High frequency of squamous intraepithelial neoplasia in pterygium related to low ultraviolet light exposure

Incidence of ocular surface squamous neoplasia in pterygium specimens

OBJECTIVE

Pterygium and ocular surface squamous neoplasia (OSSN) have been recognized as likely related conditions and share similar risk factors such as ultraviolet radiation and chronic inflammation. The purpose of this study is to review the incidence of OSSN in pathology specimens sent as pterygium at a single tertiary centre between 2010 and 2022.

METHODS

This is a retrospective chart review of patients operated on for pterygium between 2010 and 2022 at the University of Montreal Health Centre. Data collected include baseline demographics, results of pathology specimen, and clinical information for cases diagnosed as OSSN on pathology.

RESULTS

A total of 1559 patients were operated on for a clinical diagnosis of pterygium between 2010 and 2022, of which 854 patients (55%) were male. A total of 1142 specimens had available pathology reports, and most of the specimens were consistent with pterygium on pathology (1105 of 1142; 97%). There was an unexpected finding of 3 cases of OSSN (3 of 1142; 0.3%). Other diagnosis besides pterygium were seen in 3% of specimens (34 of 1142), including nevus (n = 12), spheroidal degeneration (n = 3), pyogenic granuloma (n = 3), and lymphangiectasia (n = 2). The 3 cases of OSSN included an 81-year-old male of French-Canadian background, a 52-year-old male of South Asian background, and a 59-year-old female of French-Canadian background. The pathology was diagnosed as conjunctival intraepithelial neoplasia (CIN) grade 3, CIN grade 2, and CIN grade 2, respectively.

CONCLUSION

The finding of OSSN in pterygium is rare in our population but can be clinically difficult to distinguish. It is important to send all pterygium specimens for pathology.

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.

TFOS Lifestyle Report: Impact of environmental conditions on the ocular surface

Environmental risk factors that have an impact on the ocular surface were reviewed and associations with age and sex, race/ethnicity, geographical area, seasonality, prevalence and possible interactions between risk factors are reviewed. Environmental factors can be (a) climate-related: temperature, humidity, wind speed, altitude, dew point, ultraviolet light, and allergen or (b) outdoor and indoor pollution: gases, particulate matter, and other sources of airborne pollutants. Temperature affects ocular surface homeostasis directly and indirectly, precipitating ocular surface diseases and/or symptoms, including trachoma. Humidity is negatively associated with dry eye disease. There is little data on wind speed and dewpoint. High altitude and ultraviolet light exposure are associated with pterygium, ocular surface degenerations and neoplastic disease. Pollution is associated with dry eye disease and conjunctivitis. Primary Sjögren syndrome is associated with exposure to chemical solvents. Living within a potential zone of active volcanic eruption is associated with eye irritation. Indoor pollution, "sick" building or house can also be associated with eye irritation. Most ocular surface conditions are multifactorial, and several environmental factors may contribute to specific diseases. A systematic review was conducted to answer the following research question: "What are the associations between outdoor environment pollution and signs or symptoms of dry eye disease in humans?" Dry eye disease is associated with air pollution (from NO2) and soil pollution (from chromium), but not from air pollution from CO or PM10. Future research should adequately account for confounders, follow up over time, and report results separately for ocular surface findings, including signs and symptoms.

Epstein–Barr Virus, But Not Human Papillomavirus, Is Associated With Preinvasive and Invasive Ocular Surface Squamous Neoplasias in Zambian Patients

Background

The etiopathogenesis of ocular surface squamous neoplasia (OSSN) is not fully understood. We assessed the frequency of oncogenic viruses in OSSN by immunohistochemistry (IHC) and polymerase chain reaction (PCR) for human papillomavirus (HPV), Epstein–Barr virus (EBV), Merkel cell polyomavirus (MCPyV), Kaposi sarcoma virus, and adenovirus. Cases from Zambia were prospectively enrolled using a cross-sectional study design between November 2017 and March 2020.

Methods

Demographic and clinical data [age, sex, HIV status, antiretroviral therapy (ART) history, CD4 count, plasma viral load] and tumor biopsies were collected from 243 consenting patients. Tumor samples were bisected, and half was used for DNA isolation, while the other half was formalin fixed and paraffin embedded (FFPE) for histopathology analysis. The expressions of latent EBV nuclear antigen 1 (EBNA1), CDKN2A/p16INK4A (p16), and MCPyV large T-antigen (LT) were tested by IHC. Multiplex PCR was used to detect 16 HPV genotypes and four other DNA tumor viruses [Kaposi’s sarcoma-associated herpesvirus (KSHV), EBV, MCPyV, and adenovirus]. Relationships between HIV status, viral DNA and protein expression, and tumor grades were determined by statistical analysis.

Results

OSSN tumors from patients were 29.6% preinvasive and 70.4% invasive. Patients presented with unilateral tumors that were 70.4% late stage (T3/T4). OSSN patients were HIV positive (72.8%). IHC on 243 FFPE biopsies resulted in the detection of EBNA1 (EBV), p16 high-risk HPV (HR-HPV), and MCPyV LT expression in 89.0%, 4.9%, and 0.0%, respectively. EBNA1 was expressed in all grades of preinvasive [cornea–conjunctiva intraepithelial neoplasia (CIN)1, 100%; CIN2, 85.7%; CIN3, 95.8%; and carcinoma in situ (CIS), 83.8%] and in invasive (89.2%) OSSN. PCR on 178 samples detected EBV, HR-HPV, and MCPyV in 80.3%, 9.0%, and 13.5% of tumors, respectively. EBV was detected in all grades of preinvasive and invasive OSSN. EBV detection was associated with high HIV viral loads (p = 0.022). HR-HPV was detected in 0.0% CIN1, 0.0% CIN2, 5.6% CIN3, 13.0% CIS, and 7.0% invasive OSSN.

Conclusions

Our findings of EBV DNA and EBNA1 protein in all the grades of preinvasive and especially invasive OSSN are consistent with a potential causal role for EBV in OSSN. A role of HPV in OSSN was not clearly established in this study.

Histopathological Rate of Ocular Surface Squamous Neoplasia in Clinically Suspected Pterygium Specimens: 10-Year Results

PURPOSE

The aim of this study was to evaluate the prevalence of histopathologically confirmed ocular surface squamous neoplasia (OSSN) in clinically diagnosed pterygium samples at a tertiary center in Northern California, over a 10-year period (2009-2019).

METHODS

A retrospective chart review of patients older than 18 years with clinically diagnosed benign pterygium requiring excision was conducted. Clinically suspected pterygia were excised using standard techniques and routinely submitted to the University of California Davis for pathologic evaluation. Demographic, clinical, surgical, and pathological information were recorded and analyzed. The prevalence rate of OSSN was calculated.

RESULTS

A total of 348 consecutive specimens were evaluated. The mean (±SD) age of the patients was 58 ± 12 years, with a near equal sex representation. A total of 57 (16%) pterygia were recurrent at initial presentation. Histopathologic results demonstrated a single case of OSSN. This patient did not have a documented history of carcinoma in other organs or any history of herpes virus, human papilloma virus, or human immunodeficiency virus infection.

CONCLUSIONS

The prevalence of histopathological OSSN in clinically suspected pterygia within our sample was approximately 0.3%. Because of shared clinical characteristics of pterygia and OSSN, a high index of suspicion and judicious use of anterior segment optical coherence tomography enable for effective preoperative diagnosis of OSSN. However, in the absence of clinical expertise or high-resolution optical coherence tomography, routine tissue pathologic examination may be warranted.

NLRP3 and NLRP6 expression in pterygium and normal conjunctiva and their relationship with pterygium formation and recurrence

Purpose

This study aimed to explore the pterygium formation and recurrence, by detecting the expression of Nod-like receptor pyrin domain 3 (NLRP3) and Nod-like receptor pyrin domain 6 (NLRP6) in pterygium and evaluate the correlation between NLRP3 and NLRP6 in pterygium.

Methods

In this prospective study, the expression levels of NLRP3 and NLRP6, with their related effectors, were evaluated in primary pterygium (n = 40) and recurrent pterygium (n = 32) tissue samples and compared with normal conjunctiva (n = 11) tissue samples by immunohistochemistry.

Results

Compared to the normal conjunctiva group, the expression levels of NLRP3, caspase-1, IL-18, and IL-1β, were significantly higher, and NLRP6 showed an expression that was significantly lower in pterygium tissue samples (P < 0.05, respectively). Compared to the primary pterygium group, the expression levels of NLRP3, caspase-1, IL-18 and IL-1β were significantly higher, and NLRP6 showed an expression that was significantly lower in recurrent pterygium tissue samples (P < 0.05, respectively).There was a negative correlation between NLRP3 expression and NLRP6 expression in normal conjunctival (r = −0.739, P = 0.009) and pterygium (r = −0.533, P = 0.000).

Conclusions

NLRP3 and NLRP6 may be involved in the formation and recurrence of pterygium. NLRP6 may play an anti-inflammatory role in normal conjunctival tissue to maintain conjunctival homeostasis.

Efficacy of bevacizumab in the treatment of pterygium: An updated meta-analysis of randomized controlled trials

Recurrence is the most common problem following pterygium surgery. Whether bevacizumab can prevent pterygium recurrence is controversial. To address this point, we carried out a meta-analysis of randomized controlled trials evaluating the efficacy and safety of bevacizumab in the treatment of pterygium. We searched the PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Literature, China National Knowledge Infrastructure, and Wan fang databases up to September 20, 2020 for relevant articles. We used the Cochrane assessment tool to evaluate the methodologic quality of the included studies, and calculated the relative risk (RR) and 95% confidence interval (CI) of the reported recurrence and complication rates. A total of 17 studies including 1124 patients with 1144 eyes were included in the meta-analysis. The combined results showed that bevacizumab significantly reduced the recurrence rate of pterygium after surgery (RR = 0.652, 95% CI: 0.504-0.845, Z = 3.24, P = 0.001) and was not significantly associated with the occurrence of postoperative complications compared to control treatments (RR = 0.832, 95% CI: 0.604-1.145, Z = 1.13, P = 0.259). A subgroup analysis showed that the rate of pterygium recurrence was significantly lower with bevacizumab than in the control group at a dose of 2.5 mg (RR = 0.47, 95% CI: 0.24-0.91) administered by subconjunctival injection (RR = 0.54, 95% CI: 0.39-0.75) after a follow-up time of ≤ 6 months (RR = 0.63, 95% CI: 0.45-0.88). Thus, bevacizumab can reduce the risk of pterygium recurrence after surgery, and does not differ from placebo or other drug treatments in terms of the risk of complications.

Pterygium: an update on pathophysiology, clinical features, and management

Pterygium is a relatively common ocular surface disease. The clinical aspects and the treatment options have been studied since many years ago, but many uncertainties still exist. The core pathologic pathway and the role of heredity in the development of pterygium are still attractive fields for the researchers. The role of pterygium in corneal irregularities, in addition to the refractive properties of pterygium removal, has been increasingly recognized through numerous studies. The association between pterygium and ocular surface neoplasia is challenging the traditional beliefs regarding the safe profile of the disease. The need for a comprehensive clinical classification system has encouraged homogenization of trials and prediction of the recurrence rate of the pterygium following surgical removal. Evolving surgical methods have been associated with some complications, whose diagnosis and management are necessary for ophthalmic surgeons. According to the review, the main risk factor of pterygium progression remains to be the ultraviolet exposure. A major part of the clinical evaluation should consist of differentiating between typical and atypical pterygia, where the latter may be associated with the risk of ocular surface neoplasia. The effect of pterygium on astigmatism and the aberrations of the cornea may evoke the need for an early removal with a purpose of reducing secondary refractive error. Among the surgical methods, conjunctival or conjunctival-limbal autografting seems to be the first choice for ophthalmic surgeons because the recurrence rate following the procedure has been reported to be lower, compared with other procedures. The use of adjuvant options is supported in the literature, where intraoperative and postoperative mitomycin C has been the adjuvant treatment of choice. The efficacy and safety of anti–vascular endothelial growth factor agents and cyclosporine have been postulated; however, their exact role in the treatment of the pterygium requires further studies.

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.

An Unexpected Incidence of Ocular Surface Neoplasia on Pterygium Surgery. A Retrospective Clinical and Histopathological Report

PURPOSE

To report the unexpected finding of ocular surface neoplasia (OSSN) on conjunctival tissue removed during pterygium surgery and subjected to histopathology analysis.

METHODS

This is an observational, descriptive retrospective study in which all the samples removed during surgery between 1997 and 2020 with a clinical diagnosis of pterygium were sent for histopathology analysis in which an unexpected OSSN was found.

RESULTS

There were 461 cases with a preoperative diagnosis of pterygium, with a mean age of 30.14 ± 10.6 years. In this group, there was an unexpected finding of OSSN in 69 cases (14.96%) of the surgical samples, with a mean age of 46 ± 8.2 years (31.86 ± 12.13).

CONCLUSIONS

The unexpected coincidence of pterygium and OSSN is frequent, although varies depending on the geographical location. We recommend performing a histopathology analysis on every pterygium removed.

Low-Dose Mitomycin C Decreases the Postoperative Recurrence Rate of Pterygium by Perturbing NLRP3 Inflammatory Signalling Pathway and Suppressing the Expression of Inflammatory Factors

A pterygium is generally believed to be a chronic inflammatory lesion caused by external stimuli that develops from the conjunctiva and grows onto the cornea. Simple bare sclera excision is the most commonly used method to treat pterygium. However, the high postoperative recurrence rate of pterygium remains a persistent challenge. Mitomycin C (MMC) is an antineoplastic antibiotic that inhibits DNA, RNA, and protein synthesis. In recent years, although MMC has proven useful for the treatment of pterygium, its application has been controversial because of its clear toxicity and the possibility of ocular complications. In the current study, we prospectively recruited patients to receive or not receive a local injection of MMC (0.4 mg/ml). Follow-up was conducted with the patients to determine the postoperative recurrence rate of pterygium and/or to observe any ocular complications. The remarkable results demonstrated that MMC can decrease the postoperative recurrence rate of pterygium without leading to serious eye complications. Further results indicated that MMC can inhibit the activation of the NLRP3 inflammatory signalling pathway and thus downregulate the expression of downstream molecules, including IL-18 and IL-1β. MMC also reduced the expression of inflammatory factors TGF-β1, VEGF, and IL-6. In addition to influencing these factors, MMC suppressed neovascularization and the proliferation of corneal fibroblasts to effectively reduce the recurrence rate of pterygium. Taken together, our results provide a theoretical basis for the development of prevention and treatment strategies for pterygium and suggest that MMC is highly effective as an adjunctive treatment after excision of primary pterygia.

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.

Solar Ultraviolet Radiation Exposure and Sun Protection Behaviors and Knowledge Among a High-Risk and Overlooked Group of Outdoor Workers in South Africa

The exposure of outdoor car guards to solar ultraviolet radiation (UVR), the majority with deeply pigmented skin, to solar UVR was measured for five consecutive days during early spring (September 2017) in South Africa using electronic UVR dosimeters attached to the upper arm of each participant. The exposure of the nape of the neck, forehead, nose, cheek and hand was extrapolated from the measurements. The onsite ambient solar UVR on a flat, horizontal, unshaded surface was measured concurrently. The sun-related knowledge, behavior and attitudes of the car guards were evaluated using questionnaires. Total personal daily solar UVR exposure as a percentage of the ambient solar UVR exposure was 24%. The exposure of car guards on several body sites was in excess of the occupational threshold limit value. Sleeved shirts and hats were the most commonly used sun protection measures (worn by 70% and 80%, respectively). Considering the high levels of solar UVR reported on most days throughout the year in South Africa, more studies quantifying the personal exposure of outdoor workers in both the informal and formal sectors are necessary.

The burden of ocular diseases in an underdeveloped village in Southwest Sumba, Eastern Indonesia, 2016

Background: Prevalence estimates of ocular diseases in a given district are important to plan the programs of eye care services. This study aimed to describe the burden of ocular diseases as an initial step in improving eye care services in underdeveloped areas in Indonesia.Methods: A cross-sectional study was performed among residents of Perobatang Village in Southwest Sumba district in July 2016. Eye examinations were conducted by ophthalmologists, and visual acuity was measured by optometrists. Participants were provided with appropriate treatment according to diagnosis. Surgical services were offered two months after the examination.Results: After eximining a total of 667 of 1,459 (46%) residents, the result showed that the most frequent ocular problems were presbyopia (30.8%), cataract (12.8%), refractive error (11.3%), and pterygium (10.7%). The proportion of myopia was 5.9%, hyperopia was 5.0%, and astigmatism was 2.2%. Moreover, the proportion of blindness was 10%. Cataract caused blindness in 44 participants. Other causes of blindness included age-related macular degeneration, retinopathy, optic atrophy, glaucoma, retinal detachment and trauma.Conclusion: The burden of ocular problems in Perobatang Village, Southwest Sumba, Eastern Indonesia was high. These findings showed the importance of public health action from local government and non-governmental organizations to improve eye care services in Southwest Sumba district.