The impact of prolonged face mask use on ocular surface health during COVID-19 pandemic: a clinical, and conjunctiva impression cytology study.

PURPOSE: To investigate the relationship between prolonged face mask use and ocular surface health utilizing conjunctival impression cytology, the Schirmer test, the tear break-up time (TBUT) test, and the ocular surface disease index (OSDI) questionnaire. METHODS: In this cross-sectional prospective study, individuals who used face masks for at least eight hours per day for at least six months were compared to healthy volunteers who used face masks for no more than one hour per day. Each participant completed an OSDI questionnaire. The Schirmer test (under anesthesia), the TBUT test, and conjunctiva impression cytology analysis according to the Nelson classification method were performed on each participant. RESULTS: This study included 102 (49 male, 53 female) face mask users with an average age of 33.29 ± 7.71 years and 110 (60 male, 50 female) healthy controls with an average age of 32.96 ± 7.10 years (p = 0.746). The total OSDI score was significantly higher in face mask users than the control group (25.18 ± 3.54 vs 9.46 ± 2.13, p < 0.001). The mean Schirmer test value and TBUT were significantly lower in the study group than the control group (p < 0.001, p < 0.001). There was a statistically significant difference between the two groups in total score and stage of the Nelson classification system (p < 0.001, and p = 0.024, respectively). All conjunctiva impression cytology assessments, including cellularity, cell-cell contact, nucleus/cytoplasma ratio, goblet cell amount, and metaplasia, revealed statistically significant deterioration in the study group compared to the control group (p < 0.001, p = 0.025, p < 0.001, p < 0.001, and p < 0.001, respectively). CONCLUSION: The prolonged use of face masks leads to dry eyes. The findings of conjunctiva impression cytology indicate the role of inflammation in the pathogenesis of mask associated dry eye.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

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

BACKGROUND: Stevens-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. METHODS: Ten 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. RESULTS: Ocular 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. CONCLUSIONS: Severe 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.

[Evolution of dry eye disease diagnostics]. / Evolyutsiya metodov diagnostiki sindroma sukhogo glaza.

This article reviews modern functional and instrumental examination methods included in the diagnostic algorithm for dry eye disease. The described methods can serve as an objective criterion for the effectiveness of the therapy.

Quantitation of Pax-6 protein in ocular impression cytology samples using an electrochemiluminescence immunoassay.

Paired box protein Pax-6 (oculothrombin) is a transcription factor that plays an important regulatory role in ocular, brain, and pancreatic development. Mutations of the PAX6 gene cause aniridia and Peters anomaly. Reduction in Pax-6 protein is also associated with ocular diseases such as dry eye. An electrochemiluminescence immunoassay method using the Meso Scale Discovery platform was developed to measure Pax-6 protein levels in corneal epithelial cells obtained by impression cytology. Impression cytology involves harvesting ocular epithelial cells by applying a polyethersulfone membrane patch briefly to the ocular surface using a commercially available EYEPRIM™ device. The epithelial cells that adhere to the membrane patch of the EYEPRIM™ device provide a biological sample which can be assayed for Pax-6 protein levels. Assay development identified an antibody pair capable of detecting purified recombinant Pax-6 protein produced in mammalian cells. The optimized assay has a dynamic range of 24 pg mL-1 to 100,000 pg mL-1 and a lower limit of quantification of 24 pg mL-1. Assay selectivity was demonstrated using either HeLa or HEK293 cells transfected with inhibitory RNA. Finally, the method was validated by measuring Pax-6 protein levels in impression cytology acquired samples obtained using the EYEPRIM™ device from rabbit cornea.

Impact of unilateral trigeminal neuralgia on bilateral ocular surface alterations.

OBJECTIVE: To evaluate ocular surface alterations in both eyes of patients with unilateral trigeminal neuralgia (TN) compared with controls. BACKGROUND: Corneal nerves mainly originate from the trigeminal nerve, and neurosensory abnormalities are important factors in ocular surface alterations and dry eye etiopathogenesis. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

The ocular surface findings in alopecia areata patients: clinical parameters and impression cytology.

PURPOSE: The objective of this study was to examine the effects of alopecia areata (AA) on the ocular surface and conjunctival cytology. METHODS: A total of 48 subjects were included in the present study. Twenty-three subjects were assigned to group 1 as the patient group, and 25 healthy individuals were included in group 2 as the control group. The ocular surface examination was performed, and the right eyes of all participants were included in the analysis. Both groups underwent the following tests for evaluation of ocular surface: tear break-up time (TBUT), Schirmer I test, Ocular Surface Disease Index (OSDI), and conjunctival impression cytology (CIC). Results obtained from the tests were then analyzed and compared between the groups. RESULTS: The mean TBUT value was significantly lower in Group 1 compared to Group 2 (4.96 ± 3.4 vs 10.52 ± 4.8 s) (p < 0.001). There was no significant difference between Group 1 and Group 2 in terms of the mean Schirmer I test score (p = 0.129). The mean OSDI score was higher in Group 1 compared to Group 2 (15.48 ± 10.4 vs 9.61 ± 13.4), but the difference between both groups was not statistically significant (p = 0.1). The mean CIC score was statistically significantly higher in Group 1 than in Group 2 (1.65 ± 0.7 vs 0.52 ± 0.5) (p < 0.001). CONCLUSION: The results of this study showed that AA was correlated with significant disturbances in conjunctival cytology and the tear function.

[Visualization of normal ocular surface microflora via impression cytology sample using scanning electron microscopy with lanthanide contrasting]. / Vizualizatsiya normal'noi mikroflory glaznoi poverkhnosti posredstvom impressionnoi proby s ispol'zovaniem skaniruyushchego elektronnogo mikroskopa i lantanoidnogo kontrastirovaniya.

PURPOSE: To determine the possibilities of impression cytology (IC) with subsequent visualization of the sample on a scanning electron microscope in assessment of normal microflora of the ocular surface. MATERIALS AND METHODS: The article presents a visual characteristic of the microorganisms of the ocular surface (OS) captured during impression cytology (IC) in individuals without signs of inflammatory and degenerative eye diseases. The original method of staining the sample with heavy metal salts made it possible to identify the individual signs of the microorganisms in their subsequent visualization by scanning electron microscopy (SEM). RESULTS: The paper presents photomicrographs of the microorganisms most common for the OS obtained with the help of SEM, confirming and supplementing the data of non-visual methods of studying the ocular microflora. It was shown that the detection frequency of the microbial component of the OS by the visual method presented in this study is comparable with the detection frequency when using the microbial cultivation method (<80%). Coccoid and rod-shaped microorganisms were detected with relatively equal frequency, with the coccoid organisms mainly represented in association with epithelial cells. The morphological diversity of rod-shaped microorganisms is shown. CONCLUSION: The results of the study can be used as a visual reference for the normal microbiome of the eye.

Optimization of goblet cell density quantification methods.

The purpose of this study was to develop a standardized, accurate and efficient method for estimating conjunctival goblet cell density (GCD) via optimizing sample storage conditions and quantification methods. Conjunctival impression cytology (CIC) membranes were collected from both eyes of 32 participants and were randomized to two storage durations (2-3 weeks, 6-7 weeks) and two storage container types (microcentrifuge tube, flat histology cassette). The CIC membranes were stained and subdivided into 25 areas (5 mm × 5 mm) for imaging and the GCs were counted under 200X magnification using three different methods: (1) full CIC membrane GC count of the 25 images with cell-counting software ("full"; reference method), (2) partial membrane GC count of 9 images with cell-counting software ("partial"), and (3) manual counting of the 25 images ("manual"). In all cases, GCD was determined by dividing the GC count by the counting area. The average time required for quantification was recorded to gauge efficiency. Results showed no significant difference in GC count between the two storage durations (p = 0.745) or storage container types (p = 0.552). The median (interquartile range (IQR)) time required to quantify a CIC membrane for the full, partial, and manual methods of GC counting, was 14.8(17.6), 4.6(5.2) and 5.0 (5.0) minutes, respectively. The agreement of GCD values between the full and manual methods (bias: 0.4, 95% LOA: [-4.6, 5.5]) was stronger than that comparing the full and partial methods (bias: 0.5, 95% LOA: [-18, 17]). All together, through systematic examination of key procedural variables, an optimized method for GCD quantification within 7 weeks of sample collection was outlined. Adaption of procedures described in this paper to facilitate accurate and efficient GCD quantification may serve as a valuable step in clinical trials investigating DED pathophysiology and/or novel DED treatment strategies.

Simplified ex-vivo drug evaluation in ocular surface cells: Culture on cellulose filters of cells obtained by impression cytology.

Drug development, resource- and time-intensive, extensively employs cell-based assays to assess the efficacy and safety of candidate drugs. The widely used immortalized cell lines, experimentally convenient, have limited predictive value. In contrast, ex-vivo models more faithfully reproduce diseases but are technically challenging to establish. To address this need, we developed a simplified process for ex-vivo cell culture, demonstrating its feasibility in ocular surface cells. Conjunctival cells were harvested by impression cytology and grown on mixed cellulose ester membrane filters (MCFs). Human and rabbit conjunctival cells cultured on MCFs are 100% viable at 24 h, and 43% viable at 72 h. A gene expression study evaluating 84 genes involved in ocular inflammation demonstrated that ex-vivo culturing maintains intact the expression of two thirds of these genes in human cells. That these cells are suitable for the assessment of ocular drugs was demonstrated by studying the effect of phosphosulindac (PS), a small molecule under development for the treatment of dry eye disease, in both human and rabbit conjunctival cells. PS, for example, suppressed the expression of CXCL10, a cytokine participating in the pathogenesis of dry eye disease, in human and in rabbit conjunctival cells cultured ex-vivo by 32% and 70%, respectively. Conjunctival cells cultured ex-vivo can be transfected to evaluate mechanistic questions. We successfully transfected such cells with a plasmid expressing luciferase under the control of an IFN-γ-responsive promoter or its control plasmid. IFN-γ stimulated luciferase expression by 85% in cells with the responsive plasmid but not in controls; PS significantly suppressed this induction by 37% without affecting the control plasmid. These findings demonstrate that human and rabbit conjunctival cells cultured ex-vivo with our method are viable and maintain their biological integrity; respond to biological and pharmacological agents; and are transfectable with informative plasmids. The unique advantage of this method is to potentially accelerate the development of novel drugs for the treatment of ocular surface diseases, and to advance our understanding of ocular surface pathophysiology.

Cellular Imprinting Proteomics Assay: A Novel Method for Detection of Neural and Ocular Disorders Applied to Congenital Zika Virus Syndrome.

Congenital Zika syndrome was first described due to increased incidence of congenital abnormalities associated with Zika virus (ZIKV) infection. Since the eye develops as part of the embryo central nervous system (CNS) structure, it becomes a specialized compartment able to display symptoms of neurodegenerative diseases and has been proposed as a noninvasive approach to the early diagnosis of neurological diseases. Ocular lesions result from defects that occurred during embryogenesis and can become apparent in newborns exposed to ZIKV. Furthermore, the absence of microcephaly cannot exclude the occurrence of ocular lesions and other CNS manifestations. Considering the need for surveillance of newborns and infants with possible congenital exposure, we developed a method termed cellular imprinting proteomic assay (CImPA) to evaluate the ocular surface proteome specific to infants exposed to ZIKV during gestation compared to nonexposure. CImPA combines surface cells and fluid capture using membrane disks and a large-scale quantitative proteomics approach, which allowed the first-time report of molecular alterations such as neutrophil degranulation, cell death signaling, ocular and neurological pathways, which are associated with ZIKV infection with and without the development of congenital Zika syndrome, CZS. Particularly, infants exposed to ZIKV during gestation and without early clinical symptoms could be detected using the CImPA method. Lastly, this methodology has broad applicability as it could be translated in the study of several neurological diseases to identify novel diagnostic biomarkers. Data are available via ProteomeXchange with identifier PXD014038.

Evaluation of the ocular surface by impression cytology in patients with endometriosis.

OBJECTIVE: The aim of this study was to investigate the effect of endometriosis on the ocular surface. METHODS: A total of 50 patients were included in the study and divided into two groups. Group 1 consisted of 25 patients with endometriosis. Group 2 had 25 control patients. All patients underwent complete ophthalmic examination, and the right eyes were included in the study. To evaluate the ocular surface, both groups were tested with the following: the Schirmer I test, tear breakup time (TBUT), the conjunctival impression cytology (CIC), and the Ocular Surface Disease Index (OSDI). The results were subsequently compared. RESULTS: The average Schirmer I test results were 8.40 ± 2.74 mm in group 1 and were significantly lower in patients with endometriosis (P < 0.001). The average TBUT test results were 9.04 ± 3.61 s in group 1 and were significantly lower in patients with endometriosis (P < 0.001). The average OSDI results were 24.04 ± 9.29 in group 1 and were significantly higher in patients with endometriosis (P < 0.001). The average CIC results were 1.76 ± 0.88 in group 1 and were significantly higher in patients with endometriosis (P < 0.001). CONCLUSIONS: Ocular surface changes, including squamous metaplasia, may be observed in the conjunctiva of patients with endometriosis.

Assessment of goblet cell size and density in relation to epithelial cell (multi)layering on conjunctival impression cytology samples.

PURPOSE: To assess goblet cell size and numbers in relation to the extent of multilayering of conjunctival impression cytology (CIC) samples as a basis for reducing variability in image selection for goblet cell density (GCD) estimates. METHODS: CIC was undertaken immediately postmortem off the superior bulbar conjunctiva of healthy young adult rabbits onto Millicell-CM Biopore filter units. After fixation with buffered glutaraldehyde and Giemsa staining, two × 200 images were selected from each sample representative of either slight multilayering or substantial multilayering, projected at × 1000, an overlay of the outlines of the goblet cells was made, and their dimensions and areas were measured. RESULTS: From measures of 4918 goblet cells, the average value (+/- SD) for the longest dimension was 17.7 ± 6.4 µm and 14.6 ± 5.3 µm for the shortest dimension. The GCD values ranged from 210 to 2069/mm2, with a mean of 1074 ± 601/mm2, but was lower for slightly multilayered images (at 537 ± 239 cells/mm ) compared with multilayered regions (at 1612 ± 601 cells/mm2; p < 0.001). The measured areas ranged from 72 to 491 µm2, with average values from any particular image ranging from 110 to 370 µm2, which were inversely correlated with the estimated GCD (Spearman's rho = - 0.722, p < 0.05). CONCLUSIONS: Larger goblet cells but in fewer numbers were predictably found across the filter surface where there were fewer layers of cells and vice versa. This difference could be considered in selection of images for counts of goblet cells from CIC specimens.

Correlation between clinical and cytological parameters of dry eye among diabetics in a Nigerian tertiary hospital.

PURPOSE: To correlate the clinico-cytological features of dry eye among diabetic patients attending Lagos University Teaching Hospital, Lagos. METHODS: This was a cross-sectional, comparative study among 104 diabetic and 104 age-/sex-matched non-diabetic participants. Demographics were obtained using interviewer-administered questionnaire. Ocular Surface Disease Index (OSDI) questionnaire was used for subjective assessment of dry eye. All participants underwent ocular examination and dry eye assessment including Schirmer I test, tear film break-up time (TBUT) and ocular surface staining. In addition, conjunctival impression cytology (CIC) samples were taken for histological assessment. Data were analysed using IBM Statistical Package for the Social Sciences version 20.0 (IBM Corp., Armonk, NY USA). RESULTS: The mean age was 58.5 ± 10.05 years and 58.32 ± 10.48 years among the diabetics and non-diabetics, respectively (p = 0.856). The male/female ratio was 1:1.4. Three hundred and ninety-seven (199 diabetic and 198 non-diabetic) eyes were assessed. Diabetics had a significantly higher median OSDI score and ocular surface staining grade compared to non-diabetics (p = 0.002 and 0.005, respectively). The TBUT was slightly lower, while the Schirmer test was slightly higher among the diabetics, but not significant (p = 0.058 and 0.033, respectively). The diabetics had a significantly higher CIC grade (p < 0.001). There was a moderate positive correlation between conjunctival cytology and ocular surface staining (r = 0.50, p < 0.01). CONCLUSION: This study demonstrates worse ocular surface damage among diabetics characterised by ocular surface staining and abnormal CIC. Furthermore, it shows a positive correlation between ocular surface staining and CIC. Dry eye assessment should be incorporated in routine diabetic eye screening.

Tear function and ocular surface changes following corneal collagen cross-linking treatment in keratoconus patients: 18-month results.

PURPOSE: To investigate the long-term effects that CXL has on the tear function and ocular surface in keratoconus. METHODS: Twenty-one consecutive patients (24 eyes) with progressive keratoconus scheduled for CXL were included. All patients underwent the following procedures: conjunctival impression cytology analysis, ocular surface disease index (OSDI) score, tear osmolarity test, Schirmer test, tear film breakup time (TBUT), ophthalmic surface fluorescein (Fl) staining, and topographical corneal evaluation before as well as 3 and 18 months after accelerated CXL. RESULTS: There was no change in the median OSDI score, tear osmolarity test, Schirmer test, and the Fl staining score after CXL. The median TBUT increased from 9.00 s at baseline to 12.00 s at 18 months postoperative (P < 0.001). The cytological features of the temporal and superior bulbar conjunctiva deteriorated at 3 months post-CXL (P < 0.001). An improvement in impression cytology analysis of the temporal conjunctiva was noted at 18-month follow-up (P < 0.001). Significant improvements in the median maximum keratometry and mean keratometry (K-mean) readings were also noted 18 months after CXL (P < 0.001). The changes in the K-mean correlated significantly with the changes in TBUT levels at 18-month follow-up as compared to baseline (r = - 0.688, P < 0.001). CONCLUSIONS: The improvement in TBUT, conjunctival squamous metaplasia, and the goblet cell density indicates a favorable effect of CXL on the ocular surface and tear film in keratoconus, presumably due to the reduced corneal irregularity after CXL.

Conjunctival impression cytology and tear-film changes in cases with vitamin D deficiency.

PURPOSE: To evaluate conjunctival surface cells and tear-film functions in cases with vitamin D deficiency. METHODS: Thirty-six patients with serum vitamin D deficiency and 27 control subjects with normal serum vitamin D levels were included in this prospective study. The tear break-up time (TBUT), Schirmer II test, and conjunctival impression cytology tests were performed to all participants. RESULTS: The mean serum vitamin D levels were 10.5 ± 5.0 µl in the study group and 33.9 ± 11.7 µl in the control group (p < 0.001). The median TBUT scores were 11 s and 17 s and the median Schirmer II values were 7.5 mm and 12 mm in the study and the control groups, respectively (p = 0.003, p = 0.049). According to the Nelson staging system, 69.4% of the patients in the study group had grade 2 or 3 impression cytology, whereas 18.5% of the participants in the control group had grade 2 or 3 impression cytology (p < 0.001). CONCLUSION: Our study results showed that vitamin D deficiency may lead to dry eye causing conjunctival squamous metaplasia and loss of goblet cells on the ocular surface.

Epithelial analysis of simple limbal epithelial transplantation in limbal stem cell deficiency by in vivo confocal microscopy and impression cytology.

Simple limbal epithelial transplantation (SLET) is a relatively new treatment for severe limbal stem cell deficiency. Outcomes of treatment are typically determined based on clinical manifestations. In this prospective-multicenter study, we aimed to analyze the epithelial phenotypes of the corneas after SLET using IVCM and IC, and correlated them with clinical findings. Ten eyes of nine patients, who underwent SLET (five autologous SLET and five living-related SLET) were recruited. A set of examinations included slit-lamp biomicroscopy, corneal in vivo confocal microscopy (IVCM), and impression cytology (IC) was performed in all eyes at least twice (≥ 3-month interval) postoperatively. Then, a correlation between findings of the three examinations was analyzed. There were seven eyes with clinical success (no central neovascularization) showed pure corneal epithelial phenotype or mixed corneal-conjunctival phenotypes (mostly cornea) in either IVCM or IC. Three eyes with clinical failure, presented with peripheral and central neovascularization, showed total or predominant conjunctival phenotype in IVCM and sole conjunctival phenotype in IC. From a total of 22 sets of examinations, there was a high correlation between clinical manifestation vs. IC (κ = 0.844, observed agreement = 81.82%) and a substantial correlation between clinical manifestation vs. IVCM (κ = 0.727, observed agreement = 76.19%) and between IVCM versus IC (κ = 0.729, observed agreement = 76.19%). In conclusion, IVCM and IC facilitate determination of epithelial phenotype of the cornea after SLET. There was a substantial to high correlation between IVCM, IC and clinical presentations. Findings observed by IVCM and IC may allow early detection of epithelial alterations in eyes underwent SLET before clinical recognition.

Changes in ocular surface status after phacoemulsification in patients with senile cataract.

AIM: To evaluate the signs and symptoms of dry eye after phacoemulsification; effects on the status of ocular surface using impression cytology; and associated risk factors. METHODS: Prospective study included 50 eyes (50 patients) with no dry eye signs or symptoms, who underwent clear corneal phacoemulsification for senile cataract. Dry eye indices used included Ocular Surface Disease Index scoring, Schirmer I test, tear break up time, tear meniscus height, corneal fluorescein staining, lissamine green staining and goblet cell density (GCD) with the help of impression cytology. Primary outcome measures included post-operative changes in the dry eye indices. Secondary outcome measures included correlation of the dry eye signs and symptoms with various risk factors. RESULTS: Aggravation of both the signs and symptoms of dry eye were noted in immediate post-operative period. The sharp deterioration was followed by a recovering trend towards the end of sixth week. A decrease in GCD was also noted. Risk factors for deterioration include age, duration of exposure to microscope light and effective phacoemulsification time. Diabetic status, socio-economic status and site of incision did not have any effect on dry eye status. CONCLUSION: There is a transient deterioration of "dry eye" status post-phacoemulsification. The patients should be carefully counselled about the evanescent nature of the disease. Incision can be given at the site of high corneal curvature to neutralize astigmatism without any fear of inducing dry eye. Minimum light exposure and ultrasound energy should be used during the surgery.

The analysis of human conjunctival epithelium proteome in ocular surface diseases using impression cytology and 2D-DIGE.

Conjunctival impression cytology samples from patients with meibomian gland dysfunction (MGD), dry eye (DE), and healthy subjects (CT) were collected for determination of the degree of squamous metaplasia (SM) by PAS-hematoxylin staining and for comparative proteomic analyses by 2D-DIGE. The protein spots with discriminant expression were identified by MALDI-TOF/TOF mass spectrometry. Three independent statistical studies were conducted: i). Analysis of differential protein expression between study groups: We observed increased expression of proteins S100A4, S100A8, retinal dehydrogenase-1, peroxiredoxin-1, annexin-A1, annexin-A2, α-enolase, and glutathione S-transferase-P in DE, whereas the highest expression of peroxiredoxin-6, actin cytoplasmic-1, peroxiredoxin-2, and heat shock protein HSP-90-α was observed in MGD; ii). Correlation between changes in the proteome profile and the grade of SM: The expression of 5 different cytokeratins (KRT1, KRT4, KRT8, KRT10, and KRT13) correlated with the degree of SM; iii). Proteome profile differences between pathological and CT groups: An overall proteome analysis revealed upregulation of 9 proteins in the pathological groups (Annexin-A1, α-enolase, Annexin-A2, S100A8, cytokeratin-1, Peroxiredoxin-2 and Leukocyte elastase inhibitor) and downregulation of 2 proteins (Galectin-3 and Lipocalin-1). In conclusion, a sensitive proteomic approach to study conjunctival tissue collected from minimally invasive impression cytology was implemented. Differential proteomics analyses showed that in comparison with the MGD, the DE patients presented higher overexpression of proteins related to antimicrobial defense, tissue-damage response, and regulation of body fluid secretions. Changes in MGD proteome were associated with oxidative stress and anti-apoptotic processes. We found a correlation between the grade of SM and expression of proteins associated with cytoskeleton and keratinization. The studied pathological groups shared elements related to the defense and inflammatory responses. Dot blot assays of proteins ANXA1, S100A8, and S100A4 validated the proteomic results obtained from 2D-DIGE experiments and confirmed the correlation between the expression of these proteins and the clinical parameters.

The effects of two different types of bandage contact lenses on the healthy canine eye.

OBJECTIVE: To compare two types of bandage contact lenses on the healthy canine eye. ANIMALS STUDIED: Six healthy Beagles. PROCEDURES: Two different types of bandage contact lenses (single sized human silicone contact lens 'PureVision 2' (Bausch & Lomb Incorporated, Rochester, NY, USA) and specially designed veterinary hydrogel contact lens 'AcriVet Pat D' (Bausch & Lomb Incorporated) were placed in 12 eyes of healthy Beagle dogs. Retention times and the effects of the lenses regarding irritation of the eye, changes in tear production, impact of contact lenses on tonometric readings, and cytologic and microbiological alterations of the canine eye were investigated. RESULTS: Mean retention times for veterinary hydrogel lenses with special dimensions were significantly shorter (2 days) than for one size human silicon lenses (8.8 days). Irritation scores were overall low for both types of lenses apart from one human lens causing severe irritation and keratoconjunctivitis as a sequel to folding and displacement. Tear production remained stable in human contact lenses. Intraocular pressure readings with a contact lens in place were only slightly altered; the most accurate readings were obtained through a human lens with an applanation tonometer. Cytology revealed a slight, nonsignificant increase in neutrophilic granulocytes with both types of lenses; the microflora did not change significantly. DISCUSSION: Human silicone lenses have significantly longer retention times and are less expensive than veterinary hydrogel lenses. In regard to irritation, bacterial growth and inflammation, both types of lenses can be recommended for use in canine eyes.