Clinical applications of anterior segment swept-source optical coherence tomography: A systematic review

Quality assessment of anterior segment OCT images: Development and validation of quality criteria

BACKGROUND

The utility of medical imaging is dependant on image quality. We aimed to develop and validate quality criteria for ocular anterior segment optical coherence tomography (AS-OCT) images.

METHODS

We undertook a cross-sectional study using AS-OCT images from patients aged 6-16. A novel three-level grading system (good, limited or poor) was developed based on the presence of image artefact (categorised as lid, eyelash, cropping, glare, or movement artefact). Three independent experts graded 2825 images, with agreement assessed using confusion matrices and intraclass correlation coefficients (ICC) for each parameter.

RESULTS

There was very good inter-grader IQA agreement assessing image quality with ICC 0.85 (95 %CI: 0.84-0.87). The most commonly occurring artefact was eyelash artefact (1008/2825 images, 36 %). Graders labelled 621/2825 (22 %) images as good and 384 (14 %) as poor. There was complete agreement at either end of the confusion matrix with no 'good' images labelled as 'poor' by other graders, and vice versa. Similarly, there was very good agreement when assessing presence of lash (0.96,0.94-0.98), movement (0.97,0.96-0.99), glare (0.82,0.80-0.84) and cropping (0.90,0.88-0.92).

CONCLUSIONS

The novel image quality assessment criteria (IQAC) described here have good interobserver agreement overall, and excellent agreement on the differentiation between 'good' and 'poor' quality images. The large proportion of images graded as 'limited' suggests the need for refine this classification, using the specific IQAC features, for which we also report high interobserver agreement. These findings support the future potential for wider clinical and community care implementation of AS-OCT for the diagnosis and monitoring of ocular disease.

Molecular and epigenetic mechanisms governing ocular surface squamous neoplasia: opportunities for diagnostics

INTRODUCTION

Ocular surface squamous neoplasia (OSSN) is the most common ocular malignancy; the pathophysiology is influenced by molecular, genetic, and epigenetic mechanisms. The incidence of OSSN is associated with the anatomy and physiology of the ocular surface, limbal stem cell configuration, limbal vulnerability, cancer stem cells, dysplasia, neoplasia, angiogenesis, invasion, and metastasis. The key etiological factors involved are human papillomavirus (HPV), human immunodeficiency virus (HIV), immunosuppression, p53 tumor suppressor gene, hypovitaminosis A, and failure of Deoxyribonucleic acid (DNA) repair mechanisms.

AREAS COVERED

This special report is a focussed attempt to understand the molecular mechanism, genetic and epigenetic mechanism, and diagnostic modalities for OSSN.

EXPERT OPINION

While these mechanisms contribute to genome instability, promoter-specific hypermethylation might facilitate and promote tumor formation by silencing tumor suppressor genes. OSSN understanding has improved with increased literature available on various genetic, molecular, and epigenetic mechanisms, although the exact genetic and epigenetic mechanisms still need to be elucidated. It is important to note that the molecular mechanisms of OSSN can vary among individuals, and further research is required to elucidate the underlying processes fully. Understanding these mechanisms is crucial for the development of targeted therapies and improved management of OSSN.

Early and Late Complications after Cataract Surgery in Patients with Uveitis

Background and Objectives: Uveitis, a prevalent eye disorder characterized by inflammatory processes, often leads to cataract formation and significant visual impairment. This study aimed to evaluate preoperative conditions and postoperative outcomes following cataract surgery in uveitis patients. Materials and Methods: A retrospective study was conducted at the University Hospital Center Rebro Zagreb, Croatia, involving uveitis patients who underwent cataract surgery between 2013 and 2022. Eligible patients had uveitic cataracts affecting visual acuity or posterior segment visualization in a "quiet eye" and were disease-inactive for at least three months. Patients with certain pre-existing ocular conditions were excluded. The data collected included patient demographics, uveitis type, preoperative therapy, preexisting lesions, and postoperative outcomes such as visual acuity, intraocular pressure, central macular thickness, and complications. Statistical analysis was performed to identify risk factors associated with complications. Results: This study included 105 patients. The most common uveitis types were idiopathic uveitis, HLA-B27-associated uveitis, and JIA uveitis. After cataract surgery, there was a significant improvement in visual acuity at various time points, with 90% of eyes showing improvement. Intraocular pressure decreased over time. Central macular thickness increased at three months post-surgery but remained stable thereafter. Early and late complications were observed in 52.4% and 63.8% of eyes, respectively. The most common complications were posterior capsular opacification (53.3%), macular edema (26.6%), and epiretinal membrane formation (9.52%). The factors associated with complications varied between early and late stages but included age, age at the onset of uveitis, and the uveitis type. Conclusions: In patients with quiescent uveitis undergoing cataract surgery, significant visual improvement was achieved. This study highlights the importance of careful patient selection, preoperative and postoperative inflammation management, and precise surgical techniques. Although complications were common, the risk of capsular opacification, macular edema, and epiretinal membrane formation after surgery increased. However, future investigations should address this study's limitations and further refine perioperative strategies.