Chronic Dry Eye Research Articles

ADVISE (ADenoVirus Initiative Study in Epidemiology)

AbstractPurpose ADVISE is an epidemiological, prospective, multicentric, open study to assess the characteristics and frequency of adenoviral conjunctivitis (AC) as diagnosed with the point of care AdenoPlus® test in patients suffering from acute conjunctivitis in 5 EU countries (F, It, Ger, UK, Sp).Methods Bacterial or viral conjunctivitis are usually self‐limiting but some viral cases may cause persistent disease and significant morbidity. AC causes more severe disease, is extremely contagious (transmission rate 10‐50%), of longer duration than bacterial (shed for 14‐16 days, signs and symptoms last 2‐3 weeks) and may lead to decreased visual acuity or light sensitivity from persistent subepithelial infiltrates, chronic dry eye, and visual loss from conjunctival scarring.Results AdenoPlus® is a single use, rapid (10 min.) immunoassay test for the qualitative in‐vitro detection of Adenoviral hexon protein antigens directly from human eye fluid. It is a CE marked, point‐of‐care medical device intended for health professional use as an aid in the rapid differential diagnosis of acute conjunctivitis. Study objectives are to assess the % of patients with acute conjunctivitis who have AC, the clinical profiles associated with positive and negative tests, the correlation between the initial clinical diagnosis and the final diagnosis (post‐test), the AC seasonality and geographic distribution, and to collect pharmacoeconomic data (before/after test prescribed treatments, work/school absenteeism…).Conclusion Enrollment started in June 2013 in France and in January 2014 in Germany. Italian, Spanish and UK sites will start recruiting Q2‐Q3/2014. Approximately 2500 patients are expected across EU, 500 patients from 15‐20 sites per country (20‐30 patients per site). The first interim study results will be presented with data analyses from at least 400 patients recruited in EU.

Building a Dry Eye Practice

Citation: Beckman KA (2014) Building a Dry Eye Practice. Adv Ophthalmol Vis Syst 1(1): 00001. DOI: 10.15406/aovs.2014.01.00001 Dry eye disease is one of the most frequently encountered conditions by ophthalmologists and optometrists. Millions of people in the US suffer from this condition, and the prevalence is growing rapidly. Typically, dry eye disease has been treated as an afterthought by many eye care professionals. The thought was that this condition is not significant and there is not much that can be done about it. In addition, dealing with the chronic dry eye patient can be extremely frustrating and time consuming. Many physicians prefer to get these patients out of their office so they can move on to the next cataract surgery patient.

Confocal microscopy reveals nerve fiber similarities in fibromyalgia and patients with dry eyes with a normal ophthalmic exam

Small fiber neuropathy has been shown in a subset of fibromyalgia patients, but this is a non-specific finding that has been noted in several chronic pain states. Small nerve fiber morphology can be measured non-invasively in the cornea, an area densely innervated with small fibers, using in-vivo confocal microscopy (IVCM). We used this technique to determine if 1) neuropathy is present in the corneas of fibromyalgia patients and 2) if those who suffer from idiopathic, chronic dry eyes (i.e., dry eye symptoms without dry eyes on exam) might also have compromised small fibers.

Evaluation of IL-6 and IL-8 in Tear Fluid of Sulfur Mustard Gas-Exposed Patients with Eye Lesions

The levels of IL-6, 8 in tear fluids of people exposed to mustard gas in the war between Iraq and Iran with chronic dry-eye symptoms were studied. 25 of the patients who were effected with mus- tard gas and had chronic dry eye symptoms were compared...

Safety and efficacy of cyclosporine in the treatment of chronic dry eye.

Dry-eye syndrome (DES) is a multifactorial disease affecting millions of individuals worldwide. Various factors, including age, hormonal status, genetics, sex, immune status, innervation status, nutrition, pathogens, and environmental stress, can alter the cellular and molecular structure or function of components of the ocular surface system. The resulting imbalance increases susceptibility to desiccation and epithelial damage, leading to a vicious circle in which inflammation amplifies and sustains further damage by chronic deregulation of the system. Lubricating agents and steroids have been used as treatment options. However, as the causes of the disease become better elucidated, the more chemically complex cyclosporine A has become an increasingly useful treatment option and in the United States is currently the only Food and Drug Administration (FDA)-approved prescription drug for the treatment of dry eye. The safety and efficacy of cyclosporine have been shown in numerous studies.

Evaluation of IL-6 and IL-8 in Tear Fluid of Sulfur Mustard Gas-Exposed Patients with Eye Lesions

The purpose of this study is to compare the levels of IL-6, 8 in tear fluids of people exposed to mustard gas in the war between Iraq and Iran who had the chronic dry-eye symptoms compared to the normal group. In this study, 25 of the patients who were exposed to mustard gas and had chronic dry eye symptoms were compared to 25 patients as control group, consisting of 25 people who had common chronic dry eye symptoms with blepharitis and 25 healthy people as normal group. The levels of IL-6 and IL-8 in tear fluid of people of these three groups were assessed by enzyme-linked immunosorbent assay (ELISA). The results for levels of IL-6 (P = 0.002) and IL-8 (P = 0.001) in tear fluid of patients in comparison with normal group show a significant increase. The differences were considered statistically significant at P

AAA Syndrome: Successful Management of a Rare Cause of Dysphagia

Introduction: AAA syndrome (also known as Allgrove syndrome or triple A syndrome) is a rare autosomal recessive disorder characterized by the triad of ACTH-resistant adrenal insufficiency, achalasia, and alacrima. This case highlights the gastroenterological presentation of this multisystem disorder and successful management. Case presentation: A 35-year-old Indian woman presented to the outpatient office with recurrent episodes of dysphagia to solids and liquids since childhood. Over the years, she modified her diet by avoiding meats and eating soft foods but reported an inability to gain weight. At age 17 years, she was reported to have a distal esophageal stricture at an outside facility. Four empiric endoscopic esophageal dilations were performed over a 10-year period with minor symptom improvement. In her 20s, she was diagnosed with primary adrenal insufficiency of an idiopathic nature (Addison's disease), and has been continuously treated with oral hydrocortisone. She also reported chronic dry eyes. On examination, she was 4'10”, 75 lbs with a BMI of 15.6. She had a nasal tone of voice and pigmentation of her lips and tongue. Other than a slender build, the remainder of the physical examination was unremarkable. High-resolution manometry was performed, which showed elevated lower esophageal sphincter (LES) pressures (27.2 mmHg) with abnormal LES relaxation (LES residual pressure of 34.4 mmHg), and absent esophageal body peristalsis with panesophageal compartmentalization of intrabolus pressure. These findings were consistent with achalasia, categorized as type II by the Chicago classification scheme. Upper endoscopy (EGD) revealed a mildly dilated esophageal body with a puckered and hypertonic LES. The findings on manometry and EGD confirmed the diagnosis of achalasia. The additional diagnoses of Addison's disease and longstanding alacrima were consistent with the AAA syndrome. The patient was referred for laparoscopic Heller myotomy to treat the achalasia and has remained asymptomatic 18 months after surgery. Discussion: AAA syndrome is rare, with fewer than 200 cases reported since it was initially described in 1978 by Allgrove. It usually manifests in childhood although neurological symptoms and autonomic instability may manifest later. The gene has been mapped to chromosome 12 and the protein it encodes is involved in the normal development of the nervous system. Achalasia in young patients is best treated surgically with laparoscopic myotomy and provides significant long-term relief of symptoms. AAA syndrome is uncommon, but a high index of suspicion in patients with any of the classic findings can result in early recognition and successful management.

Long-term Supplementation With n-6 and n-3 PUFAs Improves Moderate-to-Severe Keratoconjunctivitis Sicca

Supplementation with gamma-linolenic acid (GLA) and omega-3 (n-3) polyunsaturated fatty acids (PUFAs) has been found to decrease the production of disease-relevant inflammatory mediators that are implicated in the pathogenesis of chronic dry eye. This study evaluated the effect of a supplement containing both GLA and n-3 PUFAs on signs and symptoms of moderate-to-severe keratoconjunctivitis sicca in postmenopausal patients. This multicenter, double-masked placebo-controlled clinical trial enrolled 38 patients (both eyes) with tear dysfunction who were randomized to supplemental GLA + n-3 PUFAs or placebo for 6 months. Disease parameters, including Ocular Surface Disease Index, Schirmer test, tear breakup time, conjunctival fluorescein and lissamine green staining, and topographic corneal smoothness indexes (surface asymmetry index and surface regularity index), were assessed at baseline and at 4, 12, and 24 weeks. The intensity of dendritic cell CD11c integrin and HLA-DR expression was measured in conjunctival impression cytologies. The Ocular Surface Disease Index score improved with supplementation and was significantly lower than placebo (21 ± 4 vs. 34 ± 5) after 24 weeks (P = 0.05, n = 19 per group). The surface asymmetry index was significantly lower in supplement-treated subjects (0.37 ± 0.03, n = 15) than placebo (0.51 ± 0.03, n = 16) at 24 weeks (P = 0.005). Placebo treatment also significantly increased HLA-DR intensity by 36% ± 9% and CD11c by 34% ± 7% when compared with supplement treatment (n = 19 per group, P = 0.001, 24 weeks). Neither treatment had any effect on tear production, tear breakup time, or corneal or conjunctival staining. Supplemental GLA and n-3 PUFAs for 6 months improved ocular irritation symptoms, maintained corneal surface smoothness, and inhibited conjunctival dendritic cell maturation in patients with postmenopausal keratoconjunctivitis sicca.Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00883649.

Chronic dry eye disease is principally mediated by effector memory Th17 cells.

Recent experimental and clinical data suggest that there is a link between dry eye disease (DED) and T cell-mediated immunity. However, whether these immune responses are a consequence or cause of ocular surface inflammation remains to be determined. Thus far, only models of acute DED have been used to derive experimental data. This is in contrast to clinical DED which usually presents as a chronic disease. In the present study, using a murine model of chronic DED, it was established that the chronic phase of the disease is accompanied by Th17 responses at the ocular surface, and that a significant memory T cell population can be recovered from chronic DED. This memory response is predominantly mediated by Th17 cells. Moreover, adoptive transfer of this memory T cell population was shown to induce more severe and rapidly progressing DED than did the adoptive transfer of its effector or naïve counterparts. Not only do these results clearly demonstrate that effector memory Th17 cells are primarily responsible for maintaining the chronic and relapsing course of DED, but they also highlight a potentially novel therapeutic strategy for targeting memory immune responses in patients with DED.

Cyclosporine 0.05% ophthalmic emulsion for the treatment of radiation‐associated dry eye in children

Dry eye disease is a well-known late complication of radiation therapy and is often difficult to treat. We evaluated the usefulness of cyclosporine 0.05% ophthalmic emulsion for the treatment of radiation-associated dry eye in children. Eleven children received cyclosporine 0.05% emulsion twice daily after failure of conventional therapy. After 6 months, dry eye manifestations improved in three children (27.3%). The remaining eight children showed no improvement with cyclosporine 0.05% ophthalmic emulsion. These results suggest that twice-daily cyclosporine 0.05% ophthalmic emulsion has limited use in children with refractory radiation-associated chronic dry eye.

Сomparative effect of artificial tear drug usage in patients with «dry eye» syndrome and chronic blepharitis

During recent years, the problem of treatment «dry eye» syndrome in patients with chronic blepharitis is very important. But until there are no rational standards how to treat such patients. We investigated group of 44 adults with the chronic blepharitisand concomitant dry eye syndrome. In present article, рresented are the treatment results of artificial tear drug usage in patient with «dry eye» syndrome and chronic blepharitis.

Efficacy of Cyclosporine 0.05% Eye Drops in Stevens Johnson Syndrome with Chronic Dry Eye

To evaluate the efficacy of cyclosporine 0.05% (CsA) eye drops in patients with Stevens Johnson syndrome (SJS) who had chronic dry eye. Prospective noncomparative interventional case series. Thirty cases of SJS patients who developed dry eye defined by symptoms and signs, including the Schirmer I test, the fluorescein clearance test (FCT), and corneal staining (fluorescein and Rose Bengal staining) were treated with CsA 0.05% eye drops twice daily for 6 months. Dry eye symptoms, eye injection, tear break up time (TBUT), and corneal staining were evaluated before and after the treatment at 0, 2, 4, and 6 months. The Shirmer I test and FCT were evaluated at 0 and 6 months. Seventeen patients (56.67%) completed the study. Eight patients (26.67%) withdrew from the study as a result of intolerable side effects of CsA, which included pain, redness, and eyelid swelling. Five cases were lost in follow up. All 17 cases demonstrated significant improvement in dry eye symptoms, conjunctival injection, corneal staining, Schirmer I test, and FCT (P<0.05). CsA 0.05% eye drops might be beneficial in the treatment of chronic dry eye associated with SJS.

Dry eye disease and inflammation

＊ ＊ Dry eye disease is a devastating and multifactorial disorder of the tear-film layer and ocular surface. Multiple symptoms include multiple eye irritation, and visual disturbances, and signs have tear-film instability, along with the potential for injuring the ocular surface. Accumulating evidence indicates that dry eye disease is accompanied by hyperosmolarity of the tear film and inflammation of the ocular surface microenvironment. Most cases of dry eye disease are secondary to any of a vast array of inflammatory conditions and disorders, including auto- and alloimmune diseases, infection, aging, neuroinflammation, and sterile Inflammation. Sterile inflammation is induced by several different kinds of non-infectious triggers, including altered cellular and tissue states. New results have implicated damage-associated molecular patterns, microorganisms, and neurotransmitters in primary dry eye disease. Furthermore, in conjunction with inflammatory and fibrotic changes, the renin angiotensin system and epithelial mesenchymal transition may be involved in disease-associated and immune-mediated dry eye disease, such as chronic GVHD-related dry eye. Collectively, studies show that at least some and possibly many factors influence the condition of the ocular surface, leading to chronic inflammation that exacerbates dry eye symptoms in a vicious cycle. Since the pathway for each type of dry eye disease may differ, and specific pathways may be responsible for the disease in individual patients, patient-tailored therapies should be developed in the future. In this review article, we focus on emerging concepts on the role of the inflammatory process in dry eye disease.

Conjunctival Biopsy to Guide Treatment of Chronic Ocular Gvhd

AbstractAbstract 4491The treatment of chronic ocular graft-versus-host disease (GVHD) is empirical, mainly due to the lack of knowledge of its pathogenesis. The goals of this study were to describe the histopathologic and immunophenotypic characteristics of conjunctival biopsies from patients with chronic ocular GVHD and to determine whether these findings can guide immunomodulation or palliative management strategies of GVHD associated dry eye disease.A conjuctival biopsy was obtained in eleven patients who previously received an allogeneic hematopoietic stem cell transplant (HSCT) and presented with chronic GVHD and dry eye symptoms. Hematoxylin and eosin (H&E) and immunohistochemical staining of conjunctival biopsies were analyzed for presence of inflammatory cells (B and T cells), fibrosis, and apoptosis. All conjunctival biopsies showed the presence of keratosis and parakeratosis and 7/11 (64%) biopsies had evidence of conjunctival epithelial apoptosis. Immunohistochemistry demonstrated the presence of inflammatory cells in 72% (8/11). These cells were predominantly CD3+ T lymphocytes (54%), with a CD4:CD8 cell ratio of 1:1.7. No biopsies showed B cells. Fibrosis was noted in 54% of biopsies (6/11). Conjunctival apoptosis detected by caspase-3 antibody staining showed significant moderate positive correlation with goblet cell loss (r=0.6, p=0.04). Presence of inflammatory cells showed a stronger correlation with conjunctival apoptosis as compared with fibrosis (r=0.38 and 0.26 respectively), however both correlations were not significant (p<0.05).A standard dry eye treatment regimen in chronic ocular GVHD remains to be determined, thus examining the histopathologic features may help guide a more focused management strategy. In this study conjunctival apoptosis was associated with significant goblet cell loss and it more frequently accompanied inflammation as compared to fibrosis. Aggressive topical immunomodulation may reduce inflammation and goblet cell loss in patients with conjunctival biopsies positive for apoptosis. Disclosures:No relevant conflicts of interest to declare.

Association of Clinical Response and Long-term Outcome Among Patients With Biopsied Orbital Pseudotumor Receiving Modern Radiation Therapy

To retrospectively evaluate institutional outcomes for patients treated with modern radiation therapy (RT) for biopsied orbital pseudotumor (OP). Twenty patients (26 affected orbits) with OP were treated with RT between January 2002 and December 2011. All patients underwent biopsy with histopathologic exclusion of other disease processes. Sixteen patients (80%) were treated with intensity modulated RT, 3 (15%) with opposed lateral beams, and 1 (5%) with electrons. Median RT dose was 27 Gy (range 25.2-30.6 Gy). Response to RT was evaluated at 4 months post-RT. Partial response (PR) was defined as improvement in orbital symptoms without an increase in steroid dose. Complete response (CR) 1 and CR 2 were defined as complete resolution of orbital symptoms with reduction in steroid dose (CR 1) or complete tapering of steroids (CR 2). The median follow-up period was 18.6 months (range 4-81.6 months). Seventeen patients (85%) demonstrated response to RT, with 7 (35%), 1 (5%), and 9 (45%) achieving a PR, CR 1, and CR 2, respectively. Of the 17 patients who had ≥ PR at 4 months post-RT, 6 (35%) experienced recurrence of symptoms. Age (>46 years vs ≤ 46 years, P=.04) and clinical response to RT (CR 2 vs CR 1/PR, P=.05) were significantly associated with pseudotumor recurrence. Long-term complications were seen in 7 patients (35%), including 4 with cataract formation, 1 with chronic dry eye, 1 with enophthalmos, and 1 with keratopathy. RT is an effective treatment for improving symptoms and tapering steroids in patients with a biopsy supported diagnosis of OP. Older age and complete response to RT were associated with a significantly reduced probability of symptom recurrence. The observed late complications may be related to RT, chronic use of steroids/immunosuppressants, medical comorbidities, or combination of factors.

Clinical outcomes of radiotherapy as initial local therapy for Graves’ ophthalmopathy and predictors of the need for post-radiotherapy decompressive surgery

BackgroundThe optimal initial local treatment for patients with Graves’ ophthalmopathy (GO) is not fully characterized. The purpose of this retrospective study is to describe the clinical outcomes of RT as initial local therapy for GO and define predictors of the need for post-RT salvage bony decompressive surgery.Methods91 patients with active GO and without prior surgery were treated with RT as initial local therapy between 01/1999 and 12/2010, with a median follow-up period of 18.3 months (range 3.7 - 142 months). RT dose was 24 Gy in 12 fractions. 44 patients (48.4%) had prior use of steroids, with 31 (34.1%) being on steroids at the initiation of RT. The most common presenting symptoms were diplopia (79%), proptosis (71%) and soft tissue signs (62%).Results84 patients (92.3%) experienced stabilization or improvement of GO symptoms. 58 patients (64%) experienced improvement in their symptoms. 19 patients (20.9%) underwent salvage post-RT bony decompressive surgery. Smoking status and total symptom score at 4 months were independent predictors of post-RT bony decompression with odds ratios of 3.23 (95% CI 1.03 – 10.2) and 1.59 (95% CI 1.06 – 2.4), respectively. Persistent objective vision loss at 4 months post-RT was the most important symptom type in predicting salvage decompression. Chronic dry eye occurred in 9 patients (9.9%) and cataracts developed in 4 patients (4.4%).ConclusionsRT is effective and well tolerated as initial local therapy for active GO, with only 21% of patients requiring decompressive surgery post RT. Most patients experience stabilization or improvement of GO symptoms, but moderate to significant response occurs in the minority of patients. Smoking status and total symptom severity at 4 months, primarily persistent objective vision loss, are the primary determinants of the need for post-RT salvage bony decompression. Patients who smoke or present with predominantly vision loss symptoms should be advised as to their lower likelihood of symptomatic response to RT and their increased likelihood of requiring post-RT decompressive surgery.

Efficacy of Combined 0.05% Cyclosporine and 1% Methylprednisolone Treatment for Chronic Dry Eye

To compare the efficacy of topical cyclosporine 0.05% (tCsA) and combined treatment with 1% methylprednisolone acetate for the treatment of moderate-to-severe chronic dry eye. Forty-four patients with moderate-to-severe dry eye who had not responded to conventional treatment were treated with tCsA for 3 months. Twenty-one subjects (Group 1) were treated with 1% methyl prednisolone acetate and tCsA for the initial 3 weeks, and treated with tCsA only thereafter, and 23 subjects (Group 2) were treated with tCsA only. Symptom scores, tear break-up time (TBUT), Schirmer score, and corneal and conjunctival fluorescein staining were evaluated before and at 1, 2, and 3 months after treatment. Proinflammatory factors, interleukin-6 (IL-6), and interleukin-8 (IL-8) tear concentration were measured before treatment and at 3 months. Symptom scores, Schirmer scores, TBUT score, corneal fluorescein, and conjunctival staining showed significant improvement at 1 month compared to baseline in group 1 (all P < 0.001), and all the same but few exceptions in group 2 (P = 0.002 on Schirmer, P = 0.267 on cornea stating). In symptom scores, Schirmer scores, and corneal staining, greater improvements were observed for group 1 at 1 month compared to group 2 (P < 0.001, P = 0.039, P = 0.01, respectively). However, in TBUT score and conjunctival staining, there were no between-group differences (P = 0.277, P = 0.254, respectively). The time interval from treatment initiation to symptom relief was shorter for group 1 than group 2. Both groups showed decreased tear IL-6 and IL-8 concentrations at 3 months compared to baseline levels (P < 0.05). However, no between-group differences were noted in mean concentrations of IL-6 and IL-8 at baseline and at 3 months. Treatment with tCsA appears to be safe and effective in moderate-to-severe chronic dry eye. Additional short-term use of a topical steroid had the benefit of providing faster symptom relief and improvement of ocular sign without serious complications.

Effect of Topically Applied Epithelial Sodium Channel Inhibitors on Tear Production in Normal Mice and in Mice with Induced Aqueous Tear Deficiency

Dry eye syndromes affect a significant proportion of the population worldwide with reported prevalence ranging from 6% to more than 34%. Patients with dry eye can experience intense pain due to eye irritation, gritty/scratchy feeling in the eyes, blurry vision, and light sensitivity. Available treatments for dry eye syndromes remain mainly palliative. The purpose of the present study was to test the hypothesis that inhibiting sodium absorption via the epithelial sodium channel (ENaC) will increase ocular hydration in both normal as well as in animals with experimentally induced dry eye. ENaC inhibitors were dissolved in an aqueous buffer that mimics the composition of tears and were applied topically to the ocular surface of isoflurane-anesthetized mice. The effect of ENaC inhibitors was compared with that of the secretagogue uridine triphosphate (UTP; 1%), a purinergic receptor agonist which was shown to increase tear volume in animals. Tear production was measured for 10 s using phenol red-impregnated cotton threads. Fluorescein staining that assesses ocular surface damage was performed at baseline and then at days 1, 2, and 3 after the induction of dry eye in mice. Our data show that the inhibition of ENaC led to a time- and concentration-dependent increase in tear volume in normal mice. The effect of ENaC inhibition after a single application outperformed UTP, as it was long-lasting with tear volume still above baseline values 8 h postdosing. ENaC inhibition, which led to increased tear production, improved fluorescein scores in our dry eye model, when compared with nontreated or animals treated with buffer or UTP. We conclude that the inhibition of ENaC provides long-lasting increases in ocular surface hydration and that ENaC blockers could provide an effective new therapy for chronic dry eye.

Surgical management of lacrimal punctal cauterization in chronic GVHD-related dry eye with recurrent punctal plug extrusion

We investigated the efficacy of lacrimal punctal occlusion surgery with a cautery device in patients with chronic GVHD (cGVHD)-related dry eye, with recanalization of puncta and recurrent punctal plug extrusion. A total of 23 puncta from 14 eyes of 10 patients with chronic GVHD (cGVHD)-related dry eye underwent punctual thermal cauterization with a high-temperature disposable cautery device. All patients were refractory to conventional treatment, including artificial tear eye drops, autologous serum eye drops and vitamin A eye drops, and had a history of recanalization and recurrent punctal plug extrusion. The effect of lacrimal punctal cauterization by thermal cautery device was evaluated by changes in subjective symptom scores, corrected distance visual acuity, Schirmer's test values, fluorescein staining scores, rose bengal staining scores, and tear-film break-up time before and 3 months after the surgery. Subjective symptom scores, Schirmer's test values, fluorescein and rose bengal scores, and tear-film break-up time improved significantly 3 months after the surgery. Recanalization of puncta was not observed in all the cases (0 of 14 eyes, 0%). Lacrimal punctal cauterization was effective with no recanalization and significant improvements in subjective symptoms and the ocular surface environment in cGVHD-related dry eye patients who had been refractory to conventional treatments.

Levels of matrix metalloproteinases (MMPs) in tear fluid of mustard gas exposed patients with chronic dry-eye symptoms.

The purpose of this study is to compare the levels of MMP-1, 2, 8, 9 in tear fluids of people exposed to mustard gas in the war between Iraq and Iran who had the chronic dry-eye symptoms compared to the normal group. In this study, 25 of the patients who were exposed to mustard gas and had chronic dry eye symptoms were compared to 25 patients as control group; consisting of 25 people who had common chronic dry eye symptoms with blepharitis and 25 healthy people as normal group. The level of MMP-1, 2, 8, 9 in tear fluid of people of these three groups was assessed by enzyme-linked immunosorbent assay (ELISA). The results for levels of MMP-1 (P=0.8) and MMP-2 (P=0.54) in tear fluid of patients in comparison with normal group do not indicate any significant difference. On the other hand, the calculated levels for MMP-8 (P=0.002) and MMP-9 (P=0.01) in tear fluid of patients in comparison with normal group shows a significant increase. The differences were considered statistically significant at p< 0.05. The effects of exposure to mustard gas on eyes of chemical-injured veterans destroy meibomian glands which paves the way for evaporative dry-eye. As a result, MMPs in tear fluid of these patients increase which eventually elevates the matrix metalloproteinases (MMPs) levels in tear fluid and results in later eye-impairments.