Role of impression cytology in diagnosis of ocular surface neoplasia

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.

Safety and efficacy of topical interferon alpha 2B and mitomycin C for localized conjunctival intraepithelial neoplasia: long-term report of their pharmacological safety and efficacy

PURPOSE

Ocular surface squamous neoplasia (OSSN) comprises a wide spectrum of squamous tumors, from which corneal/conjunctival intraepithelial neoplasia (CIN) is the most common one. The classic treatment is complete excision, but recurrence rates are high. Antineoplastic drugs such as mitomycin C (MMC) and interferon alpha 2b (IFNα2b) have been used as adjuvants or as primary treatment. To evaluate the efficacy and safety of topical IFNα2b and MMC in patients with CIN, a phase IIb double-blind clinical trial was performed.

METHODS

Patients diagnosed with localized CIN were evaluated by slit lamp and impression cytology and were randomly given MMC 0.04% or INF2b (1 million IU/mL) 4 times daily until neoplasia resolution. Time of resolution and frequency of adverse effects were analyzed to determine the pharmacological efficacy and safety of both medications.

RESULTS

Seventeen patients were included. Nine patients were treated with MMC and 8 with IFNα2b. All patients responded to treatment. The resolution time in days was 59.11 ± 24.02 in patients treated with MMC and 143.50 ± 47.181 in those treated with IFNα2b (p < 0.001). In the MMC group, one recurrence was reported (11%). There were no recurrences at 2 years of follow-up in the IFNα2b group. Regarding adverse effects, one or more mild adverse reaction occurred in 77% of patients managed with MMC and in 50% of patients managed with IFNα2b (p > 0.05). No serious adverse effects were reported.

CONCLUSIONS

Topical chemotherapy with MMC and IFNα2b demonstrate pharmacological safety and efficacy. Therefore, these drugs could be considered as primary therapies for localized CIN .

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.

Pterygium and Ocular Surface Squamous Neoplasia: Optical Biopsy Using a Novel Autofluorescence Multispectral Imaging Technique

In this study, differentiation of pterygium vs. ocular surface squamous neoplasia based on multispectral autofluorescence imaging technique was investigated. Fifty (N = 50) patients with histopathological diagnosis of pterygium (PTG) and/or ocular surface squamous neoplasia (OSSN) were recruited. Fixed unstained biopsy specimens were imaged by multispectral microscopy. Tissue autofluorescence images were obtained with a custom-built fluorescent microscope with 59 spectral channels, each with specific excitation and emission wavelength ranges, suitable for the most abundant tissue fluorophores such as elastin, flavins, porphyrin, and lipofuscin. Images were analyzed using a new classification framework called fused-classification, designed to minimize interpatient variability, as an established support vector machine learning method. Normal, PTG, and OSSN regions were automatically detected and delineated, with accuracy evaluated against expert assessment by a specialist in OSSN pathology. Signals from spectral channels yielding signals from elastin, flavins, porphyrin, and lipofuscin were significantly different between regions classified as normal, PTG, and OSSN (p < 0.01). Differential diagnosis of PTG/OSSN and normal tissue had accuracy, sensitivity, and specificity of 88 ± 6%, 84 ± 10% and 91 ± 6%, respectively. Our automated diagnostic method generated maps of the reasonably well circumscribed normal/PTG and OSSN interface. PTG and OSSN margins identified by our automated analysis were in close agreement with the margins found in the H&E sections. Such a map can be rapidly generated on a real time basis and potentially used for intraoperative assessment.

Ocular surface squamous neoplasia in Northern Thailand: a 16-year review

Purpose

To evaluate clinical characteristics, treatments, and outcomes in patients with ocular surface squamous neoplasia (OSSN) at a tertiary center in Northern Thailand.

Methods

Patients diagnosed with either corneal-conjunctival intraepithelial neoplasia (CIN) or squamous cell carcinoma (SCC) from May 2000 to December 2015, were recruited. The patients’ demographics, symptoms, clinical characteristics, cytopathology, treatments, and outcomes were reviewed.

Results

Overall 171 eyes from 168 patients, 92 eyes were CIN and 79 eyes were SCC. Males were affected in 65.5%. The mean age was 58.8 ± 16.8 (29–99) years. In most cases (60.3%), the tumors were located at the limbus. The most common clinical characteristic was papilliform appearance (46.2%). Human immunodeficiency virus (HIV) infection was found in 37 (22.0%) patients with a mean age of 40.5 ± 7.7 years. The treatments and outcomes were evaluated in 136 eyes whose main initial treatment was wide excision with adjunctive cryotherapy (47.8%), followed by topical mitomycin C (30.9%). The mean follow-up time after treatment was 20.8 ± 2.2 (3–110) months and the recurrence occurred in 18 eyes (13.2%) during the follow-up period. The mean recurrence-free time (months) for CIN was significantly longer than that of SCC (81.3 ± 10.0 [95%CI 61.5 – 101.1] vs 33.2 ± 4.6 [95%CI 24.0 – 42.3], p = 0.030). SCC was the only significant risk factor that influences the recurrence of the tumors with the adjusted hazard ratio of 5.69 (p = 0.005).

Conclusion

OSSN in Northern Thailand usually involved a limbal area and presented as a papilliform mass. HIV infection should be suspected in young patients. CIN had better outcomes after treatments than invasive SCC.

Conjunctival Intraepithelial Neoplasia in a Patient Presenting with Pigmented Conjunctival Lesion

We report a case of conjunctival intraepithelial neoplasia (CIN) in a patient presenting with the pigmented conjunctival lesion. This study involved a 56-year-old woman that presented with right eye irritation for 1 month. She noticed brownish pigmentation arising from her right nasal conjunctiva and growing slowly over time. Biomicroscopic examination showed a gelatinous pigmented conjunctival mass with feeder vessels. Conjunctival impression cytology (CIC) was done and reported as CIN. Treatment was started with 0.02% mitomycin-C eye drops. The conjunctival lesion responded well to medication. This report shows that CIN can manifest as a pigmented tumor, resembling melanoma. CIC plays a role in the diagnosis of this condition. This tumor responded well with 0.02% mitomycin-C eye drops.

Incidentally detected primary corneal squamous neoplasia in an elderly man presenting with cataract

Primary corneal neoplasia (PCN) is a rare cancerous lesion of cornea usually encountered in elderly. The clinical symptoms are generally non-specific, with ocular irritation, redness, cosmetic disfigurement and varying degrees of visual disturbances depending on visual axis involvement. Corneal neoplasia is usually associated with surrounding conjunctival lesions and incidentally detected PCN is rarely encountered in clinical practice. Presently, we report a case of isolated unilateral PCN diagnosed incidentally in an elderly man presenting with cataract. In vivo confocal microscopy aided in its diagnosis after impression cytology was repeatedly negative. Cataract surgery was deferred and the patient was administered three cycles of mitomycin C 0.04% 4 times/day. The tumour margins receded as evident on clinical examination and on anterior segment optical coherence tomography. We discuss the role of various corneal imaging modalities in diagnosis and management of PCN besides highlighting importance of comprehensive slit-lamp examination in patients planned for cataract surgery.

Observation of angiographic dye leakage in ocular surface squamous neoplasia

Purpose

The clinical diagnosis of ocular surface squamous neoplasia is challenging, mostly requiring excisional biopsy. Human tumor angiogenesis is characterized by abnormal vessel architecture and transvascular hyperpermeability. This case report describes features of fluorescein and indocyanine green angiography in a case of conjunctival intraepithelial neoplasia.

Observations

Color photography, optical coherence tomography, fluorescein and indocyanine green angiography were performed in a patient with suspected conjunctival intraepithelial neoplasia before excisional biopsy and histologic confirmation of clinical diagnosis. Fluorescein dye showed extensive early extravascular dye leakage within the limits of the lesion. Indocyanine green dye displayed corneal terminal vessel bulbs with early leakage after 70 seconds and showed diffuse intralesional dye leakage after 7 minutes.

Conclusions

Increased fluorescein and early indocyanine green dye leakage can be used to confirm active angiogenesis already in early stages of dysplastic ocular surface squamous neoplasia. Late leakage of indocyanine green dye may be due to chronic transvascular hyperpermeability within intrinsic tumor vessels. The leakage behaviour of intravenous dyes has the potential to serve as a diagnostic indicator of active growth in dysplastic ocular surface neoplastic lesions.

Impression cytology for detection of clinically suspected ocular surface disorders: A cross-sectional study

PURPOSE

Investigating impression cytology (IC) results of various types of clinically suspected ocular surface lesions over a 14-year period in a referral center in Iran.

METHODS

IC findings obtained from patients with different types of ocular surface disorders between 2005 and 2018 were reviewed. Agreement between clinical suspicions and IC results was evaluated by calculating Cohen's Kappa coefficient (CKC).

RESULTS

Clinical suspicions in 688 surveyed eyes were ocular surface squamous neoplasia (OSSN, 42.0%), limbal stem cell deficiency (LSCD, 36.3%), dry eye-related disorders (DERD, 11.5%), Acanthamoeba keratitis (AK, 7.2%), benign pigmented lesions (BPL, 1.9%), immune-related conjunctivitis (IRC, 0.7%), and malignant pigmented lesions (MPL, 0.4%). General agreement between clinical suspicions and IC results was 0.68 for all groups. This agreement was almost perfect in AK (CKC = 0.966) and BPLs (CKC = 0.843), and was substantial in MPLs (CKC = 0.749), OSSNs (CKC = 0.684), and LSCD (CKC = 0.612). CKC in IRC (0.567) and DERDs (0.443) was moderate. Histopathologic results were available in 22 eyes and were well-correlated with corresponding IC results (CKC = 0.86). Multiple post-treatment follow-up sessions of IC were performed in 51 eyes (11.4%) that had diagnosis of LSCD (31), OSSN (17), and MPL (3) at the first IC session.

CONCLUSION

Our survey not only demonstrated an overall substantial agreement between IC results and primary clinical suspicions, but also showed an almost perfect correlation between IC results and existent histopathologic data. Therefore, IC as a non-invasive diagnostic modality can be of great importance in proper diagnosis of various ocular surface diseases especially when distinguishing malignant from benign lesions is required.

Update on Diagnosis and Management of Conjunctival Papilloma

Conjunctival papilloma is an acquired benign squamous cell tumor that can present at any age, but most frequently in the third and fourth decades of life. Papillomas have been associated with human papilloma virus (HPV) infection, usually types 6 and 11. Although histopathological diagnosis remains the gold standard, the advent of newer non-invasive imaging modalities such as optical coherence tomography (OCT) is transforming the way we diagnose and treat ocular surface tumors, including conjunctival papilloma. Management of these lesions can prove a challenge to the treating physician since not all lesions respond to medical and/or surgical therapy and in fact may worsen after surgical manipulation. In this review, the epidemiology, pathophysiology, clinical characteristics, and diagnosis of conjunctival papilloma including the use of OCT are discussed. Indications, efficacy, and side effects of currently available management options are also reviewed to guide the selection of the best treatment approach.

Characterisation of corneal impression cytology in dogs and its application in the diagnosis of keratoconjunctivitis sicca

OBJECTIVE

Determine morphological and morphometric parameters of corneal epithelium in dogs, and determine the cellular alterations that occur in canine keratoconjunctivitis sicca (KCS) using impression cytology.

STUDY ANIMALS

60 dogs divided into two groups: dogs with Schirmer tear test (STT) at least 15 mm/minute and absence of ocular disease, and dogs with STT less than 15 mm/minute and clinical signs of KCS.

PROCEDURES

Impression cytology was used to collect corneal samples. The percentage of eyes with cell changes, the number of such cells and the percentage of cells with structural alterations in each group were determined. The possible correlation between corneal epithelium alterations and decreased tear production was evaluated.

RESULTS

A significant positive correlation existed between STT and the area of the cytoplasm and nucleus of corneal cells. A significant negative correlation was found between STT ​​and the nucleus/cytoplasm ratio, and the presence of cellular changes. A significant difference existed between the numbers of pyknotic nuclei, being higher among animals with all stages of KCS.

CONCLUSION

Corneal impression cytology can be used to assess the corneal epithelium in healthy eyes and eyes with KCS, demonstrating its usefulness as a diagnostic tool especially in mild and early cases.

Novel automated non invasive detection of ocular surface squamous neoplasia using multispectral autofluorescence imaging

PURPOSE

Diagnosing Ocular surface squamous neoplasia (OSSN) using newly designed multispectral imaging technique.

METHODS

Eighteen patients with histopathological diagnosis of Ocular Surface Squamous Neoplasia (OSSN) were recruited. Their previously collected biopsy specimens of OSSN were reprocessed without staining to obtain auto fluorescence multispectral microscopy images. This technique involved a custom-built spectral imaging system with 38 spectral channels. Inter and intra-patient frameworks were deployed to automatically detect and delineate OSSN using machine learning methods. Different machine learning methods were evaluated, with K nearest neighbor and Support Vector Machine chosen as preferred classifiers for intra- and inter-patient frameworks, respectively. The performance of the technique was evaluated against a pathological assessment.

RESULTS

Quantitative analysis of the spectral images provided a strong multispectral signature of a relative difference between neoplastic and normal tissue both within each patient (at p < 0.0005) and between patients (at p < 0.001). Our fully automated diagnostic method based on machine learning produces maps of the relatively well circumscribed neoplastic-non neoplastic interface. Such maps can be rapidly generated in quasi-real time and used for intraoperative assessment. Generally, OSSN could be detected using multispectral analysis in all patients investigated here. The cancer margins detected by multispectral analysis were in close and reasonable agreement with the margins observed in the H&E sections in intra- and inter-patient classification, respectively.

CONCLUSIONS

This study shows the feasibility of using multispectral auto-fluorescence imaging to detect and find the boundary of human OSSN. Fully automated analysis of multispectral images based on machine learning methods provides a promising diagnostic tool for OSSN which can be translated to future clinical applications.

Potential utility of dermoscopy in the examination of ocular pigmentations

Background

Dermoscopy is a fundamental method in the examination of melanocytic neoplasms. Limited data exist about the dermoscopic features of ocular pigmentations (OPs).

Objectives

We aimed to investigate the usefulness of dermoscopy in the examination of OPs.

Methods

Dermoscopic images of OPs of 20 consecutive patients were recorded. Impression cytology (IC) was performed to these lesions. Dermoscopic images were evaluated for specific dermoscopic structures and patterns without knowing the cytological examination results.

Results

Fifteen percent (3/20) of the lesions presented with suspicious cytological findings. More of the suspicious lesions had 4 colors compared to benign lesions (66.7% vs 11.8%, p=0.088). This was also determined for blue-gray (66.7% vs 11.8%, p=0.088) and white (66.7% vs 17.7%, p=0.14) colors. At least 3 structures were observed in all suspicious lesions (100%), but were observed in only in 41.2% of benign lesions (p=0.105). Besides, two-thirds of suspicious lesions had more than 4 structures, but none of the benign lesions reported this (p=0.016). Most of the benign lesions showed asymmetry in one axis (93.3%), whereas all suspicious lesions showed asymmetry in 2 axes (p=0.004).

Conclusions

Dermoscopy seems to be a useful method in the evaluation of OPs. The existence of dermoscopic patterns, colors, and dermoscopic structure plurality and asymmetry raise suspicion in OPs, similarly to skin pigmentations. Dermatologists should be aware of the ocular area, and closer collaboration should be developed between dermatologists and ophthalmologists in the management of pigmented lesions.

Cytology of the healthy canine and feline ocular surface: comparison between cytobrush and impression technique

BACKGROUND

Impression cytology (IC) is a noninvasive technique in which filters are used to sample superficial layers of ocular epithelium.

OBJECTIVES

The aim of this study was to compare cytology specimens obtained by IC and cytobrush from healthy canine and feline eyes.

METHODS

Dogs and cats were prospectively sampled using polytetrafluorethylene filters on the right eye, and cytobrush on the left eye. Wright-Giemsa-stained specimens were evaluated by 2 observers. Cellularity, preservation, and morphology of cells and presence of goblet and inflammatory cells were scored with a 4-grade scale. Inter-observer agreement and effects of topical anesthesia were analyzed.

RESULTS

In 20 canine IC samples, 10 showed good cellularity (score 2-3) and 13 good preservation. Superficial epithelial cells (SEC) were present in 13/20 of IC, while basal-intermediate cells (BIC) were seen in 14/20. In 6/20 and 7/20, goblet and inflammatory cells were noted, respectively. In 20 cats, 15 of IC showed good cellularity and 14 good preservation, and SEC were present in 16/20 of IC and BIC in 17/20. In 13/20 and 3/20 cats, goblet cells and inflammatory cells were noted, respectively. Canine cytobrush specimens appeared well preserved (9/20) and had good cellularity (8/20). In feline cytobrush specimens, good preservation and cellularity were observed in 16/20 and 14/20, respectively. In both species, all cell types were present without a clear separation. There was moderate to fair agreement about cellular morphology in IC between observers. Specimens obtained with and without anesthesia were comparable.

CONCLUSION

Impression cytology allowed collection of samples with maintained cytoarchitecture, while cytoplasmatic and nuclear details were often difficult to evaluate.

Impression Cytology in a Series of Clinically Diagnosed Ocular Surface Melanocytic Lesions

PURPOSE

To report impression cytology (IC) results of clinically diagnosed ocular surface melanocytic lesions.

METHODS

Ten patients with a clinical diagnosis of an ocular surface melanocytic lesion underwent IC using cellulose acetate strips and Periodic acid Schiff-Papanicolaou staining. Excisional biopsy of lesions was performed in case of observing atypical cells on IC or at the patient's request, and excised specimens were subjected to histopathological analysis. Agreement between clinical diagnoses and IC results and between IC results and histopathology were evaluated.

RESULTS

Clinical diagnoses were nevi in 6, primary acquired melanosis (PAM) with atypia/melanoma in 2, and atypical nevus versus pigmented conjunctival intraepithelial neoplasia (CIN) in 2 cases. IC results were suggestive of a benign nevus in 7, PAM with atypia/melanoma in 2 and CIN versus an atypical epithelioid type melanocytic lesion in 1 case. IC results were consistent with the clinical diagnoses in 9 cases (Cohen's kappa index of 0.83) and excluded CIN in 1. Histopathology in 6 cases disclosed benign melanonevus in 3, malignant melanoma in the context of PAM with atypia in 2, and CIN in 1 case. Histologic results were well correlated with the IC features (Cohen's kappa index of 0.74).

CONCLUSION

By demonstrating typical cytomorphological features of ocular superficial layers IC diagnosed the true nature of melanocytic ocular surface lesions in the majority of cases. Although IC does not substitute histopathology, given the high correlation between IC results and histopathology, it can be of great assistance in diagnosis and management of ocular surface melanocytic lesions.

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.

Corneal epithelial debridement for diagnosis and therapy of ocular surface disease

BACKGROUND

There is a wide range of ocular surface conditions that can be diagnosed or treated with epithelial debridement. The purpose of this study is to analyse the indications, instrumentation and outcomes of corneal epithelial debridement for anterior segment pathology.

METHODS

One hundred and thirty-three eyes of 129 patients with ocular surface disease were treated with epithelial debridement. Different methods were used, appropriate to the specific disease, aetiology and outcome measure.

RESULTS

The mean patient age was 56 years and 81 (60.9 per cent) were male. Sixty-two eyes (46.6 per cent) were undertaken for diagnosis and 71 (53.4 per cent) for therapy. Common indications for diagnostic corneal debridement included infective keratitis 48 (36.1 per cent), neoplasia 14 (10.5 per cent), while those for therapeutic corneal debridement included recurrent erosion 30 (22.5 per cent) and band keratopathy 16 (12.0 per cent). The most common post-operative complication was pain, occurring in all patients to some extent. Band keratopathy was seen to recur in two (12.5 per cent) of the treated eyes and there was a single relapse of recurrent erosion during the follow-up period.

CONCLUSION

The techniques presented can be undertaken in the office rather than a day procedural unit, improving time and cost-effectiveness for the ophthalmologist and patient.

Management of conjunctival malignant melanoma: a review and update

Conjunctival malignant melanoma is a pigmented lesion of the ocular surface. It is an uncommon but potentially devastating tumor that may invade the local tissues of the eye, spread systemically through lymphatic drainage and hematogenous spread, and recur in spite of treatment. Despite its severity, the rarity of available cases has limited the evidence for diagnosis and management. This review will provide an overview of the epidemiology, presentation, diagnosis, management, and surveillance of conjunctival melanoma, with an emphasis on recent advances in biological therapies to treat this disease.

Subconjunctival bevacizumab injection for ocular surface squamous neoplasia

PURPOSE

To determine the efficacy and safety of perilesional/subconjunctival bevacizumab injections in the management of ocular surface squamous neoplasia (OSSN).

METHODS

Ten eyes of 10 patients with an OSSN diagnosis confirmed by impression cytology received 2 perilesional/subconjunctival injections of bevacizumab at a 2-week interval. Patients were evaluated for 3 months, during which time, changes in the lesions were documented using digital photography. After this period, excisional biopsy of the remaining tumor and cryotherapy of the conjunctival borders were performed if deemed necessary.

RESULTS

The mean age of the patients was 65 ± 12 years (± SD). All of the tumors were nasal in origin and had varying degrees of vascularization. The mean lesion area before treatment was 16 ± 6.9 mm2. Two weeks after the first injection, the mean reduction observed in the tumor area was 25% ± 5.65% and ranged from 17% to 33% (P = 0.001). Two weeks after the second injection, the mean tumor area was further decreased (42% ± 33%, ranging from 15% to 100%, P = 0.049). Corneal extension of the tumor was not affected significantly in 8 of the eyes with concomitant conjunctival and corneal involvement. Complete disappearance of the tumor was demonstrated by impression cytology and occurred in 2 cases involving lesions clinically confined to the conjunctiva. No systemic or ocular side effects occurred during the study period.

CONCLUSIONS

Perilesional/subconjunctival injections of bevacizumab decrease the size and vascularity of OSSN and may be curative in lesions limited to the conjunctiva. However, this treatment has no significant effect on the corneal extension of OSSN.

Techniques, indications and complications of corneal debridement

The cornea is the most exposed surface of the eye and, as such, is vulnerable to external trauma and the risk of infection. Many corneal diseases alter shape, surface, and transparency and thus result in reduced vision. The external position of the cornea, however, lends itself to diagnostic and therapeutic maneuvers that are commonly performed and readily done in the clinic. More sophisticated techniques require the use of complex equipment such as excimer and femtosecond laser. Complications that develop from poor healing and/or secondary infection are best avoided with appropriate technique, antisepsis, and modification of wound healing. We review corneal debridement in the management of corneal disease.

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.

Mitomycin C therapy for corneal intraepithelial neoplasia masquerading as limbal stem cell deficiency with recurrent epithelial defect

Diagnosis of corneal intraepithelial neoplasia was missed in a patient who presented with recurrent large epithelial defects with pannus. The patient was eventually diagnosed and successfully treated with topical mitomycin C. Mitomycin C may be preferable to surgery in lesions with extensive corneal involvement. Impression cytology should be used for early diagnosis in suspicious lesions.

In vivo confocal microscopy of ocular surface squamous neoplasia

PURPOSE

To analyse in vivo structural and cellular features of ocular surface squamous neoplasia using clinical confocal microscopy.

METHODS

Ten consecutive cases of untreated ocular surface squamous neoplasia were in vivo investigated using clinical confocal microscopy (ConfoScan4, Nidek Co. Ltd, Gamagori, Japan) with a × 40 surface non-contact objective lens. Confocal microscopy images were compared with cytologic samples obtained by scraping technique.

RESULTS

Confocal microscopy examination revealed large areas of superficial cells debris and/or keratin debris accompanied by syncytial-like groupings, loss of the normal structure of the conjunctival epithelium and or of the corneal basal epithelium layer, papillomatous organization, large fibrovascular structures, and fine vessels perpendicular to the tumour surface. Sub-epithelial (pre-Bowman) space involvement was documented in four cases (50%). Irregular healthy tissue infiltration at the lateral edge of the lesion was documented in two cases (20%) whereas abrupt demarcation between neoplastic cells and normal epithelium was documented in eight cases (80%). In vivo cyto-morphologic study using clinical confocal microscopy showed cellular anisocytosis, pleocytosis, and anisonucleosis, enlarged nuclei with high nuclear to cytoplasmic ratio, high reflective cytoplasm and indistinct cytoplasmic borders in all cases (100%) .

CONCLUSION

CCM appears to be a promising and non-invasive method for in vivo structural and cellular analysis of OSSN.

Ocular surface tumors

Tumors of the conjunctiva and cornea comprise a large and varied spectrum of conditions. These tumors are grouped into two major categories of congenital and acquired lesions. The acquired lesions are further subdivided based on origin of the mass into surface epithelial, mucoepidermoid, melanocytic, vascular, fibrous, neural, histiocytic, myxoid, myogenic, lipomatous, lymphoid, leukemic, metastatic and secondary tumors. Ocular surface tumors include a variety of neoplasms originating from squamous epithelium, melanocytic tumors and lymphocytic resident cells of the conjunctival stroma. In this review, we highlight clinical features of these lesions, important diagnostic and investigative tools and standard care of management.

Predictive index to differentiate invasive squamous cell carcinoma from preinvasive ocular surface lesions by impression cytology

BACKGROUND/AIMS

In the literature, no cytological features have been identified that reliably differentiate invasive squamous cell carcinoma (SCC) from preinvasive lesions in impression cytology (IC) samples. The aim was to identify cytological features related to malignancy and apply them in a quantitative model to determine an index score with the best predictive power to differentiate SCC from preinvasive ocular surface lesions by IC.

METHODS

39 patients with ocular surface epithelial lesions were enrolled. IC was obtained from all lesions before surgical excision. Specimens with atypical cells were evaluated regarding 11 cytological parameters based on the 2001 Bethesda system.

RESULTS

Histopathological diagnosis was pterygium in one case, actinic keratosis in nine cases, intraepithelial neoplasia in nine cases and SCC in 20 cases. Analysis of the receiver operating characteristic curve revealed that a predictive index score (cut-off point) > or =4.25 presented the best relationship between sensitivity and specificity in identifying SCC (sensitivity of 95%, specificity of 93%, positive predictive value of 95% and negative predictive value of 93%).

CONCLUSION

The scoring system model presented is suitable for clinical practice in differentiating SCC from preinvasive ocular surface lesions by IC and can be better evaluated with prospective use.