The presence of PS is associated with a structurally and functionally worse course of high myopia that can lead to visual disability. Unfortunately, the pathogenesis of PS is unclear so far. Thus, due to the increasing prevalence of myopia which has been further exacerbated by the advent of COVID-19 lockdown, researchers are eager to elucidate the pathogenesis of pathologic myopia and that of its complications, especially PS, which will allow the development of preventive strategies. The aim of this work was to review the morphological characteristics of PS with emphasis on similarities with peripapillary staphyloma and to discuss the pathogenesis of PS considering recent suggestions about that of peripapillary staphyloma.

Myopic (Peri)papillary Changes and Visual Field Defects

Purpose

Myopic eyes combining gamma peripapillary atrophy and peripapillary staphyloma were sorted according to the presence of intrachoroidal cavitation (PICCs) or its absence (combinations). Visual field defects (VFDs) and factors discriminating these groups were analyzed.

Methods

These groups were sorted by optical coherence tomography. VFDs were assessed using the Humphrey® Field Analyzer 3, SITA standard. Ovality index (OI) was the ratio between the shortest and longest diameters of the disc. The proportions of PICCs, lamina cribrosa defects (LCDs) and clusters in each Garway-Heath's sector (A-F) were analyzed. All variables were compared between PICCs and combinations. A multivariate logistic regression analysis was performed ultimately.

Results

Of the 93 eyes, we obtained, 20 PICCs and 73 combinations. The prevalence of VFDs and LCDs in PICCs were 65% (13/20) and 30% (6/20), respectively. PICCs 85% (17/20) and LCDs 12% (11/93) predominated in sector B (inferotemporal) and clusters 9.7% (9/93) in the corresponding sector. The proportion of VFDs was significantly higher in PICCs than combinations (p < 0.001). In sector B, the proportion of LCDs was significantly higher in PICCs than combinations (p = 0.011). The mean OI was significantly lower (p < 0.001) in PICCs than combinations. Multivariate logistic regression analysis concluded that mean OI (p < 0.001) was the only statistically significant factor discriminating PICCs and combinations.

Conclusion

Mean OI discriminating PICCs from combinations is further evidence of a gradation of structural changes between them. It could be related to the higher proportion of VFDs in PICCs. The predominant distribution of PICCs infero-temporally supports PICC as a cause of uncertainty in glaucoma diagnosis in high myopia. Furthermore, the highest proportion of PICCs and LCDs in this sector highlights its vulnerability to damage in myopic eyes and deserves further investigation as it is also primarily involved in glaucoma.

Peripapillary Intrachoroidal Cavitation

Peripapillary intrachoroidal cavitation (PICC) is a yellow-orange lesion, located at the outer border of the myopic conus. First described as a localized detachment of the retinal pigment epithelium, its intrachoroidal location was later revealed, justifying its current name. PICC is related to other myopic complications such as posterior staphyloma, but its pathogenesis is not clear to date. Although it has been considered a benign condition, most eyes with PICC show visual field defects, which leads to diagnostic uncertainty as these deficits resemble those seen in glaucoma. Furthermore, eyes with PICC may develop macular detachment with retinoschisis. Finally, misdiagnosis of PICC as a metastatic choroidal tumor may lead to unnecessary and anxiety-inducing investigations. Advances in optical coherence tomography (OCT) imaging have improved the visualization of ocular structures, contributing to the understanding of PICC. Recently, high optic nerve sheath traction forces during eye movements in highly myopic eyes have been suggested as promoters of PICC, renewing interest around this condition. However, a review of PICC is still lacking. Therefore, we aimed to provide a concise yet comprehensive overview of the current state of the art, focusing on OCT illustrations, pathophysiology and potential future perspectives based on the biomechanics of the optic nerve.