Conjunctival Impression Cytology Research Articles

Ocular surface involvement and histopathologic changes in the acute stage of Stevens-Johnson syndrome and toxic epidermal necrolysis: a cross-sectional study

BackgroundStevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare and extremely serious drug-induced dermatological disorders. The ocular surface condition at the early stage has been little studied and should contribute to novel perspectives in early and effective topical therapy of these diseases. The objectives of the study were to evaluate the acute phase of ocular surface involvement and histopathologic changes in patients with acute SJS/TEN.MethodsTen patients with acute phase of SJS/TEN onset and eleven age- and sex-matched healthy volunteers were recruited. Ocular surface symptoms and signs, conjunctival impression cytology, and tear multi-cytokine were assessed.ResultsOcular surface objective signs were normal at the acute stage of SJS/TEN, while most patients have abnormal ocular surface subjective symptoms and meibomian gland secretion. Conjunctival impression cytology showed a significant decrease in goblet cell density and severe ocular surface squamous metaplasia in acute SJS/TEN patients. Tear multi-cytokine analysis showed all 21 pro- and anti-inflammatory cytokines all sharply elevated. Goblet cell density was significantly negatively correlated with tear C-X3-C motif chemokine ligand 1 (CX3CL1) and interleukin 13.ConclusionsSevere pathologic squamous metaplasia and inflammation onset in the ocular surface at the acute stage of the SJS/TEN, even if the ocular surface condition seemed basically normal with adequate systemic immunosuppressant and general supportive treatment. Early topical anti-inflammatory therapy should be carried out actively.

Decellularized Porcine Conjunctiva in Treating Severe Symblepharon.

This prospective study aimed to evaluate the effectiveness of decellularized porcine conjunctiva (DPC) in the management of severe symblepharon. Sixteen patients with severe symblepharon were enrolled in this study. After symblepharon lysis and Mitomycin C (MMC) application, tarsus defects were covered with residual autologous conjunctiva (AC), autologous oral mucosa (AOM), or DPC throughout the fornix, and DPC was used for all the exposed sclera. The outcomes were classified as complete success, partial success, or failure. Six symblepharon patients had chemical burns and ten had thermal burns. Tarsus defects were covered with DPC, AC, and AOM in two, three, and eleven cases, respectively. After an average follow-up of 20.0 ± 6 months, the anatomical outcomes observed were complete successes in twelve (three with AC+DPC, four with AC+AOM+DPC, and five with AOM+DPC) (75%) cases, partial successes in three (one with AOM+DPC and two with DPC+DPC) (18.75%) cases, and failure in one (with AOM+DPC) (6.25%) case. Before surgery, the depth of the narrowest part of the conjunctival sac was 0.59 ± 0.76 mm (range, 0-2 mm), tear fluid quantity (Schirmer II tests) was 12.5 ± 2.26 mm (range, 10-16 mm), and the distance of the eye rotation toward the opposite direction of the symblepharon was 3.75 ± 1.39 mm (range, 2-7 mm). The fornix depths increased to 7.53 ± 1.64 mm (range, 3-9 mm), eye movement was significantly improved, and the distance of eye movement reaching 6.56 ± 1.24 mm (range, 4-8 mm) 1 month after the operation; the postoperative Schirmer II test (12.06 ± 2.90 mm, range, 6-17 mm) was similar to that before surgery. Goblet cells were finally found in fifteen patients by conjunctival impression cytology in the transplantation area of DPC, except for one patient who failed. DPC could be considered an alternative for ocular surface reconstruction of severe symblepharon. Covering tarsal defects with autologous mucosa is necessary for extensive reconstruction of the ocular surface.

Comparison of mucin levels at the ocular surface of visual display terminal users with and without dry eye disease

BackgroundThe long-term use of visual display terminals (VDT) is linked to an increased risk of dry eye disease (DED). Numerous studies have indicated that ocular mucins play a vital role in the pathogenesis of DED. Therefore, we aimed to evaluate (1) whether mRNA levels of membrane-associated mucins (MAMs), including MUC1, MUC4, MUC16, and MUC20, as well as MUC5AC are altered in conjunctival cells of VDT users with and without DED and (2) the relationship between mucin levels and subjective and objective tests of DED in VDT users.MethodsSeventy-nine VDT users were enrolled and divided into DED (n = 53) and control (n = 26) groups. All participants were evaluated for parameters of DED using the Ocular Surface Disease Index (OSDI) questionnaire, tear breakup time (TBUT), corneal fluorescein staining (CFS), lissamine green (LG) staining, and tear meniscus height (TMH). Based on the conjunctival impression cytology (CIC) method, differences in MUC1, MUC4, MUC16, MUC20, and MUC5AC mRNA expression levels were observed between the DED and control groups, and between symptomatic and asymptomatic participants.ResultsThe DED group showed significantly decreased MUC1, MUC16, and MUC20 expressions (all P < 0.05) compared to the control group. In addition, these mucin levels were lower in subjects with frequent ocular symptoms (foreign body sensation, blurred vision and painful or sore eyes) than in asymptomatic participants (all P < 0.05). Correlation analysis revealed that MUC1, MUC16, and MUC20 levels in VDT users were positively correlated with TBUT or TMH, or both. However, no significant relationship was found between MUC4 and MUC5AC levels and the DED parameters.ConclusionVDT users with an increased frequency of ocular discomfort or a diagnosis of DED had a decreased MUC1, MUC16 and MUC20 mRNA expression in their conjunctival cells. MAMs deficiency in the conjunctival epithelium may be one of the mechanisms leading to tear film instability and DED in VDT users.

Effect of Vitamin D Deficiency and Its Supplementation on Both Conjunctival Impression Cytology and Tear-Film Changes

Effect of Vitamin D Deficiency and Its Supplementation on Both Conjunctival Impression Cytology and Tear-Film Changes

Conjunctival Impression Cytology for Diagnosis and Grading of Dry Eye

Conjunctival Impression Cytology for Diagnosis and Grading of Dry Eye

Dupilumab-associated ocular surface disease in atopic dermatitis patients: clinical characteristics, ophthalmic treatment response, and conjunctival goblet cell analysis.

Dupilumab-associated ocular surface disease (DAOSD) is frequently reported as side effect in atopic dermatitis (AD) patients. Therefore, the aim of this study was to investigate the frequency and severity of DAOSD, ophthalmic treatment response, and to learn more about the effect of dupilumab on conjunctival goblet cells (GC). This prospective study included dupilumab-treated AD patients between February 2020 and June 2022 from the University Medical Centre Utrecht. Patients were examined by an ophthalmologist and a dermatologist before start (baseline), and after 4 and 28 weeks of dupilumab treatment. Ophthalmological examination was assessed by the Utrecht Ophthalmic Inflammatory and Allergic disease (UTOPIA) score. DAOSD was defined as an increase in UTOPIA score of ≥3 points from baseline. To quantify conjunctival GCs and to investigate the percentage of Cytokeratin 19 (CK19)-CD45-Mucin 5AC (MUC5AC)+ cells, conjunctival impression cytology samples were analysed. Ocular surface disease (OSD) was present in 91.3% (n=63/69) patients at baseline. DAOSD was observed in 28.9% (n=20/69) patients, in whom GC numbers remained stable and the percentage of CK19-CD45-MUC5AC+ cells decreased at onset of DAOSD compared with baseline. After 28 weeks of dupilumab treatment, DAOSD was seen in 14.5% (n=10/69) patients. Of the 85.5% (n=59/69) patients without DAOSD or with controlled DAOSD at week 28, 40.7% (n=24/59) patients received anti-inflammatory ophthalmic drugs. OSD is common in moderate-to-severe AD patients before starting dupilumab. During treatment with dupilumab DAOSD severity improves with early ophthalmic treatment. The decrease in percentage of CK19-CD45-MUC5AC+ cells during dupilumab treatment suggests an impairment of the GC function due to dupilumab treatment.

Clinical observation of recombinant human nerve growth factor in the treatment of neurotrophic keratitis.

To characterize changes of corneal nerve morphology and tear indices in patients with neurotrophic keratitis (NK) treated with recombinant human nerve growth factor (rhNGF). In a prospective observational study, six patients (nine eyes) were locally treated with rhNGF. Visual acuity, corneal fluorescein staining score, the heights of the tear river, lipid layer thickness (LLT), tear ferning (TF) test, conjunctival impression cytology (CIC) examination, the densities of cornea subbasal nerve fibers were determined before and after treatment. Compared with baseline, there was a significant difference in corneal fluorescence staining scores (P<0.01); all patient corneal epithelial defects recovered completely within 8wk, but there was no significant improvement in the height of the tear river (P=0.202). LLT was significantly increased when compared with baseline (P=0.042); however, the function of conjunctival goblet cells and mucin content did not significantly improve using the TF test and CIC examination (P=0.557, P=0.539). After 8wk of treatment, the average corneal subbasal nerve fiber density increased significantly (P<0.01), as did the number of corneal nerve fiber branches (P=0.001). RhNGF can increase the density of corneal subbasal nerve fibers, promote the healing of persistent corneal epithelial defects and corneal ulcers in patients with NK, also improving tear function partially.

Evaluation of Dry Eye Severity and Ocular Surface Inflammation in Patients with Pemphigus and Pemphigoid

ABSTRACT Purpose To evaluate ocular surface involvement, tear cytokine levels, and histopathological changes in pemphigus and pemphigoid patients. Methods A total of 22 patients (15 pemphigus and 7 pemphigoids) and 21 non-diseased controls were enrolled in our study. All participants underwent ocular surface evaluation, which included ocular surface disease index test, slit lamp observation, dry eye-related examination, tear multicytokine analysis, and conjunctival impression cytology. Results Pemphigus and pemphigoid patients presented much more severe conjunctivochalasis, corneal epithelial defects, corneal opacity, symblepharon and dry eye. Severe ocular surface squamous metaplasia and a significant increase of tear macrophage inflammatory protein-1beta, tumor necrosis factor-alpha, interleukin (IL)-1β, IL −6, and IL-8 occurred in pemphigus and pemphigoid patients. Conclusions Our results revealed that ocular surface inflammation and dry eye persist in most pemphigus and pemphigoid patients, and do not occur in parallel with the systemic course. Regular ophthalmological examinations and local anti-inflammatory should be provided for pemphigus and pemphigoid patients.

Clinico-cytological analysis of conjunctiva and ocular surface symptoms of patients on topical anti-glaucoma medications attending Lagos University Teaching Hospital, Lagos, Nigeria: A case-control study.

The long-term use of topical anti-glaucoma medications is often associated with ocular surface toxicity that can affect the patient's drug compliance and quality of life. This study assessed the effect of these medications, using cytological changes of the conjunctiva and ocular surface symptoms. This was a clinic-based, case-control study that was conducted at the Lagos University Teaching Hospital that compared glaucoma patients on topical medications with age-sex-matched controls. The controls were non-glaucoma patients, who were not on any topical ocular medications at least 6 months prior to the study. The Ocular Surface Disease Index (OSDI) questionnaire was used to assess ocular surface symptoms. Schirmer's I test, tear film break-up time (TBUT) test and corneal fluorescein staining of the ocular surface were used for ocular surface disease (OSD) assessment and conjunctival impression cytology (CIC) for histological assessment and grading. Six hundred and ninety-six eyes of 348 respondents, 174 cases and 174 controls, were assessed for OSD. The mean ages of the case and control groups were 56.3 ± 12.9 years and 55.5 ± 13.2 years, respectively, with no statistical difference (P = 0.589). All ocular parameters assessed were significantly abnormal in the case group compared to the control group. The use of topical anti-glaucoma medications was significantly associated with abnormal TBUT (P < 0.001), Schirmer's test (P < 0.001), ocular surface staining (P < 0.001), CIC (P < 0.001) and OSDI scores (P = 0.001). A significant association was seen between abnormal TBUT and the number of medications (P = 0.044, odds ratio [OR] =0.79, 95% confidence interval [CI]: 0.44-1.14), between abnormal ocular surface staining and duration of anti-glaucoma medications usage (P = 0.0104, OR = 1.2, 95% CI: 1.04-1.43) and between abnormal CIC and the duration of anti-glaucoma medications (P = 0.0007, OR = 0.7, 95% CI: 0.59-0.86). The study demonstrates that prolonged use of topical anti-glaucoma medications may be associated with damage to the ocular surface structures.

Dry eye syndrome model established in rabbits via mitomycin C injection in the lacrimal gland.

To develop a new dry eye syndrome (DES) animal model by injecting mitomycin C (MMC) into the lacrimal glands (LGs) of rabbits evaluated by clinical examinations. A volume of 0.1 mL of MMC solution was injected in the LG and the infraorbital lobe of the accessory LG of rabbits for DES induction. Twenty male rabbits were separated into three groups, the control group, and different concentration of MMC, (MMC 0.25: 0.25 mg/mL or MMC 0.50: 0.5 mg/mL) were tested. Both MMC-treated groups received MMC twice injection on day 0 and day 7. Assessment of DES included changes in tear production (Schirmer's test), fluorescein staining pattern, conjunctival impression cytology, and corneal histological examination. After MMC injection, no obvious changes in the rabbit's eyes were noted by slit-lamp examination. Both the MMC 0.25 and the MMC 0.5 groups revealed decreased tear secretion after injection, and the MMC 0.25 group showed a continuous decrease in tear secretion up to 14 days. Fluorescent staining showed punctate keratopathy in both MMC-treated groups. In addition, both MMC-treated groups demonstrated decreased numbers of conjunctival goblet cells after injection. This model induced decreased tear production, punctate keratopathy, and decreased numbers of goblet cells, which are consistent with the current understanding of DES. Therefore, injecting MMC (0.25 mg/mL) into the LGs is an easy and reliable method to establish a rabbit DES model which can apply in new drug screening.

Conjunctival impression cytology and its varying patterns in controlled and uncontrolled diabetic patients

Conjunctival impression cytology and its varying patterns in controlled and uncontrolled diabetic patients

Conjunctival impression cytology in chronic cement exposure: A comparative study

Conjunctival impression cytology in chronic cement exposure: A comparative study

Correlation of Conjunctival Impression Cytology and Clinical Examination in University Students at Lahore during the COVID-19

During COVID 19 pandemic every home-bound school, college, and university student was using computers and electronic gadgets for social networking and online education. To assess the effects of these gadgets on ocular and vision-related problems, very little research had been done on the Pakistani population, especially among university students. An analytical cross-sectional study was carried out on 355 students of University of the Punjab. Questionnaire-based data were collected by measurement of tearfilm breakup time(TBUT), the number of corneal dry spots, Schirmer’s test, and conjunctival impression cytology(CIC). Pearson correlation analysis was done on CIC score versus TBUT, Schirmer’s test and Goblet Cell Density (GCD). Analysis of variance (ANOVA) was used for mean comparison of visual acuity, TBUT, cornea spots, and Schirmer’s test to see the significance of the results. P-value≤0.05 was considered statistically significant. Out ofthe 355 students, 65% were females. The mean age of the students was 22.30 ± 6.8 years. At each level of visual acuity, there was no statistically significant difference between the meansof the different levels of visual acuity (F=0.488, p=0.614). A statistically significant meandifference was found between CIC score and TBUT (F=208.45p=&lt;0.001), CIC score andcornea spot (F=39.31, p=&lt;0.001), CIC score and Schirmer’s test (F=5.83, p=0.001). Forthe early diagnosis and management of CVS, in addition to applying the validated questionnaire and clinical dry eye tests, the Conjunctival impression cytology can be tested on a larger population to be proven as a gold slandered test.

Evidence of air pollution-related ocular signs and altered inflammatory cytokine profile of the ocular surface in Beijing

We evaluated how different degrees of air pollution affect the ocular surface of a cohort of human subjects in Beijing by correlating in-patient test outcomes with tear cytokines. A cross-sectional study involving 221 volunteers was carried out in different districts of Beijing. Air pollution indices were recorded for 7 d (including the visit day). The indices recorded were the air quality index (AQI), which is a dimensionless measure that quantitatively describes the state of air quality, concentrations of particulate matter smaller than 2.5 μm (PM2.5) and 10 μm (PM10), sulfur dioxide (SO2), ozone (O3), and nitrogen dioxide (NO2). The Ocular Symptom Disease Index (OSDI) questionnaire provided. Subsequently, subjects underwent slit-lamp examination, which included meibomian gland examination, conjunctival congestion score, conjunctivochalasis grade, tear meniscus height (TMH), tear breakup time (TBUT), corneal fluorescein staining (CFS), Schirmer I test, and conjunctival impression cytology. The concentrations of vascular endothelial growth factor (VEGF), interleukins (IL)-1β, IL-6 and IL-8 in tears were measured by microsphere-based immunoassay analysis. According to the value of the AQI, participants are divided into a slightly polluted (SP) group (n = 103) which the AQI value is less than or equal to 100 and a heavily polluted (HP) group (n = 118) whose AQI value is more than 100. Air pollution is related to ocular discomfort based on tear cytokine concentrations. PM2.5, PM10 and NO2 were positively correlated with OSDI, MG expressibility, meibum score, meiboscore, conjunctival congestion score, Schirmer I test value, TMH, goblet-cell density, concentrations of IL-6, and VEGF were negatively correlated with TBUT. PM2.5 and PM10 appear to be the major risk factors to the ocular surface, with NO2 being another important risk factor based on this study. The symptoms and signs of eye discomfort in the SP group were significantly less severe than those in the HP group, and tear cytokine concentrations (IL-6 and VEGF) were lower. Air pollution degrees were significantly correlated with tear cytokine concentrations, indicating an alteration of cytokine balance at the ocular surface under different degrees of air pollution.

Analytical Study of Ocular Surface Changes in Patients of Chronic Kidney Disease undergoing Hemodialysis and Peritoneal Dialysis

Objectives The idiopathic group is a significant cause of chronic kidney disease (CKD) in developing countries. Literature available on ocular surface changes has predominantly been reported in patients undergoing hemodialysis. Little is known about the changes in patients undergoing peritoneal dialysis. The present study aimed to identify ocular surface changes in an idiopathic group of CKD undergoing dialysis. Aim To compare tear film disorders and the severity of ocular surface changes (goblet cell density, squamous metaplasia, and corneoconjunctival calcification) in patients of idiopathic etiology with CKD undergoing hemodialysis and peritoneal dialysis. This is an analytical study. Materials and Methods Asymptomatic adult patients of idiopathic CKD, on treatment with dialysis underwent comprehensive ophthalmic examination, including best-corrected visual acuity, slit-lamp examination, and a dilated fundus examination. Dry eye assessment was done by ocular surface staining score, Schirmer test, and tear breakup time (TBUT). Conjunctival impression cytology was studied to assess changes on ocular surface. Chest X-rays for aortic calcification were reviewed and data analyzed. Results Both eyes of 76 patients of hemodialysis and 32 patients of peritoneal dialysis were studied. Ocular surface staining (OSS) scores were low. Impression cytology showed a drop in goblet cell density, presence of squamous metaplasia, and conjunctival keratinization significantly more in the hemodialysis group. No correlation was seen between the presence of conjunctival calcification and aortic calcification. Conclusion The hemodialysis group had mild subclinical dry eye but keratinization of conjunctiva was seen. Similarly, advanced squamous metaplasia was seen in the peritoneal dialysis group. These changes were positively correlated to decrease in goblet cell density.

Ocular Surface in Patients With Obstructive Sleep Apnea Syndrome: Evaluation of Clinical Parameters and Impression Cytology.

To evaluate the effect of obstructive sleep apnea syndrome (OSAS) on the ocular surface and conjunctival cytology and the relationship between the findings and disease severity. One hundred six eyes of 106 patients (77 patients with OSAS and 29 control subjects) were included in the study. Twenty-three patients with an apnea-hypopnea index (AHI) of 5 to 15 were classified as mild OSAS (group 1), 27 patients with an AHI of 15 to 30 were classified as moderate OSAS (group 2), and 27 patients with an AHI≥30 were classified as severe OSAS (group 3). The following tests were used to evaluate the ocular surface: tear break-up time (TBUT), Schirmer I test, ocular surface disease index (OSDI), and conjunctival impression cytology (CIC). The results obtained from the tests were analyzed and compared between the groups. The mean value of the Schirmer I test was 15.03±10.16 (1-35) mm in the control group, whereas it was found as 13.39±8.80 (3-35) mm, 9.85±7.81 (1-30) mm, and 9.41±7.53 (2-35) mm in the mild, moderate, and severe OSAS groups, respectively, and the difference between the groups was significant ( P =0.002). Although the mean TBUT score was 9.83±5.03 (3-23) seconds in the control group, it was 11.04±6.22 (3-20), 6.26±3.48 (1-16), and 5.44±3.09 (1-10) in the mild, moderate, and severe OSAS groups, respectively, and the difference between the groups was significant ( P <0.001). Although the mean OSDI score was 12.76±14.84 (range, 0-41.65) in the control group, it was 11.52±12.95 (range, 0-44.40), 25.06±19.45 (range, 0-75), and 20.31±19.87 (range, 0-77.70) in the mild, moderate, and severe OSAS groups, respectively, and the difference between the groups was significant ( P =0.015). Although the mean CIC stage was 0.47±0.60 (0-2) in the control group, it was 0.89±0.74 (0-2), 1.52±0.75 (0-3), and 1.83±0.69 (1-3) in the mild, moderate, and severe OSAS groups, respectively, and the difference between groups was significant ( P <0.001). In addition to decreased tear production and TBUT, cytological changes including squamous metaplasia were detected between patients with OSAS and the control group.

Ocular surface characteristics in pediatric vernal keratoconjunctivitis: a clinico-cytological study

To compare the ocular surface parameters of children with vernal keratoconjunctivitis (VKC) with those of healthy controls and to correlate cytological characteristics with clinical findings and disease severity. Newly diagnosed cases of VKC, not currently being treated, were recruited, along with age-matched controls with no ocular comorbidities. The Ocular Surface Disease Index questionnaire (OSDI) was administered to all children. Slit lamp biomicroscopy for meibomian gland dysfunction and ocular surface analysis was performed, including tear meniscus height, noninvasive tear film break-up time, lipid layer thickness, meibomian gland morphology, and meibomian gland duct distortion on meibography imaging. Conjunctival impression cytology was also performed. A total of 68 VKC patients and 33 controls were included. Statistically significant difference was seen in the mean OSDI score (30 ± 13.7 vs 16.1 ± 3 [P ≤ 0.01]), lipid layer thickness (24.2 ± 7.9 nm vs 69.9 ± 15.1 nm [P <0.001]), and noninvasive tear film break-up time (6.8 ± 1.7 vs 12.5 ± 1.8 sec [P < 0.01]) between groups. Mean tear meniscus height was 0.22 ± 0.06 mm in the VKC and 0.24 ± 0.04 mm in the control group (P = 0.096). Significant association was seen between grade of squamous metaplasia and severity of VKC (P<0.01). Severity of VKC was found to be positively correlated with OSDI score (r=0.767), grade of squamous metaplasia (r = 0.64) and negatively correlated with noninvasive tear film break-up time (r = -0.468), and lipid layer thickness (r = -0.253). This study highlights the poor ocular surface health of children with VKC, with severe disease being associated with worse forms of dry eye disease.

Impact of unilateral trigeminal neuralgia on bilateral ocular surface alterations.

To evaluate ocular surface alterations in both eyes of patients with unilateral trigeminal neuralgia (TN) compared with controls. Corneal nerves mainly originate from the trigeminal nerve, and neurosensory abnormalities are important factors in ocular surface alterations and dry eye etiopathogenesis. Twenty-four patients with idiopathic unilateral TN and 24 healthy controls with similar sex and age distributions were included in this cross-sectional study conducted from February 15 to September 15, 2021. The eyes on the affected sides of the patients with TN were treated as Group 1, their contralateral eyes as Group 2, and the right eyes of the controls as Group 3. All participants were evaluated for tear film and ocular surface using the Schirmer 1 test, tear breakup time (TBUT), Ocular Surface Disease Index (OSDI) score, and conjunctival impression cytology grading. The mean (SD) ages of the patients with TN (17 of 24 females, 70.8%) and controls (15 of 24 females, 62.5%) were 49.7 (11.7) and 48.5 (9. 6) years, respectively. The median [25th, 75th percentile] Schirmer 1 test results in Groups 1, 2, and 3 were 5.0 [4.0, 14.0], 7.0 [3.2, 11.7], and 10.0 [6.0, 15.7] mm, respectively, with no statistically significant differences between Groups 1 and 2 (p=0.697), Groups 1 and 3 (p=0.133), or Groups 2 and 3 (p=0.129). The median TBUT scores in Groups 1, 2, and 3 were 7.0 [5.0, 10.0], 8.0 [5.2, 10.0], and 12.5 [8.0, 13.0] s, respectively, showing reduced times for both Groups 1 and 2 versus Group 3 (median difference=-3.0 [95% CI: -5.0, -1.0], p=0.001, and median difference=-3.0 [95% CI: -5.0, -2.0], p=0.001, respectively). Conjunctival impression cytology grades were significantly higher in Groups 1 and 2 versus Group 3 (median difference=2.0 [95% CI: 1.0, 2.0], p < 0.001, and median difference=1.0 [95% CI: 1.0, 2.0], p < 0.001, respectively). The median OSDI score in TN patients (30.2 [25.0, 34.9]) was significantly higher than in the controls (8.3 [0.0, 18.7]), with a median difference of 20.8 (95% CI: 14.7, 27.1), p < 0.001. Even if pain is unilateral in patients with TN, there are significant abnormalities in conjunctival cytology and tear functions in both eyes. There seem to be various pathophysiological mechanisms of TN that affect the bilateral ocular surface and lead to significant alterations.

Evaluation and comparison of subjective and objective anterior ocular surface damage in patients with type 2 diabetes mellitus and dry eye disease.

To evaluate anterior ocular surface damage in patients with type 2 diabetes mellitus and dry eye disease in comparison to non-diabetic controls based on conjunctival impression cytology, objective scales (Efron, Oxford) and OSDI, to correlate vision-related quality of life with grades of squamous metaplasia in T2DM patients suffering from DED. All participants underwent complete ophthalmologic examination including Shirmer test, TBUT, conjunctival/corneal staining (Oxford scheme), evaluation of conjunctival redness (Efron grading scale), and conjunctival impression cytology (Nelson's scale). The OSDI questionnaire was completed by both groups of patients to assess severity of DED and QoL. Squamous metaplasia was observed in 94% of the study group and 19.3% of controls (p = 0.0000). Based on the OSDI scores, 73.5% of patients reported mild DED and 26.5% suffered from moderate DED in the study group. The mean OSDI score for the study group with Nelson's grade 2 was 18 ± 3.52 and 20.8 ± 4.68 for Nelson's grade 3, respectively (p = 0.0745). Hence, no significant difference in QoL between grade 2 and grade 3 of squamous metaplasia was observed in patients of the study group. Impression cytology is a reliable minimally invasive tool for an accurate evaluation of the ocular surface damage in patients with DED and type 2 diabetes mellitus. Severe squamous metaplasia (Nelson's grade 3) was observed in 29.4% (10/34) of T2DM patients. In contrast, it was not detected in the control group (p = 0.0032). The absence of goblet cells in T2DM patients nether significantly reduces QoL nor contributes to the subjective DED severity (OSDI) due to complex pathways leading to DED. Thus, diagnosis of DED severity should not be solely based on subjective symptoms in this population.

Changes in tear glucose and insulin concentrations following an oral glucose tolerance test

ABSTRACT Clinical relevance Tear glucose and insulin are responsible for the health of the ocular surface; thus, it is important for clinicians to detect the tear glucose and insulin using point-of-care methods. Aim To determine if changes in blood glucose and insulin levels following an oral glucose tolerance test are reflected in the tears and to test the association between gene expression and tear insulin and glucose. Methods Twenty healthy young adults were enrolled. Basal tears and peripheral blood samples were collected to assess glucose and insulin using a point-of-care glucometer and ELISA assays in fasted subjects, and 1.5 and 3 h after an oral glucose challenge. Conjunctival impression cytology was collected to determine gene expression of insulin receptor (INSR) and glucose transporters (GLUT1 and GLUT4). Changes were examined using non-parametric one-way ANOVA. Spearman tests were conducted to examine associations between variables. Results Glucose and insulin levels increased 1.5 h after oral glucose in both blood (P < 0.001) and tears (P < 0.049) and returned to near baseline values after 3 h. There was a positive correlation between glucose levels in the blood and tears (rho = 0.57, P < 0.001), but not between blood and tear insulin levels (P = 0.18). Glucose and insulin levels in tears were correlated (rho = 0.32, P = 0.048). Tear glucose concentration at 1.5 h after oral glucose was associated with INSR expression (rho = 0.49, P = 0.03), and there was a trend with GLUT1 (P = 0.06) but not GLUT4. Conclusion Tear glucose reflected blood glucose levels but this correspondence was not observed for insulin. Further studies are required to determine the role of glucose and insulin on the ocular surface in both health and diabetes.