Retrospective Comparative Study of Topical Interferon α2b Versus Mitomycin C for Primary Ocular Surface Squamous Neoplasia

Oncological principles in the management of ocular surface squamous neoplasia - A Review

Ocular surface squamous neoplasia (OSSN) is the most common neoplasia of the anterior segment. Accurate and timely diagnosis, including detailed clinical assessment and imaging, is essential to ascertain the extent of the disease. The gold standard treatment for OSSN has evolved over the years, transitioning from wide-margin surgical excision using the "no-touch" technique to topical immunotherapy, plaque brachytherapy, and targeted immunotherapy. The choice of treatment modality depends on a tailored approach based on the initial presentation and progression of the disease. This review consolidates a comprehensive understanding of the variable clinical presentations of OSSN, diagnostic and imaging techniques, and available treatment options. It also provides a foundation for the oncologic principles of managing OSSN while offering insights into future therapeutic approaches.

Comparison of postoperative topical interferon-α2b versus intraoperative mitomycin C for pterygium recurrence prevention: a randomized clinical trial

PURPOSE

To evaluate the effect of postoperative interferon-alpha 2b (IFN-α2b) ophthalmic drops versus intraoperative mitomycin-c (MMC) on preventing pterygium recurrence.

METHODS

This prospective randomized clinical trial was conducted on patients who were candidates for pterygium surgery. A total of 75 patients were included in the study from December 2021 to December 2022, of which 64 patients (one eye each) were examined and analyzed based on the inclusion criteria. Then the patients were randomly assigned to control groups, intra-operative MMC (32 patients) and the intervention group, IFN-α2b drops after the operation (32 patients). All patients underwent pterygium surgery using the rotational conjunctival flap method.

RESULTS

In terms of pterygium grading, 8 (12.5%), 25 (39.06%), and 31 (48.44%) eyes were in grades 1, 2, and 3, respectively. The average size of the pterygium was 3.6 ± 0.7 mm. The grade and size of pterygium had the same distribution in the two groups. There was no statistically significant difference between the two groups in the level of post-operative clinical inflammation. The present study showed no significant difference in complications between the two groups (p = 0.999). The recurrence rate in the control group was 9.4% (3 eyes), and 0% (no recurrence) in the intervention group (p = 0.119).

CONCLUSIONS

interferon-alpha 2b group did not show a statistically significant difference in preventing pterygium recurrence compared to the mitomycin C group. The post-surgery administration of IFN-α 2b drops can effectively prevent pterygium recurrence with a comparable and even more compelling effect than MMC during surgery.

Punctal and Canalicular Stenosis Following Topical 1% 5-Fluorouracil Eye Drop Therapy for Ocular Surface Squamous Neoplasia

PURPOSE

To present the first known cases of punctal and canalicular stenosis following topical 5-fluorouracil (5-FU) eye drops for ocular surface squamous neoplasia (OSSN).

METHODS

A retrospective chart review of patients with OSSN receiving topical 1% 5-FU eye drops as a primary or adjuvant treatment between 2013 and 2021 was performed. Individuals diagnosed with punctal or canalicular stenosis during or after topical 5-FU use were included in this study. Four individuals met these criteria; we report clinical findings and treatment course for each patient.

RESULTS

We reviewed 303 patients (316 eyes) with OSSN. All patients were treated with topical 1% 5-FU eye drops in cycles, given 4 times daily for 1 week with 3 weeks off. Four patients (5 eyes) developed punctal stenosis, for a frequency of 1.3%. The mean age at 5-FU initiation in the 4 individuals was 61 years (range 53-69). Most individuals were male (75%), White (75%), and non-Hispanic (100%). The most common presenting symptom of stenosis was epiphora, noted 4.6 ± 3 months after initiating topical 5-FU (after 4.9 ± 2.0 cycles). This occurred in 4 eyes while on therapy (3, 2, 4, and 4 months since 5-FU initiation) and in 1 eye after stopping therapy (10.3 months since 5-FU initiation). In 1 eye, punctal stenosis and epiphora resolved spontaneously after stopping 5-FU. Punctal dilation led to symptom resolution in 2 eyes. Surgical intervention (punctoplasty and external dacryocystorhinostomy) was needed in 2 eyes for punctal and canalicular stenosis, respectively.

CONCLUSIONS

Punctal or canalicular stenosis is a rare and previously unreported adverse effect of topical 5-FU that may require surgical treatment.

Efficacy and safety of topical 0.5% 5-Fluorouracil as primary treatment of ocular surface squamous neoplasia

OBJECTIVE

To assess the efficacy and safety of topical 0.5% 5-Fluorouracil (5-FU) as a primary therapy of ocular surface squamous neoplasia (OSSN).

DESIGN

Retrospective study.

PARTICIPANTS

Patients with clinically suspected OSSN referred to a Brazilian tertiary health center between October 2015 and December 2022.

METHODS

After diagnostic confirmation of OSSN with exfoliative cytology, 0.5% 5-FU was administered topically 4 times daily for 2 weeks followed by a pause of 2 weeks.

RESULTS

A total of 54 patients were included in this study, 32 males (59.3%), mean age of 62.9 years old. Complete resolution of OSSN was achieved in 70.4%. The median number of cycles was 2 (range 1-5). Side effects were reported in 35.2%, which included eyelid erythema, conjunctival hyperemia, and punctal stenosis. None of the patients stopped treatment due to adverse effects. Patients who had partial response to 0.5% 5-FU had complementary treatment with surgery, Mitomycin-C and/or Interferon ⍺2b. Overall recurrence was 14.8%. Median follow-up was 14 months (range 2-92 months). In a multivariate Cox regression analysis, the risk of relapse was 84% lower in patients who had complete response to 0.5% 5-FU (p = 0.018).

CONCLUSION

Topical 0.5% 5-FU may be considered a safe and effective primary therapy for OSSN, with a low rate of side effects.

Toxicity and efficacy of type I interferons on the ocular surface: in vitro, animal, and clinical studies

PURPOSE

To investigate the toxicity of type I interferons (IFNs) on the ocular surface and assess their efficacy in ocular surface tumors.

METHODS

We examined the effects of IFN-α2a, IFN-α2b and IFN-β on corneal epithelial cells and stromal fibroblasts in vitro as well as the impact of IFN-α2a on the ocular surface in mice. Additionally, we analyzed the therapeutic and adverse effects of topically administered IFN-α2a and IFN-α2b in patients with ocular surface tumors. Risk factors contributing to side effects were explored.

RESULTS

IFN-α2a, IFN-α2b or IFN-β reduced cell viability and induced pro-inflammatory cytokines in corneal epithelial cells and stromal fibroblasts. Furthermore, IFNs enhanced the expression of major histocompatibility complex class II and CD40 in corneal epithelial cells. In mice, subconjunctival IFN-α2a injection did not induce corneal epithelial defects or opacity, nor did it reduce aqueous tears or conjunctival goblet cells. In patients, topical IFN-α2a or IFN-α2b administration decreased tumor size and prevented recurrence; however, it was associated with mild side effects, including corneal epitheliopathy and conjunctival hyperemia. These complications were associated with longer IFN use, the presence of underlying ocular surface disease and concurrent use of mitomycin C or anti-glaucoma eye drops.

CONCLUSION

Although type I IFNs cause direct toxicity on corneal cells, they do not induce significant side effects on the healthy ocular surface. Considering its therapeutic and preventive effects, topical type I IFN is safe and effective for treating ocular surface tumors. The potential for ocular side effects should be considered in eyes with identified risk factors.

Ocular Surface Squamous Neoplasia: Changes in the Standard of Care 2003 to 2022

PURPOSE

The aim of this review was to elucidate treatment preferences for ocular surface squamous neoplasia and to examine the changes in treatment modalities over the past 2 decades.

METHODS

An electronic survey was distributed to members of The Cornea Society, Ocular Microbiology and Immunology Group, and 4 international corneal specialist listservs. Questions examined medical and surgical treatment preferences, and results were compared with surveys administered in 2003 and 2012.

RESULTS

A total of 285 individuals responded to the survey; 90% of respondents were self-classified as corneal specialists. Seventy-three percent reported using primary topical monotherapy to treat ocular surface squamous neoplasia as compared with 58% in 2012 ( P = 0.008). Compared with 2003, the percentage use of topical interferon significantly increased ( P < 0.0001) from 14% to 55%, 5-fluorouracil increased ( P < 0.0001) from 5% to 23%, and mitomycin C decreased ( P < 0.0001) from 76% to 19% as a primary monotherapy. The frequency of performing excision without the use of postoperative adjunctive medical therapy decreased significantly ( P < 0.0001), from 66% to 26% for lesions <2 mm, 64% to 12% for lesions between 2 and 8 mm, and 47% to 5% for lesions >8 mm from 2003 to 2022. More clinicians initiated topical immuno/chemotherapy without performing a biopsy as compared to 2003 (31% vs. 11%, P < 0.0001).

CONCLUSIONS

These results demonstrate a paradigm shift in the management of ocular surface squamous neoplasia. The use of primary medical therapy as a first approach has significantly increased, with a reduction in the frequency of performing surgical excision alone.

Periocular and ocular surface nonmelanoma skin cancer

Periocular and ocular surface nonmelanoma malignancies, including basal cell carcinoma (BCC), squamous cell carcinomas (SCC), and ocular surface squamous neoplasia (OSSN), are rare, but their management requires special considerations. The most common periocular malignancy is BCC, which constitutes 80% to 96% of tumors, followed by SCC, which represents 5% to 10% of tumors. OSSN represents a spectrum of diseases that encompass dysplastic alteration to the squamous epithelium of the eye. OSSN ranges from squamous dysplasia to conjunctival intraepithelial neoplasia/carcinoma in situ to invasive SCC, which is the most common ocular malignancy. These tumors can be staged using the eighth edition of the American Joint Committee on Cancer categorization system. The standard of care for periocular malignancies is Mohs micrographic surgery, while medical management with 5-fluorouracil (5-FU), interferon alfa-2b (INF), and mitomycin C (MMC) or "no touch" surgical excision are options for OSSN. Systemic therapies, including sonic hedgehog inhibitors for BCC and epidermal growth factor inhibitors and immune-checkpoint inhibitors for SCC, can be utilized for advanced disease. Recurrence rates are higher for periorbital and ocular malignancies than their respective cutaneous counterparts. These carcinomas and their respective treatments have unique side effects and considerations in an effort to preserve visual function.

Long term study of topical interferon α-2b eye drops as primary treatment of ocular surface squamous neoplasia

PURPOSE

To assess the efficacy of topical interferon α-2β(IFN) eye drops as a primary treatment for ocular surface squamous neoplasia(OSSN) and evaluate factors that impact response to treatment and recurrence of OSSN.

METHOD

A retrospective study of 143 OSSN patients treated with topical IFN(1MIU/ml) from January 1998 to June 2021. The diagnosis was based on clinical examination and anterior segment optical coherence tomography, with histologic confirmation was present in 46.2% of patients. Data on demographic, tumor characteristics, treatment outcome, and side effects were collected. The primary outcomes were tumor resolution frequency and recurrence rate. Secondary outcomes were predictive factors for resolution and recurrence and side effects of treatment.

RESULT

Participants were mostly older (mean age, 69 years, SD 12.9, range 29-97), white(89%) males (74%). Complete tumor resolution was achieved in 80.4% of individuals with a mean time to resolution of 4.2 months (SD 2, range 0.5-12.3 months). On multivariable analysis, history of skin cancer (HR: 0.66, p = 0.05, 95%CI: 0.44-0.99) and immune system abnormalities (HR: 0.37, p = 0.009, 95%CI: 0.18-0.79) reduced the risk of tumor resolution, while a prior history of OSSN (HR: 3.49, p < 0.001, 95%CI: 1.76-6.93) increased the risk of resolution. With a mean follow-up time of 44.3 months (SD 50.9, 0-290 months), the recurrence rate was 0%, 2.3% and 3.1% at 1, 2, and 5 years respectively. Mild hyperemia(18.9%) and pain(10.6%) were the two most common side effects.

CONCLUSION

Topical IFN eye drops are a safe and effective primary treatment modality for OSSN with a reasonable side effect profile.

Topical 1% 5-fluorouracil eye drops as primary treatment for ocular surface squamous neoplasia: Long-term follow-up study

PURPOSE

To determine the efficacy and safety of topical 1% 5-fluorouracil (5FU) eye drops as primary treatment of ocular surface squamous neoplasia (OSSN).

METHODS

Patients were diagnosed with OSSN based on slit-lamp examination and anterior segment optical coherence tomography (AS-OCT). In ambiguous cases an incisional biopsy was performed. All were treated with 5FU eye drops as primary therapy and retrospectively reviewed. Data on demographics, tumor characteristics, treatment outcome, and side effects were collected. The primary outcome measures were resolution frequency and recurrence rate of OSSN. Secondary outcomes were risk factors for resolution and recurrence, and side effects of treatment.

RESULTS

The mean age of 251 subjects (258 eyes) was 67.5 ± 11.7 years, 182 were male. Patients were followed up on average for 752 ± 580 days. Overall, 87% of patients experienced complete tumor resolution. Multivariable analysis revealed that superior tumor location (HR: 0.62, 95% CI: 0.41-0.93, p = 0.02) and leukoplakia (HR: 0.65, 95% CI: 0.41-0.93, p = 0.02), decreased the likelihood of tumor resolution. The recurrence rate was 4% at six months, 8% at one year, and 19% at two years. Larger tumor area increased chances of tumor recurrence (HR: 1.01, 95% CI: 1.00-1.02 p = 0.03). The most common side effects of 5-FU were mild hyperemia and pain, which occurred in 26% and 23% of patients, respectively. Among the sight-threatening side effects, limbal stem cell deficiency occurred in only 3% of patients.

CONCLUSIONS

Topical 1% 5FU eye drops are a safe and effective medication for OSSN. Superior tumor location and leukoplakia decreased the chance of tumor resolution.

The Management of Ocular Surface Squamous Neoplasia (OSSN)

The rise of primary topical monotherapy with chemotherapeutic drugs and immunomodulatory agents represents an increasing recognition of the medical management of ocular surface squamous neoplasia (OSSN), which may replace surgery as the standard of care in the future. Currently, there is no consensus regarding the best way to manage OSSN with no existing guidelines to date. This paper seeks to evaluate evidence surrounding available treatment modalities and proposes an approach to management. The approach will guide ophthalmologists in selecting the most appropriate treatment regime based on patient and disease factors to minimize treatment related morbidity and improve OSSN control. Further work can be done to validate this algorithm and to develop formal guidelines to direct the management of OSSN.

Efficacy and safety of topical 5-fluorouracil in conjunctival intraepithelial neoplasia refractory to interferon alpha-2b

PURPOSE

To report the efficacy and safety of 5-fluorouracil as the second line of treatment for two cases of conjunctival intraepithelial neoplasia refractive to topical interferon alpha-2b.

CASE REPORT

In the first case, a 77-year-old woman was evaluated because of a fleshy vascularized lesion in the temporal conjunctiva on her right eye with leukoplakia of the corneal epithelium from 10- to 5-o'clock limbus. In the second case, an 81-year-old man, a nodular lesion in the temporal conjunctiva on his RE, with corneal adjacent opalescence, one millimeter in extent, was observed. Both patients were initially treated with excisional surgery, the samples being reported as conjunctival intraepithelial neoplasia with high-grade dysplasia. Co-adjuvant treatment with topical interferon alpha-2b 1 mIU/mL was indicated 4 times/day uninterruptedly. In the first case, there was no response despite 8 months of treatment, while in the second, the corneal lesion progressed in an arboriform pattern after 4 months of topical chemotherapy.

MANAGEMENT & OUTCOME

In the absence of efficacy, the treatment was then changed to topical 5-fluorouracil (1%), 4 times/day for 7 days with a time-lapse of 21 days off, which constitutes a course. Two and four courses of treatment with 5-fluorouracil 1% were completed in both cases in the absence of important side effects. After the first course, both patients showed complete remission of the lesions. No clinical signs of relapse were noted after 1 year of follow-up.

DISCUSSION

The treatment with 5-fluorouracil is a good option as the second line of treatment for conjunctival intraepithelial neoplasia who are low-responders to interferon alpha-2b, with fewer side effects than other currently available alternatives.

Topical pharmacotherapy for ocular surface squamous neoplasia: systematic review and meta-analysis

Ocular surface squamous neoplasia (OSSN) has different treatment modalities. Although surgical excision has been the gold standard therapeutic option, topical pharmacotherapy agents such as 5-fluorouracil (5-FU), interferon alfa-2b (IFN) and mitomycin-C (MMC) are also commonly used. The protocol was registered (CRD42021224961). Comprehensive literature research was carried out to compare topical pharmacotherapy (5-FU or IFN or MMC) to surgical excision regarding clinical success (tumor resolution), recurrence and complications in patients undergoing treatment for OSSN. From 7859 records, 7 articles were included in the qualitative and 4 in the quantitative synthesis. The outcomes of surgical excision and topical pharmacotherapy were comparable in the included articles. There were no significant differences between surgical excision and topical pharmacotherapy regarding the clinical success [odds ratio (OR): 0.785; confidence interval (CI): 0.130-4.736, P = 0.792)] and tumor recurrence (OR: 0.746; CI: 0.213-2.609; P = 0.646). The most common side effect of the different therapeutic options was dry eye. The highest rate of dry eye symptoms was reported after surgical excision (in 59%). Topical pharmacotherapy with all the 3 agents is as effective and well-tolerable as surgical excision in terms of tumor resolution, recurrence rate and side effects in all OSSN patients suggesting similar long-term clinical benefits.

Topical Chemotherapy for Treating Ocular Surface Squamous Neoplasia with a Combination of Interferon α-2b and 5-Fluorouracil

Introduction

This study evaluated the efficacy of combined interferon α-2b (IFNα2b) and 5-fluorouracil (5-FU) as primary treatment for ocular surface squamous neoplasia (OSSN).

Methods

In this retrospective study, 27 eyes with OSSN followed by topical application of combined IFNα2b and 5-FU were examined. Reported outcome measures were tumor response, visual acuity, time to complete resolution, recurrence and treatment complications.

Results

Twenty-six patients (17 male, 9 female) had a mean age of 63.9 (median, 67; range 22–83) years. Complete tumor response was observed in 24 eyes (88.9%). Three eyes (11.1%) showed partial response to the chemotherapy agents and later underwent surgical tumor removal. The median time to complete resolution was 6 (mean, 6.1; range, 3–11) weeks. Of these, the patients received between one to three cycles of 5-FU therapy (median, 2; mean, 1.8). Complications noted were transient irritation at 5-FU cycle (11 eyes, 40.7%). There was no tumor recurrence at mean follow-up of 16.1 (median, 12; range 6–38) months.

Conclusions

Combination therapy of IFNα2b and 5-FU was a safe and effective treatment, inducing a short duration of administration and low recurrence rate for OSSN.

Trial Registration

Retrospectively registered, UHCT22048.

Management of ocular surface squamous neoplasia: Bowman Club Lecture 2021

The gold-standard treatment for ocular surface squamous neoplasia (OSSN) has traditionally been surgical excision with wide margins and a no-touch technique. However, surgery may be associated with several unfavourable sequelae, as well as significant recurrence rates if margins are positive. In recent years, topical chemotherapy with 5-fluorouracil, interferon α-2b and mitomycin C have emerged as valuable agents capable of effectively treating OSSN with varying adverse effects. These medical treatment options usually present additional costs to the patient but can allow patients to avoid surgery with fewer long-term effects. Anterior segment high-resolution optical coherence tomography is an excellent tool for diagnosing and monitoring OSSN and can be a useful aid for both surgical and medical treatments of OSSN.

The Effect of a Novel Strategy in Treating Primary Pterygium: A Prospective Randomized Clinical Study

OBJECTIVE

We sought to compare the efficacy and safety of conjunctival autograft (CAG), amniotic membrane transplantation (AMT) with postoperative interferon alfa-2b (IFN alfa-2b), and modified conjunctival autograft plus amniotic membrane transplantation (mCAG plus AMT) with postoperative IFN alfa-2b for primary pterygium.

DESIGN

Randomized controlled clinical trial.

METHODS

Eyes with nasal and primary pterygia were randomized in a 1:1:1 ratio to receive CAG, AMT with IFN alfa-2b, or mCAG plus AMT with IFN alfa-2b. Subjects were followed up for 12 months. Primary outcomes included recurrence rate and complications. Secondary outcomes included corneal epithelium status, ocular surface symptom score, and visual acuity change.

RESULTS

Eighty-five subjects (30 in the CAG group, 25 in the AMT group, and 30 in the CAG+AMT group) completed the 12-month follow-up. No complication or grade 4 recurrence was found. There was no significant difference among the 3 groups in recurrence grade, corneal epithelium status, and visual acuity change. Compared with mCAG+AMT, CAG has a negative effect (β = -0.62, P = .001), and AMT has a negative effect (β = -2.02, P < .001) on postoperative symptom scores. Compared with AMT, CAG has a positive effect (β = 1.28, P < .001) on postoperative symptom scores.

CONCLUSIONS

All 3 strategies had good safety and clinical efficacy in the study. Compared with conjunctival autograft, the 2 surgeries using no autograft or limited autograft was less traumatic and gave more flexibility for future ocular surface condition changes.

Ocular surface complications of local anticancer drugs for treatment of ocular tumors

Local chemotherapy is increasingly used, either in combination with surgery or as monotherapy, for management of ocular tumors. Yet many of the local chemotherapeutic agents used for ocular tumors are cytotoxic drugs that are frequently associated with toxicities in normal ocular tissues. Understanding and managing these side effects are important because they affect treatment tolerability, outcome and quality of vision. Herein, we review local anticancer drugs administered for the treatment of ocular tumors, with an emphasis on their toxicities to the ocular surface, adnexa and lacrimal drainage system. We provide the underlying mechanisms and management strategies for the ocular side effects. Recent innovations in anticancer immunotherapy and ocular drug delivery systems also are discussed as new potential therapeutic modalities for alleviation of side effects.

Observational study of ocular surface squamous neoplasia: Risk factors, diagnosis, management and outcomes at a tertiary eye hospital in South Africa

BACKGROUND

Ocular surface squamous neoplasia (OSSN) is the most common ocular surface tumour. Diagnosis and management have traditionally been by excision biopsy. Recently there has been success with the use of topical chemo or immunotherapy, which has resulted in a move from invasive diagnosis by histology to an array of non-invasive diagnostic tests.

METHODS

This observational study aims to describe the characteristics of patients with OSSN at St John Eye Hospital in Johannesburg, South Africa. Non-invasive diagnostic tests (impression cytology, anterior segment-OCT, methylene blue staining) will be compared to the gold standard, histology. Treatment success, recurrence and adverse events will be documented between three treatment options that include: surgical excision, topical 5-Fluorouracil (5FU) chemotherapy, and topical 5FU with retinoic acid therapy.

DISCUSSION

There is a trend to the use of less invasive diagnosis and management for OSSN. Minimally invasive diagnostic tests include cytology, anterior-segment OCT and methylene blue staining. The study will compare these to the gold standard histology, thereby providing evidence for their use in clinical practice. Interferon alpha 2b is commonly used as immunotherapy for OSSN. The cost of this medication is prohibitive to its adoption in a developing country. We therefore decided to use 5FU as the chemotherapeutic agent of choice in this study. The success, adverse events and recurrence rates with this agent may provide additional evidence for its use in the management of OSSN. Overall, if diagnosis and management can be implemented with good success in the outpatient environment, care can be improved for this condition in a developing country.

Interferon Alpha-2b Eye Drops Prevent Recurrence of Pterygium After the Bare Sclera Technique: A Single-Center, Sequential, and Controlled Study

To investigate the efficacy and safety of interferon (IFN) alpha-2b eye drops in preventing pterygium recurrence after the bare sclera technique.

Update on pharmacotherapy for ocular surface squamous neoplasia

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

Comparison of Topical 5-Fluorouracil and Interferon Alfa-2b as Primary Treatment Modalities for Ocular Surface Squamous Neoplasia

PURPOSE

To compare the efficacy of topical 5-fluorouracil 1% (5FU) and interferon alfa-2b 1 MIU/mL (IFN) eye drops as primary treatment modalities for ocular surface squamous neoplasia (OSSN).

DESIGN

Retrospective, comparative, interventional case series.

METHODS

Fifty-four patients who received 5FU and 48 patients who received IFN as primary therapy for OSSN were included. Primary outcome measures were the frequency of clinical resolution and time to OSSN recurrence by treatment modality. Secondary outcome was the frequency of side effects with each therapy.

RESULTS

The mean age of patients was 68 years. More Hispanics were treated with 5FU. In a univariable analysis, frequency of OSSN resolution was higher with 5FU (96.3%, n = 52) than with IFN (81.3%, n = 39), P = .01. In a multivariable analysis, treatment modality did not remain a significant predictor of resolution. In patients whose OSSN resolved, time to resolution was similar with both agents, (5FU mean 6.6 months, standard deviation (SD) 4.5 vs IFN mean 5.5 months, SD 2.9, P = .17). Of the 52 eyes whose OSSN resolved with 5FU, 11.5% of lesions (n = 6) recurred, whereas of the 39 eyes whose OSSN resolved with IFN, 5.1% of lesions (n = 2) recurred, P = .46. Kaplan-Meier survival curves of OSSN recurrence were similar between groups (log-rank = 0.16). One-year recurrence rates were 11.4% with 5FU and 4.5% with IFN. Eyelid edema (P = .04) and tearing (P = .02) were more significant with 5FU.

CONCLUSIONS

This is the first direct comparison study between 5FU and IFN eye drops as primary treatment modalities for OSSN. Both modalities resulted in a high frequency of tumor resolution and low recurrence rates and are effective treatment options for OSSN.

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.