The Use of 1% Toluidine Blue Eye Drops in the Diagnosis of Ocular Surface Squamous Neoplasia

Topical 5-Fluorouracil 0.5% as primary treatment for Ocular Surface Squamous Neoplasia

PURPOSE

To evaluate the efficacy of topical treatment with 5-Fluorouracil (5-FU) 0.5% in cases of Ocular Surface Squamous Neoplasia (OSSN), and to assess the tolerance of patients undergoing treatment.

METHODS

Patients with clinical diagnosis of OSSN referred to the Ocular Oncology division from the Federal University of Sao Paulo, Brazil, were recruited for the current study. Patients were treated with topical 5-FU 0.5% using a regimen of 4 times daily for 10 days, followed by a 3-week drug holiday, continued up to 3 cycles before an alternative treatment. Lesions were evaluated at baseline and throughout treatment. Treatment adherence was assessed using the Morisky Medication Adherence scale. Any adverse events along the treatment were noted.

RESULTS

A total of 30 eyes of 30 patients adherent to the treatment were included in the study. Among the total cases treated with 5-FU 0.5%, 24 patients achieved therapeutic success after a mean treatment duration of 21.71 ± 7.77 days, representing a success rate of 80.00% (95% CI: 60.75-91.18%). For each 1 mm2 increase in the lesion area, the odds of treatment success decrease by 6% (OR: 0.94; 95%CI: 0.88-0.99; p = 0.033). Only mild adverse events such as ocular discomfort, ocular burning and tearing were observed along the treatment in 8 patients.

CONCLUSIONS

Topical 5-FU 0.5% is an effective therapeutic option in the treatment of OSSN, with an 80% therapeutic success rate, showing good tolerability. The size of the lesion was identified as a factor influencing treatment success, therefore it should be taken into consideration when defining treatment approaches.

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.

Clinic-pathological agreement in the diagnosis of conjunctival tumours: Analysis of 195 cases

PURPOSE

The present study aims to assess the agreement between clinical and pathological diagnosis in conjunctival tumours in a specialist ocular oncology unit.

METHODS

retrospective study of consecutive patients with conjunctival tumours diagnosed at the Ocular Oncology Unit of the University Hospital of Valladolid was performed from 1992 to 2017. Tumours were classified according to their origin (epithelial, melanocytic, lymphoid and others) and degree of malignancy (benign, premalignant, malignant). A biopsy was performed in cases of symptomatic or growing lesions. Cohen´s kappa (κ) statistics was used as an indicator of agreement between clinical and pathological diagnosis.

RESULTS

Of 462 consecutive patients, a biopsy was required in 195 (42.2%). The agreement with the pathological diagnosis was successful in 154 (79.0%) cases. Analysis according to the grade of malignancy showed the lowest rate of agreement among benign (n = 83; 91.6%) and premalignant (n = 62; 90.3%) lesions, with a total agreement in malignant lesions (n = 50; 100%); the Cohen´s kappa coefficient (κ) was 0.90. The highest rates of concordance were found in epithelial, melanocytic and soft tissue lesions with κ values of 1, 0.8 and 1 respectively. The worst rate of concordance was found in lymphoid lesions with a κ value of 0.3.

CONCLUSION

Most of the conjunctival tumours were correctly identified clinically; benign and malignant lesions showed the highest rate of accuracy; however, premalignant tumours can hide micro-invasive diseases that can go unnoticed on clinical examination. The biopsy is essential for accurate diagnosis and treatment.

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.

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.

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.

Role of high resolution optical coherence tomography in diagnosing ocular surface squamous neoplasia with coexisting ocular surface diseases

PURPOSE

Coexistence of an ocular surface disease can mask the typical features of ocular surface squamous neoplasia (OSSN). The purpose of this study was to evaluate high resolution optical coherence tomography (HR-OCT) as an adjunct in the detection and differentiation of OSSN within coexisting ocular surface pathologies.

METHODS

Retrospective study of 16 patients with ocular surface disease and lesions suspicious for OSSN that were evaluated with HR-OCT. HR-OCT images of the lesions were taken to look for evidence of OSSN. Biopsies were performed in all cases, and the HR-OCT findings were compared to the histological results.

RESULTS

Of the 16 patients with OSSN and a coexisting ocular surface disease, 12 were found to have OSSN by HR-OCT and all were subsequently confirmed by biopsy. Two patients had OSSN with rosacea, one with pingueculum, two within pterygia, one with Salzmann' nodular degeneration, six with limbal stem cell deficiency (LSCD)/scarring. In all 12 cases HR-OCT images revealed classical findings of hyper-reflective, thickened epithelium and an abrupt transition from normal to abnormal epithelium. OSSN was ruled out by HR-OCT in four cases (2 Salzmann's, 1 mucous membrane pemphigoid, and 1 LSCD). Negative findings were confirmed by biopsy. HR-OCT was used to follow resolution of the OSSN in positive cases, and it detected recurrence in 1 case.

CONCLUSIONS

While histopathology is the gold standard in the diagnosis of OSSN, HR-OCT can be used to noninvasively detect the presence of OSSN in patients with coexisting ocular conditions.

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.

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

IMPORTANCE

Clinical features are unreliable for distinguishing ocular surface squamous neoplasia (OSSN) from benign conjunctival lesions.

OBJECTIVE

To evaluate the adverse effects, accuracy, and interobserver variation of toluidine blue 0.05% vital staining in distinguishing OSSN, confirmed by histopathology, from other conjunctival lesions.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study in Kenya from July 2012 through July 2014 of 419 adults with suspicious conjunctival lesions. Pregnant and breastfeeding women were excluded.

EXPOSURES

Comprehensive ophthalmic slitlamp examination was conducted. Vital staining with toluidine blue 0.05% aqueous solution was performed before surgery. Initial safety testing was conducted on large tumors scheduled for exenteration looking for corneal toxicity on histology before testing smaller tumors. We asked about pain or discomfort after staining and evaluated the cornea at the slitlamp for epithelial defects. Lesions were photographed before and after staining.

MAIN OUTCOMES AND MEASURES

Diagnosis was confirmed by histopathology. Six examiners assessed photographs from a subset of 100 consecutive participants for staining and made a diagnosis of OSSN vs non-OSSN. Staining was compared with histopathology to estimate sensitivity, specificity, and predictive values. Adverse effects were enumerated. Interobserver agreement was estimated using the κ statistic.

RESULTS

A total of 143 of 419 participants (34%) had OSSN by histopathology. The median age of all participants was 37 years (interquartile range, 32-45 years) and 278 (66%) were female. A total of 322 of the 419 participants had positive staining while 2 of 419 were equivocal. There was no histological evidence of corneal toxicity. Mild discomfort was reported by 88 (21%) and mild superficial punctate keratopathy seen in 7 (1.7%). For detecting OSSN, toluidine blue had a sensitivity of 92% (95% CI, 87%-96%), specificity of 31% (95% CI, 25%-36%), positive predictive value of 41% (95% CI, 35%-46%), and negative predictive value of 88% (95% CI, 80%-94%). Interobserver agreement was substantial for staining (κ = 0.76) and moderate for diagnosis (κ = 0.40).

CONCLUSIONS AND RELEVANCE

With the high sensitivity and low specificity for OSSN compared with histopathology among patients with conjunctival lesions, toluidine blue 0.05% vital staining is a good screening tool. However, it is not a good diagnostic tool owing to a high frequency of false-positives. The high negative predictive value suggests that a negative staining result indicates that OSSN is relatively unlikely.

A 10-year survey: prevalence of ocular surface squamous neoplasia in clinically benign pterygium specimens

PURPOSE

It is essential to assess the yield of routine histopathological examination of pterygium specimens excised from clinically benign pterygium. The purpose of this study was to determine the rate of histopathologically identified ocular surface squamous neoplasia (OSSN) in clinically benign pterygium specimens.

MATERIALS AND METHODS

This retrospective consecutive study consisted of patients from the cornea services of the ophthalmology departments of Meir Medical Center, Kfar Sava, and Rabin Medical Center, Petah Tikva, Israel. Included patients were those with clinically benign pterygium who underwent pterygium excision between January 2002 and December 2011. The pterygium specimens were sent for histopathological examination and the pathology reports were reviewed for evidence of OSSN.

RESULTS

Overall, pathology reports of 682 eyes of 585 sequential patients were included in the study. There was a male predominance of cases (59%). Patients' age ranged from 16 to 87 years with an average age of 56 years. Six hundred and forty-three cases were primary (94%) and 39 cases were recurrent (6%).

CONCLUSIONS

Cases of clinically benign pterygium diagnosed and excised by an experienced corneal expert are less likely to harbor OSSN. The yield of routine histopathological examination of such specimens may be low.

Ocular rhinosporidiosis mimicking conjunctival squamous papilloma in Kenya - a case report

BACKGROUND

Ocular rhinosporidiosis is a chronic granulomatous infection caused by a newly classified organism that is neither a fungus nor bacterium. It often presents as a benign conjunctival tumour but may mimic other ocular conditions. It is most often described in India. In Africa cases have been reported from South Africa, Kenya, Tanzania, Malawi, Uganda, Congo and Ivory Coast.

CASE PRESENTATION

A 54 year old man was seen in Kenya with a lesion that resembled a conjunctival papilloma. We report resemblance to conjunctival papilloma and the result of vital staining with 0.05% Toluidine Blue.

CONCLUSION

Ocular rhinosporidiosis occurs in East Africa. It may resemble conjunctival squamous papilloma. Vital staining with 0.05% Toluidine blue dye did not distinguish the two lesions well.

Risk factors for ocular surface squamous neoplasia recurrence after treatment with topical mitomycin C and interferon alpha-2b

PURPOSE

To determine the rate of recurrence and associated risk factors after the use of mitomycin C (MMC), interferon alpha-2b, or both for management of noninvasive ocular surface squamous neoplasia (OSSN).

DESIGN

Retrospective, noncomparative, interventional case series.

METHODS

Clinical practice setting of 135 patients treated consecutively with topical MMC (0.4 mg/mL), interferon alpha-2b (1 million units/mL), or both for OSSN observed for clinical recurrence.

RESULTS

Clinical recurrences were diagnosed in 19 (14.1%) of 135 eyes after topical treatment. The mean time to recurrence was 17.2 months (range, 4 to 61 months), with 14 eyes (73.7%) recurring within a 2-year period. There was no greater risk of recurrence identified for variables including lesion size, lesion location, gender, age, treatment type, or treatment duration. Post hoc log-rank pairwise comparisons revealed that lesions initially treated using surgery alone had significantly reduced time to recurrence (21.1 ± 5.6 months) compared with previous topical treatment with MMC (with or without surgery; 29.6 ± 4.7 months; P = .04) and primary OSSN (23.2 ± 1.8 months; P = .09).

CONCLUSIONS

Topical MMC and interferon alpha-2b are an effective treatment method for a wide range of noninvasive OSSNs. Topical therapy avoids the morbidity of excisional surgery with equivalent or reduced recurrence rates and should be considered as primary therapy.

Identification of ocular surface squamous neoplasia by in vivo staining with methylene blue

AIM

To evaluate the diagnostic accuracy of methylene blue used as a non-invasive in vivo stain to detect ocular surface squamous neoplasia (OSSN).

METHODS

A test validation study was performed according to Standards for the reporting of diagnostic accuracy studies (STARD) guidelines on 75 consecutive patients who presented with ocular surface lesions suspicious of OSSN. Methylene blue 1% was instilled in vivo following local anaesthetic. Stain results were documented photographically and read by an independent observer. Lesions were excised at the same visit and evaluated histologically by pathologists who were blind to the stain results. Sensitivity, specificity, positive and negative predictive values were determined.

RESULTS

Thirty-three patients had histologically malignant lesions, of which 32 stained with methylene blue, and 42 patients had benign or premalignant lesions, of which 21 stained with methylene blue. Methylene blue had a sensitivity of 97%, specificity of 50% and positive and negative predictive values of 60% and 96%, respectively.

CONCLUSIONS

The topical application of methylene blue is a simple, inexpensive, non-invasive diagnostic test that can be helpful in excluding malignant ocular surface lesions but cannot replace histology as gold standard for diagnosis of OSSN.