Evaluating an impression cytology grading system (IC score) in patients with dry eye syndrome

Efficacy and Safety of Plasma Rich in Growth Factor in Patients with Congenital Aniridia and Dry Eye Disease

Congenital aniridia is a rare bilateral ocular malformation characterized by the partial or complete absence of the iris and is frequently associated with various anomalies, including keratopathy, cataract, glaucoma, and foveal and optic nerve hypoplasia. Additionally, nearly 50% of individuals with congenital aniridia experience symptoms of ocular dryness. Traditional treatment encompasses artificial tears and autologous serum. This study aimed to assess the effectiveness and safety of using platelet rich in growth factors (PRGF) plasma in patients with congenital aniridia and ocular dryness symptoms.

METHODS

The included patients underwent two cycles of a 3-month PRGF treatment. At 6 months, symptomatology was evaluated using the OSDI and SANDE questionnaires, and ocular surface parameters were analyzed.

RESULTS

The OSDI and SANDE values for frequency and severity demonstrated statistically significant improvements (p < 0.05). Ocular redness, corneal damage (corneal staining), and tear volume (Schirmer test) also exhibited statistically significant improvements (p < 0.05). No significant changes were observed in visual acuity or in the grade of meibomian gland loss.

CONCLUSION

The use of PRGF in patients with congenital aniridia and ocular dryness symptoms led to significant improvements in symptomatology, ocular redness, and ocular damage. No adverse effects were observed during the use of PRGF.

Efficacy and safety of platelet-rich plasma and autologous-serum eye drops for dry eye in primary Sjögren's syndrome: a randomized trial

We compared the efficacy and safety of autologous-serum (AS) and platelet-rich plasma (PRP) eye drops for dry eye (DE) treatment in primary Sjögren's syndrome (SS). This prospective, randomized, double-blinded clinical study included patients diagnosed with primary SS DE. Thirty-eight participants were randomly assigned to the AS or PRP groups. Corneal and conjunctival staining scores, Schirmer I test, tear film break-up time (TBUT), and ocular surface disease index (OSDI) scores were evaluated at 4 and 12 weeks. Conjunctival impression cytology (CIC) metaplasia grade and goblet cell density grade at 12 weeks were compared with those at baseline. Corneal and conjunctival staining scores and TBUT significantly improved at 4 and 12 weeks in both groups (all p < 0.005). No significant difference between the AS and PRP groups was observed at 4 and 12 weeks. The Schirmer I values, OSDI scores, CIC metaplasia grade, and goblet cell density grade did not significantly change at 4 and 12 weeks in either group. Both AS and PRP eye drops are effective for primary SS DE without a significant difference. Considering that the preparation time of PRP is shorter than that of AS, PRP can be a good alternative treatment for primary SS DE.

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.

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.

An Improved Ocular Impression Cytology Method: Quantitative Cell Transfer to Microscope Slides Using a Novel Polymer

PURPOSE

To develop a more efficient impression cytology (IC) method for the transfer of ocular surface cells onto glass microscope slides for cytochemical, immunocytochemical, and immunofluorescence studies.

METHODS

Cells are lifted off the ocular surface with a mixed cellulose ester membrane and then firmly attached to a glass slide using a novel triblock copolymer comprised of collagen type I, polyethylenimine and poly-L-lysine (CPP), and crosslinking cells and glass slide by heating and cooling. The membrane is removed intact after softening it with a butanol/ethanol solution. Transfer of cells is complete in about 10-15 minutes and is ready for staining. The efficiency of our cell transfer method was compared to current methods based on poly-L-lysine and albumin paste.

RESULTS

Our method ensured almost complete transfer of cells. In contrast, the transfer of rabbit conjunctiva cells onto poly-L-lysine-covered slides was 37.5 ± 6.3% lower, and onto albumin-paste covered slides 62.5 ± 5.6% lower (mean ± SD); the transfer of rabbit goblet cells was even less efficient. The new method was also more efficient for transfer of cells from human oral mucosa obtained by IC. Transferred cells were successfully stained with H&E, chemiluminescence, and immunofluorescence agents. Using our method, we stained ocular surface cells for S100A4 and ATF4, both of which play a role in the pathophysiology of dry eye disease. We obtained similar results with oral mucosal cells, suggesting the generalizability of our approach. We propose an explanation for the strong adhesion of cells to the glass slide, which is based on their interactions with the triblock copolymer.

CONCLUSIONS

We developed a novel approach for the efficient and rapid transfer of cells obtained by IC onto glass microscope slides using a novel copolymer. Compared to available methods, our improved approach makes IC robust and simple, and should increase its diagnostic yield and clinical applicability.

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.

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.

Ocular cytology: Diagnostic features and ongoing practices

Ocular cytology specimens are small, with limited options for a repeat biopsy. Appropriate handling of these specimens and triaging for ancillary testing can be taxing. In this article, the author reviews a selection of potentially challenging diagnoses and current common practices and methods used in diagnosing ocular diseases by cytology. The majority of cytology specimens submitted for evaluation of ocular diseases can be divided into 3 major categories: surface epithelial corneal and conjunctival cytology samples, intraocular fluids from the anterior (aqueous fluid) or posterior (vitreous fluid) chambers of the eye, and intraocular fine-needle aspiration specimens. The clinical findings, testing, and cytologic features of ocular surface epithelial infections, inflammations and neoplasia are discussed; and challenges in processing and diagnosing intraocular infections, chronic uveitis, and vitreoretinal lymphoma are reviewed. Novel molecular testing in the cytologic diagnosis and classification of uveal melanoma also is explored. Cytology evaluation of corneal epithelial and stromal cells, anterior chamber and vitreous samples, and fine-needle aspiration biopsies can provide detailed diagnostic findings to aid in the treatment and follow-up of patients with ocular diseases.

Impression cytology for detection of clinically suspected ocular surface disorders: A cross-sectional study

PURPOSE

Investigating impression cytology (IC) results of various types of clinically suspected ocular surface lesions over a 14-year period in a referral center in Iran.

METHODS

IC findings obtained from patients with different types of ocular surface disorders between 2005 and 2018 were reviewed. Agreement between clinical suspicions and IC results was evaluated by calculating Cohen's Kappa coefficient (CKC).

RESULTS

Clinical suspicions in 688 surveyed eyes were ocular surface squamous neoplasia (OSSN, 42.0%), limbal stem cell deficiency (LSCD, 36.3%), dry eye-related disorders (DERD, 11.5%), Acanthamoeba keratitis (AK, 7.2%), benign pigmented lesions (BPL, 1.9%), immune-related conjunctivitis (IRC, 0.7%), and malignant pigmented lesions (MPL, 0.4%). General agreement between clinical suspicions and IC results was 0.68 for all groups. This agreement was almost perfect in AK (CKC = 0.966) and BPLs (CKC = 0.843), and was substantial in MPLs (CKC = 0.749), OSSNs (CKC = 0.684), and LSCD (CKC = 0.612). CKC in IRC (0.567) and DERDs (0.443) was moderate. Histopathologic results were available in 22 eyes and were well-correlated with corresponding IC results (CKC = 0.86). Multiple post-treatment follow-up sessions of IC were performed in 51 eyes (11.4%) that had diagnosis of LSCD (31), OSSN (17), and MPL (3) at the first IC session.

CONCLUSION

Our survey not only demonstrated an overall substantial agreement between IC results and primary clinical suspicions, but also showed an almost perfect correlation between IC results and existent histopathologic data. Therefore, IC as a non-invasive diagnostic modality can be of great importance in proper diagnosis of various ocular surface diseases especially when distinguishing malignant from benign lesions is required.

Characterisation of corneal impression cytology in dogs and its application in the diagnosis of keratoconjunctivitis sicca

OBJECTIVE

Determine morphological and morphometric parameters of corneal epithelium in dogs, and determine the cellular alterations that occur in canine keratoconjunctivitis sicca (KCS) using impression cytology.

STUDY ANIMALS

60 dogs divided into two groups: dogs with Schirmer tear test (STT) at least 15 mm/minute and absence of ocular disease, and dogs with STT less than 15 mm/minute and clinical signs of KCS.

PROCEDURES

Impression cytology was used to collect corneal samples. The percentage of eyes with cell changes, the number of such cells and the percentage of cells with structural alterations in each group were determined. The possible correlation between corneal epithelium alterations and decreased tear production was evaluated.

RESULTS

A significant positive correlation existed between STT and the area of the cytoplasm and nucleus of corneal cells. A significant negative correlation was found between STT ​​and the nucleus/cytoplasm ratio, and the presence of cellular changes. A significant difference existed between the numbers of pyknotic nuclei, being higher among animals with all stages of KCS.

CONCLUSION

Corneal impression cytology can be used to assess the corneal epithelium in healthy eyes and eyes with KCS, demonstrating its usefulness as a diagnostic tool especially in mild and early cases.

A Non-invasive Way to Isolate and Phenotype Cells from the Conjunctiva

Traditionally, ocular surface cytology is studied with techniques such as spatula technology and brush technology. The problem with these techniques is that they may induce traumatic lesions on the surface of the eye, which can progress to scarring, eyelid deformity, limbal stem cell deficiency and in some cases, cause great discomfort to the subject. To avoid these clinical problems, impression cytology (IC) was developed to diagnose dry eye disease and later neoplasia, atopic disease, vernal keratoconjunctivitis and keratoconjunctivitis sicca. Typically, clinicians manually cut filter papers into required shapes and apply these to the ocular surface. Here, we describe how to perform IC using a commercially available medical device. This technique is explained here followed by immunophenotyping by flow cytometry. This technique requires less manual handling and causes less injury to the ocular surface.

Giemsa-based cytological assessment of area, shape and nucleus:cytoplasm ratio of goblet cells of rabbit bulbar conjunctiva

Goblet cells were visualized in impression cytology specimens from bulbar conjunctiva of the rabbit eye using Giemsa staining. Highly magnified images were used to generate outlines of the goblet cells and their characteristic eccentric nuclei. Using sets of 10 cells from 15 cytology specimens, I found that the longest dimension of the goblet cells averaged 16.7 ± 2.3 μm, the shortest dimension averaged 14.4 ± 1.8 μm and the nucleus averaged 6.3 ± 0.8 μm. The goblet cells were ellipsoid in shape and the longest:shortest cell dimension ratio averaged 1.169 ± 0.091. The goblet cell areas ranged from 108 to 338 μm² (average 193 ± 50 μm²). The area could be predicted reliably from the longest and shortest dimensions (r² = 0.903). The areas of goblet cell nuclei were 15-58 μm² (average 33 ± μm²) and the nucleus:cytoplasm area fraction was predictably greater in smaller goblet cells and less in the larger goblet cells (Spearman correlation = 0.817). The nuclei were estimated to occupy an average of 9.5% of the cell volume. The differences in size, shape and nucleus:cytoplasm ratio may reflect differences in goblet cell maturation.

Cytology of the healthy canine and feline ocular surface: comparison between cytobrush and impression technique

BACKGROUND

Impression cytology (IC) is a noninvasive technique in which filters are used to sample superficial layers of ocular epithelium.

OBJECTIVES

The aim of this study was to compare cytology specimens obtained by IC and cytobrush from healthy canine and feline eyes.

METHODS

Dogs and cats were prospectively sampled using polytetrafluorethylene filters on the right eye, and cytobrush on the left eye. Wright-Giemsa-stained specimens were evaluated by 2 observers. Cellularity, preservation, and morphology of cells and presence of goblet and inflammatory cells were scored with a 4-grade scale. Inter-observer agreement and effects of topical anesthesia were analyzed.

RESULTS

In 20 canine IC samples, 10 showed good cellularity (score 2-3) and 13 good preservation. Superficial epithelial cells (SEC) were present in 13/20 of IC, while basal-intermediate cells (BIC) were seen in 14/20. In 6/20 and 7/20, goblet and inflammatory cells were noted, respectively. In 20 cats, 15 of IC showed good cellularity and 14 good preservation, and SEC were present in 16/20 of IC and BIC in 17/20. In 13/20 and 3/20 cats, goblet cells and inflammatory cells were noted, respectively. Canine cytobrush specimens appeared well preserved (9/20) and had good cellularity (8/20). In feline cytobrush specimens, good preservation and cellularity were observed in 16/20 and 14/20, respectively. In both species, all cell types were present without a clear separation. There was moderate to fair agreement about cellular morphology in IC between observers. Specimens obtained with and without anesthesia were comparable.

CONCLUSION

Impression cytology allowed collection of samples with maintained cytoarchitecture, while cytoplasmatic and nuclear details were often difficult to evaluate.

Assessment of Consistency in Assignment of Severe (Grade 3) Squamous Metaplasia to Human Bulbar Conjunctiva Impression Cytology Cell Samples

Nucleus-to-cytoplasm (N:C) characteristics of published images of human bulbar conjunctival cells designated as showing severe (grade 3) squamous metaplasia were retrospectively assessed. From publications over a 40-year period, measurements were made from images of cell and nucleus size (based on areas and dimensions) and four different calculations were made for nucleo-cytoplasmic (N:C) ratios. From 54 published images, the mean nucleus-to-cytoplasm area ratio (NU/CYT AREA ratio) was 0.145 +/- 0.077 (range 0.052 to 0.346), compared to two different reference set values of 0.069 +/- 0.017 and 0.080 +/- 0.021. Similarly, a nucleus-to-cytoplasm length ratio (as LNLONG) was 0.308 +/- 0.080 (range 0.191 to 0.475) compared to reference values of 0.226 +/- 0.032 and 0.236 +/- 0.034. Similar differences in reference values were obtained using two other N:C ratio calculations. A wide range of values was found for morphometric N:C indices from published images, especially those without a scale bar, indicating a high incidence of inconsistent grading assignments. Overall, only about 30% of the published images showed morphological features consistent with severe squamous metaplasia (i.e., with the rest neither enlarged nor showing substantially changed N:C ratios) with no substantial pictorial evidence indicating that cells from the human bulbar conjunctiva have pyknotic nuclei. Current evidence indicates that grade 3 squamous metaplasia cells should be substantially enlarged.

Evaluation of ocular surface and tear film function following modified Hughes tarsoconjunctival flap procedure

PURPOSE

To evaluate ocular surface characteristics and tear film function following modified Hughes flap for eyelid reconstruction.

METHODS

This is an institutional study including 18 patients (6 male, 12 female) who underwent a tarsoconjunctival flap for reconstructing the lower eyelid's posterior lamella in one eye between 2005 and 2010. The median age of the patients was 72 (49-93) years at the time of surgery and 77 (51-97) years at the time of evaluation. The median follow-up time was 34 (9-69) months. All patients had large malignant or semi-malignant lid tumours. Data for subjective symptoms (OSDI questionnaire), lid margin morphology, tear break-up time (BUT), vital staining, Schirmer test, impression cytology, tear film osmolarity, lipid layer interference patterns, meibography and the size of the tumour and flap were recorded and compared with the contralateral side.

RESULTS

Statistical analysis of the data revealed a significant difference between the surgically treated lid and the untreated side in meibomian gland loss, more lid margin abnormalities in the upper and lower eyelid (p<0.001) and increased fluorescein staining of the cornea (p=0.031). For the operated side, the median OSDI score was higher (17.2 versus 14.7), and the median BUT value was shorter (4.2 versus 5.6 seconds) compared with the median values of the contralateral side.

CONCLUSION

Despite the favourable cosmetic and functional results of the Hughes tarsoconjunctival flap, our results indicate that this procedure does affect the ocular surface health in the treated eyes.

Evaluation of dry eye

Dry eye is a common yet complex condition. Intrinsic and extrinsic factors can cause dysfunction of the lids, lacrimal glands, meibomian glands, ocular surface cells, or neural network. These problems would ultimately be expressed at the tear film-ocular surface interface. The manifestations of these problems are experienced as symptoms such as grittiness, discomfort, burning sensation, hyperemia, and secondary epiphora in some cases. Accurate investigation of dry eye is crucial to correct management of the condition. Techniques can be classed according to their investigation of tear production, tear stability, and surface damage (including histological tests). The application, validity, reliability, compatibility, protocols, and indications for these are important. The use of a diagnostic algorithm may lead to more accurate diagnosis and management. The lack of correlation between signs and symptoms seems to favor tear film osmolarity, an objective biomarker, as the best current clue to correct diagnosis.

Effects of tear hyperosmolarity on conjunctival cells in mild to moderate dry eye

PURPOSE

To analyze the effects of tear hyperosmolarity on conjunctival cells in mild to moderate dry eye.

METHODS

Sixty-eight subjects (35 females and 33 males, mean age 43, S.D. 20.3, range 18-87 years) with symptoms of dry eye were enrolled in the study. Patients with severe dry eye or any other condition that induces ocular inflammation were excluded. The sample was divided into two groups according to the tear osmolarity cut-off value of 308 mOsmol L(-1) measured in the right eye of each patient. Impression cytology of the temporal interpalpebral conjunctiva was performed and goblet cell density, nucleus diameter, cytoplasm diameter and nucleus/cytoplasm ratio of epithelial cells quantitatively assessed. A battery of tear tests (ferning test, tear break-up time and Schirmer I test) was also carried out in order to more completely describe the groups and understand the process. Analysis of variance (anova) was applied to establish cytological and tear differences between hyperosmolar and normal tear osmolarity eyes. Pearson's correlation was calculated between the cytological variables and tear osmolarity.

RESULTS

The normal tear osmolarity group included patients with symptoms of dry eye, grade 1-2 of squamous metaplasia, and a number of positive tear signs of dry eye ranging between 0 and 3. The hyperosmolar tear group included patients with symptoms of dry eye, grade 1-2 of squamous metaplasia with significantly lower values of nucleus diameter (F(1,66) = 4.3, p = 0.040), and a number of positive tear signs of dry eye ranging between 1 (hyperosmolar tear) and 4. Mean reflex secretion of tears was clearly normal in both groups but significantly lower (F(1,66) = 7.2, p = 0.009) in the hyperosmolar tear group. Significant correlations were established for tear osmolarity and goblet cell density (r(33) = 0.45, p = 0.006) and nucleus/cytoplasm ratio (r(33) = -0.44, p = 0.009) in the normal tear osmolarity group but not in the hyperosmolar tear group.

CONCLUSIONS

Mild to moderate hyperosmolar tear conditions seem to lead to an initial reduction of the conjunctival cell nucleus before the cytoplasm diameter showed a clear tendency to enlarge. The relationship between tear osmolarity and conjunctival cell characteristics seems to be linear only in the normal tear osmolarity group. These results also provide a plausible link between lower reflex secretion of tears and hyperosmolarity.

Goblet cells of the normal human bulbar conjunctiva and their assessment by impression cytology sampling

Goblet cells of the conjunctiva are the main source of mucus for the ocular surface. The objectives of this review are to consider the goblet cells as assessed by various histological, cytological and electron microscopy methods, and to assess the consistency of published reports (over more than 25 years) of goblet cell density (GCD) from impression cytology specimens from nominally healthy human subjects. Reported GCD values have been notably variable, with a range from 24 to 2226 cells/mm² for average values. Data analysis suggests that a high density of goblet cells should be expected for the healthy human conjunctiva, with a tendency toward higher values in samples taken from normally covered locations (inferior and superior bulbar conjunctiva) of the open eye (at 973 +/- 789 cells/ mm²) than in samples taken from exposed (interpalpebral) locations (at 427 +/- 376 cells/mm²). No obvious change in GCD was found with respect to age, perhaps because the variability of the data did not allow detection of any age-related decline in GCD. Analyses of published data from 33 other sources indicated a trend for GCD to be lower than normal across a spectrum of ocular surface diseases.

Morphology of contact lens-induced conjunctival epithelial flaps: a pilot study

PURPOSE

Conjunctival epithelial flap (CEF) is a conjunctival condition most commonly seen in silicone hydrogel contact lens wearers. This study utilized impression cytology to investigate the cellular composition and health of CEFs.

METHODS

Nine (9) subjects were enrolled - 3 non-lens wearers, 3 contact lens wearers without CEF, and 3 contact lens wearers with CEFs wearing 8.4/13.8 lotrafilcon A lenses. Impression cytology samples were collected from the flap or similar locations, if CEF was absent, using rectangular 5 mm × 2 mm Millipore HAWP02500 membrane filters. The filters were gently pressed onto the conjunctiva, subsequently fixed in 95% alcohol, stained with hematoxylin-eosin and evaluated under an Olympus IX70 microscope. Measurements of the longest cell and nucleus dimensions were measured on 40 cells from each filter by utilizing NIH Image 1.63.

RESULTS

CEF consisted of multilayers of epithelial and goblet cells and were devoid of inflammatory cells, basement membrane material and stromal tissue. The cytoplasmic and nuclear dimensions were similar within the groups and the cytoplasm-to-nucleus ratio was not different between the flap group and the non-lens wearing group.

CONCLUSION

The CEF appeared to be formed by healthy epithelial and goblet cells that have been dislocated from their normal location along the conjunctival surface by the lens edge. No inflammatory cells were present in this contact lens induced condition, which is reported to be associated most commonly with the silicone hydrogel material.

Contact lens wear and the goblet cells of the human conjunctiva-A review

PURPOSE

To review the reported effects of contact lens wear on the goblet cells of the human conjunctiva.

METHODS

A literature search was undertaken to identify reports on the conjunctival health after contact lens wear, principally as assessed using the conjunctival impression cytology (CIC) technique in which cells are examined ex vivo, after fixation and staining. Details of technique, data on duration of contact lens wear and then CIC outcome in terms of goblet cell density (GCD) were extracted.

RESULTS

Of 24 reports identified, 22 examined the bulbar conjunctiva and 2 examined the tarsal conjunctiva. A decrease in GCD was considered, directly or indirectly, to be a consequence of contact lens wear in 18 of the studies, but there was no obvious overall relationship between duration of lens wear and the GCD changes. Conversely, four reports indicated an increase in GCD or goblet cell-related mucins. Two reports concluded that there was no change in goblet cells or their mucin, a result however that is consistent with a recent conclusion that no statistically significant change in GCD was detectable in contact lens wearers assessed by in vivo imaging of the human conjunctiva by confocal microscopy.

CONCLUSIONS

The majority of published studies have concluded that contact lens wear results in a decrease in goblet cells in the conjunctiva. While there are reports that draw a very different conclusion, it should be noted that there has been limited consistency in technique or the method of reporting the results across the various studies.

Polyquad-preserved travoprost/timolol, benzalkonium chloride (BAK)-preserved travoprost/timolol, and latanoprost/timolol in fixed combinations: a rabbit ocular surface study

INTRODUCTION

The aim of this study was to use a validated acute rabbit model to test the toxicity of a novel formulation of fixed-combination travoprost 0.004%/timolol 0.5% ophthalmic solution, which contains the antimicrobial preservative polyquaternium-1 (PQ), compared with the commercial formulation of fixed combinations travoprost 0.004%/timolol 0.5% ophthalmic solution and latanoprost 0.005%/timolol 0.5% ophthalmic solution, which both contain the preservative benzalkonium chloride (BAK).

METHODS

Adult male New Zealand albino rabbits (n=24) were randomly divided into four groups. Phosphate-buffered saline (PBS), travoprost/timolol PQ, travoprost/timolol BAK, or latanoprost/timolol BAK were instilled onto rabbit eyes one drop, 15 times at 5 minute intervals. The ocular surface reactions were investigated at hour 4 and day 1 using slit lamp examination; in-vivo confocal microscopy (IVCM) for cornea, limbus, and conjunctiva-associated lymphoid tissue (CALT); conjunctival impression cytology; and standard immunohistology in cryosections for detecting CD45+ infiltrating cells and MUC-5AC-labeled cells.

RESULTS

Travoprost/timolol PQ was better tolerated than travoprost/timolol BAK or latanoprost/timolol BAK. This improved tolerance was evident via clinical observation under slit lamp, IVCM in different layers of the cornea and conjunctiva, conjunctival impression cytology of superficial epithelium aspects, and immunohistochemistry for inflammatory infiltration of CD45+ cells in the cornea and goblet cell distribution. Travoprost/timolol PQ was similar to PBS in regards to in-vivo findings, the Draize test for ocular irritation, and epithelial and limbal aspects as evaluated with IVCM. Treatment with either travoprost/timolol PQ or PBS produced no obvious inflammatory infiltration inside and outside the CALT follicles, yielded similar IVCM toxicity scores and CD45+ cell counts, and eyes treated with either solution had normal goblet cells.

CONCLUSION

The fixed combination of travoprost/timolol with 0.001% PQ had decreased ocular surface toxicity relative to the BAK-containing solutions. The potential benefit to the human ocular surface with oncedaily dosing needs to be evaluated clinically.

Myofibroblasts in the normal conjunctival surface

PURPOSE

To investigate the occurrence of myofibroblasts (MFBs) in the normal conjunctival surface and to evaluate any anatomical and time-related variations.

METHODS

MFBs were screened among healthy individuals (35 eyes) by collecting impression cytology (IC) samples from the bulbar conjunctiva. A cohort of volunteers (12 eyes) was followed for 1 year by taking two to five imprints every month. MFBs were identified by immunohistochemical localization of the MFB marker alpha-smooth-muscle actin (alpha-SMA).

RESULTS

Using a filter imprint technique, MFBs were found consistently in 94% of samples from the conjunctival surface of participating individuals. The overall MFB levels, expressed as percentage of all cells on the filter, were highest in March-May [mean 4.1%, standard deviation (SD) +/- 1.5] and lowest in December-February (mean 1.2%, SD +/- 0.5). The difference was statistically significant [p < 0.0005, Friedman test, one-way repeated measures analysis of variance (anova)]. Moreover, there was a clear divergence of MFB density between the nasal, temporal, superior and inferior bulbar conjunctiva (mean 1.7%, 1.9%, 22% and 9.7%, respectively).

CONCLUSION

MFBs, known as a cellular constituent of granulation tissue in wound healing, occur in the normal conjunctival surface, which is a novel finding. Our results also show that MFB level follows a seasonal variation pattern in a temperate climate, increasing in April-September and decreasing in October-March. This variation might reflect a degree of a transient or ongoing state of tissue repair after conjunctival trauma or stress caused by exposure to environmental factors.

Impression cytology: recent advances and applications in dry eye disease

Impression cytology (IC) allows cells to be harvested from the ocular surface noninvasively. Superficial layers of the epithelium are removed by application of cellulose acetate filters or Biopore membranes, and the cells can be subsequently analyzed by various methods, depending on the objective of the investigation or pathology involved. IC techniques are easily learned, can be performed in an outpatient setting, and cause virtually no discomfort to the patient. IC facilitates the diagnosis of ocular surface disorders, including, among others, keratoconjunctivitis sicca, ocular surface squamous neoplasia, and ocular surface infections. During the past decade, IC has been used increasingly to assist in diagnosis of ocular surface disease, improve our understanding of the pathophysiology of ocular surface disease, and provide biomarkers to be used as outcome measures in clinical trials. Dry eye disease is one area in which IC has contributed to significant advances.

Long-term follow-up of punctal and proximal canalicular stenoses after silicone punctal plug treatment in dry eye patients

PURPOSE

To determine the clinical value and relevance of punctal and proximal canalicular stenoses after punctal plug therapy in moderate to severe dry eye syndrome.

DESIGN

Retrospective, observational case series.

METHODS

Seventeen eyes were determined to have punctum or proximal canalicular stenoses after spontaneous loss of a collared silicone punctal plug. After initial diagnosis all patients had 12 months or more of follow-up (mean, 39; range, 12 to 87 months). The clinical data collected included gender and age of patients, localization of the stenosis, plug size, duration of punctal occlusion, subjective symptoms, objective ocular surface disease parameters, and occurrence of complications.

RESULTS

A statistically significant correlation between localization of the stenosis and plug size, and localization of the stenosis and duration of punctal occlusion could not be found. At follow-up, subjective symptoms (P < .01) and frequency of artificial tear application (P < .001) were significantly reduced compared to data before plug insertion. Schirmer I test results (P < .001), corneal fluorescein staining (P < .01), and rose bengal staining (P < .001) improved significantly, whereas tear break-up time (P < .2) and impression cytology scores of the conjunctival surface (P = .2) remained almost unchanged. Complications could not be found.

CONCLUSION

Within the observation period of up to seven years, all stenoses remained asymptomatic. Additionally, subjective symptoms and most dry eye parameters in our study population improved.

Impression cytology of a case of conjunctival metaplasia associated with oral carbamazepine use?

PURPOSE

To report a case of conjunctival squamous metaplasia associated with oral carbamazepine use.

METHODS

Following completion of an ocular comfort questionnaire, biomicroscopy and a phenol red thread test, impression cytology from the inter-palpebral zone (nasal) of the bulbar conjunctival surface was undertaken using a Millcell-CM filter after topical anaesthesia with oxybuprocaine 0.4%. The filter was stained with Giemsa and colour images taken at 400x magnification by light microscopy. The images were graded and also a 35 mm was prepared. From the projected image, an overlay method was used to outline the borders such that the cell and nucleus area, and the longest and shortest dimensions could be measured by planimetry.

RESULTS

A male subject, added 22 years, presented with slight conjunctival injection but no substantial symptoms and only slight surface staining with fluorescein. The subject reported use of oral carbamazepine (200mg, b.d.s.). Impression cytology showed large sheets of squamous cells (grade 2-3) with few goblet cells. The average cell area was 1509 microm(2), the long:short dimension ration averaged 1.42 and the average nucleus/cytoplasm (N/C) value was just 0.092 (or 1:11.5 as a ratio).

CONCLUSIONS

Since the drug has been reported to be excreted in the tear film, and with no other risk factors (such as contact lens wear, smoking or dry eye disease), the squamous metaplasia is attributed to the use of carbamazepine.