Toluidine Blue 0.05% Vital Staining for the Diagnosis of Ocular Surface Squamous Neoplasia in Kenya

Novel automated non-invasive detection of ocular surface squamous neoplasia using artificial intelligence

Ocular surface squamous neoplasia (OSSN) is a common eye surface tumour, characterized by the growth of abnormal cells on the ocular surface. OSSN includes invasive squamous cell carcinoma (SCC), in which tumour cells penetrate the basement membrane and infiltrate the stroma, as well as non-invasive conjunctival intraepithelial neoplasia, dysplasia, and SCC in-situ thereby presenting a challenge in early detection and diagnosis. Early identification and precise demarcation of the OSSN border leads to straightforward and curative treatments, such as topical medicines, whereas advanced invasive lesions may need orbital exenteration, which carries a risk of death. Artificial intelligence (AI) has emerged as a promising tool in the field of eye care and holds potential for its application in OSSN management. AI algorithms trained on large datasets can analyze ocular surface images to identify suspicious lesions associated with OSSN, aiding ophthalmologists in early detection and diagnosis. AI can also track and monitor lesion progression over time, providing objective measurements to guide treatment decisions. Furthermore, AI can assist in treatment planning by offering personalized recommendations based on patient data and predicting the treatment response. This manuscript highlights the role of AI in OSSN, specifically focusing on its contributions in early detection and diagnosis, assessment of lesion progression, treatment planning, telemedicine and remote monitoring, and research and data analysis.

Toluidine blue 1% eye drop versus optical coherence tomography for margin delimitation of ocular surface squamous neoplasia

PURPOSE

To compare the use of toluidine blue 1% eye drops with anterior segment optical coherence tomography (OCT) for the determination of tumour margins in patients with ocular surface squamous neoplasia (OSSN).

METHODS

The study was conducted from July 2020 to June 2021 at the Ocular Oncology department at the Federal University of São Paulo, Brazil. Slit-lamp photographs after toluidine blue staining and OCT of the anterior segment were taken on the same day from patients with OSSN. Photographs and OCT images were analyzed quantitatively using the software ImageJ and IMAGEnet®, respectively. The agreement between techniques was evaluated qualitatively through the Bland-Altman graph and quantitatively through intraclass correlation (ICC).

RESULTS

A total of 21 participants (71.43% males) with a clinical diagnosis of OSSN were included in the study. The average + SD diameter along the chosen axes was 4.43 ± 2.08 mm with OCT of 4.37 ± 2.03 mm with toluidine blue, a difference not statistically significant (p = 0.2891). The Bland-Altman analysis indicated a good qualitative agreement between the methods, with all cases inserted within the limits of agreement from -0.3217 to 0.4268. The ICC quantitative analysis showed an almost perfect agreement of 99.57% (95%CI: 98.96-99.83%; p < 0.001).

CONCLUSIONS

Our findings showed that OCT and toluidine eye drops are equivalent in determining margins for tumour measurements, which is particularly relevant in low-income settings where anterior segment OCT is not available. The use of toluidine blue 1% could be an useful alternative to quantify the size of the tumour, help to monitor tumour growth, and outline margins for surgical planning.

Comparison of non-invasive diagnostic modalities for ocular surface squamous neoplasia at a tertiary hospital, South Africa

AIMS

The aim of the study is to assess non-invasive diagnostic modalities for ocular surface squamous neoplasia (OSSN) when compared to histology.

METHODS

A prospective case-control study was conducted of patients presenting with conjunctival masses at a tertiary eye hospital in Johannesburg, South Africa. Patients completed an interview and had three non-invasive diagnostic tests: optical coherence tomography, impression cytology and methylene blue stain. A biopsy with histology was performed as the gold standard to confirm the diagnosis.

RESULTS

One hundred and eighty-two conjunctival masses of 175 patients were evaluated. There were 135 lesions identified as OSSN on biopsy and 47 lesions were benign on histology. Optical coherence tomography had a sensitivity and specificity of 87.2% (95% CI: 80.0-92.5) and 75.6% (95% CI: 60.5-87.1), respectively, when an epithelial thickness cutoff of 140 um was used. Shadowing was found in 46% of cases due to leukoplakia or increased thickness of the mass. Cytology had a sensitivity of 72.4% (95% CI: 62.5-81.0) and a specificity of 74.3% (95% CI: 56.7-87.5). Twenty-seven per cent of cytology specimens were excluded from analysis due to inadequate cellularity. Methylene blue had a high sensitivity of 91.9% (95% CI: 85.9-95.9), but low specificity of 55.3% (95% CI: 40.1-69.8).

CONCLUSION

Optical coherence tomography had a high sensitivity and specificity as a non-invasive test and liquid-based cytology performed well but had a lower sensitivity and specificity than with optical coherence tomography. Methylene blue performed well as a screening test, with a high sensitivity but low specificity.

Prevalence of co-existent neoplasia in clinically diagnosed pterygia in a UK population

INTRODUCTION

Ocular surface squamous neoplasia (OSSN) and pterygia share risk factors and co-exist in only a minority of cases. Reported rates of OSSN in specimens sent as pterygium for histopathological analysis vary between 0% and nearly 10%, with the highest rates reported in countries with high levels of ultraviolet light exposure. As there is a paucity of data in European populations, the aim of this study was to report the prevalence of co-existent OSSN or other neoplastic disease in clinically suspected pterygium specimens sent to a specialist ophthalmic pathology service in London, United Kingdom.

METHODS

We performed a retrospective review of sequential histopathology records of patients with excised tissue submitted as suspected "pterygium" between 1997 and 2021.

RESULTS

In total, 2061 specimens of pterygia were received during the 24-year period, with a prevalence of neoplasia in those specimens of 0.6% (n = 12). On detailed review of the medical records of these patients, half (n = 6) had the pre-operative clinical suspicion of possible OSSN. Of those cases without clinical suspicion pre-operatively, one was diagnosed with invasive squamous cell carcinoma of the conjunctiva.

CONCLUSION

In this study, rates of unexpected diagnoses are reassuringly low. These results may challenge accepted dogma, and influence future guidance for the indications for submitting non-suspicious pterygia for histopathological analysis.

Ocular Surface Squamous Neoplasia: A 12-Month Prospective Evaluation of Incidence in Waikato, New Zealand

Ocular surface squamous neoplasia (OSSN) has a high incidence in the southern hemisphere. This prospective study evaluated the incidence of OSSN in the Waikato region of New Zealand. All patients presenting with pterygium or conjunctival lesions in the Waikato region in 2020 were included. All surgeons in the region were asked to send all conjunctival and corneal specimens excised for histopathologic examination. The primary outcome measure was the incidence of OSSN. Eighty-eight percent of all excised specimens were sent for histopathologic examination. Of the 185 excised lesions sent for histopathological assessment, 18 (10%) were reported as OSSN. Patients were on average 69.4 years of age (standard deviation, SD = 6.9), predominantly male (78%), and of New Zealand-European ethnicity (89%). The OSSN annual incidence was 3.67/100,000/year. Histology grades included conjunctival intraepithelial neoplasia (CIN)-I (25%), CIN-II (25%), CIN-III (12.5%), carcinoma in situ (25%), and invasive squamous cell carcinoma (SCC) (12.5%). One patient with invasive SCC required exenteration. This study identified a high incidence rate of OSSN and is the first prospective study to analyze OSSN epidemiology in New Zealand.

Diagnosis and staging of ocular surface squamous neoplasia

Background: Ocular surface squamous neoplasia (OSSN) is the most common ocular tumour. The diagnosis of OSSN is based on clinical suspicion and confirmed by various diagnostic modalities, of which histology is the gold standard. With the move to less invasive management options such as topical chemo- or immunotherapy, less invasive diagnostic options have come to the fore.Aim: The purpose of this article was to review the current staging and diagnostic modalities for OSSN with a focus on less invasive modalities.Method: A literature review was performed for publications on ocular surface neoplasia and diagnostic modalities.Results: Histology is the gold standard for diagnosing OSSN. Cytology has been shown to be a simple, repeatable and minimally invasive diagnostic modality, which also allows for additional testing such as polymerase chain reaction. Anterior segment optical coherence tomography provides a non-contact method of evaluating the ocular surface, with OSSN showing a thickened hyper-reflective epithelium, abrupt transition zone and demarcation line. Vital dyes are used less commonly with high sensitivity, but lower specificity for OSSN. Finally, confocal microscopy provides en-face images of the ocular surface, with OSSN showing a classic ‘starry night’ appearance.Conclusion: Histology remains the gold standard for diagnosis; however, with the increasing use of topical therapy for OSSN, there has been an increase in the uptake of less invasive diagnostic modalities.

Invasive conjunctival melanoma mimicking ocular surface squamous neoplasia: a case series

BACKGROUND

Conjunctival melanoma is the second most common conjunctival malignant tumour after squamous cell carcinoma, usually arising from primary acquired melanosis and less commonly from a conjunctival naevus or de novo. We report four cases of conjunctival melanoma masquerading as ocular surface squamous neoplasia.

METHODS

Four patients (2 females and 2 males; mean age 60.7 years; range 41-72 years) were referred for suspicious conjunctival lesions. In all cases, the lesions had a perilimbal location, were non-pigmented (cases 1 and 3) or mildly pigmented (cases 2 and 4), had a fleshy (cases 1, 2 and 4) or papillomatous (case 3) appearance and involved the corneal surface. In each case, our main clinical differential diagnosis included conjunctival intraepithelial neoplasia and squamous cell carcinoma. All four patients underwent an excisional biopsy with double freeze-thaw cryotherapy and alcohol keratoepitheliectomy.

RESULTS

In all four cases, the histopathological diagnosis was of invasive conjunctival melanoma with extension to the deep surgical margins. Adjuvant therapy consisting of strontium-90 β radiotherapy (all 4 patients) and topical Mitomicyn C (patient 2) was administered.

CONCLUSION

Conjunctival melanoma can clinically resemble ocular surface squamous neoplasia. Clinical impressions therefore need to be confirmed histopathologically.

Update on pharmacotherapy for ocular surface squamous neoplasia

The most frequently encountered non-pigmented tumor of the ocular surface is ocular surface squamous neoplasia (OSSN). Over the past two decades, the pharmacological management of OSSN has grown, with topical 5-fluorouracil, mitomycin, and interferon alpha 2b all being successfully used to treat this disease. Other agents, such as anti-vascular endothelial growth factor (VEGF), retinoic acid, cidofovir and Aloe vera, have less frequently been used in the treatment of OSSN. This review will discuss these pharmacologic agents, summarizing available data and presenting the approach to the treatment of these tumors.

Characteristics, management, and outcome of squamous carcinoma of the conjunctiva in a single tertiary cancer center in Jordan

AIM

To evaluate the features and outcome of management of malignant conjunctival squamous tumors in King Hussein Cancer Center (a referral tertiary cancer center in the Middle East).

METHODS

Retrospective case series of 31 eyes for 31 patients with conjunctival squamous neoplasia. Main outcome measures included: age, gender, laterality, tumor location, pathological features, tumor stage, treatment modality, and outcome.

RESULTS

Twenty (65%) patients were males and median age was 58y. Twenty-two (71%) eyes had the tumor in the nasal quadrant. Tumor invasion to nearby structures was seen in 19 (61%) eyes, including the cornea, fornix, eyelid, and orbit in 17 (55%), 1 (3%), 2 (6%), and 3 (10%) eyes, respectively. Eye salvage was achieved by surgical excision with cryotherapy followed by topical chemotherapy in 28 (90%) eyes, and orbital exenteration was necessary in 3 (10%) eyes due to orbital tumor invasion. Tumor recurrence was seen in 7 (23%) eyes, and the significant predictive factors for recurrence were tumor extension onto the nearby structures (P=0.04), tumor invasiveness (P=0.038), and tumor TNM stage (P=0.031). No significant change in visual acuity was seen, and disease related mortality was 6% (2 patients, both had orbital invasion by invasive squamous carcinoma).

CONCLUSION

Conjunctival squamous carcinoma is more common in males. Advanced American Joint Committee on Cancer (AJCC) T-stage, tumor local invasion, more pathologically aggressive tumors, and surgical treatment alone (without adjuvant therapy) are associated with higher risk for recurrence, and orbital invasion is the most important poor prognostic factor for metastasis and death. Treatment strategies should be affected by tumor characteristics at presentation.

Novel treatment of papillomatous conjunctival lesions using pattern scanning laser photocoagulation: 1-Year results

PURPOSE

To evaluate the safety and 1-year effect of pattern scanning laser photocoagulation treatment for pedunculated papillomatous and sessile conjunctival lesions in a low-resource setting with extremely limited operating room access.

METHODS

Adult patients with clinical diagnosis of conjunctival papilloma underwent complete ophthalmologic exam including anterior segment photography. After topical anesthesia and toluidine blue 1% instillation, the lesion was treated by pattern scanning photocoagulation using a duration time that varied from 20 to 100 ms and power from 600 to 1800 mW, treating the entire lesion surface with a 2 mm margin. Patients were examined weekly for a month then monthly and underwent retreatment as necessary.

RESULTS

Six patients and seven eyes that had clinically significant non-malignant pedunculated or sessile papillomatous lesions were treated. All lesions responded to treatment, with complete resolution after an average of 2.3 sessions. Procedures were well tolerated with only minor mild discomfort persisting up to two days post-treatment. Patients were followed for a mean follow-up time of 13 months with no recurrences reported.

CONCLUSION

Short-term results of the pattern scanning laser photocoagulation approach, with toluidine blue for papillomatous conjunctival lesions are favorable with a 100% success rate in this cohort. This rate is comparable to surgical excision. This novel strategy proved to be a less resource intensive alternative that not only could demonstrate its usefulness in settings with chronic operating room shortages, but also in recurrent cases. Longer follow-ups with a larger sample size and cost-analysis are necessary to confirm our findings.

HIV-associated malignancies in sub-Saharan Africa: progress, challenges, and opportunities

PURPOSE OF REVIEW

To summarize recent developments for HIV-associated malignancies (HIVAM) in low-income and middle-income countries (LMIC) with particular focus on sub-Saharan Africa (SSA).

RECENT FINDINGS

Antiretroviral therapy (ART) scale-up is leading to epidemiologic transitions in LMIC similar to high-income countries, with aging and growth of HIV-infected populations, declining infectious deaths, increasing cancer deaths, and transitions from AIDS-defining cancers to non-AIDS defining cancers. Despite ART scale-up, the HIVAM burden remains high including an enormous AIDS-defining cancers burden in SSA. For Kaposi sarcoma, patients treated with ART and chemotherapy can experience good outcomes even in rural SSA, but Kaposi sarcoma heterogeneity remains insufficiently understood including virologic, immunologic, and inflammatory features that may be unique to LMIC. For cervical cancer, scale-up of prevention efforts including vaccination and screening is underway, with benefits already apparent despite continuing high disease burden. For non-Hodgkin lymphoma, curative treatment is possible in the ART era even in SSA, and multifaceted approaches can improve outcomes further. For many other prevalent HIVAM, care and research efforts are being established to guide treatment and prevention specifically in LMIC.

SUMMARY

Sustained investment for HIVAM in LMIC can help catalyze a cancer care and research agenda that benefits HIV-positive and HIV-negative patients worldwide.

Anterior Segment Imaging in Ocular Surface Squamous Neoplasia

Recent advances in anterior segment imaging have transformed the way ocular surface squamous neoplasia (OSSN) is diagnosed and monitored. Ultrasound biomicroscopy (UBM) has been reported to be useful primarily in the assessment of intraocular invasion and metastasis. In vivo confocal microscopy (IVCM) shows enlarged and irregular nuclei with hyperreflective cells in OSSN lesions and this has been found to correlate with histopathology findings. Anterior segment optical coherence tomography (AS-OCT) demonstrates thickened hyperreflective epithelium with an abrupt transition between abnormal and normal epithelium in OSSN lesions and this has also been shown to mimic histopathology findings. Although there are limitations to each of these imaging modalities, they can be useful adjunctive tools in the diagnosis of OSSN and could greatly assist the clinician in the management of OSSN patients. Nevertheless, anterior segment imaging has not replaced histopathology's role as the gold standard in confirming diagnosis.

Prevalence and Severity of Ocular Surface Neoplasia in African Nations and Need for Early Interventions

Ocular surface squamous neoplasia (OSSN) is a common ocular surface tumor with an increased incidence in African countries (3.4 and 3.0 cases/year/100,000). Despite its potential for vision loss and death, OSSN remains largely neglected by both eye and HIV care programs in Africa. The purpose of this review is to identify the barriers to timely diagnosis and early interventions for OSSN in Africa. PubMed searches were conducted targeting previous use of topical chemotherapy (interferon alpha 2b, Mitomycin-C, 5-Fluorouracil) and Human papillomavirus (HPV) vaccination in Africa. We found that OSSN is a significant vision and life-threatening health problem in Africa leading to significant loss of vision, as well as facial disfigurement and social stigma. We did not find any reports on the use of topical interferon, Mitomycin-C or HPV vaccination for OSSN in Africa. One report on the use of topical 5-FU for OSSN in Africa was found. Common barriers to early detection and management of OSSN in Africa include lack of sufficient laboratory infrastructure, lack of trained healthcare personnel, lack of compliance with follow-up visits, cost of topical chemotherapies, and cultural preferences for traditional medicines. In conclusion, OSSN is a significant vision and life-threatening health problem in Africa. There is not much literature on prevention or treatment options for early stages of OSSN in Africa. The use of topical chemotherapy as early interventions and judicious use of smart phone Apps to help with remote diagnosis of early OSSN should be further explored.