Pathophysiology of ocular surface squamous neoplasia

The effect of topical voriconazole on conjunctiva in rats as revealed by histopathology and immunohistochemistry

The aim of this study was to evaluate the effects of topical voriconazole with histopathological and immunohistochemical analysis of the conjunctiva in rats. Twenty-eight Sprague Dawley rats were divided into four groups as two study (S1, S2) and two control (C1, C2). Voriconazole was instilled four times daily to S1, S2 rats. Physiologic saline (0.9%) was instilled four times daily in C1 and C2 rats. S1 and C1 were followed in a dark room; S2 and C2 were held in a room with sunlight. Impression cytology was performed at 0, 15, 30, 45 and 60th d after instillations. After 2 months of treatment conjunctival tissue was removed for histological and immunohistochemical analysis. In impression cytology evaluation, there was no difference between S1 and S2. At 60 d the difference between S1 and C1 was significant. In other comparisons, there was no difference between S1 and C1, C2. The scores of S2 was higher than C1 and C2 for all comparisons except 15th day scores of S2 and C2. In study groups, epithelial and gland degeneration were higher in S2, but inflammation scores were similar. The comparison of immunreactivity of ERK, TGFβ and E-cadherin were different in the study groups than the control groups for all comparisons. In conclusion, voriconazole has side effects due to phototoxicity including squamous cell carcinoma. Clinicians should particularly be careful with the long-term use of topical voriconazole and should follow-up patients strictly in terms of ocular surface alterations.

Human health in relation to exposure to solar ultraviolet radiation under changing stratospheric ozone and climate

The Montreal Protocol has limited increases in the UV-B (280-315 nm) radiation reaching the Earth's surface as a result of depletion of stratospheric ozone. Nevertheless, the incidence of skin cancers continues to increase in most light-skinned populations, probably due mainly to risky sun exposure behaviour. In locations with strong sun protection programs of long duration, incidence is now reducing in younger age groups. Changes in the epidemiology of UV-induced eye diseases are less clear, due to a lack of data. Exposure to UV radiation plays a role in the development of cataracts, pterygium and possibly age-related macular degeneration; these are major causes of visual impairment world-wide. Photodermatoses and phototoxic reactions to drugs are not uncommon; management of the latter includes recognition of the risks by the prescribing physician. Exposure to UV radiation has benefits for health through the production of vitamin D in the skin and modulation of immune function. The latter has benefits for skin diseases such as psoriasis and possibly for systemic autoimmune diseases such as multiple sclerosis. The health risks of sun exposure can be mitigated through appropriate sun protection, such as clothing with both good UV-blocking characteristics and adequate skin coverage, sunglasses, shade, and sunscreen. New sunscreen preparations provide protection against a broader spectrum of solar radiation, but it is not clear that this has benefits for health. Gaps in knowledge make it difficult to derive evidence-based sun protection advice that balances the risks and benefits of sun exposure.

Human papilloma virus identification in ocular surface squamous neoplasia by p16 immunohistochemistry and DNA chip test: A strobe-compliant article

The aim of this study was to identify the association between human papilloma virus (HPV) infection and ocular surface squamous neoplasia (OSSN) using p16 immunohistochemistry (IHC) and deoxyribonucleic acid (DNA) chip test.Thirty-eight patients who underwent surgical excision of OSSN were retrospectively studied using tissue samples. The IHC was performed to assess the expression of p16 and DNA chip test was used to detect 24 HPV serotypes.Among the 38 OSSN samples, 32 cases (84.2%) were histopathologically categorized as pre-invasive type and 6 cases (15.8%) as invasive type. The IHC for p16 showed strong positivity in 12 cases (31.6%), whereas it was negative in 26 cases (68.4%). On the other hand, only one case (2.6%) of invasive OSSN was positive for the HPV16 serotype, as assessed by DNA chip test.In OSSN, p16 expression was positive in approximately 1/3rd of the cases, whereas the majority of the 24 HPV serotypes were negative for p16. Our findings suggest that only a weak association exists between HPV infection and OSSN.

Primary limbal stem cell transplantation in the surgical management of extensive ocular surface squamous neoplasia involving the limbus

Purpose

To determine the role of primary limbal stem cell transplantation (LSCT) in managing extensive ocular surface squamous neoplasia (OSSN) with more than 3 quadrants of limbal involvement to prevent manifestations of limbal stem cell deficiency.

Methods

A multi-center, comparative, and interventional clinical study of cases and historical controls was done. Patients with a limbal mass suggestive of OSSN involving more than 3 quadrants of limbus (> 9 clock hours) and no local, regional or systemic metastasis, who underwent primary surgical excision with or without adjuvant chemotherapy and had a minimum follow-up of 12 months were included in this study. Two historical controls underwent tumor excision with only amniotic membrane grafting. Three cases underwent tumor excision along with LSCT in the form of conjunctival limbal autograft (CLAG) or simple limbal epithelial transplant (SLET).

Results

None of the eyes had any recurrences of OSSN during the follow-up period. Cases with primary LSCT with tumor excision showed better ocular surface stability in the long term.

Conclusion

Concomitant LSCT either in the form of CLAG or SLET appears to provide better long-term outcomes and is advocated while excision of extensive OSSN involving the limbus.

[Topical cyclosporine A and risk of ocular surface neoplasia]

INTRODUCTION

Cyclosporine A (CsA) has well-known cutaneous carcinogenic effects when administered systemically. In ophthalmology, it is increasingly used in the form of eye drops since its indication for moderate to severe eye dry eye. The goal of this review of the literature is to evaluate a possible link between topical ocular CsA use and the occurrence of ocular surface neoplasia.

MATERIALS AND METHODS

A literature review was performed. Publications evaluating the safety and efficacy of topical CsA as well as studies on the epidemiology and risk factors for conjunctival neoplasia and cases of conjunctival neoplasia were analyzed. Finally, post-market surveillance data from commercially available CsA eye drops were also evaluated.

RESULTS

Five cases of conjunctival neoplasia in patients treated with systemic and/or topical CsA have been described in the literature, three with systemic administration alone, another with combined systemic and local administration, and one case of local administration alone. In these cases, no direct link with the administration of ocular topical CsA could be determined. Among the numerous prospective studies evaluating the safety and efficacy of topical CsA as well as the case-control studies evaluating the risk factors for developing conjunctival neoplasia, no relationship between the occurrence of conjunctival neoplasia and the use of topical ocular CsA was observed.

CONCLUSION

Despite plausible pathophysiologic mechanisms, to date there is no evidence of an increased risk of ocular surface neoplasia with the use of topical ocular CsA. Further studies specifically addressing this question and with a longer duration are needed in order to precisely evaluate this theoretical risk.

Factors related to survival outcomes following orbital exenteration: a retrospective, comparative, case series

BACKGROUND

Orbital exenteration is a disfiguring procedure that aims to achieve local control. It is commonly a part of the management of malignant orbital tumor which is a life-threatening condition. It is necessary to determine predictive factors associated with overall survival (OS) following orbital exenteration.

METHODS

This was a retrospective, comparative, case series of 39 patients with malignant tumors who underwent orbital exenteration. Patient records were reviewed for age, clinical presentation, preoperative visual acuity (VA), tumor size, surgical margin, tumor invasiveness, recurrent disease, and status of distant metastasis. Kaplan-Meier curves were used to assess OS and event-free survival (EFS). The predictive factors related to OS were identified using multivariate analysis.

RESULTS

The mean age was 62.9 years (range, 5.5 to 89.7 years), 68.4% presented with VA < 20/400. The mean size of all tumors was 32 ± 18 mm. Distant metastasis at diagnosis was reported in 11 patients (28.2%). Twenty-two patients died during follow-up. The median OS and EFS were 3.89 years and 3.01 years, respectively. The predictive factors for worse OS on multivariate analysis were preoperative VA < 20/400 (adjusted hazard ratio [aHR] 4.67, P = 0.003), tumor size larger than 20 mm (aHR 3.14, P = 0.022,) and positive distant metastasis at diagnosis (aHR 15.31, P <  0.001).

CONCLUSIONS

The prognostic factors for poor survival outcome following orbital exenteration were a preoperative VA < 20/400, tumor size > 20 mm, and distant metastasis at diagnosis mostly due to patient negligence.

Clinical Management of Ocular Surface Squamous Neoplasia: A Review of the Current Evidence

Ocular surface squamous neoplasia (OSSN) is the most common non-pigmented malignancy of the ocular surface and is represented in a wide range of histologic diagnoses, ranging from mild epithelial dysplasia to invasive squamous carcinoma. Although surgical excision is still the gold standard for OSSN treatment, interest in conservative medical approaches is steadily growing. We have reviewed all of the literature on OSSN published in English in the MEDLINE database up to May 2018, using the keywords “ocular surface squamous neoplasia,” “squamous conjunctival carcinoma,” and “conjunctival carcinoma in situ,” with the aim to provide a comprehensive review of the most recent evidence on this distinct clinical entity.

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.

Squamous cell carcinoma in the anophthalmic socket: a series of four cases with HPV-16 profiling

PURPOSE

To present the clinical and histological features of squamous cell carcinoma (SCC) in the anophthalmic socket in four adult patients, and to determine the presence of human papillomavirus infection (HPV).

METHODS

Retrospective case series of four adult patients with SCC of the anophthalmic socket. P16 immunohistochemistry and HPV testing was carried out in all cases. The authors report clinical findings, histopathology, management and outcomes for all four patients with conjunctival SCC. Previously reported cases of conjunctival SCC in anophthalmic sockets were reviewed.

RESULTS

Four adult patients presented with eyelid lumps, discharge or change in prosthesis fit. Common examination findings included papillomatous changes, eyelid masses and epithelial changes. Three out of the four cases (75%) were positive for p16 by immunohistochemistry and the same cases positive for HPV-16 DNA. All patients received cryotherapy, topical or intralesional chemotherapy. Two patients proceeded to exenteration for control of invasive disease.

CONCLUSIONS

To the authors' knowledge, this is the largest series of SCC in the anophthalmic socket with comprehensive annotation of HPV status. Although socket conjunctiva is protected from environmental radiation, there is still a risk of neoplastic transformation in this tissue, thus patient education and regular checking of sockets by ophthalmologists should be undertaken as a preventative measure. The potential role of HPV in these tumours warrants further investigation.

Treatment and Pathology of an Unusual Large Carcinoma of the Conjunctiva

Carcinoma of the conjunctiva is a malignant tumor which is mostly detected and surgically treated at an early stage because of medical or cosmetic problems. Exceptions of this rule may occur in developing countries, where patients do not have access to standard medical care systems. We report the case of a conjunctival carcinoma in an African patient with an unusually late presentation. Because of local medical shortcomings, and considering the severe, transmural inflammation of anterior ocular structures, an exenteration was performed although the orbit was not deeply involved with the tumor. The strong nuclear expression of p53 indicates a major role of UV exposure in this case. A total of 16-month follow-up in this patient and larger published series suggest that the risk of metastasis is rather low under those circumstances, even with invasive tumors.

Clinicodemographic profile and treatment outcome in patients of ocular surface squamous neoplasia

Purpose:

The aim is to study the clinicodemographic profile and treatment outcome of ocular surface squamous neoplasia (OSSN).

Methods:

This was a retrospective observational study of 57 eyes (56 cases) with clinically diagnosed OSSN, presenting in our center over the past year.

Results:

The median age of presentation was 55 years with male:female ratio being 4.5:1. Systemic predisposing conditions were xeroderma pigmentosa (1) postkidney transplant immunosuppression (1), and human immunodeficiency virus infection (1). Patients with predisposing conditions had a younger median age of onset (33 years). The majority of tumors were nodular (61.4%), gelatinous (61.4%), and had limbal involvement (96%). On ultrasound biomicroscopy (UBM), mean tumor height was 2.93 ± 1.02 mm, and intraocular extension was evident in seven eyes. OSSN with intraocular extension had a mean tumor height of 4.3 ± 1.32 mm. Nodal metastasis was seen in one case at presentation. As per American Joint Committee for Cancer Classification seventh edition staging-two cases were T1, one was T2, 46 were T3 and eight were T4. Treatment advised included conservative therapy for 39; wide local excision (4 mm margin clearance) with cryotherapy for seven; enucleation in four; and exenteration in four eyes. Overall, complete regression was achieved in 88% of cases during a mean follow-up of 13.5 ± 4.6 months. Recurrence was seen in three cases, which were treated with exenteration, radical neck dissection, and palliative chemo-radiotherapy, respectively.

Conclusion:

Although associated with old age, earlier onset of OSSN is seen in patients with systemic predisposing conditions. Thicker tumors in the setting of a previous surgery or immunocompromised status should be considered high-risk features for intraocular extension and should be evaluated on UBM.

Conjunctival Squamous Cell Neoplasia Associated With Ocular Cicatricial Pemphigoid

The purpose of this study was to describe a possible causal relationship between ocular cicatricial pemphigoid (OCP) and ocular surface squamous neoplasia. Two middle-aged female patients with already diagnosed OCP were studied in regard to the subsequent onset of conjunctival squamous neoplasia. Their clinical histories, ocular examinations, clinical photographs, and results of biopsies and any ancillary immunofluorescent laboratory evaluation studies were carefully reviewed. One patient had a preinvasive squamous dysplasia and the other an invasive squamous cell carcinoma, both in the unequivocal setting of OCP with bilateral conjunctivitis, symblephara, and forniceal foreshortening. The patients had been receiving intensive immunotherapy consisting of some combination of corticosteroids, rituximab, and interferon alpha. Both patients had a positive immunofluorescent study demonstrating immunoreactants at the level of the epithelial basement membrane. Each patient had 2 earlier negative immunofluorescent studies before a third was positive. While rare, there is 1 previous report of an association between OCP and conjunctival squamous neoplasia. The current report provides more data supporting the proposal that this conjunction is more than a random event. Repeat immunofluorescent studies after an initial negative result in a patient with strong clinical signs of OCP are imperative due to the frequency of false negative studies in the context of clinically persuasive disease.

Mitomycin C or interferon as adjuvant therapy to surgery for ocular surface squamous neoplasia: comparative study

Background:

Traditionally, surgical excision has been the treatment of choice for ocular surface squamous neoplasia (OSSN). Recurrences after surgery are high. To reduce the risk of recurrence, adjuvant therapies have been increasingly used.

Purpose:

We compared recurrences and complications of 3 forms of treatment for OSSN: surgical excision (group A), surgical excision plus adjuvant topical mitomycin C (MMC) (group B), and surgical excision plus subconjunctival interferon-α-2b (IFN-α-2b) (group C).

Methods:

A retrospective comparative study was conducted between January 2006 and March 2016 at the Ocular Oncology Service of the Catholic University of Rome. Seventy-nine patients with a confirmed histological diagnosis of OSSN were included: 43 were treated with surgical excision (group A), 16 underwent surgical excision plus topical MMC (group B), and 20 underwent surgical excision plus adjuvant subconjunctival IFN-α-2b (group C).

Results:

The recurrences were different in the 3 groups. Thirty-one recurrences (72%) were seen in group A, 5 (31%) were found in group B, and 3 (15%) were seen in group C. Eight (50%) patients who received MMC 0.02% complained of ocular discomfort, 10 (62.5%) presented conjunctival hyperemia, while conjunctival chemosis and corneal epitheliopathy were noticed in 2 (13%) and 2 (13%) patients, respectively. All patients treated with subconjunctival IFN-α-2b reported flu-like symptoms. Two patients (10%) complained of ocular discomfort.

Conclusions:

Our study revealed that OSSN is not always manageable with simple excision. Adjuvant chemotherapy is strongly advisable after surgery to reduce recurrences. Interferon injections and MMC drops are effective in preventing recurrences and should be administered after surgery.

Severe Phenotype of Keratitis-Ichthyosis-Deafness Syndrome With Presumed Ocular Surface Squamous Neoplasia

PURPOSE

The aim of this study was to describe a case of severe keratitis-ichthyosis-deafness (KID) syndrome with ocular surface squamous neoplasia.

METHODS

The affected patient underwent complete ocular and systemic examinations. The molecular studies included polymerase chain reaction amplification and automated DNA sequencing of the complete gap junction beta-2 (GJB2) gene coding sequence.

RESULTS

A 30-year-old man presented with generalized erythro-hyperkeratosis and deafness and complaints of decreased visual acuity, tearing, and photophobia. Ophthalmic examination showed corneal erosion, vascularization, and a gray gelatinous lesion partially covering the right cornea, suggestive of squamous neoplasia. The clinical features were characteristic of KID syndrome. This diagnosis was confirmed with a DNA analysis showing the pathogenic variant p.D50N in the GJB2 gene. Presumed squamous neoplasia was treated with topical interferon α2b.

CONCLUSIONS

KID syndrome is a very rare disease that has been reported with an incremental incidence of squamous cell carcinoma of the mucous membranes and skin (12%-15%). Here, we presented a case of severe systemic KID syndrome with ocular surface squamous neoplasia.

KLF4 Plays an Essential Role in Corneal Epithelial Homeostasis by Promoting Epithelial Cell Fate and Suppressing Epithelial-Mesenchymal Transition

Purpose

The purpose of this study was to test the hypothesis that KLF4 promotes corneal epithelial (CE) cell fate by suppressing the epithelial–mesenchymal transition (EMT), using spatiotemporally regulated CE-specific ablation of Klf4 in Klf4^Δ/ΔCE (Klf4^LoxP/LoxP/Krt12^rtTA/rtTA/Tet-O-Cre) mice.

Methods

CE-specific ablation of Klf4 was achieved by feeding Klf4^Δ/ΔCE mice with doxycycline chow. The wild-type (WT; normal chow-fed littermates) and the Klf4^Δ/ΔCE histology was compared by hematoxylin and eosin–stained sections; EMT marker expression was quantified by quantitative PCR, immunoblots, and immunofluorescent staining; and wound healing rate was measured by CE debridement using Algerbrush. KLF4 and EMT markers were quantified in human corneal limbal epithelial (HCLE) cells undergoing TGF-β1–induced EMT by quantitative PCR, immunoblots, and immunofluorescent staining.

Results

The epithelial markers E-cadherin, Krt12, claudin-3, and claudin-4 were down-regulated, whereas the mesenchymal markers vimentin, β-catenin, survivin, and cyclin-D1 and the EMT transcription factors Snail, Slug, Twist1, Twist2, Zeb1, and Zeb2 were up-regulated in the Klf4^Δ/ΔCE corneas. The Klf4^Δ/ΔCE cells migrated faster, filling 93% of the debrided area within 16 hours compared with 61% in the WT. After 7 days of wounding, the Klf4^Δ/ΔCE cells that filled the gap failed to regain epithelial characteristics, as they displayed abnormal stratification; down-regulation of E-cadherin and Krt12; up-regulation of β-catenin, survivin, and cyclin-D1; and a 2.5-fold increase in the number of proliferative Ki67⁺ cells. WT CE cells at the migrating edge and the HCLE cells undergoing TGF-β1–induced EMT displayed significant down-regulation of KLF4.

Conclusions

Collectively, these results reveal that KLF4 plays an essential role in CE homeostasis by promoting epithelial cell fate and suppressing EMT.

Interferon alpha-2a as alternative treatment for conjunctival squamous cell carcinoma

CASE REPORT

A 35 year-old male patient with a history of HIV infection characterized by progressive tumour growth in bulbar conjunctiva of the left eye, corresponding to conjunctival squamous cell carcinoma that responded to treatment with interferon alpha-2a.

DISCUSSION

Interferon alpha-2b has been used at conjunctival level as a topical immunomodulator treatment, with complete remission of epithelial neoplasms being observed. However, there have not been any previous publications on the use of interferon alpha-2a, which differs from interferon alpha-2b in a single amino acid, for the treatment of conjunctival squamous cell carcinoma.

Multifocal Ocular Surface Squamous Neoplasia

A 64-year-old healthy female presented with a papillomatous limbal lesion involving 6 clock hours of superior limbus and diffuse involvement of upper tarsal conjunctiva of left eye of 6 months duration. Excision of superior limbal lesion on histopathology showed carcinoma in situ with focal breach in basement membrane and moderate degree of differentiation. The surgical base and margins were uninvolved. The tarsal lesion was initially treated with subconjunctival interferon alpha 2b (IFN alpha 2b) (3 cycles of IFN alpha 2b) with poor response. Subsequently treatment with topical mitomycin C 0.04% showed a dramatic response in the upper eyelid tarsal lesion. A small residual lesion needed excision. One year after treatment, she was completely tumor-free. In multifocal ocular surface squamous neoplasia, multimodal treatment with excision and topical mitomycin C may be effective in cases refractory to immunotherapy.

Conjunctival Tumors: Review of Clinical Features, Risks, Biomarkers, and Outcomes--The 2017 J. Donald M. Gass Lecture

Conjunctival tumors encompass a broad range of diagnoses. The 3 most important malignant tumors include ocular surface squamous neoplasia (OSSN) (14%), melanoma (12%), and lymphoma (7%). Conjunctival malignancies are rarely found in children. Regarding OSSN, pre-disposing conditions include chronic solar radiation, immune deficiency (HIV), organ transplant, autoimmune conditions, xeroderma pigmentosum, and chronic exposure to cigarette smoke. OSSN is managed surgically or with topical/injection immunotherapy or chemotherapy. Metastasis occurs in <1%. Regarding melanoma, predisposing conditions include primary acquired melanosis (PAM), chronic nevus, and chronic solar radiation. Treatment of PAM or nevus can prevent melanoma. Melanoma management involves surgical resection with clean margins and avoidance of direct tumor manipulation ("no touch" technique). The first surgery is most important, to minimize tumor seeding. Biomarkers including BRAF, TERT, and PTEN provide information regarding risk for metastasis and allow for targeted antibiomarker therapies. Ten-year risk for melanoma metastasis is 25%. Tumors >2 mm thickness or those located in fornix, caruncle, or orbit are at highest risk for metastasis. Regarding lymphoma, predisposing conditions include benign reactive lymphoid hyperplasia, immune deficiency (HIV), immune dysfunction, and chronic inflammation/infection (Helicobacter pylori, Chlamydia psittaci). The 4 most important subtypes include extranodal marginal zone lymphoma (ENMZL), follicular lymphoma, mantle cell lymphoma (MCL), and diffuse large B-cell lymphoma. Treatment includes surgical resection, cryotherapy, radiotherapy, systemic chemotherapy, or targeted anti-B-cell therapy (rituximab). Lymphoma-related survival (5-year) depends on subtype and ranges from 97% (ENMZL) to 9% (MCL). Recognizing conjunctival tumors and understanding predisposing factors, biomarkers, and treatment strategies are vital to patient outcomes.

Damaging Effects of Ultraviolet Radiation on the Cornea

The cornea sits at the anterior aspect of the eye and, like the skin, is highly exposed to ultraviolet radiation (UVR). The cornea blocks a significant proportion of UVB from reaching the posterior structures of the eye. However, UVA can penetrate the full thickness of the cornea, even reaching the anterior portion of the lens. Epidemiological data indicate that UVR is a contributing factor for a multitude of diseases of the cornea including pterygium, photokeratitis, climatic droplet keratopathy and ocular surface squamous neoplasia (OSSN), although the pathogenic mechanisms of each require further elucidation. UVR is a well-known genotoxic agent, and its effects have been well characterized in organs such as the skin. However, we are only beginning to identify its effects on the cornea, such as the UVR signature C → T and CC → TT transversions identified by sequencing and increased proliferative and shedding rates in response to UVR exposure. Alarmingly, a single low-dose exposure of UVR to the cornea is sufficient to elicit genetic, molecular and cellular changes, supporting the consideration of using protective measures, such as wearing sunglasses when outdoors. The aim of this review was to describe the adverse effects of UVR on the cornea.

Environmental effects of ozone depletion and its interactions with climate change: progress report, 2015

The Environmental Effects Assessment Panel (EEAP) is one of three Panels that regularly informs the Parties (countries) to the Montreal Protocol on the effects of ozone depletion and the consequences of climate change interactions with respect to human health, animals, plants, biogeochemistry, air quality, and materials. The Panels provide a detailed assessment report every four years. The most recent 2014 Quadrennial Assessment by the EEAP was published as a special issue of seven papers in 2015 (Photochem. Photobiol. Sci., 2015, 14, 1-184). The next Quadrennial Assessment will be published in 2018/2019. In the interim, the EEAP generally produces an annual update or progress report of the relevant scientific findings. The present progress report for 2015 assesses some of the highlights and new insights with regard to the interactive nature of the effects of UV radiation, atmospheric processes, and climate change.

Risk factors for ocular surface squamous neoplasia in Kenya: a case-control study

OBJECTIVE

To determine modifiable risk factors of ocular surface squamous neoplasia (OSSN) in Kenya using disease-free controls.

METHODS

Adults with conjunctival lesions were recruited at four eye care centres in Kenya and underwent excision biopsy. An equal number of controls having surgery for conditions not affecting the conjunctiva and unrelated to ultraviolet light were group-matched to cases by age group, sex and eye care centre. Associations of risk factors with OSSN were evaluated using multivariable logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). Continuous variables were compared using the t-test or the Wilcoxon-Mann-Whitney U-test depending on their distribution.

RESULTS

A total of 131 cases and 131 controls were recruited. About two-thirds of participants were female, and the mean age of cases and controls was 42.1 years and 43.3 years, respectively. Risk factors for OSSN were HIV infection without antiretroviral therapy (ART) use (OR = 48.42; 95% CI: 7.73-303.31) and with ART use (OR = 19.16; 95% CI: 6.60-55.57), longer duration of exposure to the sun in the main occupation (6.9 h/day vs. 4.6 h/day, OR = 1.24; 95% CI: 1.10-1.40) and a history of allergic conjunctivitis (OR = 74.61; 95% CI: 8.08-688.91). Wearing hats was protective (OR = 0.22; 95% CI: 0.07-0.63).

CONCLUSION

Measures to prevent and control HIV, reduce sun exposure such as wearing hats and control allergic conjunctivitis are recommended.

Topical fluorouracil after surgery for ocular surface squamous neoplasia in Kenya: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Ocular surface squamous neoplasia (OSSN) is an aggressive eye tumour particularly affecting people with HIV in Africa. Primary treatment is surgical excision; however, tumour recurrence is common. We assessed the effect of fluorouracil 1% eye drops after surgery on recurrence.

METHODS

We did this multicentre, randomised, placebo-controlled trial in four centres in Kenya. We enrolled patients with histologically proven OSSN aged at least 18 years. After standard surgical excision, participants were randomly allocated to receive either topical fluorouracil 1% or placebo four times a day for 4 weeks. Randomisation was stratified by surgeon, and participants and trial personnel were masked to assignment. Patients were followed up at 1 month, 3 months, 6 months, and 12 months. The primary outcome was clinical recurrence (supported by histological assessment where available) by 1 year, and analysed by intention to treat. The sample size was recalculated because events were more common than anticipated, and trial enrolment was stopped early. The trial was registered with Pan-African Clinical Trials Registry (PACTR201207000396219).

FINDINGS

Between August, 2012, and July, 2014, we assigned 49 participants to fluorouracil and 49 to placebo. Four participants were lost to follow-up. Recurrences occurred in five (11%) of 47 patients in the fluorouracil group and 17 (36%) of 47 in the placebo group (odds ratio 0·21, 95% CI 0·07-0·63; p=0·01). Adjusting for passive smoking and antiretroviral therapy had little effect (odds ratio 0·23; 95% CI 0·07-0·75; p=0·02). Adverse effects occurred more commonly in the fluorouracil group, although they were transient and mild. Ocular discomfort occurred in 43 of 49 patients in the fluorouracil group versus 36 of 49 in the placebo group, epiphora occurred in 24 versus five, and eyelid skin inflammation occurred in seven versus none.

INTERPRETATION

Topical fluorouracil after surgery substantially reduced recurrence of OSSN, was well-tolerated, and its use recommended.

FUNDING

British Council for Prevention of Blindness and the Wellcome Trust.

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.