Utility of high-resolution anterior segment optical coherence tomography in the diagnosis and management of sub-clinical ocular surface squamous neoplasia

Can high-resolution optical coherence tomography provide an optical biopsy for ocular surface lesions?

High-resolution optical coherence tomography (HR-OCT) has transformed the diagnosis and management of ocular surface lesions. Providing a detailed cross-sectional view of the cornea and conjunctiva, HR-OCT can be used to identify characteristic features of various benign and malignant ocular surface lesions, aiding in their diagnosis and guiding treatment. When incorporated into an ophthalmology clinic, HR-OCT provides morphological images of lesions in a noninvasive means, akin to an "optical biopsy". The characteristic HR-OCT features of several lesions have been well described in the literature, including for ocular surface squamous neoplasia, papilloma, melanoma, primary acquired melanosis, complexion associated melanosis, nevus, pterygium, pinguecula, lymphoma, and amyloidosis. HR-OCT can be used to differentiate between lesions with similar clinical features, lesions that co-exist on the same ocular surface, and atypically presenting lesions, such as pigmented ocular surface squamous neoplasia or amelanotic melanoma. The management of ocular surface lesions has been transformed by the implementation of HR-OCT, providing clinicians with the ability to monitor tumor response to topical chemotherapies, follow previously excised lesions for recurrence, and map out tumor borders intraoperatively. While there are some limitations to HR-OCT, including imaging of thick or deep lesions, it has become an essential tool for ocular oncologists in the management of ocular surface lesions.

It Is All About the Angle: A Clinical and Optical Coherence Tomography Comparison of Corneal Ocular Surface Squamous Neoplasia and Corneal Pannus

PURPOSE

The aim of this study was to compare clinical characteristics and high-resolution optical coherence tomography (HR-OCT) findings between corneal ocular surface squamous neoplasia (OSSN) and corneal pannus.

METHODS

Retrospective study of 9 individuals, 3 with lesions histologically confirmed to be OSSN, 3 with lesions histologically confirmed to be pannus, 1 with lesions histologically confirmed to be OSSN followed by pannus, and 2 with long-standing, nonchanging lesions clinically diagnosed as pannus. All individuals presented to the Miami Veterans Affairs Medical Center eye clinic or Bascom Palmer Eye Institute between 2015 and 2023. Clinical characteristics and HR-OCT findings were evaluated and compared.

RESULTS

Mean age of the population was 72.8 ± 5.1 years, 100% self-identified as male, 100% as White, and 11.1% as Hispanic. Clinically, all lesions appeared as whitish, opalescent, variably vascularized opacities extending from the limbus. None of the OSSN cases had vessels that extended to the border, whereas 4 cases of pannus (67%) had at least 1 vessel that reached the border. On HR-OCT, epithelial hyperreflectivity was observed in all cases of OSSN and pannus. Epithelial thickening was observed in all cases of OSSN, but in none of the cases of pannus. An important distinction between the 2 groups was the transition between normal and abnormal epithelium. All cases of OSSN had a vertical transition, whereas all cases of pannus had an angled transition.

CONCLUSIONS

Corneal OSSN and corneal pannus can both present with clinical findings of an opalescent lesion and may have overlapping findings on HR-OCT. Although both entities may show epithelial hyperreflectivity on HR-OCT, OSSN demonstrates an abrupt transition at a vertical, 90 degrees angle perpendicular to the Bowman layer, whereas pannus appears as an angled transition around 45 degrees. Therefore, the angle of transition between normal and abnormal epithelium can be useful in distinguishing between the 2 entities.

Anterior segment optical coherence tomography in ocular surface tumours and simulating lesions

This study aims to systematically review the reported literature on the use of anterior segment optical coherence tomography (AS-OCT) in ocular surface tumours and simulating lesions. A systematic literature search was done using PubMed, Scopus, and Web of Science databases between January 2002 and December 2021. On AS-OCT, ocular surface squamous neoplasia typically demonstrate epithelial thickening, epithelial hyperreflectivity, and an abrupt transition between normal and abnormal epithelium. Conjunctival nevi usually show mildly hyperreflective epithelium of normal thickness, internal hyperreflectivity, and intralesional cysts which is the hallmark of this tumour. Primary acquired melanosis presents with normal thickness epithelium, basal epithelial hyperreflectivity, and absence of cysts. Conjunctival melanoma demonstrates hyperreflective normal/thickened epithelium, hyperreflective basal epithelium, internal hyperreflectivity, and absence of intralesional cysts. Conjunctival lymphoma shows homogenous, low-medium reflective subepithelial lesions with smooth borders, and dot-like infiltrates. Benign reactive lymphoid hyperplasia findings are similar to lymphoma but the infiltrates are more hyperreflective compared to lymphoma. Pterygium shows thickened conjunctival epithelium, epithelial hyperreflectivity, and subepithelial wedge-shaped hyperreflective tissue separated from the overlying epithelium by a cleavage plane. Pinguecula demonstrates mildly thickened epithelium and similar findings with pterygium but does not extend beyond the corneal limbus. This review shows that AS-OCT, as a noninvasive tool, has potential uses in the differential diagnosis of ocular surface tumours and simulating lesions. Major limitations of AS-OCT include limited visualization of the posterior border of thick, keratinized, and pigmented tumours and lack of assessment of large conjunctival tumours in a single cut.

Clinical and Optical Coherence Tomography Comparison Between Ocular Surface Squamous Neoplasia and Squamous Metaplasia

PURPOSE

The purpose of this study was to compare the clinical characteristics and high-resolution optical coherence tomography (HR-OCT) findings between corneal squamous metaplasia and ocular surface squamous neoplasia (OSSN).

METHODS

A retrospective case-control study of 8 patients, 4 with histologically confirmed squamous metaplasia and 4 with histologically confirmed OSSN, who presented to the Miami Veterans Administration Medical Center and Bascom Palmer Eye Institute between 2016 and 2020 was performed. Clinical characteristics, HR-OCT findings, and pathology were evaluated and compared.

RESULTS

Four patients with squamous metaplasia and 4 with OSSN were evaluated. In the metaplasia group, 75% were male, 2 were White, and 2 were Black. In the OSSN group, all 4 were White males. All lesions were opalescent and occurred at the limbus; however, the borders were more smooth and rounded in the metaplastic lesions compared with OSSN. HR-OCT findings were indistinguishable between the 2 groups.

CONCLUSIONS

There is overlap in clinical characteristics and HR-OCT findings between corneal squamous metaplasia and OSSN, highlighting one limitation of HR-OCT. As such, if a corneal opacity has some but not all HR-OCT findings of OSSN, squamous metaplasia should also be considered. A biopsy may be indicated to further evaluate and guide treatment.

Medical treatment for ocular surface squamous neoplasia

Ocular surface squamous neoplasia (OSSN) is the most common non-melanocytic tumour of the ocular surface. Surgical excision with wide margins using the "no-touch" method was originally the most popular treatment for OSSN. However, in the past two decades, the use of topical medications for OSSN treatment has gained a reputation amongst ophthalmologists for being an effective alternative to surgical excision. Furthermore, technological advancements, such as those seen in high-resolution optical coherence tomography (HR-OCT) for the anterior segment, have facilitated the diagnosis and monitoring of OSSN. When selecting a topical agent, interferon alpha-2b (IFNα-2b) and 5-fluorouracil (5-FU) are two of the gentlest medications used for OSSN and are often considered first line therapies due to their high-resolution rates and mild side effect profiles. Mitomycin C (MMC), on the other hand, has a highly toxic profile; therefore, while effective, in our hands it is considered as a second-line treatment for OSSN if the other modalities fail. In addition, newer and less studied agents, such as immune checkpoint inhibitors, retinoic acid, aloe vera, and anti-vascular endothelial growth factor have anti-neoplastic properties and have shown potential for the treatment of OSSN. We enclose an updated literature review of medical treatments for OSSN.

Treatment of ocular-involving monkeypox virus with topical trifluridine and oral tecovirimat in the 2022 monkeypox virus outbreak

Purpose

To report a case of ocular involving monkeypox infection in the United States during the 2022 outbreak, and to review the literature regarding its clinical manifestations and management known to date.

Observations

A 36-year-old man with well controlled HIV presented to the emergency department with anal pain, diffuse rash, right eye pain, and right eye redness after he tested positive for monkeypox one week prior. Ocular examination showed bilateral periorbital vesicular lesions, right eye conjunctival injection, and a single white plaque on his right medial bulbar conjunctiva. Macular, vesicular, and pustular lesions were noted throughout his body, including the genital and perianal region. His ocular and systemic symptoms completely resolved after treatment with a ten-day course of 1% trifluridine and moxifloxacin drops in both eyes, as well as two weeks of oral tecovirimat.

Conclusion and Importance

In July of 2022, monkeypox virus was declared a global health emergency by the World Health Organization; however, there are no standard guidelines for monkeypox treatment. Data on its clinical presentation and course, especially pertaining to ocular manifestations, is limited. We highlight the importance of recognizing ophthalmic manifestations of monkeypox virus and a possible therapeutic approach to help guide the management of these patients.

The Management of Ocular Surface Squamous Neoplasia (OSSN)

The rise of primary topical monotherapy with chemotherapeutic drugs and immunomodulatory agents represents an increasing recognition of the medical management of ocular surface squamous neoplasia (OSSN), which may replace surgery as the standard of care in the future. Currently, there is no consensus regarding the best way to manage OSSN with no existing guidelines to date. This paper seeks to evaluate evidence surrounding available treatment modalities and proposes an approach to management. The approach will guide ophthalmologists in selecting the most appropriate treatment regime based on patient and disease factors to minimize treatment related morbidity and improve OSSN control. Further work can be done to validate this algorithm and to develop formal guidelines to direct the management of OSSN.

Ocular Surface Squamous Neoplasia Masquerading as Recalcitrant Epithelial Keratitis

PURPOSE

The purpose of this study was to report a unique case of ocular surface squamous neoplasia that masqueraded as a nonresolving toxic epithelial keratitis.

METHODS

This was a case report and review of the literature.

RESULTS

A 79-year-old man presented with decreased vision, redness, and a foreign body sensation in his right eye that was refractory to treatment with lubrication and topical nonsteroidal antiinflammatory drops. Before presentation, the referring provider believed that he had medicamentosa-related keratitis and placed him on oral methazolamide. Slitlamp biomicroscopy of the right eye revealed diffuse epitheliopathy with punctate fluorescein staining and subtle underlying corneal epithelial opalescence. A mildly thickened and inflamed pinguecula was noted from 2 to 5 o'clock at the limbus of the right eye. An anterior segment high-resolution optical coherence tomography revealed thickened, hyperreflective epithelium with an abrupt transition. An incisional biopsy confirmed conjunctival and corneal intraepithelial neoplasia. The patient improved after 4 cycles of topical chemotherapy with 1% 5-fluorouracil eye drops with complete resolution of the corneal and conjunctival pathology.

CONCLUSIONS

Ocular surface squamous neoplasia can rarely masquerade as a recalcitrant medicamentosa and epithelial keratitis. In subtle cases or in cases with combined ocular surface morbidities, anterior segment high-resolution optical coherence tomography can be helpful to diagnose and direct therapy.

Topical Chemotherapy for Treating Ocular Surface Squamous Neoplasia with a Combination of Interferon α-2b and 5-Fluorouracil

Introduction

This study evaluated the efficacy of combined interferon α-2b (IFNα2b) and 5-fluorouracil (5-FU) as primary treatment for ocular surface squamous neoplasia (OSSN).

Methods

In this retrospective study, 27 eyes with OSSN followed by topical application of combined IFNα2b and 5-FU were examined. Reported outcome measures were tumor response, visual acuity, time to complete resolution, recurrence and treatment complications.

Results

Twenty-six patients (17 male, 9 female) had a mean age of 63.9 (median, 67; range 22–83) years. Complete tumor response was observed in 24 eyes (88.9%). Three eyes (11.1%) showed partial response to the chemotherapy agents and later underwent surgical tumor removal. The median time to complete resolution was 6 (mean, 6.1; range, 3–11) weeks. Of these, the patients received between one to three cycles of 5-FU therapy (median, 2; mean, 1.8). Complications noted were transient irritation at 5-FU cycle (11 eyes, 40.7%). There was no tumor recurrence at mean follow-up of 16.1 (median, 12; range 6–38) months.

Conclusions

Combination therapy of IFNα2b and 5-FU was a safe and effective treatment, inducing a short duration of administration and low recurrence rate for OSSN.

Trial Registration

Retrospectively registered, UHCT22048.

Role of AS-OCT in Managing Corneal Disorders

Optical coherence tomography (OCT) is analogous to ultrasound biometry in the cross sectional imaging of ocular tissues. Development of current devices with deeper penetration and higher resolution has made it popular tool in clinics for visualization of anterior segment structures. In this review, the authors discussed the application of AS-OCT for diagnosis and management of various corneal and ocular surface disorders. Further, recent developments in the application of the device for pediatric corneal disorders and extending the application of OCT angiography for anterior segment are introduced.

The use of high resolution optical coherence tomography (HR-OCT) in the diagnosis of ocular surface masqueraders

INTRODUCTION

Ocular surface masqueraders encompass any ocular surface lesion masquerading as another ocular surface lesion. High resolution optical coherence tomography (HR-OCT) has emerged as an adjunctive tool to clinical acumen. This study's purpose is to evaluate the utility of HR-OCT images in guiding the diagnosis and management of those lesions.

MATERIAL AND METHODS

22 individuals with a clinically ambiguous ocular surface lesion with slit lamp photographs (SLP), HR-OCT images, and histopathological examination were included in the study. The presumptive clinical diagnosis based on SLP was compared to the diagnosis suggested by HR-OCT findings and to definitive diagnosis by histopathology. The main outcome of this study was the frequency in which HR-OCT findings guided the clinician to the correct diagnosis.

RESULTS

7 lesions were epithelial, 3 had an epithelial and a subepithelial component, and 12 were subepithelial. HR-OCT was most effective in discerning lesion location, successfully identifying the location in 100% of cases. Classic HR-OCT findings were detected in 68.2% of cases while suggestive features were detected in 31.8% of cases. The epithelial lesions' mean epithelial thickness was 265.4 ± 140.6 μm, the subepithelial lesions' mean was 58.0 ± 25.0 μm, and the combined lesions' mean was 140.0 ± 70.0 μm. The epithelium was significantly thicker in epithelial lesions compared to subepithelial and combined lesions. By ROC analysis we identified that using a cut off of 156 μm, the sensitivity was 86% and the specificity was 93%.

DISCUSSION

HR-OCT can be a valuable diagnostic tool, assisting in the differentiation of ambiguous ocular surface pathologies by providing a cross-sectional, morphological image of the lesion.

Update on the Management of Ocular Surface Squamous Neoplasia

Purpose of review

To review and update the latest findings in diagnosis and management of ocular surface squamous neoplasia (OSSN).

Recent findings

OSSN is the most common anterior segment neoplastic disease process. Several ocular surface imaging techniques have been developed for the early diagnosis and management of clinical and subclinical ocular surface squamous neoplasia, including high-resolution optical coherence tomography (HR-OCT), in vivo confocal microscopy, and ultrasound biomicroscopy. Treatment modalities include both surgical and medical management, with a recent trend towards primary and adjunctive pharmacotherapy.

Summary

There is increasing use of HR-OCT for the diagnosis and monitoring of clinical and subclinical OSSN lesions. Topical pharmacotherapy agents, including interferon α-2b, 5-fluorouracil, and mitomycin C, have demonstrable efficacy in the treatment of OSSN and their use may be dictated based upon tumor factors, patient factors, cost, and side effect profile. Both surgical excision and adjunctive topical medications have excellent success, with the favored treatment method trending towards topical pharmacotherapy as primary therapy.

Management of ocular surface squamous neoplasia: Bowman Club Lecture 2021

The gold-standard treatment for ocular surface squamous neoplasia (OSSN) has traditionally been surgical excision with wide margins and a no-touch technique. However, surgery may be associated with several unfavourable sequelae, as well as significant recurrence rates if margins are positive. In recent years, topical chemotherapy with 5-fluorouracil, interferon α-2b and mitomycin C have emerged as valuable agents capable of effectively treating OSSN with varying adverse effects. These medical treatment options usually present additional costs to the patient but can allow patients to avoid surgery with fewer long-term effects. Anterior segment high-resolution optical coherence tomography is an excellent tool for diagnosing and monitoring OSSN and can be a useful aid for both surgical and medical treatments of OSSN.

Case Series: High-resolution Optical Coherence Tomography as an Optical Biopsy in Ocular Surface Squamous Neoplasia

SIGNIFICANCE

Ocular surface squamous neoplasias are superficial tumors of the cornea and conjunctiva that can be sight threatening if neglected. Therefore, accurate noninvasive diagnostic modalities are needed.

PURPOSE

The purpose of this case series was to describe the hallmark features of ocular surface squamous neoplasia on high-resolution optical coherence tomography (HR-OCT) imaging and its use in the evaluation and management of superficial ocular tumors.

CASE SERIES

Five eyes of four patients with ocular surface squamous neoplasia are described. Whereas two eyes displayed the classic clinical features of ocular surface squamous neoplasia, three of the five eyes had more subtle atypical features. However, all shared features on HR-OCT of epithelial thickening and hyperreflectivity with abrupt transitions between normal and abnormal tissue, classic features of ocular surface squamous neoplasia. All lesions ultimately underwent incisional or excisional biopsy and were confirmed to be ocular surface squamous neoplasia on histopathology.

CONCLUSIONS

Ocular surface squamous neoplasia may present as a classic tumor but can also have subtle features or masquerade. Accurate methods to diagnose and manage patients with ocular surface squamous neoplasia are necessary. With recent advancements in technology, HR-OCT has been demonstrated to accurately identify ocular surface squamous neoplasia with the repeatable optical findings of (1) epithelial thickening, (2) epithelial hyperreflectivity, and (3) abrupt transition zone between normal and abnormal tissue. This case series demonstrates how HR-OCT can help provide an optical biopsy to guide appropriate diagnosis and management of this neoplastic lesion.

Spectrum of AS-OCT features of ocular surface tumors and correlation of clinico-tomographic features with histopathology: a study of 70 lesions

PURPOSE

To assess the correlation between clinical and anterior segment optical coherence tomographic (AS-OCT) details and histopathological changes in various ocular surface lesions.

METHODS

Prospective case series of 70 lesions in 65 patients.

RESULTS

AS-OCT revealed epithelial changes in OSSN (n = 19; 44%), squamous papilloma (n = 3; 60%), nevus (n = 1; 33%), epithelial hyperplasia (n = 1; 33%), granular dystrophy (n = 1; 100%) and granulation tissue (n = 1; 100%); subepithelial changes in chronic inflammation (n = 4, 100%), lymphoma (n = 3; 100%) and arteriovenous malformation (n = 1; 100%); combined epithelial and subepithelial changes in OSSN (n = 24; 56%), squamous papilloma (n = 2; 40%), PEH (n = 3; 100%), nevus (n = 2; 67%), epithelial hyperplasia (n = 2; 67%), solar elastosis (n = 1; 100%), lobular capillary hemangioma (n = 1; 100%) and sebaceous carcinoma (n = 1; 100%). Epithelial involvement on AS-OCT paralleled the histopathological findings in 98% (n = 69) and subepithelial involvement in 83% (n = 58). The correlation of clinico-tomographic diagnosis with histopathology diagnosis was seen in 77% (n = 54) lesions. Sensitivity and specificity of AS-OCT as a diagnostic tool for detection of epithelial involvement were 100% and 92% and for subepithelial involvement was 98% and 100%, respectively.

CONCLUSION

The correlation between AS-OCT and histopathology features determining epithelial and subepithelial involvement is excellent. It is a useful adjunctive tool for the diagnosis of ocular surface lesions.

The role of imaging technologies for ocular surface tumors

PURPOSE OF REVIEW

This review will discuss the utility of high-resolution anterior segment optical coherence tomography (HR-OCT), in-vivo confocal microscopy (IVCM) and ultrasound biomicroscopy (UBM) in characterizing and diagnosing various ocular surface tumors, namely ocular surface squamous neoplasia (OSSN), conjunctival lymphoma and conjunctival melanoma. The strengths and limitations of each imaging modality will be discussed along with the characteristics findings of each lesion on each imaging platform.

RECENT FINDINGS

HR-OCT can consistently be utilized in the clinic setting to distinguish between epithelial ocular surface tumors such as OSSN as compared with subepithelial tumors such as conjunctival lymphoma and conjunctival melanoma given their distinctive findings. IVCM can be used as an adjunct to HR-OCT to obtain cellular and surface characteristics, whereas UBM can be used to assess tumor depth and thickness for larger and highly pigmented lesions as well as to detect intraocular invasion.

SUMMARY

HR-OCT, IVCM and UBM are all helpful imaging modalities to diagnose and characterize various ocular surface tumors and can serve as valuable adjuncts to monitor treatment response and assess for recurrence ocular surface tumors.

Bilateral ocular surface squamous neoplasia: A study of 25 patients and review of literature

PURPOSE

To describe the risk factors, clinical presentation, management, and outcomes of patients with bilateral ocular surface squamous neoplasia (OSSN).

METHODS

Retrospective case series.

RESULTS

Of the 25 patients with bilateral OSSN, the mean age at diagnosis of OSSN was 31 years (median, 24 years; range, 2-60 years). Risk factors for bilateral OSSN included xeroderma pigmentosum (n = 15, 60%), human immunodeficiency virus infection (n = 3, 12%), conjunctival xerosis (n = 1, 4%), and topical steroid use (n = 1, 4%). There were no identifiable ocular or systemic risk factors in 7 (28%) patients. Presentation was synchronous in 14 (56%) and metachronous in 11 (44%) patients. Tumor morphology was bilaterally similar in 12 (48%) patients. Histopathological examination (n = 36) revealed conjunctival intraepithelial neoplasia (CIN) grade 1 in 4 (8%); grade 2 in 7 (14%); carcinoma in situ in 5 (10%), and invasive carcinoma in 20 (40%). Primary management of OSSN (n = 49) included excisional biopsy (n = 31, 62%), topical immunotherapy (IFN α2B) (n = 11; 22%), topical Mitomycin C (MMC) (n = 3, 6%), enucleation (n = 1, 2%), orbital exenteration (n = 2, 4%), and plaque brachytherapy (PBT) (n = 1, 2%). One patient was lost to follow-up after detection of tumor in the second eye. Recurrent tumors were noted in 16 (32%) eyes and binocular globe salvage was achieved in 16 (64%) patients at a mean follow up of 41 months (median 30 months; range, 1-164 months).

CONCLUSION

OSSN occurrence can be synchronous or metachronous. Meticulous examination of the fellow eye is important for an early diagnosis of OSSN.

Histopathological Variability and Concomitant Lesions in Pterygium in a Large Case Series

Pterygium is a common lesion consisting of fleshy conjunctival growth extending towards the cornea. There is no documented risk of malignant transformation; however, concomitant disease is not rare, and its link to sunlight exposure indicates a risk of other malignancies. The purpose of our study is to describe histopathological features of resected pterygiums and to recognize patients at risk of other conjunctival diseases. One hundred and forty-nine formalin-fixed and paraffin-embedded pterygium samples were subjected to histopathological analysis. Histological H&E sections were obtained and digitalized using a Zeiss Axio Scan.Z1 slide scanner. Thirteen predefined morphological features were used to record histopathological changes in the epithelium and substantia propria. Neovascularization was observed in 54% of the samples. Sun damage, comprising solar elastosis and stromal plaque, was present in 81% of the samples. Variation in epithelial thickness was the most common change, with acanthosis and atrophy being observed in 62% and 26% of the samples, respectively. In our series, 21% (31/149) of pterygiums showed mild to moderate dysplasia, a finding that may be associated to ocular surface squamous neoplasia (OSSN). Moreover, 32% (47/149) of the cases showed melanocytic hyperplasia, which could represent primary acquired melanosis (PAM). There is a positive correlation between dysplasia and chronic inflammation (p=0.012) and an inverse correlation with epithelial atrophy (p=0.001) and neovascularization (p=0.05). Similarly, a positive correlation is observed between goblet cell hyperplasia and melanocytic hyperplasia (p=0.02). Our findings show that pterygiums harbour histological features that may be suggestive of OSSN or PAM in 53% of our patients. Whilst being on the benign side of the spectrum, these two entities are known for their potential progression to malignancy. A recommendation is made for all surgically excised pterygiums to be sent for histopathological diagnosis, and clear guidelines for reporting of these lesions should be established. Associated histopathological findings suggestive of other concomitant diseases should be identified to insure adequate follow-up of these patients.

Optical Coherence Tomography of Peri-Ocular Skin Cancers: An Optical Biopsy

Introduction

Optical coherence tomography (OCT) imaging has been used as a diagnostic tool for retinal disease for several years, and OCT apparatuses are becoming increasingly powerful. However, OCT has yet to reach its full potential in ophthalmology clinics. Alike retinal layers, it has been shown that OCT is able to generate cross-sectional images of the skin and allows visualization of skin lesions in a histopathology-like manner.

Objective

We aim to validate OCT as an imaging modality for peri-ocular skin cancer. Through a series of cases, we highlight findings for 3 common eyelid malignancies: basal cell carcinoma, squamous cell carcinoma and sebaceous carcinoma. We propose an OCT image-based signature for basal cell carcinoma.

Methods

This is a prospective study. Fifty-eight lesions suspicious of malignancy from 57 patients were subjected to OCT imaging prior to the surgical excision of the lesion. OCT images were analysed and scored according to previously identified OCT features. Eight representative examples are presented, highlighting the OCT patterns for each malignancy side by side to its corresponding histopathological sections.

Results

Out of the 58 lesions analysed, 53 were malignant. A loss of the dermal-epidermal junction is observed in all malignant lesions. A strong link is observed between the presence of subepithelial hyporeflective nests on OCT and the diagnosis of basal cell carcinoma (present in 83% of cases). Conversely, lesions of epithelial origin such as squamous cell carcinoma are most often represented on OCT by acanthosis. Two supplementary cases, one basal cell carcinoma and one sebaceous carcinoma, are provided to illustrate how OCT imaging is a valuable tool in cases where clinical observations may be unusual.

Conclusions

We provide evidence supporting the use of OCT for the evaluation of peri-ocular cancers. OCT enables visualization of the skin layers in vivo, before biopsy. Our results show that certain OCT features can contribute to include or exclude a diagnosis of basal cell carcinoma. By integrating this non-invasive imaging methodology into the routine assessment of peri-ocular skin lesions, especially in health care centres where access to specialists is limited, OCT imaging can increase clinical precision, reduce delays in patient referral and enhance patient care.

Intraoperative optical coherence tomography in anterior segment surgery

Intraoperative optical coherence tomography (iOCT) enables real-time visualization of ocular structures during surgery and enhances our understanding of intraoperative dynamics. iOCT aids in decision-making during various anterior segment surgeries, and its efficacy and feasibility in anterior lamellar keratoplasty and endothelial keratoplasty is well established. The landmark DISCOVER study observed that iOCT altered the surgeon decision in 38% of cases undergoing lamellar keratoplasty and provided guidance regarding the need for secondary surgical intervention. iOCT also finds an application in phacoemulsification wherein it helps to assess corneal incisions, intralenticular pressure, and posterior capsule integrity during nuclear emulsification. iOCT aids in the visualization of angle structures during placement of tubes and shunts in glaucoma surgeries and allows precise creation of partial thickness scleral flaps. In addition, iOCT helps in establishing a diagnosis, as well as provide intraoperative guidance, in pediatric patients who are not cooperative for examination. The role of iOCT in refractive surgeries and ocular surface disorders is increasingly being evaluated. The limitations of present-day iOCT systems are related to instrument compatibility, automated tracking of the surgical field, and on-table volumetric analysis of the real-time images. Technological advances may facilitate complete integration of OCT in the surgical microscopes for all surgical procedures.