Conjunctival Intraepithelial Neoplasia Research Articles

Corneal Microaneurysm-A Vascular Feature of Conjunctival Squamous Intraepithelial Neoplasia.

The diagnosis of conjunctival squamous intraepithelial neoplasia (CSIN) can be difficult because of the heterogeneous appearance. Despite established risk factors and diagnostic support by high-resolution optical coherence tomography (hrOCT) and indocyanine green angiography (ICGA), the only reliable diagnostic method is a histological work-up. This case report is the first to describe corneal microaneurysms in CSIN as a vascular feature for conjunctival tumor angiogenesis. An 84-year-old male patient was referred with a suspected diagnosis of pterygium. Biomicroscopic examination revealed a whitish epithelial lesion of conjunctival origin with centripetal corneal growth and extension over 5 limbal hours. Intralesional vascularization showed highly altered morphology with aneurysmal changes. After imaging with hrOCT and ICGA, excision was performed in a "no-touch double-freeze and thaw" technique, followed by histological and immunohistochemical work-up. hrOCT showed an epithelial, hyperreflective lesion with a maximum thickness of 272 µm and sharp central border. ICGA confirmed active perfusion and partial thrombosis of the aneurysmal terminal vascular buds dilated to 405 μm with early dye leakage within the first minute. Histological examination confirmed the clinical diagnosis of CSIN with focal high-grade dysplasia. Postoperatively, there was no recurrence during the observation period of 5 months. Intralesional terminal microaneurysms are a feature of tumor angiogenesis in CSIN. The relevance and frequency of this potential new risk factor for malignancy should be investigated in further studies.

Atopic Keratoconjunctivitis: Pathophysiology, Clinic, and Potential New Therapeutic Concepts.

Atopic dermatitis (AD) is a chronic recurrent inflammatory skin disease with a bipolar age distribution in childhood, adolescence and middle adulthood. Up to 50% of AD patients show ocular involvement, which can be potentially sight threatening. Clinically, the majority of cases present with atopic blepharo(kerato)conjunctivitis or atopic keratoconjunctivitis (AKC); other clinical variants from this group of inflammatory ocular surface diseases are keratoconjunctivitis vernalis in childhood and adolescence and allergic conjunctivitis. In addition to the aforementioned blepharitis, keratitis and conjunctivitis, AD is also associated with eyelid involvement with subsequent eyelid malposition, limbal insufficiency with the development of pseudopterygia, (chronic) cicatrizing conjunctivitis with symblephara formation and fornix shortening, as well as ocular surface malignancies such as conjunctival intraepithelial neoplasia (CIN) and squamous cell carcinoma. In addition, an association with AD or AKC has been described for keratoconus. Whereas the therapy of AD in dermatology has made revolutionary advances in recent years through the use of biologicals, the primary use of these biologicals in ophthalmological complications is still very hesitant. Treatment here is often provided using topical steroids and calcineurin inhibitors. The following article summarises recent developments in basic and clinical dermatological research and discusses them in the context of current concepts for ophthalmological therapy.

Clinicopathological Correlates of Ocular Surface Squamous Neoplasia

Introduction: This study examined the distribution of histopathological disease severity amongst a cohort of patients treated for clinically suspected ocular surface squamous neoplasia and evaluated the relationship between various patient and clinical factors and the severity of pathological grade as well as treatment outcomes. Methods: A retrospective cohort study of demographic and clinicopathological factors of 150 patients clinically diagnosed with suspected ocular surface squamous neoplasia who underwent excision of lesion with histopathological diagnosis. Results: The study included 125 cases; the mean age at diagnosis was 64 years (SD = 11.26). 74% of cases were histologically confirmed as ocular surface squamous neoplasia. Pathological distribution was conjunctival intraepithelial neoplasia I (13.6%), conjunctival intraepithelial neoplasia II (16.8%), conjunctival intraepithelial neoplasia III (21.6%), carcinoma in situ (21.6%), and squamous cell carcinoma (2.4%). Lesion appearance was leukoplakic (18%), gelatinous (15%), dysplastic (11%), vascular (6%), papilliform (2%), nodular (2%). Lesion location was nasal (43%), temporal (42%), and superior or inferior (14%). Recurrence occurred in 7 cases (5.6%). A significant association was found between presence of leukoplakia and pathological grade (p = 0.05). Conclusions: Ocular surface squamous neoplasia is most frequently diagnosed in conjunctival intraepithelial neoplasia III and carcinoma in situ stages, and treatment outcomes are usually favourable.

Topical 5-fluorouracil 1% for moderate to extensive ocular surface squamous neoplasia in 73 consecutive patients: Primary versus secondary treatment

ImportanceOcular surface squamous neoplasia (OSSN) is a spectrum of malignancies that generally includes conjunctival intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC). OSSN can be treated with topical therapies including interferon α-2b (IFN), mitomycin C (MMC), or 5-fluorouracil 1% (5FU). Recently, due to unavailability of IFN and toxicity associated with MMC, therapy has shifted towards 5FU. ObjectiveHerein, we compare the use of 5FU 1% as a primary versus (vs) secondary treatment regimen in eyes with moderate to extensive OSSN. Design Setting and ParticipantsRetrospective cohort study of 73 consecutive patients with unilateral moderate to extensive OSSN treated at a single tertiary ocular oncology center from 2016 to 2023. Mean follow up time was 478.2 days overall, with 283.0 days for primary 5FU group and 860.3 days for secondary 5FU group. InterventionTopical 5FU 1% 4 times daily for 2 weeks with option for 2-weekly extension until tumor control, either as primary treatment or as secondary treatment to surgical resection, topical IFN or topical MMC, or cryotherapy. Main OutcomesOutcome measures included tumor response, need for additional surgery, complications, and visual outcomes. ResultsA comparison (primary vs secondary treatment) revealed no difference in mean tumor basal dimension (19.6 vs 17.2 mm, P = 0.46), thickness (3.7 vs 3.4 mm, P = 0.64), or tumor extent (4.4 vs 4.5 clock hours, P = 0.92). The primary treatment group showed greater complete tumor control (77% vs 38%, P = 0.04). Multivariable analysis comparison (primary vs secondary treatment) showed primary treatment more likely to achieve complete tumor control (P = 0.01). There was no difference in the complication rate from 5FU treatment between the groups. There was no difference in visual outcome, and no tumor-related metastasis (0%) or death (0%). Conclusion and RelevanceTopical 5FU 1% is efficacious and safe as a primary or secondary treatment for moderate to extensive OSSN. Tumors treated with primary 5FU 1% demonstrated more complete resolution. In patients with moderate to extensive OSSN, primary treatment with topical 5FU 1% may be warranted.

PHOTO ESSAY: “New” Red Eye - A Case of Conjunctival Intraepithelial Neoplasia

Ocular surface squamous neoplasia (OSSN) covers a wide range of ocular diseases that affect the squamous epithelial cells on the surface of the eye. This includes conjunctival intraepithelial neoplasia, corneal epithelial dysplasia, squamous cell carcinoma, and mucoepidermoid carcinoma. Anterior segment OCT can be used to differentiate between CIN and other benign conjunctival lesions, by evaluating for epithelial activity, stromal invasion, and corneal involvement.

OSSN: An underrated neoplasia of the eye

: Ocular surface squamous cell carcinoma (OSSN) is a general term for various conjunctival tumors, including conjunctival intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC).: To evaluate the clinico-demographic characteristics and histopathological findings of ocular surface squamous cell carcinoma. : eyes of 47 patients aged 21 to 80 years with conjunctival tumors were included in the study and underwent excisional biopsy and subsequent histopathological examination. : Statistically significant associations were found with age, symptom duration, and lesion size (p<0.05). Benign and preinvasive lesions are more common than invasive lesions.

COMPARISON OF HSP90 EXPRESSION IN CONJUNCTIVAL INTRAEPITHELIAL NEOPLASIA AND CONJUNCTIVAL SQUAMOUS CELL CARCINOMA

Abstract
 Introduction & Objectives : Heat shock protein 90 (HSP90) participates in stabilizing and activating client proteins involved in malignant transformation. This study aims to determine whether there are different values for the expression of HSP90 in Conjunctival Intraepithelial Neoplasia (CIN) and Conjunctival Squamous Cell Carcinoma (CSCC).
 Methods : A total of 24 OSSN samples, including 15 cases of CIN and 9 cases of CSCC were evaluated. The immunohistochemical expression of HSP90 was assessed using a scoring system based on the percentage of positive staining of nuclear and cytoplasmic cells, then the intensity of staining was evaluated using the German Immunoreactive Score.
 Results : In the study, the average cytoplasmic Immunoreactive Score in CIN was 9.87 and CSCC was 16.89 with a significant result (p=0.007), while the average nuclear Immunoreactive Score in CIN was 11.30 and CSCC was 14.50 with insignificant results (p=0.274). The results of the correlation test showed that the cytoplasmic expression groups with low categories were all in CIN as much as 6 (100%) so they had a ratio of 6:0. and the high category of HSP90 cytoplasmic expression group was only found in CSCC as many as 2 (100%) samples with a ratio of 0:2. The results of the correlation test using the Pearson test obtained a significant correlation value (p=0.006) with a moderate correlation strength (r=0.545).
 Conclusion : There are differences in the expression of cytoplasmic and nuclear HSP90 but only the cytoplasmic expression of HSP90 is significantly associated with CIN and CSCC.

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

PurposeOcular surface squamous neoplasia (OSSN) comprises a wide spectrum of squamous tumors, from which corneal/conjunctival intraepithelial neoplasia (CIN) is the most common one. The classic treatment is complete excision, but recurrence rates are high. Antineoplastic drugs such as mitomycin C (MMC) and interferon alpha 2b (IFNα2b) have been used as adjuvants or as primary treatment. To evaluate the efficacy and safety of topical IFNα2b and MMC in patients with CIN, a phase IIb double-blind clinical trial was performed.MethodsPatients diagnosed with localized CIN were evaluated by slit lamp and impression cytology and were randomly given MMC 0.04% or INF2b (1 million IU/mL) 4 times daily until neoplasia resolution. Time of resolution and frequency of adverse effects were analyzed to determine the pharmacological efficacy and safety of both medications.ResultsSeventeen patients were included. Nine patients were treated with MMC and 8 with IFNα2b. All patients responded to treatment. The resolution time in days was 59.11 ± 24.02 in patients treated with MMC and 143.50 ± 47.181 in those treated with IFNα2b (p < 0.001). In the MMC group, one recurrence was reported (11%). There were no recurrences at 2 years of follow-up in the IFNα2b group. Regarding adverse effects, one or more mild adverse reaction occurred in 77% of patients managed with MMC and in 50% of patients managed with IFNα2b (p > 0.05). No serious adverse effects were reported.ConclusionsTopical chemotherapy with MMC and IFNα2b demonstrate pharmacological safety and efficacy. Therefore, these drugs could be considered as primary therapies for localized CIN .

Development and Validation of UPLC–MS/MS Method for Quantitative Analysis of 5-Fluorouracil in Aqueous Humor of Rabbits

5-Fluorouracil (5-FU) is now used in eye drops for the management of conjunctival malignant melanoma, intraepithelial neoplasia, and corneal and conjunctival squamous cell carcinoma. The previously used methods for 5-FU quantification in AqH were time-consuming and less sensitive. Herein, a highly perceptive bioanalytical UPLC–MS/MS method was developed for the quantitative determination of 5-FU in the aqueous humor (AqH) of rabbits using allopurinol as the internal standard (IS). The 5-FU and IS were well separated in an Acquity™ HILIC column. Acetonitrile and 10 mM of ammonium acetate at 95:5 (v/v) were isocratically pumped at a 0.3 mL/min flow rate with a total runtime of 2.5 min. AqH samples were processed with a liquid–liquid extraction method in ethyl acetate. The 5-FU and IS were identified in the negative mode with electrospray ionization. The parent to daughter ion transitions for the 5-FU and IS occurred at m/z 128.92→41.68 and 134.80→64.10, respectively, as quantified using the multiple reaction monitoring mode. The developed method was validated with the ICH-Harmonized Guideline for Bioanalytical Method Validation, and the parameters were within acceptable limits. The calibration curve was linear at the 10.5–2000 ng/mL concentration range, with a correlation coefficient (R2) of 0.9946, and the lower limit of detection was 3.55 ng/mL. The developed and validated method was rapid, sensitive, accurate and robustly able to quantify 5-FU in rabbit AqH. The method was effectively applied to establish the ocular pharmacokinetics of 5-FU following the topical instillation of 5-FU-containing preparations in rabbits.

Demographics, clinical presentation and risk factors of ocular surface squamous neoplasia at a tertiary hospital, South Africa

AimsThe aim of this study is to describe the demographic, presenting features and associated risk factors of ocular surface squamous neoplasia (OSSN) at a tertiary eye hospital in Johannesburg, South Africa.MethodsAn interventional prospective study of patients presenting with conjunctival masses was conducted. An electronic questionnaire was completed to document demographic data, presenting history, and associated risk factors. A slit lamp examination and photos were used to document and describe the clinical features at presentation. Cases (OSSN) and controls (benign lesions) were determined by histology.ResultsThere were 130 cases and 45 controls. Median age was 44 years (IQR: 35–51) with an equal gender distribution in cases. The prevalence of HIV in cases was 74% and was strongly associated with OSSN (p < 0.001). Vascularisation, leukoplakia and pigmentation were clinical features that distinguished cases from controls. A fibrovascular morphology was strongly associated with a benign histology (p < 0.001), whereas leukoplakic and gelatinous morphologies were associated with OSSN. Conjunctival intra-epithelial neoplasia made up 82% of cases.ConclusionOur study describes a sample of OSSN that is young and has no gender predisposition. The majority of cases presented with CIN lesions, rather than SCC reported in other African countries. HIV was the most significant risk factor in this study population.

Histopathology and Ultrasound Biomicroscopy Correlation in Conjunctival Intraepithelial Neoplasia

An 83-year-old man with squamous cell carcinoma of the left conjunctiva presented for tumor recurrence. Slit-lamp examination showed an amelanotic lesion on the left bulbar conjunctiva extending from the 5 to 9 o’clock meridians involving fornix and caruncule (A). Prominent feeder and intrinsic vessels were visible (white arrows). Ultrasound biomicroscopy (UBM) revealed a solid, well-circumscribed lesion, measuring 1.4 × 15 × 9 mm, without scleral invasion (B, C, longitudinal and transverse scan, respectively). Internally, multiple linear formations with high reflectivity (white arrows) were visible. Pathology confirmed a diagnosis of conjunctival intraepithelial neoplasia (CIN III). Large, dilated blood vessels (white arrow) were visible (D), consistent with the noted UBM findings. Therefore, UBM is a noninvasive aid in the diagnosis and management of CIN (Magnified version of Figure A-D is available online at www.aaojournal.org).

Impression Cytology in the Evaluation of Ocular Surface Squamous Neoplasia- A Retrospective Cohort Study

Introduction: Ocular Surface Squamous Neoplasia (OSSN) are a diverse group of lesions varying from Conjunctival Intraepithelial Neoplasia (CIN) to invasive Squamous Cell Carcinomas (SCC). Histopathological examination is the gold standard technique in diagnosing them. However, it is invasive and may not be suitable in recurrent cases. Numerous minimally invasive techniques are available to diagnose OSSN cytologically. This study employs Impression Cytology (IC) to diagnose ocular squamous neoplastic lesions and compare it with the histological diagnosis. Aim: To utilise IC in the diagnosis of OSSN and to compare its findings with histopathological diagnosis. Materials and Methods: This was a retrospective cohort study, conducted in a Tertiary Eye care Hospital, Hubli, Karnataka, India during January 2023. The data included was over a period of three years (from July 2016 to June 2019). A total of 44 eyes (34 patients), in which both biopsy and IC done, were included. The patients’ age, sex and ocular examination findings were recorded. The cytological and histopathological slides were retrieved from the archives and examined morphologically. The cytological findings were compared with histopathological diagnosis and the sensitivity and specificity of the IC technique were calculated. The data was analysed using Microsoft excel sheets. Results: A total of 34 patients were studied ranging from 19 to 85 years. The mean age was 49 years, 21 (61.76%) of them were males and 13 (38.24%) were females. In 24 patients, single eye was affected and in 10 patients bilateral eye involvement was seen. Histology revealed that there were 18 (40.90%) CIN I cases, 4 (9.09%) CIN II, 5 (11.36%) CIN III and 17 (38.65%) SCC. On cytology, 3 (6.82 %) were normal conjunctival epithelium, 30 (68.18 %) were dysplasia and 11 (25.00 %) were SCC. On cyto- histomorphological analysis, 35 (79.55 %) were concordant, out of 44 diagnosis. IC has a sensitivity of 88.89% and specificity of 64.71% to detect dysplasia. To diagnose SCC, it has sensitivity of 64.71% and 100% specificity. Conclusion: According to the present study observations, IC is an excellent preliminary tool to investigate suspected neoplastic lesions of ocular surface. It has a very good concordance with histopathological diagnosis. IC is highly sensitive to detect dysplasia (CIN) and is very specific to diagnose SCC.

Conjunctival Ocular Surface Squamous Neoplasia with Spheroidal Degeneration: A Rare Case of UV-B Associated Ocular Neoplasia and Keratopathy

Ocular Surface Squamous Neoplasia (OSSN) is an umbrella term that includes a broad spectrum of conjunctival and corneal malignancies, ranging from mild epithelial dysplasia to invasive squamous cell carcinoma. These are uncommon ocular surface lesions but harbour the potential to cause significant ocular morbidity and rarely mortality. Human Papilloma Viruses (HPV) and Ultraviolet-B light (UV) have been identified as important risk factors in aetiopathogenesis. The present OSSN patient is a 48- year-old male with redness, growth, and a foreign body sensation in his left eye over the past four months. Examination of the left eye revealed a growth in the nasal limbus with a feeder vessel measuring 0.9x0.3x0.1 cm in size. Diagnosis was confirmed by anterior segment Optical Coherence Tomography (OCT). The patient was admitted for an excision biopsy accompanied by intraoperative Mitomycin-C. The lesion’s histopathology revealed grade 2 in situ carcinoma with spheroidal formation. This case is considered rare due to the infrequent association between Conjunctival Intraepithelial Neoplasia (CIN) and spheroidal degeneration.

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

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. 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. 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. 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.

Recurrence of Primary Acquired Melanosis and Conjunctival Intraepithelial Neoplasia

Introduction: The aim of this study was to investigate the frequency of recurrences, time to recurrence, and which patients had a recurrence after treatment of conjunctival intraepithelial neoplasia (CIN), carcinoma in situ, and primary acquired melanosis (PAM) with atypia. Methods: A retrospective chart review of all patients included in the follow-up program after completion of treatment for CIN or PAM with atypia on October 18, 2021, at the Department of Ophthalmology, Sahlgrenska University Hospital, was conducted. Results: There were five recurrences (5/31, 17%) in the group with CIN or carcinoma in situ: two for patients with CIN grade II and three for individuals with carcinoma in situ. Time to diagnosis of recurrence ranged from 6 to 288 months. No recurrence was diagnosed for the 26 patients followed after treatment for PAM with atypia. Conclusion: With the strategy of radical treatment for CIN and PAM with atypia, whenever possible, subsequent follow-up can probably be ceased after 10 years if the patient is not immunocompromised. For completely excised PAM with atypia grade I, there is most likely no need for further clinical controls.

A case of conjunctival intraepithelial neoplasia with spheroidal degeneration: a clinicopathological study.

A case of conjunctival intraepithelial neoplasia with spheroidal degeneration: a clinicopathological study.

Ocular Surface Squamous Neoplasia: A 12-Month Prospective Evaluation of Incidence in Waikato, New Zealand.

Ocular surface squamous neoplasia (OSSN) has a high incidence in the southern hemisphere. This prospective study evaluated the incidence of OSSN in the Waikato region of New Zealand. All patients presenting with pterygium or conjunctival lesions in the Waikato region in 2020 were included. All surgeons in the region were asked to send all conjunctival and corneal specimens excised for histopathologic examination. The primary outcome measure was the incidence of OSSN. Eighty-eight percent of all excised specimens were sent for histopathologic examination. Of the 185 excised lesions sent for histopathological assessment, 18 (10%) were reported as OSSN. Patients were on average 69.4 years of age (standard deviation, SD = 6.9), predominantly male (78%), and of New Zealand-European ethnicity (89%). The OSSN annual incidence was 3.67/100,000/year. Histology grades included conjunctival intraepithelial neoplasia (CIN)-I (25%), CIN-II (25%), CIN-III (12.5%), carcinoma in situ (25%), and invasive squamous cell carcinoma (SCC) (12.5%). One patient with invasive SCC required exenteration. This study identified a high incidence rate of OSSN and is the first prospective study to analyze OSSN epidemiology in New Zealand.

Detection of Human Papillomavirus in Squamous Lesions of the Conjunctiva Using RNA and DNA In-Situ Hybridization.

In-situ hybridization provides a convenient and reliable method to detect human papillomavirus (HPV) infection in formalin-fixed paraffin-embedded tissue. Cases of conjunctival papillomas, conjunctival intraepithelial neoplasia (CIN), conjunctival carcinoma in situ (cCIS), and invasive squamous cell carcinoma (SCC), in which low-risk (LR) and/or high-risk (HR) HPV types were evaluated by RNA or DNA in-situ hybridization, were retrospectively identified. LR HPV types were frequently detected in conjunctival papillomas (25/30, 83%), including 17/18 (94%) with RNA probes, compared to 8/12 (75%) with DNA probes. None of the CIN/cCIS or SCC cases were positive for LR HPV by either method. HR HPV was detected by RNA in-situ hybridization in 1/16 (6%) of CIN/cCIS cases and 2/4 (50%) of SCC cases, while DNA in-situ hybridization failed to detect HPV infection in any of the CIN/cCIS lesions. Reactive atypia and dysplasia observed in papillomas was generally associated with the detection of LR HPV types. Collectively, our findings indicate RNA in-situ hybridization may provide a high-sensitivity approach for identifying HPV infection in squamous lesions of the conjunctiva and facilitate the distinction between reactive atypia and true dysplasia. There was no clear association between HPV infection and atopy in papillomas or dysplastic lesions.

Visualizing Ocular Surface Squamous Neoplasia

A 66-year-old man presented with subtle conjunctival thickening (Fig A) 3 years after treatment for conjunctival intraepithelial neoplasia in the same location by primary surgical excision, cryotherapy, and adjuvant topical mitomycin C (MMC) 0.02%. Visualization of the ocular surface with a yellow barrier filter over cobalt blue light after instillation of fluorescein identified stippled staining of recurrent tumor, and the tumor margins were also clearly outlined (Fig B) corresponding to those found by anterior-segment OCT (Fig C).

Use of optical coherence tomography angiography in assessment in conjunctival vascular architecture in health and pathology

Investigation of the capabilities of anterior segment (AS) optical coherence tomography angiography (OCTA) in evaluation of conjunctival vascular architecture in healthy individuals and in various pathological conditions. The study included 17 healthy volunteers (34 eyes; the control group) and 62 patients (68 eyes) with conjunctival lesions of various nature. All participants underwent AS-OCT and AS-OCTA with assessment of qualitative (vessels pattern, lumen, pathologic tortuosity) and quantitative parameters (vessel density (VD, %) in the lesion area). Mean VD (MVD) and local VD (LVD) were determined, as well as VD in perifocal tissues (PVD). OCTA scans in 8 conjunctival sectors showed mostly radial pattern of the vascular architecture, with vessel lumen remaining the same over their entire visible length. Larger-sized vessels in deeper conjunctival layers were discovered in most cases. The lowest VD value (33.3%) was registered in the superotemporal quadrant, and the highest (38.9%) - in the nasal. Tortuosity of the vessels with course disruption, uneven lumen over the length of the vessels and increase in VD were observed in the area of conjunctival lesions in all cases excluding congenital abnormalities, pingueculae and conjunctival melanocytic intraepithelial neoplasia. The malignant nature of the tumors was indicated by dense vessel distribution and difficulties for visualization of intravascular space, and confirmed by pathohistological analysis. An increase in the number of areas with a lace-like pattern was characteristic for melanomas, with mean VD of more than 50% in the most vascularized areas. AS-OCTA is an informative method for the visualization of vessels in healthy conjunctiva and in conjunctival pathology. Local VD in the lesion area should be measured when the vessels are unevenly distributed.