Impression cytology following mitomycin C therapy for ocular surface squamous neoplasia

Ocular surface squamous neoplasia: management and outcomes

Ocular surface squamous neoplasia (OSSN) is the most common ocular tumour with an incidence ranging from 0.03 to 1.9 per 100,000 persons/year. The diagnosis is made on clinical suspicion and confirmed with anterior-segment optical coherence tomography (AS-OCT), cytology, or histology. The purpose of this review is to provide an overview of the management options available for OSSN and review their success and recurrence rates. Surgery is the gold standard for the management of small OSSN lesions. With the increased use of less invasive diagnostic modalities such as AS-OCT and cytology, there has been a move to use topical therapies for the management of OSSN. The most commonly used agents are interferon-α2b (IFN), mitomycin-C (MMC) and 5-fluorouracil (5FU). They have been shown to have similar resolution and recurrence rates but differ in cost and side effect profile. IFN has the lowest side effect profile, but is also the most expensive, whereas MMC has the greatest surface toxicity and is priced midway between the three. 5FU is the cheapest of the three topical agents with less surface toxicity than MMC. Radiotherapy is mostly employed as adjuvant therapy. Newer novel therapies are available but have not been widely adopted as mainstream therapy due to cost and lack of clinical evidence. OSSN has the benefit of many management options. No single modality has been shown to superior and some patients will need the use of combination therapy to achieve an optimal clinical outcome.

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.

Impression Cytology of Melanocytic Conjunctival Tumors Using the Biopore Membrane

Purpose

To compare a new Biopore membrane impression cytology method with the routinely used exfoliative cytology in patients with a melanocytic lesion of the conjunctiva.

Methods

Sixty-eight consecutive patients with a conjunctival melanocytic lesion underwent Biopore membrane impression cytology as well as exfoliative cytology. A histologic sample was also available in 26 cases. All Biopore samples were stained immediately with RAL 555. Both Biopore and exfoliative cytology samples were assessed by two cytopathologists and graded into four different categories of atypia.

Results

Twenty-three out of 26 Biopores and 20 out of 24 for the exfoliative smears correlated with the corresponding histologic sample. Biopore cytology resulted in higher numbers of cells with a greater density compared to exfoliative cytology.

Conclusions

Biopore cytology can be used for cytologic sampling of conjunctival melanocytic lesions. Because of the larger amount and higher density of cells obtained with the Biopore membrane, interpretation by a pathologist is easier and faster. Sampling of the fornix, caruncula, and ocular material in children is difficult with the Biopore method, and exfoliative cytology seems to be the favorable test in those situations.

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

PURPOSE

To compare the efficacy and safety of topical interferon alpha 2b (IFNα2b) and mitomycin C (MMC) for ocular surface squamous neoplasia.

METHODS

In this retrospective study, medical records of 51 eyes of 50 patients with a diagnosis of primary ocular surface squamous neoplasia were included. All cases were treated with either topical IFNα2b (1 million IU/mL) or MMC (0.4 mg/mL) 4 times a day. The primary outcome measure was frequency of clinical resolution of tumors along with failure and recurrence rates after treatment. Other outcome measures included the duration of treatment and adverse effects associated with both topical therapies.

RESULTS

Twenty-six eyes were treated with topical IFNα2b and 25 eyes were treated with topical MMC. A complete response was achieved in 23 (89%) and 23 (92%) eyes with topical IFNα2b and MMC, respectively (P = 0.67). The median time to lesion resolution was significantly different between the groups (median 3.5 months in the IFNα2b group and 1.5 months in the MMC group) with an average difference of 1.7 months (P < 0.005). Five (10%) of 51 patients showed no or partial response to topical therapy. Subsequently, they underwent surgical excision. Adverse effects occurred in 3 (12%) patients using IFNα2b and 22 (88%) patients using MMC (P < 0.005).

CONCLUSIONS

Both IFNα2b and MMC seemed to be equally effective topical monotherapies. Despite a prolonged time to lesion resolution, IFNα2b-treated eyes had better safety and tolerance in comparison with MMC-treated eyes.

Pharmacotherapy and Immunotherapy of Conjunctival Tumors

Conjunctiva and cornea tumors represent a large spectrum of conditions ranging from benign lesions to aggressive and life-threatening malignancies. Topical pharmacotherapies and immunotherapies have recently acquired a relevant role in the management of conjunctival tumors and, in the past 2 decades, there has been a shift from surgery alone toward the use of these agents, both as a sole therapy or as adjunct to surgery (before or after surgery). The 3 main agents that have been used for topical medical treatment of conjunctival tumors are mitomycin-C, 5-fluorouracil, and interferon-α2b. Advantages of topical pharmacotherapies and immunotherapies include the ability to treat the entire ocular surface and prevention of surgical side effects and complications. The aim of this review is to summarize the current use of topical pharmacotherapy and immunotherapy in the management of conjunctival tumors.

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.

Topical chemotherapy for ocular surface squamous neoplasia

PURPOSE OF REVIEW

Ocular surface squamous neoplasia (OSSN) is an umbrella term for a spectrum of epithelial dysplasias of the cornea, conjunctiva, and limbus. Treatment for OSSN has historically been surgery, but nonsurgical interventions have been increasingly adopted. Advantages of medical treatments include the ability to treat the entire ocular surface and prevention of surgical complications.

RECENT FINDINGS

The primary medical treatments for OSSN include mitomycin C, 5-fluorouracil, and interferon α2b. Mitomycin C has been shown in studies to be highly effective but has short-term and long-term side-effects that may be intolerable. 5-Fluorouracil and interferon α2b have been found to be similar in efficacy to mitomycin, with interferon being extremely well tolerated in the majority of patients. Most recently, other chemotherapeutic agents have been tried for OSSN including antivascular endothelial growth factor agents and vitamin A. The data regarding these latter treatment strategies are still limited.

SUMMARY

An understanding of the recent literature, with respect to the efficacy, advantages, and disadvantages of the various therapies for OSSN will allow us to tailor treatment to each patient.

Ocular surface neoplasias and human immunodeficiency virus infection

PURPOSE OF REVIEW

Ocular surface malignancy is a serious complication in HIV infection, but can often result in successful treatment if diagnosed appropriately. In the literature, most reviews focus on information for the ophthalmic community. Here, we provide a review of the literature with the pertinent information for the nonophthalmologist, as they are the first point of contact for most HIV patients.

RECENT FINDINGS

Ocular surface squamous neoplasia (OSSN) is the most common nonpigmented ocular surface malignancy. It can be treated well with surgery or topical chemotherapy, the newest method of treatment. When presenting in young patients, a high percentage have been found to be HIV positive. Kaposi's sarcoma is an AIDS-defining malignancy and critical to diagnose. It cannot be cured, but treatment is effective for keeping it controlled. Conjunctival lymphoma can be recognized with the salmon patch appearance. External beam radiation, systemic chemotherapy, and intralesional injections are the mainstays of treatment.

SUMMARY

Ocular surface malignancy manifests significantly in the HIV population. OSSN, Kaposi's sarcoma and conjuctival lymphoma all have different clinical presentations. The capacity of the managing physician to recognize these tumours and refer to an ophthalmologist is essential for appropriate treatment.

Interventions for squamous cell carcinoma of the conjunctiva in HIV-infected individuals

BACKGROUND

Squamous cell carcinoma of the conjunctiva is described in the ophthalmic literature as a rare, slow-growing tumour of the eye, normally affecting elderly men around 70 years of age. In Africa, however, the disease is different. The incidence is rising rapidly, affecting young persons (around 35 years of age), and usually affecting women. It is more aggressive, with a mean history of three months at presentation. This pattern is related to the co-existence of the HIV/AIDS pandemic, high HPV exposure, and solar radiation in the region. Various interventions exist, but despite therapy, there is a high recurrence rate (up to 43%) and poor cosmetic results in late disease. This review was conducted to evaluate the interventions for treatment of conjunctival squamous cell carcinoma in HIV-infected individuals.

OBJECTIVES

To evaluate the effect of interventions for treating squamous cell carcinoma of the conjunctiva in HIV-infected individuals on local control, recurrence, death, time to recurrence, and adverse events.

SEARCH METHODS

Using a sensitive search strategy, we attempted to identify all relevant trials, regardless of language or publication status, from the following electronic databases; PubMedPubMed, EMBASE and The Cochrane Library. We also searched clinical trial registries; WHO International Clinical Trials Registry Platform (ICTRP) and the US National Institutes of Health Clinicaltrials.gov. We searched the international conference proceedings of HIV/AIDS and AIDS-related cancers from the AIDS Education Global Education System (AEGIS). Searches were conducted between January and February 2012.

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving HIV-infected individuals with ocular surface squamous neoplasia.

DATA COLLECTION AND ANALYSIS

We independently screened the results of the search to select potentially relevant studies and to retrieve the full articles. We independently applied the inclusion criteria to the potentially relevant studies. No studies were identified that fulfilled the selection criteria.

MAIN RESULTS

No RCTs of interventions currently used against conjunctival squamous cell carcinoma in HIV-infected individuals were identified.There is one ongoing RCT in Kenya that was registered in July 2012.

IMPLICATIONS FOR PRACTICE

Current clinical practice in treatment of squamous cell carcinoma of the conjunctiva rests on a weak evidence base of case series and case reports.

IMPLICATIONS FOR RESEARCH

Randomised controlled trials for treatment of this disease are needed in settings where it occurs most frequently. Preventive interventions also need to be identified. HIV/AIDS research has not focused on treatment of this tumour.

Comparison of standard and low dose intraoperative mitomycin C in prevention of corneal hazeafter photorefractive keratectomy

BACKGROUND

This study aimed to compare two doses of Mitomycin C in reducing haze formation after photorefractive keratectomy.

METHODS

170 eyes of 85 patients enrolled; in each patient one eye randomly assigned to be treated by low dose intraoperative MMC (LDMMC) and other eye by standard dose MMC (SDMMC). Then the patients were followed up to 6 months and refraction, Uncorrected Distant Visual Acuity (UCDVA), Best Corrected Distant Visual Acuity (BCDVA) and haze formation submitted in each postoperative exam.

RESULTS

The mean preoperative refraction in LDMMC eyes was -3.08 (SD 1.65) sphere and 0.92 (SD 0.88) cylinder. These values for SDMMC eyes were -3.25 (SD 1.80) sphere and 0.81 (SD 0.84) cylinder. Mean postoperative sphere in LDMMC group was -0.132 (SD 0.503) and -0.138 (SD 0.484) in 3 and 6 months after PRK. These results was -0.041 (SD 0.501) and -0.076 (SD 0.489) for SDMMC group. Mean postoperative cylinder 3 and 6 month after PRK was 0.435 (SD 0.218) and 0.423 (SD 0.255). In LDMMC group and 0.435 (SD 0.247) and 0.426 (SD 0.261) in SDMMC group. In third month 14 eyes in LDMMC group presented with grade 1 score of clinical haze. From these eyes only 2 still had this haze after 6 month. 7 eyes in SDMMC group had grade 1 clinical haze at third month- but no clinical haze was seen at the end of 6(th) month.

CONCLUSION

The results of the two doses of Mitomycin C were not significant. We suggest to use the lower dose to reduce its side effects.

The clinical value of in vivo confocal microscopy for diagnosis of ocular surface squamous neoplasia

PURPOSE

To determine the reliability and efficiency of in vivo confocal microscopy for the diagnosis of ocular surface squamous neoplasia (OSSN).

METHODS

A case series with five consecutive cases of OSSN were investigated retrospectively, of which the characteristics and subspecial types had been estimated by in vivo confocal microscopy before surgery. The structure and cellular features of OSSN were analyzed with other examinations, such as anterior-segment optical coherence tomography (AS-OCT), and confirmed by histopathological biopsy.

RESULTS

The tumors revealed red gelatinous surfaces with vascular dilatation on the ocular surface of the conjunctival and corneal epithelium in anterior segment photography. Involvement of only corneal epithelium was observed by AS-OCT in three cases, whereas the Bowman's layer and anterior stroma were also invaded in the other two cases. In vivo confocal microscopy showed cellular anisocytosis and enlarged nuclei with high nuclear to cytoplasmic ratio in three cases diagnosed as conjunctival intraepithelial neoplasia; moreover, nests were partially formed by isolated keratinized, binucleated, and actively mitotic dysmorphic epithelial cells in the other two cases diagnosed as carcinoma in situ and ocular surface squamous carcinoma (OSSC). The characteristics assessed from histopathological biopsy were similar to that revealed by in vivo confocal microscopy in all five cases.

CONCLUSION

In vivo confocal microscopy analysis of cytological characteristics of OSSN is a safe, relatively noninvasive, and effective diagnostic tool in detecting characteristics of OSSN before surgical resection. Although in vivo confocal microscopy cannot replace excisional biopsy for definitive diagnosis, it can be valuable for initial diagnosis and management of patients with OSSN.

Topical treatment options for conjunctival neoplasms

Topical therapies offer a nonsurgical method for treating conjunctival tumors by delivering high drug concentrations to the ocular surface. Over the past ten years, topical agents have been used by investigators to treat various premalignant and malignant lesions of the conjunctiva, such as primary acquired melanosis with atypia, conjunctival melanoma, squamous intraepithelial neoplasia and squamous cell carcinoma of the conjunctiva, and pagetoid spread of the conjunctiva arising from sebaceous cell carcinoma. Despite the enthusiasm generated by the success of these agents, there are unanswered questions regarding the clinical efficacy of this new nonsurgical approach, and whether a single topical agent can achieve cure rates comparable with traditional therapies. Furthermore, the long-term consequences of prolonged courses of topical chemotherapeutic drugs on the ocular surface are unknown, and the ideal regimen for each of these agents is still being refined. In this review, we present specific guidelines for treating both melanocytic and squamous neoplasms of the conjunctiva, utilizing the available data in the literature as well as our own clinical experience at the Memorial Sloan-Kettering Cancer Center.

Histopathological change of oral malignant tumour and epithelial dysplasia subjected to photodynamic therapy

Objectives

The purpose of this study is to analyze the morphological change of cell nuclei and the change of proliferating activity of oral malignancy and epithelial dysplasia between before and after photodynamic therapy in order to predict recurrence.

Material and methods

We experienced 14 cases of oral squamous cell carcinoma, one case of verrucous carcinoma and seven cases of epithelial dysplasia treated by photodynamic therapy (PDT). The mean nuclear area (NA) and coefficient of variation of the nuclear area (NACV) of 100 nuclei per slide were calculated using computer-assisted image analysis in hematoxylin and eosin stained biopsy specimens before and after PDT. Additionally, proliferating cell nuclear antigen (PCNA) immunohistochemistry was carried out in each specimen.

Results

The mean NA after PDT was significantly lower than that before PDT in the nonrecurrent group. However, there was no significant difference in mean NA before and after PDT in the recurrent group. There were no significance differences in NACV before and after PDT in either the nonrecurrent or recurrent group. Furthermore, the PCNA labelling indices of the specimens after PDT was significantly lower than that before PDT in both the nonrecurrent and the recurrent group.

Conclusions

Mean nuclear area in the biopsy specimen after photodynamic therapy is likely to be a predictive marker for the recurrence of oral squamous cell carcinoma or epithelial dysplasia subjected to photodynamic therapy, while coefficient of variation of the nuclear area and proliferating cell nuclear antigen labelling indices are less helpful in predicting the recurrence of such lesions.

Role of impression cytology in diagnosis of ocular surface neoplasia

PURPOSE

To compare the accuracy of impression cytology in the diagnosis of ocular surface neoplasia with tissue histology.

METHODS

We reviewed the histories of patients diagnosed with ocular surface neoplasia at the Chiang Mai University Hospital. All patients underwent both impression cytology and tissue biopsy. We compared the results of both methods.

RESULTS

There were 55 patients (33 men and 22 women), with an age range of 12-99 years (mean, 51 years). Twenty patients had lesions in the right eye and 35 had them in the left eye. The most common histologic report was conjunctival-corneal intraepithelial neoplasia (38.2%), followed by squamous cell carcinoma (34.5%), nonneoplastic changes of squamous epithelia (10.9%), squamous papilloma (7.3%), conjunctival nevi (7.3%), and malignant melanoma (1.8%). Compared with histologic findings, the positive and negative predictive accuracy of impression cytology was 97.4% and 52.9%, respectively. For squamous neoplasms, squamous cell carcinoma had the highest correlation with histology. The presence of dysplastic cells suggested malignancy.

CONCLUSIONS

This study shows that impression cytology might have a promising role in diagnosing ocular surface neoplasia for its high positive predictive accuracy compared with tissue histology. However, a fair negative predictive accuracy indicates that impression cytology is a valuable screening technique, but it is not a "gold standard."

Effect of topical mitomycin C on corneal endothelium

PURPOSE

To evaluate patients with ocular surface squamous neoplasia (OSSN) on treatment with topical mitomycin C (MMC) with regard to changes in corneal thickness and endothelial count.

DESIGN

Prospective, nonrandomized, interventional series.

METHODS

In this prospective evaluation, 25 patients with OSSN with different clock hours of involvement (range, one to eight), age varying from 19 to 76 years, were treated with topical MMC 0.04% in a cyclic manner. Preoperative corneal thickness measurement and endothelial cell density were obtained, and the tests were repeated after one, three, and six months of complete resolution. The fellow eyes of the same patients served as controls.

RESULTS

Mean +/- standard deviation (SD) pachymetry and endothelial cell counts before and after instillation were 504.48 +/- 5.45 microm and 2325.76 +/- 192.52 cells/mm2 and 503.52 +/- 5.75 microm and 2297.60 +/- 192.08 cells/mm2, respectively, suggesting no significant difference in the above two parameters. Similarly, in the fellow control eyes, mean +/- SD pachymetry and endothelial cell counts before and after instillation were 502.80 +/- 4.34 microm and 2326.72 +/- 191.93 cells/mm2 and 504.64 +/- 5.19 microm and 2313.60 +/- 192.03 cells/mm2, respectively.

CONCLUSIONS

Topical 0.04% MMC drops do not significantly affect the corneal endothelium. However, its judicious use and long-term follow-up are mandatory.

Interventions for squamous cell carcinoma of the conjunctiva in HIV-infected individuals

BACKGROUND

Squamous cell carcinoma of the conjunctiva is a rare, slow-growing tumour of the eye, normally affecting elderly men around 70 years of age. In Africa, however, the disease is different. The incidence is rising rapidly, affecting young persons (around 35 years off age), and usually affecting women. It is more aggressive, with a mean history of three months at presentation. This pattern is related to the co-existence of the HIV/AIDS pandemic, high HPV exposure, and solar radiation in the region. Various interventions exist, but despite therapy, there is a high recurrence rate (up to 43%) and poor cosmetic results in late disease. This review was conducted to evaluate the interventions for treatment of conjunctival squamous cell carcinoma in HIV-infected individuals.

OBJECTIVES

To evaluate the effect of interventions for treating squamous cell carcinoma of the conjunctiva in HIV-infected individuals on local control, recurrence, death, time to recurrence, and adverse events.

SEARCH STRATEGY

Using a sensitive search strategy, we attempted to identify all relevant trials, regardless of language or publication status, from the following electronic databases; Medline/PubMed, CENTRAL, AIDSearch, EMBASE, LILACS, African Healthline, Cochrane HIV/AIDS Specialised Register, and the Cochrane Cancer Network Specialised Register. We searched the clinical trial register of the US National Institutes of Health, searched the international conference proceedings of AIDS and AIDS-related cancers, and contacted individual researchers, research organisations, and pharmaceutical companies that manufacture the drugs used as interventions. Searches were done between September 2005 and June 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving HIV-infected individuals with ocular surface squamous neoplasia.

DATA COLLECTION AND ANALYSIS

We independently screened the results of the search to select potentially relevant studies and to retrieve the full articles. We independently applied the inclusion criteria to the potentially relevant studies. No studies were identified that fulfilled the selection criteria.

MAIN RESULTS

No RCTs of interventions currently used against conjunctival squamous cell carcinoma in HIV-infected individuals were identified.

IMPLICATIONS FOR PRACTICE

Current clinical practice in treatment of squamous cell carcinoma of the conjunctiva rests on a weak evidence base of case series and case reports.

IMPLICATIONS FOR RESEARCH

Randomised controlled trials for treatment of this disease are needed in settings where it occurs most frequently. Preventive interventions also need to be identified. HIV/AIDS research has not focused on treatment of this tumour.

Short-Term Mitomycin C Followed By Long-Term Interferon α2β for Conjunctiva-Cornea Intraepithelial Neoplasia

PURPOSE

To report a case of extensive conjunctiva-cornea intraepithelial neoplasia (CIN) treated topically with mitomycin C (MMC) and interferon (INF)-alpha2beta without surgical resection.

METHODS

Case report.

RESULTS

: An 82-year-old woman showed an extensive gelatinous red mass in the bulbar conjunctiva with invasion into the caruncle, inferior fornix, and tarsal conjunctiva and extending for 270 degrees of the corneal surface. A diagnosis of CIN was made by surgical biopsy. Surgical excision with safety margins carried the risk of limbal stem cell depletion. A conservative treatment strategy was used with 2 cycles of topical MMC (0.02%), followed by INF-alpha2beta eye drops at a dose of 1 million IU/mL, 4 times a day until tumor disappearance. Total resolution was noted after 75 days of treatment with INF, with no clinical evidence of limbal stem cell deficiency. After 1 year of monitoring, no signs of CIN recurrences were observed.

CONCLUSION

MMC (0.02%), followed by INF-alpha2beta (1 million IU/mL) 4 times a day, is an effective treatment against highly extensive CIN, in cases where surgical resection with safety margins is unfeasible.

The use of mitomycin C as an adjunctive treatment for equine ocular squamous cell carcinoma

OBJECTIVE

To assess the effectiveness of topical mitomycin C application as an alternative adjunctive therapy to CO2 laser ablation in the treatment of equine ocular squamous cell carcinoma.

DESIGN

A retrospective clinical study of eight client owned horses in which 10 affected eyes were treated for ocular squamous cell carcinoma over a 17 month period. (March 2003 to August 2004).

PROCEDURE

Each horse was given a general anaesthetic to allow CO2 laser ablation of the lesion(s). Mitomycin C at a concentration of 0.4 mg/mL was then applied intraoperatively to the affected areas for 1 or 5 minutes. Postoperatively a triple antibiotic eye ointment was applied to the eye twice daily and each horse was treated with systemic non-steroidal anti-inflammatory drugs for 7 days.

RESULTS

Recurrence following treatment was noted in three eyes. Two of these were retreated and no further signs developed. The remaining eye was enucleated at the request of the owner. Overall 90% of treated eyes appeared free of tumour a minimum of 11 months post treatment.

CONCLUSION

In this case series mitomycin C appeared to offer a valid alternative to other adjunctive therapies currently employed in the treatment of equine ocular squamous cell carcinoma.

Presence of mitomycin-C in the anterior chamber after photorefractive keratectomy

PURPOSE

To assess the presence of mitomycin-C (MMC) in hen aqueous humor after photorefractive keratectomy (PRK).

SETTING

Instituto Universitario de Oftalmobiología Aplicada, Faculty of Medicine, University of Valladolid, and Department of Analytical Chemistry, Faculty of Sciences, University of Valladolid, Valladolid, Spain.

METHODS

Mitomycin-C 0.02% was applied topically for 2 minutes to a right hen's eye after PRK (Group A) and to the left eye with intact epithelium (Group B). At different time points (10, 30, 60, 360, and 720 minutes), aqueous humor was extracted and high-performance liquid chromatography was performed to detect and quantify MMC levels.

RESULTS

The mean maximum drug concentration of MMC measured in the aqueous humor was 187.250 microg/L +/- 4.349 (SD) in Group A and 93.000 +/- 4.899 microg/L in Group B, both detected 10 minutes after topical application. Statistically significant differences were found between Groups A and B at 10, 30, and 60 minutes, with decreasing MMC levels in both groups but a higher concentration in Group A. After 360 minutes, MMC levels were undetectable in Group B and after 720 minutes in Group A.

CONCLUSIONS

Mitomycin-C was detectable in the aqueous humor of the hen eye after topical application in PRK-treated eyes and in eyes with intact epithelium. The presence of MMC is of concern as it may lead to ocular toxicity in the long term.

Conjunctival impression cytology in dogs

OBJECTIVE

Ocular conjunctivas of healthy dogs were studied by conjunctival impression cytology for evaluation of feasibility, protocol standardization, and normal cytologic pattern recognition of this technique.

ANIMALS STUDIED

Twenty healthy, adult, cross-breed dogs.

PROCEDURES

Samples of the bulbar conjunctiva were collected after instillation of topical anesthetic drops at the ocular surface. Impression cytology was performed by applying asymmetric strips of Millipore filter on the superior temporal bulbar conjunctiva near the limbus. The filter strip was gently pressed against the conjunctiva for 5 s and removed with a peeling motion. Samples were immediately fixed in 95% ethyl alcohol, stained with periodic acid-Schiff and hematoxylin, and mounted on slides cover-slipped using synthetic resin. The slides were examined by light microscopy.

RESULTS

Microscopic examination of the impressions revealed superficial, intermediate and basal epithelial cells arranged in sheets. Keratinized epithelial cells, goblet cells and leukocytes, as well as cellular debris and mucus were observed.

CONCLUSIONS

Feasibility of impression cytology for sampling the bulbar conjunctiva of the dog and the standardization the the proposed protocol was shown. The results allowed the recognition the the normal cytologic pattern of healthy conjunctivas in dogs.

Impression cytology of the ocular surface

Impression cytology refers to the application of a cellulose acetate filter to the ocular surface to remove the superficial layers of the ocular surface epithelium. These cells can then be subjected to histological, immunohistological, or molecular analysis. Proper technique is essential as the number of cells sampled can vary considerably. Generally two to three layers of cells are removed in one application but deeper cells can be accessed by repeat application over the same site. Applications for impression cytology include diagnosing a wide range of ocular surface disorders, documenting sequential changes in the conjunctival and corneal surface over time, staging conjunctival squamous metaplasia, and monitoring effects of treatment. It is also a useful investigational tool for analysing ocular surface disease with immunostaining and DNA analysis. It is non-invasive, relatively easy to perform, and yields reliable information about the area sampled with minimal discomfort to the patient. Major ophthalmic centres should develop and introduce this technique into routine clinical practice. This is best achieved with a team approach including the ophthalmologist, pathologist, microbiologist, and the immunologist.

Subconjunctival cyst-like formations following impression cytology

PURPOSE

To report a case of an unusual adverse event subsequent to undertaking Conjunctival Impression Cytology (CIC).

METHODS

CIC was undertaken on a 54-year-old healthy Caucasian female, using a 10 mm Millipore membrane on the bulbar conjunctiva. Prior to the CIC procedure, two drops of topical proparacaine (Alcaine were instilled and following the procedure two drops of artificial tears (GenTeal were administered.

RESULTS

The subject reported excessive bulbar conjunctival hyperaemia in the left eye 5 min postprocedure, with no marked pain or discomfort. Slitlamp biomicroscopic evaluation revealed several "bubbles" or cystic formations trapped underneath the conjunctival tissue, in association with moderate to severe bulbar conjunctival redness. These cysts began to regress fairly rapidly and completely disappeared within 1h.

CONCLUSION

CIC is a useful tool for studying the ocular surface; however, care should be taken while performing this mildly invasive procedure. This is the first report of bubble formation in the conjunctiva following CIC. Subjects should be advised about the short term redness and discomfort that could occur following CIC.

Topical 0.002% Mitomycin C for the Treatment of Conjunctival-Corneal Intraepithelial Neoplasia and Squamous Cell Carcinoma

PURPOSE

To demonstrate the efficacy of topical 0.002% mitomycin C (MMC) as an adjunctive and alternative treatment in primary and recurrent conjunctival-corneal intraepithelial neoplasia (CCIN) and squamous cell carcinoma (SCC).

METHODS

The medical records of 7 patients with histopathologically confirmed CCIN and conjunctival SCC were retrospectively reviewed. All cases were treated with topical 0.002% MMC 4 times daily. The tumor size pre- and post-treatment, clinical response, and ocular complications were evaluated.

RESULTS

The mean age of the patients was 56 +/- 13.4 years. The most common presenting symptom was foreign body sensation (57.1%) with a mean duration of 2.3 +/- 3.8 months. Six patients had pathologically proven CCIN (85.7%) and 1 had SCC (14.3%). Before MMC treatment, 6 eyes (85.7%) had recurrences after surgical excision. The tumor-free period ranged from 2 to 19 months. Two patients had multiple recurrences. MMC 0.002% 4 times daily was applied for a period of 5.4 +/- 4.4 weeks (range, 2-14). All had complete tumor regression as observed clinically and confirmed by impression cytology. Side effects of MMC therapy included ocular irritation, mild conjunctival hyperemia, and punctate keratopathy. There were no serious complications detected. The mean follow-up time was 30.7 +/- 15 months (range, 2-52) with no evidence of clinical recurrence in any case.

CONCLUSIONS

Topical 0.002% MMC showed a favorable outcome as an adjunctive and alternative treatment of CCIN and SCC with regression of primary and recurrent tumors.

Morphometric analysis of mouse tumor nuclei subjected to photodynamic therapy

PURPOSE

The diachronic changes in nuclei in tumor cells subjected to photodynamic therapy (PDT) were investigated using computer assisted analysis to elucidate the degeneration process of tumor cell nuclei.

MATERIALS AND METHODS

A photosensitizer was injected intraperitoneally to mice bearing NR-S1 mouse squamous cell carcinoma in the dorsum 48 hours before laser irradiation. Mice were sacrificed at intervals of 0, 0.5, 1.5, 2.5, 6, 24, 48, and 72 hours after PDT, and tumors were excised. Neither photosensitizer nor laser irradiation was administered to control mice. A 4-mum section was prepared from each specimen, followed by hematoxylin and eosin staining. The nuclei of the tumor cells were examined under a light microscope. The mean nuclear area and coefficient of variation of the nuclear area of 100 nuclei per slide were calculated.

RESULTS

Both nuclear area and coefficient of variation of the nuclear area were significantly lower in the experimental groups nuclei than in control mouse nuclei at 24 and 48 hours after PDT.

CONCLUSION

These results suggest that maximum damage to tumor nuclei occurs between 24 to 48 hours after PDT.

The treatment of primary acquired melanosis (PAM) with atypia by topical Mitomycin C

PURPOSE

To report our results of 12 consecutive patients with conjunctival primary acquired melanosis (PAM) with atypia who were treated by topical Mitomycin C (MMC).

DESIGN

Retrospective interventional consecutive case series.

METHODS

Twelve patients with PAM with atypia in one of their eyes who were treated by topical chemotherapy with MMC were included in this case study. Eyes with histologically proven PAM with atypia were treated by two to five courses of 0.04% (0.4 mg/ml) MMC four times a day. Each course lasted 2 continuous weeks. Follow-up was conducted on patients for control of local disease, side effects, and visual acuity in the treated eye.

RESULTS

In all patients, there was complete or partial response to treatment. In four patients, the pigmentation disappeared, whereas in eight patients, some remnants of the pigmentation remained. In seven of these eight patients, the remnants of the pigmentation were stable during the follow-up period of 4 months to 9 years, whereas one in whom re-growth of the PAM was noticed was successfully treated again by topical MMC. No patients lost visual acuity at the end of the follow-up. All side effects of the local chemotherapy were resolved after cessation of the treatment.

CONCLUSIONS

Topical MMC chemotherapy is a good alternative to surgical excision and cryotherapy in treating conjunctival PAM with atypia.

Early corneal edema following topical application of mitomycin-C

PURPOSE

To determine the effect of mitomycin-C (MMC) on the cornea after a single intraoperative application.

SETTING

Department of Ophthalmology, Far Eastern Memorial Hospital, Ban-Chiao, Taipei, Taiwan.

METHODS

Mechanical epithelium debridement of the central 10.0 mm of the cornea was performed in 63 pigmented rabbits. One group of corneas (MMC1, n = 42) was soaked with MMC 0.01% solution for 2 minutes; the second group (MMC2, n = 42) was soaked with MMC 0.02% solution for 2 minutes. Control corneas (n = 42) were soaked with balanced salt solution for 2 minutes. Changes in the central corneal thickness, clarity, epithelial defect size, endothelial cell density, and endothelial apoptosis in the 3 groups were examined on days 0, 1, 2, 3, 5, 7, and 14.

RESULTS

There was a dose-dependent increase in corneal thickness, decrease in corneal clarity, and increase in endothelial apoptosis after a single intraoperative application of MMC. The endothelium was significantly swollen and became pleomorphic and polymegethic with a concomitant decrease in endothelial cell density, also in a dose-dependent manner.

CONCLUSIONS

A single application of MMC on the corneal surface caused dose-dependent corneal edema and endothelial apoptosis in the rabbit model. Further clinical study of human eyes is warranted.

Impression cytology of the ocular surface: a review

PURPOSE

To historically review the technique of impression cytology as a minimally invasive diagnostic tool for ocular surface pathology.

METHODS

A comprehensive review of published literature cited in PubMed since the first description of impression cytology in 1977 up to date has been undertaken.

RESULTS

A wide range of processing methods have been adapted to the technique of impression cytology (from conjunctiva, cornea or limbus): regular light microscopy with different stainings, transmission and scanning electron microscopy, immunofluorescence, immunocytochemistry, polymerase chain reaction analysis, immunoblotting analyses, or flow cytometry. At present, it is widely used as a non-invasive alternative to the full-thickness biopsy for the obtention of epithelial cells from the ocular surface.

CONCLUSIONS

Impression cytology represents a non- or minimally invasive biopsy of the ocular surface epithelium with no side effects or contraindications. It has demonstrated to be a useful diagnostic aid for a wide variety of processes involving the ocular surface. In addition, and mainly during the last decade, its use as a research tool has experienced an enormous growth and has greatly contributed to the understanding of ocular surface pathology.

Mitomycin C as an adjunct in the treatment of localised ocular surface squamous neoplasia

AIM

To report the outcome of topical mitomycin C (MMC) used as adjunctive treatment following primary excision of ocular surface squamous neoplasia (OSSN).

METHOD

Prospective, non-comparative interventional case series of 27 primary OSSN lesions from 26 patients treated in a single ocular oncology centre over a 4 year period.

RESULT

27 cases of OSSN received a treatment regimen of surgical excision, followed by topical MMC. Mean follow up of 27 (SD 12) months (range 12-50, median 25 months) revealed zero recurrences.

CONCLUSION

MMC treatment following surgical excision decreases the recurrence rate of primary ocular surface neoplasia and should be considered as adjunctive therapy in primary treatment.

Ocular surface impression cytology

Impression cytology, either using cellulose acetate strips or the Biopore membrane device, is a simple, noninvasive technique that aids in the diagnosis of several disorders of the ocular surface. These disorders include ocular surface squamous neoplasia, dry eye syndrome, limbal stem-cell deficiency, specific viral infections, vitamin A deficiency, allergic disorders, conjunctival melanosis, and malignant melanoma. Another advantage is the preservation of limbal stem cells, which occur in the basal layer of the limbal epithelium and are responsible for renewal of the corneal epithelium. The Biopore membrane device is particularly user friendly, with little expertise required and adequate specimens obtained in a very high percentage of cases. The most common applications in diagnostic ocular pathology are:(i) primary diagnosis and follow-up of ocular surface squamous neoplasia, including after therapy with topical mitomycin C. The sensitivity is high (78-87%); and (ii) dry eye syndrome where squamous metaplasia and/ or hyperkeratosis are noted. Certain limitations of the technique for diagnosis of squamous neoplasia include the fact that dysplasias are often keratinizing and may yield very few or even no dysplastic cells with impression cytology. Secondly, no definite cytologic criteria reliably distinguish invasive SCC of ocular surface from in situ disease. Other applications include the rapid specific diagnosis of ocular surface infections with herpes simplex, adeno-, and varicella zoster viruses. Impression cytology samples may also be used to obtain mRNA, cells for phenotyping by flow cytometry, and proteins for Western blotting for research studies.

Ocular Surface Squamous Neoplasia

Even though ocular surface squamous neoplasia (OSSN) has been recognized for well over a century, the past decade has witnessed advances that have helped rewrite many of the paradigms for the diagnosis and management of these lesions. OSSN occurs predominantly in the elderly for whom they are the third most common oculoorbital tumors after melanoma and lymphoma. In addition to advanced age and male sex, other major risk factors linked to its pathogenesis are ultraviolet light, cigarette smoking, and the human papilloma virus. Although the latter has been linked to OSSN for nearly 4 decades, its identification and role in the pathogenesis of these tumors has been elucidated recently and is addressed in detail in this review. Newer techniques of impression cytology represent a noninvasive and reliable method of diagnosing OSSN and monitoring treated cases. The efficacy of chemotherapeutic agents such as mitomycin C and 5-fluorouracil have been proven in the recent past, making them a clear alternative to the time-tested treatment of surgical excision and cryotherapy. Early reports on the efficacy of topical Iterferon alpha 2b indicate significant promise in providing another alternative for the treatment of some of these neoplasms. These advances thus represent a minimally invasive and highly successful approach to the diagnosis and treatment of OSSN.

Tear Function and Ocular Surface Changes with Topical Mitomycin (MMC) Treatment for Primary Corneal Intraepithelial Neoplasia

PURPOSE

To evaluate the tear function and ocular surface alterations in patients with primary CIN before and after treatment with topical mitomycin (MMC).

PATIENTS AND METHODS

We describe seven patients with unilateral CIN treated with 0.04% topical MMC three times daily until full eradication of the lesion. The patients underwent tear and ocular surface examinations including Cochet-Bonnet corneal sensitivity measurements, tear film break-up time (BUT), Schirmer test, and Rose-Bengal staining before, at the time of resolution of the CIN, and at the final follow-up. Conjunctival impression cytology was performed before treatment and at the last visit.

RESULTS

The mean pretreatment corneal sensitivity was 30.3 +/- 7.4 mm and improved to 55 +/- 5 mm at the final visit (P < 0.05). There were no aqueous-deficient eyes. The BUT values and Rose-Bengal staining scores also showed significant improvement at the last follow-up compared with the pretreatment values (P < 0.05). Initial impression cytology specimens showed goblet cell loss, higher grades of squamous metaplasia, areas of isolated keratinized, binucleated, and actively mitotic disfigured epithelial cells in all patients. The mean goblet cell density and squamous metaplasia grade were observed to improve significantly at the last visit (P < 0.05). MMC-induced cytologic changes were seen to persist long after cessation of treatment in some patients. All eyes remained free of recurrence and complications during the follow-up period.

CONCLUSION

We found 0.04% topical MMC treatment tid until full eradication to be effective in the management of CIN. The ocular surface disease of CIN was characterized by disturbance of tear film stability, goblet cell loss, and increased squamous metaplasia in all patients. Impression cytology proved useful in attaining the diagnosis of CIN, evaluating the effect of treatment, and showing MMC-related long-term changes on the ocular surface.