Conjunctival Impression Cytology Research Articles

In Vivo and Impression Cytology Study on the Effect of Compatible Solutes Eye Drops on the Ocular Surface Epithelial Cell Quality in Dry Eye Patients.

The aim of this study is to investigate in vivo and ex vivo ocular surface alterations induced by dry eye disease and modification after osmoprotective therapy. Forty-eight eyes of 24 patients suffering from dry eye have been recruited. All patients received Optive (compatible solutes) eye drops in one randomly selected eye and Hylogel (sodium hyaluronate 0,2%) in the other. Follow-up included a baseline visit and further examination 30-, 60-, and 90-day intervals (which comprises clinical evaluation, in vivo confocal microscopy—IVCM—of the ocular surface, and conjunctival impression cytology). No significant difference in Schirmer I Test, TBUT, and vital staining results was observed during the follow-up period in both groups. IVCM showed in all patients an improvement of ocular surface epithelial morphology and signs of inflammation (oedema and keratocyte activation). However, these modifications were more evident in patients treated with Optive therapy. A significant reduction of the expression of MMP9 and IL6 in Optive group was observed during the follow-up period in comparison to Hylogel treatment. Our results show that in dry eye disease therapy based on osmoprotective eye drops determines a reduction of inflammatory activation of ocular surface, with consequent improvement of the quality of corneal and conjunctival epithelium.

4A syndrome: ocular surface investigation in an Italian young patient

BackgroundAllgrove’s 4A syndrome determines ocular surface changes. This is the first report providing an up-to-dated analysis of the ocular surface in an affected patient.Case presentationAn 18-years-old male Caucasian patient, with a complex progressive gait disorder and adrenal insufficiency, was referred for ophthalmic evaluation, as part of the clinical assessment. He underwent the following tests: best corrected visual acuity, tear osmolarity, tear film break-up time (BUT), corneal fluorescein staining, Schirmer’s I test, lid margin assessment, corneal sensitivity, in vivo corneal confocal microscopy, conjunctival impression cytology, tonometry and fundus exam. A dry eye condition was documented by the Schirmer’s I test of 0 mm/5’ in both eyes, accompanied by tear hyperosmolarity, mild meibomian gland dysfunction, reduced BUT, mucus filaments in the tear film and conjunctival epithelium metaplasic changes. The corneal confocal microscopy showed the presence of activated keratocytes, while the nerve pattern was normal.ConclusionsThe dry eye in this patient appears to be due to tear aqueous deficiency and can be considered as part of the 4A syndrome. The decreased tear production, resulting from a deterioration of the autonomic innervation of the lacrimal glands rather than an impaired corneal innervation, can be considered as part of the systemic autonomic dysfunction present in this disease.

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AIM: To study the correlation of dry eye status with severity of diabetic retinopathy. MATERIALS AND METHODS: SETTINGS AND DESIGN: Prospective study. One hundred patients with diabetes mellitus attending the outpatient and in-patient department, Department of Ophthalmology, K. R. Hospital, Mysore, were included under the study, between the periods from January 2014 to July 2014 (6 months). Informed and written consent was taken from all the patients. After detailed history, all necessary ocular and systemic examination was done. All diabetes mellitus patients were analyzed for dry eye status and presence of diabetic retinopathy changes. Dry eye status was evaluated with Schirmer’s test, Tear film break up time and conjunctival impression cytology. Retinal status evaluation was done by direct ophthalmoscopy, indirect ophthalmoscopy and Slit lamp Biomicroscopy using 78D lens after pupillary dilation. Diabetic retinopathy was graded accordingly to ETDRS classification. STATISTICAL ANALYSIS: All data were analyzed using descriptive statistics and Chi square test and contingency coefficient analysis was applied. RESULTS: A total of 100 diabetes mellitus patients were analyzed. 56 (56%) patients had Diabetic retinopathy and 44(44%) had normal fundus picture. Out of the 100 diabetes mellitus patients, 36 (36%) patients had dry eye. Significant association (P – 0.001) between dry eye and diabetes mellitus was seen. CONCLUSION: Dry eye and diabetes mellitus have a common association. Dry eye is more frequent in diabetes mellitus patients with longer duration and in patients with Diabetic retinopathy.

Conjunctival impression cytology in patients with normal and impaired OSDI scores

PurposeTo describe goblet cell density and Nelson grading in different areas of the ocular surface using conjunctival impression cytology (CIC) among patients with normal and impaired Ocular Surface Disease Index (OSDI) scores. Materials and methodsPatients (n=166) under assessment for dry eye were recruited between 2011 and 2012 and classified according to the OSDI score in 4 categories (normal and impaired). Cytological study (CIC plus Papanicolaou staining) using the Nelson grading system, with modifications in staging, and goblet cell counting were performed on the nasal, temporal, inferior, and superior bulbar conjunctival surfaces. ResultsNelson grading was significantly higher in patients with a severely impaired OSDI score (1.41±0.14) compared to normal patients (0.86±0.09) (p<.01). Goblet cell density was significantly reduced in patients with a severely impaired OSDI score (310.24±56.24 cells per sample) compared with normal subjects (497.31±50.07 cells per sample) (p<.001). Compared with the photoexposed bulbar conjunctiva, goblet cell density on the non-photoexposed conjunctiva was significantly higher both in patients with mild (p<.01) and moderate (p<.001) OSDI scores. ConclusionPatients with severely impaired OSDI scores have less goblet cells and a higher Nelson grade. Goblet cells are more abundant on the non-photoexposed conjunctiva.

A comparative study of tear film function and tear secretion among diabetics

The present work aims to study the changes in tear film function by studying tear film stability, amount of tear secretion and conjunctival impression cytology among diabetics and to compare with that in non-diabetics. In this prospective case control study, 100 eyes of 50 patients with type II Diabetes Mellitus and 100 eyes of 50 normal patients coming to OPD of a tertiary hospital were chosen. The tests done included Tear film Break Up Time, Rose Bengal staining, Schirmer’s test and Conjunctival Impression Cytology (CIP). For CIP, samples were taken from nasal and temporal conjunctiva and smeared on slides and stained with Papanicolau stain and observed under light microscope of 400x magnification. The mean age among diabetics was 53.4±11.2 years and non-diabetics was 48.8±15.3years. The TBUT was significantly reduced in diabetics with a mean of 9.8±7.01 seconds and 12.8±5.71 seconds in non-diabetics (p<0.005). 30% patients had values less than 10 seconds. The Rose Bengal test did not show a statistically significant difference. Schirmer’s test was positive in 26% in diabetics and 10% in non- diabetics. The mean was 7.7±3.9 in diabetics and 13.4±5.7 in non-diabetics (p=0.003). The mean grade of squamous metaplasia in diabetics was 1.58±0.62 and 0.52±0.57 in non-diabetics (p=0.001). Corneal sensitivity was found to be significantly lower in diabetics (29.17mm) when compared to controls (54.58mm). Dry eye is a significant ocular surface disorder in diabetes. The tear film parameters were significantly reduced in diabetics but Rose Bengal test did not show much difference.

Comparative role of 20% cord blood serum and 20% autologous serum in dry eye associated with Hansen's disease: a tear proteomic study

BackgroundTo compare the role of topically applied serum therapy with preservative-free artificial tear (AT) drops in patients with moderate to severe dry eye in Hansen's disease along with change in...

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AIM: To evaluate the cytological epithelial modification of conjunctiva in VKC and correlate with its various clinical features, hematological. Investigations and response to treatment. MATERIALS AND METHOD: This was a prospective study of 50 consecutive patients of VKC presenting to M.S Ramaiah Hospital, who were willing to undergo laboratory Investigations. A detailed preliminary eye examination, including Best Corrected Visual Acuity (BCVA), Tear film examination including Schirmer's test, Tear Break Up Time, Mucin ferning patterns, Tears pH, Conjunctival Impression Cytology (CIC), Skin Prick Test and Blood Investigations like Hemoglobin, Complete Blood Count, ESR, Absolute Eosinophil Count(AEC), Serum IgE Levels (S.IgE) were done. RESULT: Patients belonged to the age group of 4 to 25 years and M:F ratio was 4:1.Total number of patients with Palpebral VKC & mixed VKC were 13 And 37 respectively and none had limbal VKC. Total number of patients with VKC was 50 out of which Patients with normal AEC and normal S.IgE were 4(8%), with raised AEC & normal S.IgE Were 4(8%) and with raised or normal AEC & raised IgE were 42 (84%). All patients had alkaline tear film, abnormal ferning patterns were observed in 49 (98%), and abnormal TBUT in 37(74%) patients. 28(56%) had abnormal CIC grading.89.28 % (25/28) patients of abnormal CIC had Raised S.IgE levels. Only 37.5% (3/8) of VKC cases with normal S.IgE levels showed abnormal CIC. Only in 52.38% of patients with severe VKC could the allergen (skin prick test) be identified. 80. 95 b% of severe VKC cases had raised S.IgE. 59.95% (N: 25) cases had positive skin prick test out of 42 cases with raised S.IgE. VKC patients with Normal AEC &IgE levels were easily cured with mast cell stabilizers, antihistaminics and artificial tears VKC patients with raised AEC levels & Normal IgE levels were treated with topical steroids during the attacks and mast cell stabilizers and artificial tears, VKC patients with raised AEC &IgE were resistant to treatment with steroids and immunomodulators. CONCLUSION: VKC seems to be a strongly IgE mediated. There is need for a more robust skin prick test to identify the allergens/atopy. Immunotherapy should probably be considered early in the disease status reduce ocular morbidity

Ocular Surface Findings in Chronic Renal Failure

The purpose of this study was to describe the ocular surface findings in chronic renal failure (CRF). Sixty eyes of 30 patients with CRF group and 70 eyes of 35 healthy subjects were evaluated. Schirmer-I, tear film break-up time tests and conjunctival impression cytology were performed in addition to complete ophthalmologic examination. The presence of dry eye symptoms and conjunctival calcification were noted. The groups were age and gender matched. The mean break-up time was 10.3±3.1 in group-1 and 11.2±1.7 seconds in the group-2 (p=0.03). The mean Schirmer score was 11.2±2.8 mm and 12.0±1.7 mm in the CRF and control group (p=0.095), respectively. In CRF group, conjunctival impression cytology was revealed as grade-0 findings in 16 eyes, grade 1 findings in 41 eyes and grade 2 findings in 3 eyes, in control group, it was revealed grade-0 findings in 48 eyes, grade 1 findings in 22 eyes and showed no changed in grade 2 (p<0.001). In CRF group, conjunctival calcification was regarded as grade 0 findings in 18 eyes, grade 1 findings in 34 eyes and grade 2 findings in 8 eyes. Grade 0 changes were seen in all subjects in group 2 (p<0.001). Itching (45%), redness (95%) and foreign body sensation (83%) were observed more frequently in the CRF group and also in all eyes with conjunctival calcification in both groups (p<0.001). Chronic renal failure patients suffer more than normal subjects from ocular surface complaints because of conjunctival calcifications and tear film instability although they have the same tear production with their contemporaries.

Clinical efficacy of 0.1% pranoprofen in treatment of dry eye patients: a multicenter, randomized, controlled clinical trial

Background Dry eye is a multifactorial disease of the tears and the ocular surface. This study aimed to investigate the clinical efficacy of a non-steroidal anti-inflammatory drug, pranoprofen, in the treatment of dry eye. Methods It is a prospective, multi-center, randomized, controlled, parallel group study. One hundred and fifteen patients with mild to moderate dry eye disease (55-60 in each treatment group) participated in this multi-center study. Patients were randomly administered with eyedrops containing 0.1% pranoprofen (PRA) plus 0.1% sodium hyaluronate (SH) or SH only, three times daily for 28 days, followed by a 1-week after treatment observation. Dry eye symptom score (DESS), fluorescein corneal staining (FLCS), tear break-up time (TBUT), and Shirmer 1 tear test (ST1, without anesthesia) were evaluated or conducted before treatment and at each study visit. Conjunctival impression cytology was taken from the patients treated with PRA plus SH before and after treatment and real-time polymerase chain reaction (RT-PCR) was performed to detect the changes of human leukocyte antigen DR (HLA-DR) and intercellular adhesion molecule 1 (ICAM-1). Results Patients treated with PRA plus SH showed gradual improvements of DESS, FLCS, and TBUT. Between-group comparisons of FLCS and TBUT have statistically significant differences from day 14. Good tolerance with no severe adverse events was found in both groups. Patients treated with PRA plus SH had a reduced expression level of HLA-DR and were statistically different after 28 days of therapy. Conclusions The application of PRA at a dose of 0.1% was well tolerated and benefited to the patients with mild to moderate dry eye disease. The underlying mechanism of its efficacy may be associated with the reduction of inflammatory factors of conjunctival epithelial cells.

Ocular Surface Evaluation in Allogenic Hematopoietic Stem Cell Transplantation Patients

To evaluate ocular surface of chronic graft versus host disease (GVHD) patients in allogeneic hematopoietic stem cell transplantation (allo-HSCT). Cross-sectional study of allo-HSCT patients. Data recorded included Ocular Surface Disease Index (OSDI) score, fluorescein tear break-up time (FTBUT), Schirmer I test, ocular surface staining, dry eye severity, and conjunctival impression cytology (CIC). Of 40 allo-HSCT patients (mean age 25.7 ± 11.03 years) studied, dry eye disease was noted in 30%. The OSDI was mild in 16.67%, moderate in 45.83%, and severe in 20.83% ocular GVHD (oGVHD) eyes; mild in 94.64%, moderate in 5.36% non-oGVHD eyes (p<0.001). The FTBUT was ≤5 seconds in 45.83%, >5 seconds in 54.17% of eyes with chronic oGVHD. Schirmer I test score was ≤5 mm in 58.33% of eyes with oGVHD. Conjunctival staining score was <3 in 25%, ≥3 in 75% of oGVHD eyes. Corneal staining score of <3 in 79.17%, ≥3 in 20.83% was seen in oGVHD eyes. Chronic oGVHD was seen in 24 eyes, with dry eye severity of level 3 in 17.5%, level 2 in 2.5%, level 1 in 10%. The CIC was abnormal in 75% with altered morphology seen in 22 eyes with oGVHD (91.7%) and 38 eyes without oGVHD (67.9%) (p = 0.024). Significant ocular surface changes occur due to chronic oGVHD in allo-HSCT patients. The OSDI score, corneal involvement, and Schirmer I test are indicative of ocular morbidity in post allo-HSCT eyes. Conjunctival impression cytology abnormality is also seen in eyes without oGVHD.

The diagnostic value and accuracy of conjunctival impression cytology, dry eye symptomatology, and routine tear function tests in computer users.

Aims and Objectives:To compare the diagnostic value and accuracy of dry eye scoring system (DESS), conjunctival impression cytology (CIC), tear film breakup time (TBUT), and Schirmer's test in computer users.Methods:A case–control study was done at two referral eye centers. Eyes of 344 computer users were compared to 371 eyes of age and sex matched controls. Dry eye questionnaire (DESS) was administered to both groups and they further underwent measurement of TBUT, Schirmer's, and CIC. Correlation analysis was performed between DESS, CIC, TBUT, and Schirmer's test scores. A Pearson's coefficient of the linear expression (R2) of 0.5 or more was statistically significant.Results:The mean age in cases (26.05 ± 4.06 years) was comparable to controls (25.67 ± 3.65 years) (P = 0.465). The mean symptom score in computer users was significantly higher as compared to controls (P < 0.001). Mean TBUT, Schirmer's test values, and goblet cell density were significantly reduced in computer users (P < 0.001). TBUT, Schirmer's, and CIC were abnormal in 48.5%, 29.1%, and 38.4% symptomatic computer users respectively as compared to 8%, 6.7%, and 7.3% symptomatic controls respectively. On correlation analysis, there was a significant (inverse) association of dry eye symptoms (DESS) with TBUT and CIC scores (R2 > 0.5), in contrast to Schirmer's scores (R2 < 0.5). Duration of computer usage had a significant effect on dry eye symptoms severity, TBUT, and CIC scores as compared to Schirmer's test.Conclusion:DESS should be used in combination with TBUT and CIC for dry eye evaluation in computer users.

Citología de impresión conjuntival en pacientes con valores OSDI normales y alterados

PurposeTo describe goblet cell density and Nelson grading in different areas of the ocular surface using conjunctival impression cytology (CIC) among patients with normal and impaired Ocular Surface Disease Index (OSDI) scores. Material and methodsPatients (n=166) under assessment for dry eye were recruited between 2011 and 2012 and classified according to the OSDI score in 4 categories (normal and impaired). Cytological study (CIC plus Papanicolaou staining) using the Nelson grading system, with modifications in staging, and goblet cell counting were performed on the nasal, temporal, inferior, and superior bulbar conjunctival surfaces. ResultsNelson grading was significantly higher in patients with a severely impaired OSDI score (1.41±0.14) compared to normal patients (0.86±0.09) (P<.01). Goblet cell density was significantly reduced in patients with a severely impaired OSDI score (310.24±56.24 cells per sample) compared with normal subjects (497.31±50.07 cells per sample) (P<.001). Compared with the photoexposed bulbar conjunctiva, goblet cell density on the non-photoexposed conjunctiva was significantly higher both in patients with mild (P<.01) and moderate (P<.001) OSDI scores. ConclusionPatients with severely impaired OSDI scores have less goblet cells and a higher Nelson grade. Goblet cells are more abundant on the non-photoexposed conjunctiva.

Effects of Polyquaternium- and Benzalkonium-Chloride-Preserved Travoprost on Ocular Surfaces: An Impression Cytology Study

To compare the toxicity effect of polyquaternium (PQ) and benzalkonium chloride (BAK) preservation of travoprost on the ocular surface. This prospective study included 44 eyes of 44 patients with newly diagnosed glaucoma. Twenty-two patients used PQ-preserved travoprost (PQ group) and 22 patients used BAK-preserved travoprost (BAK group). To investigate the effect on the ocular surface, conjunctival impression cytology (IC) was performed at baseline and the 1- and 6-month follow-up visits. Additionally, the ocular surface disease index (OSDI) questionnaire, Schirmer I test, and tear break-up time (TBUT) measurement were administered at baseline, and at 1-, 3-, and 6-month follow-up visits. While both groups showed statistically significant IC grade increases at 1 and 6 months when compared with baseline measurements, IC grades were significantly higher for patients using PQ-preserved travoprost compared with patients using BAK-preserved travoprost. The Schirmer I test and TBUT scores were not statistically significant between group 1 and BAK group at baseline and at 1-, 3-, and 6-month visits (P>0.05). OSDI scores did not statistically differ at baseline and the 1-month measurements between the 2 groups (P>0.05), but the 3- and 6-month OSDI scores were significantly higher for BAK group (P=0.001). Differences in OSDI and Schirmer I test scores were statistically significant at 1, 3, and 6 months in both groups as compared with baseline values (P<0.05). Statistically significant differences in the TBUT scores were seen for both groups at 3 and 6 months, while BAK group, but not PQ group, had insignificant score differences at 1 month as compared with baseline values of PQ group (P=0.083). PQ-preserved travoprost was found to be safer and better-tolerated than BAK-preserved travoprost. PQ-preserved travoprost provided better ocular surface comfort, and therefore a better patient experience, which would likely result in higher treatment compliance.

Increased Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) Expression in the Conjunctival Epithelium Exposed to Antiglaucoma Treatments

Objective: To analyze the effect of preserved antiglaucoma eye drops on the expression of extracellular matrix (ECM) metalloproteinase inducer (EMMPRIN) in conjunctival epithelial cells.Methods: A total of 18 patients treated for primary open-angle glaucoma with benzalkonium chloride (BAK) preserved eye drops and eight age-matched controls were included in this study. Glaucoma patients were divided into two groups according to their daily exposure to BAK: high-exposure (HE) group and low-exposure (LE) group. HLA-DR and EMMPRIN were quantified on conjunctival impression cytology specimens using flow cytometry. In parallel, IOBA-NHC conjunctival epithelial cells were exposed to different BAK concentrations, in the presence or absence of cyclosporine A (CsA), and their total and surface expressions of EMMPRIN were assessed by flow cytometry and results are given in relative fluorescence intensities (RFIs).Results: Compared to the control group (1.71 ± 0.39 RFI), EMMPRIN was significantly increased in the HE (4.19 ± 1.50 RFI, p < 0.001) and LE groups (2.55 ± 0.40 RFI, p = 0.029). Similar increase was observed in HLA-DR expression in the HE (4.58 ± 1.38 RFI, p < 0.001) and LE groups (2.52 ± 0.47 RFI, p = 0.046) as compared to control subjects (1.75 ± 0.27 RFI). Across all subjects enrolled in the study, there was a significant correlation between HLA-DR and EMMPRIN (R2 = 0.875, p < 0.0001). IOBA-NHC cells exposed to BAK presented a significant increase in EMMPRIN, which was proportional to the concentration of BAK. The surface expression of EMMPRIN was inhibited by CsA.Conclusions: The increased expression of EMMPRIN in patients topically treated with multiple antiglaucoma BAK-preserved eye drops suggests a matrix metalloproteinase-related modification of conjunctival ECM remodeling. In vitro results suggest that CsA has the potential to limit BAK effects on EMMPRIN.

A New Nonhuman Primate Model of Severe Dry Eye

The aim of this study was to establish a new rhesus monkey model of severe dry eye. A total of 8 rhesus monkeys were used for the study. Four monkeys had their main lacrimal gland and nictitating membrane surgically removed (group 1). Another 4 monkeys had a similar surgery with further application of 50% trichloroacetic acid on the bulbar conjunctiva (group 2). The ocular surface was evaluated before and after the surgery (1, 4, 8, 12, and 24 weeks) using Schirmer-1 test, corneal fluorescein staining, and the lissamine green test. Conjunctival impression cytology was also performed before and 24 weeks after the surgery. Finally, the cornea and the conjunctiva were evaluated using light microscopy. A significant decrease in tear secretion was observed in all operated eyes. Schirmer test data measured were ≤4 mm in all the operated eyes. Slit-lamp examination also revealed abnormal staining in all the operated eyes that remained stable until the end of the experiment. In group 2, corneal fluorescein staining and lissamine green test values were always ≥5 (max 12) and ≥4 (max 9), respectively. Impression cytology specimens of both the treated groups showed conjunctival squamous metaplasia and a decreased number of goblet cells. Under light microscopy, the corneal epithelium appeared irregular with edematous basal epithelial cells. The conjunctiva showed a decreased goblet cell density with infiltration of inflammatory cells. Complete removal of the principal lacrimal gland and nictitating membrane associated with the application of 50% trichloroacetic acid on the conjunctiva could induce severe dry eye in rhesus monkeys.

Conjunctival impression cytology in non-proliferative and proliferative diabetic retinopathy.

To examine the integrity of the ocular surfaces of subjects with and without diabetes with no conjunctival and dry eye signs and symptoms and compare conjunctival impression cytology findings in diabetics with non-proliferative and proliferative diabetic retinopathy. Conjunctival impression cytology was performed on 43 eyes of 43 subjects with non-proliferative diabetic retinopathy (NPDR), 42 eyes of 42 subjects with proliferative diabetic retinopathy (PDR), and 30 eyes of 30 control subjects. Impression cytology specimens of each group were graded and scored in the range 0-3 according to Nelson's method. There were 45 (52.9%) women and 40 (47.1%) men. The mean age of the patients was 59.6±9.3y (range, 43-76y) in NPDR group and 58.0±8.8y (range, 41-85y) in PDR group. Cases with NPDR and PDR showed statistically significant higher impression cytology scores than control group (P<0.05). There was no difference between the NPDR and PDR patients for impression cytology grading scores. It is determined that impression cytology grades are altered in patients with NPDR and PDR. Consequently, we suggest that there might be an association between the impression cytology grading scores and the severity of diabetic retinopathy.

Polymorphism in THBS1 Gene Is Associated with Post-Refractive Surgery Chronic Ocular Surface Inflammation

To determine the association of single nucleotide polymorphisms (SNPs) of the thrombospondin 1 (THBS1) gene with development of chronic ocular surface inflammation (keratoconjunctivitis) after refractive surgery. Retrospective cohort study. Active duty U.S. Army soldiers (n = 143) who opted for refractive surgery. Conjunctival impression cytology samples collected from participants before the surgery were used to harvest DNA for genotyping 5 THBS1 SNPs (rs1478604, rs2228262, rs2292305, rs2228262, and rs3743125) using the Sequenom iPLEX Gold platform (Sequenom, San Diego, CA). Samples collected after surgery were used to harvest RNA for gene expression analysis by real-time polymerase chain reaction (PCR). Participants were followed for 1 year after surgery to monitor the status of keratoconjunctivitis. Genetic basis of the development of chronic keratoconjunctivitis after refractive surgery. Carriers of minor alleles of 3 SNPs each were found to be more susceptible to developing chronic keratoconjunctivitis (rs1478604: odds ratio [OR], 2.5; 95% confidence interval [CI], 1.41-4.47; P = 2.5 × 10(-3); rs2228262 and rs2292305: OR, 1.9; 95% CI, 1.05-3.51; P = 4.8 × 10(-2)). Carriers of the rs1478604 minor allele expressed significantly reduced levels of thrombospondin 1 (TSP1) (P = 0.042) and increased levels of an inflammatory cytokine associated with keratoconjunctivitis, interleukin-1β (P = 0.025), in their ocular surface epithelial cells compared with homozygous major allele controls. Genetic variation in the THBS1 gene that results in decreased expression of the encoded glycoprotein TSP1 in ocular surface epithelial cells significantly increases the susceptibility to develop chronic ocular surface inflammation after refractive surgery. Further investigation of THBS1 SNPs in a larger sample size is warranted.

Effects of ambient levels of traffic-derived air pollution on the ocular surface: Analysis of symptoms, conjunctival goblet cell count and mucin 5AC gene expression

PurposeTo quantify ocular symptoms, goblet cells (GC) and mucin 5AC (MUC5AC) gene expression on the conjunctiva of healthy subjects exposed to ambient levels of traffic-derived air pollution and to estimate its correlation with NO2 and particulate matter smaller than 2.5μm (PM2.5) levels. MethodsTwenty-one taxi drivers or traffic controllers were assessed with the Ocular Surface Disease Index (OSDI) questionnaire and conjunctival impression cytology. MUC5AC mRNA levels were determined based on the cytology of the right eye, and GC density was assessed based on the cytology of the left eye. Mean individual levels of 24-h NO2 and PM2.5 exposure were assessed the day before examination. Possible associations between NO2 or PM2.5 levels, OSDI scores, GC densities and MUC5AC mRNA levels were verified. ResultsThe subjects were exposed to mean PM2.5 levels of 35±12μg/m3 and mean NO2 levels of 189±47μg/m3. OSDI scores were low (7.4±8) and GC densities were 521±257 and 782±322 cell/mm2 on the bulbar and tarsal conjunctivas, respectively. The mean GC-derived MUC5AC mRNA expression was 14±7fM/μg of total RNA. A significant and positive correlation was observed between MUC5AC mRNA levels and tarsal GC density (p=0.018). A trend toward association between PM2.5 levels and tarsal GC cell density (p=0.052) was found. ConclusionExposure to ambient levels of air pollution impacts conjunctival GC density. An increase in MUC5AC mRNA levels may be part of an adaptive ocular surface response to long-term exposure to air pollution.

Comparison of Morphology of Bulbar Conjunctival Cells Assessed by Impression Cytology versus Scrape and Smear Methods

Purpose: To assess the morphology of superficial bulbar conjunctival cells collected by impression cytology or by scraping.Methods: Freshly procured sheep eyes from a slaughterhouse were washed and then conjunctival impression cytology (CIC) samples taken from the nasal aspect of the bulbar conjunctiva on a Biopore Millicell filter unit, or cells scraped from the same location and smeared onto glass slides. After alcohol fixation, all samples were stained with Giemsa. Cell images were obtained by light microscopy at 200× magnification, and subjected to morphometry.Results: Cells obtained by scrape/smear processing appeared larger and less densely staining than cells procured by CIC. This appearance was confirmed by morphometry with measures of cell longest dimension LONG being 27.7 ± 1.3 μm and 21.7 ± 1.5 μm, respectively, while cell AREAC measures averaged 543 ± 42 μm2 and 333 ± 51 μm2; these differences were significant (p < 0.001). Similarly, cell nucleus length (NUCLONG) and nucleus area (AREANUC) were also larger in smeared cells (p < 0.001). Various calculations of nucleo-cytoplasmic ratios as based on dimensions or area were only slightly different when comparing cells obtained by the two methods, indicating that the glass slide-smeared cells simply spread out more than cells on the CIC filters.Conclusions: Differences in cell and nucleus size can result from use of different processing methods. Therefore, in making comparisons between sets of conjunctival cells, it is important that cell collection and processing methods be considered.

The Correlation of Routine Tear Function Tests and Conjunctival Impression Cytology in Dry Eye Syndrome

PurposeTo establish the strength of the association between routine tear function tests and conjunctival impression cytology (CIC) and to determine whether they simulate the morphological and cytological changes that occur on the ocular surface in dry eye. What are the sensitivity, specificity and positive predictive values of these tests when CIC is considered the gold standard?MethodsThe tear film profile included tear film break up time (TBUT), Schirmer's-1, Rose Bengal scores (RBS), and impression cytology. CIC samples were obtained from the inferior bulbar conjunctiva and stained with periodic acid-Schiff and counter stained with hematoxylin and eosin.ResultsThe mean Schirmer's value was 11.66 ± 5.90 in patients and 17.17 ± 2.97 in controls (p < 0.001). The mean TBUT in participants was 8.88 ± 3.54 and 13.53 ± 2.12 in controls (p < 0.001). Patients had a mean goblet cell density (GCD) of 490 ± 213, while the value for controls was 1,462 ± 661 (p < 0.001). Abnormal CIC was observed in 46.7% cases of dry eye and in 32.8% of controls. The correlation coefficient (L) for Schirmer's was 0.2 and 0.24 for participants and controls, respectively, while TBUT values were 0.26 and 0.38, RBS were 0.5 and 0.5, and GCD was 0.8 and 0.6 in cases and controls, respectively.ConclusionsGCD, RBS, and TBUT were better predictors of morphological and cytological changes in the conjunctiva than Schirmer's in dry eye syndrome. The sensitivity of tear function tests in diagnosing dry eye was TBUT > Schirmer's > RBS, and the specificity was Schirmer's > TBUT > RBS in decreasing order when CIC was considered the gold standard.