Collagen changes in rabbit conjunctiva after conjunctival crosslinking.

This study aims to determine the ultrastructural changes in collagen fibrils in rabbit conjunctiva after conjunctival crosslinking using riboflavin and ultraviolet A (UVA) light at an irradiation intensity of 45 mW/cm2. Conjunctival crosslinking may increase conjunctival stiffness. The supertemporal quadrants of the right eyes of 24 adult rabbits were treated with a topical riboflavin solution (0.25%) before irradiation with UVA light at 45 mW/cm2 for 4 min. After 3 weeks, the collagen fibrils in fibril bundles were examined by electron microscopy. Immunohistochemical staining was used to detect the expression levels of collagen I and collagen III in the rabbits' conjunctiva. The diameter of the collagen fibrils in the fibril bundles varied slightly, ranging from 30 to 60 nm in the conjunctival stroma of the control group. In the treatment group, the diameter of collagen fibrils ranged from 60 to 90 nm. The thickest collagen fibrils were observed in the treatment group (up to 90 nm in diameter). In contrast, those in the conjunctival stroma of the control group were considerably smaller (up to 60 nm in diameter). However, thicknesses of collagen fibrils displayed a unimodal distribution. Both collagen I and collagen III increased after treatment with riboflavin and UVA light irradiation at 45 mW/cm2. The data indicate that in rabbits, conjunctival crosslinking with riboflavin and UVA light at 45 mW/cm2 for 4 min is safe and does not induce ultrastructural alterations of the conjunctival cells. The conjunctival crosslinking with riboflavin and UVA light at 45 mW/cm2 can increase the diameter of collagen fibrils, but the average densities of collagen I and collagen III have no statistical significance.

A preliminary study on the establishment of an animal model of conjunctivochalasis.

AIM: To explore a feasible method on the establishment of an animal model of conjunctivochalasis (CCH). METHODS: Twelve clean-grade New Zealand white rabbits were divided into four groups (n=3/group): the control group (one received no interventions, and the others underwent subconjunctival injection of sterile water), the matrix metalloproteinases (MMPs) group (administered subconjunctival injection of MMP-3), the aging group (administered subcutaneous injection of D-galactose), the tumor necrosis factor-α (TNF-α) solution group (administered eye drops of TNF-α). Anterior segment photography, conjunctival tissue light microscopy and transmission electron microscopy (TEM) were performed after 12wk. RESULTS: Among all groups, the MMPs group had the following changes: the looser connection between the inferior bulbar conjunctiva and sclera; the more disordered collagen fibers (Trichrome staining) and the broken elastic fibers (Aldehyde-fuchsin staining); the focal necrosis of fibroblasts (TEM). CONCLUSION: Administration of MMPs may be a feasible method for the establishment of an animal model of CCH.

Expressions of matrix metalloproteinases 1 and 3 and their tissue inhibitors in the conjunctival tissue and fibroblasts cultured from conjunctivochalasis.

AIM: To investigate the expression of matrix metalloproteinases 1 and 3 (MMP-1 and MMP-3) and their tissue inhibitors of metalloproteinases 1 and 3 (TIMP-1 and TIMP-3) in the conjunctiva of eyes with conjunctivochalasis (CCh). METHODS: The conjunctival tissue was obtained from the CCh patients and controls, the MMPs/TIMPs expression concentration was determined by enzyme-linked immuno-sorbent assay (ELISA) and immunofluorescence staining. The expression levels of MMPs/TIMPs in the CCh fibro-blasts were determined by analyzing its concentration in the cellular supernatant that was abstracted from the in vitro cultured CCh fibroblasts. RESULTS: MMP-1 and MMP-3 levels determined by ELISA were both significantly higher in the CCh group than that in the control group (P=0.042, 0.022, respectively), so was the levels of TIMP-1 (P=0.010). No significant difference in the expression of TIMP-3 in conjunctiva was found between the two groups (P=0.298). The expression of MMP-1 and MMP-3 were both up-regulated significantly in the CCh group (P=0.040, 0.001, respectively) on immuno-fluorescence staining. MMP-1 and MMP-3 expression in the fibroblasts were both significantly higher in the CCh group than that in the control group (P=0.027, 0.001, respectively), while neither the TIMP-1 nor TIMP-3 expression was significantly different between the two groups (P=0.421, 0.237, respectively). CONCLUSION: The overexpression of MMP-1 and MMP-3 in conjunctival tissue and fibroblasts may play an important role in the pathogenesis and development of CCh.

[Clinical observation of lymphangiectasis in conjunctivochalasis cases].

OBJECTIVE: To investigate the relationship between the occurrence and development of conjunctivochalasis and bulbar conjunctival lymphangiectasia. METHODS: Case control study. One hundred cases with conjunctivochalasis treated from January to March 2012 were selected to study, and 100 cases with no conjunctivochalasis as the control group at the same time. To observe bulbar conjunctiva lymphatic duct dilatation using slit lamp microscope, analysis bulbar conjunctiva and fascia images by OCT scanning, and ablate lymphatic of conjunctival tissue for pathologic examine. RESULTS: Twenty-nine eyes of the bulbar conjunctiva lymphangiectasia associated with 100 cases (183 eyes) conjunctivochalasis patients, accounting for 15.84%; 8 eyes of the ball conjunctival lymphatic dilation in control group of 100 cases ( 200 eyes), accounting for 4.00%. The difference between the two groups was statistically significant (χ(2) = 15.36, P < 0.001). OCT scanning showed that lymphangiectasia of the conjunctiva is at the subcutaneous mainly, some in the conjunctival lamina propria. They are border-clear, full-filled fluid, single-lumen or multi lumens, not involving the fascia. The histopathological examination showed that the lamina propria of the bulbar conjunctiva mildly chronic inflammatory changes accompanied by a large number of lymphangiectasia. CONCLUSION: Bulbar conjunctival lymphangiectasia may be one of the reasons for the conjunctivochalasis.

Comparison study of two diagnostic and grading systems for conjunctivochalasis.

BACKGROUND: Different diagnostic and grading systems of conjunctivochalasis have resulted in apparent disparity between the prevalence rates of recent population-based studies. This study aimed to investigate the disparity between 4-level system cited from Meller and Tseng in 1998 (abbreviated here as Meller's system) and 5-level system modified from Meller's system cited from Zhang and associates (abbreviated here as Zhang's system) regarding the diagnosis and the patients' preferences for the treatment of conjunctivochalasis in the general population. METHODS: A total of 546 senile residents living in the Guiyangyuan community of Shanghai, China, participated in the study. The diagnostic criteria for conjunctivochalasis were based on two diagnostic grading systems: Meller's system and Zhang's system, which was modified from Meller's system. The participants' preference regarding medical treatment for conjunctivochalasis was determined according to the response to a question. One year later, a follow-up interview determines whether the patient had undergone surgery for conjunctivochalasis. RESULTS: With Meller's system, 398 participants were confirmed as having conjunctivochalasis, and the prevalence rate was 72.89%. According to Zhang's system, only 213 participants were diagnosed as having conjunctivochalasis, and the prevalence rate was 39.01%. A total of 109 eyes underwent medical treatment or surgery for conjunctivochalasis in the following year, including eight eyes that were diagnosed as grade II and 101 eyes that were diagnosed as grade III according to Meller's system and five eyes that were diagnosed as grade I, 55 eyes that were diagnosed as grade II, 31 eyes that were diagnosed as grade III, and 18 eyes that were diagnosed as grade IV according to Zhang' system. CONCLUSION: Diagnoses of conjunctivochalasis using Zhang's system are more consistent with patient requests and the medical treatment strategies used than diagnoses made using Meller's system.

The effect of age and conjunctivochalasis on conjunctival thickness.

PURPOSE: To determine the effect of age and conjunctivochalasis (CCh) on conjunctival thickness. METHODS: One hundred and nineteen normal subjects aged 60-79 years and 83 subjects with CCh graded I-II (39 males and 44 females) aged 60-79 years were recruited. Cirrus HD-optical coherence tomography 4000 was used to measure the thickness of the lower temporal conjunctiva 3-5 mm from the corneal limbus. RESULTS: The conjunctiva was significantly thicker in normal subjects compared to CCh patients (p < 0.0001), and in normal subjects aged 60-69 years compared to normal subjects aged 70-79 years (p = 0.0466). There was no significant difference between age groups for patients with CCh (p = 0.1001). After subdividing groups by age, normal subjects had a thicker conjunctiva compared to CCh patients for those aged 60-69 years (p = 0.0152) as well as those aged 70-79 years (p = 0.0120). CONCLUSIONS: The conjunctiva is thinner in older subjects and subjects with CCh.

Efficacy of treatment for pterygium by autologous conjunctival transplantation and mitomycin C.

BACKGROUND: The recurrence of pterygium after surgery is high. A variety of adjunctive treatment approaches have been developed to improve the clinical efficacy and many related articles have been published. This study aimed to determine the risk for postoperative pterygium recurrence comparing autologous conjunctival transplantation (ACT) versus mitomycin C (MMC). METHODS: Relevant literature published until December 2010 in Medline, Embase, Cochrane, Cochrane library, Science Citation Index, and Google Scholar were searched. Qualified random clinical trial (RCT) studies on the comparison of recurrence rate of pterygium after ACT and MMC treatment were included in this study. RESULTS: Eight RCTs with 663 eyes entered the final analysis. The recurrent rate of pterygium was 8.7% (30/343) for ACT and 18.75% (60/320) for MMC. Using fixed-effect meta analysis, we found that the recurrence was significantly lower after ACT than MMC treatment (odds ratio (OR) = 0.40, 95% confidence index (CI), 0.25 - 0.63, P < 0.0001). In sensitivity analyses, we employed random-effects model and excluded studies of low quality or studies in which MMC was administrated after the operation. All the sensitivity analyses confirmed that ACT led to lower recurrence rates than MMC. Sub-group analysis revealed that the recurrence rate was 20.2% (20/99) and 27.65% (26/94) for conjunctival autograft (CA) and MMC respectively, and no significant difference in the recurrence rate was detected (OR = 0.65, 95%CI 0.33 - 1.28, P = 0.22). However, we found that conjunctival limbal autograft (CLA) had lower recurrence rate than MMC (OR = 0.26, 95%CI 0.14 - 0.48, P = 0.0001). CONCLUSION: CLA has better therapy efficacy against the recurrence of pterygium than MMC.

Clinical evaluation of the quantitative locator for conjunctiva resection used as an instrument for the treatment of conjunctivochalasis.

BACKGROUND: The crescent excision of the inferior bulbar conjunctiva has been advised as a surgical procedure in the management of conjunctivochalasis refractory to medical treatments. However, it is difficult for this procedure to design how much conjunctival tissue should be excised. This study aimed to present a quantitative locator for conjunctiva resection and evaluate its effect on the treatment of conjunctivochalasis (CCh). METHODS: Poly ß-hydroxyethyl methacrylate resin/ß-hydroxyethyl methacrylate (HEMA, water gel) was used as the material to make the quantitative locator which was designed to suit the specific patient. Forty-six patients with bilateral symptomatic CCh were included in this prospective study. Of the patients, while the right eye underwent the popularly used crescent-shaped conjunctiva resection (group I), the left eye was treated with conjunctiva resection assisted by the quantitative locator (group II). International Ocular Surface Disease Index (OSDI), scores of remnant conjunctiva fold, complications and conjunctival cut healing, height of tear meniscus, tear break-up time (BUT), and time of surgery were evaluated. Tasting chloromycetin test (TCT) was used to evaluate how the lacrimal duct worked. RESULTS: OSDI in group II (8.82 ± 2.36) was significantly lower than that in group I (14.67 ± 2.21) (t = 12.22, P < 0.01). The amount of conjunctiva fold remaining in group II was less than that in group I. Scores of remnant conjunctiva fold in group I were significantly higher than those in group II (t = 31.85, P < 0.01). While evaluation scores of conjunctival cut healing in group I were lower than those in group II, scores of complication in group I were significantly higher than those in group II at 8 weeks after surgery (t = 89.60, P < 0.01). There was no significant difference in eyes with normal BUT (χ(2) = 0.031, P = 0.985) between the two groups, as the case was in eyes with positive TCT (χ(2) = 0.14, P = 0.930) and in eyes with normal height of tear meniscus (χ(2) = 0.48, P = 0.780). Mean surgery time in group II ((17.11 ± 2.08) minutes) was significantly shorter than that in group I ((25.22 ± 4.78) minutes) (t = 13.84, P < 0.01). CONCLUSION: A quantitative locator can be used as an effective, safe, and less time-consuming instrument to facilitate conjunctival excision for symptomatic CCh treatment.

[Epidemiologic study of conjunctivochalasis in populations equal or over 60 years old in Caoyangxincun community of Shanghai, China].

OBJECTIVE: To investigate the prevalence and relative factors of conjunctivochalasis among people over 60 years old in Caoyangxincun community of Shanghai. METHODS: A cross-sectional study based on local residents in this community was carried out from September 2008 to October 2008. Cluster sampling was used in randomly selecting individuals aged > or = 60 years. Slit-lamp ophthalmoscope was used for eye examination and diagnosis. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. A database was set using SPSS 10.0 software, Chi-square test was used for data analysis. RESULTS: 2110 residents took part in this study, with the response rate 94.85%. 930 cases (1762 eyes) were confirmed as conjunctivochalasis, so the prevalence rate is 44.08%. The prevalence of conjunctivochalasis was increasing with age (chi(2) = 10.44, P < 0.01). 556 cases (943 eyes) were confirmed as degree I, 246 cases (647 eyes) as degree II, 120 cases (162 eyes) as degree III and the rest 8 cases (10 eyes) as degree IV. Several symptoms, such as blurred vision, asthenopia and eye pain were more frequent in patient group than in the normal ones (chi(2) value was 15.44, 20.54 and 19.74, respectively, P < 0.01). In the disease eyes, the conjunctiva usually piled up on the nasal and temporal side (944 eyes, 53.58%), the location of inferior lid margin was usually above corneal limbus (2589 eyes, 61.35%) and inferior lid margin entropion and introversion were always found (7.04% and 6.63%). Abnormal lacrimal river was found in 87.23% of the diseased eyes, more than the non-conjunctivochalasis eyes (chi(2) = 1615.81, P < 0.01). CONCLUSIONS: Conjunctivochalasis is a common eye disease in aged population, with obvious signs and symptoms of ocular surface and lacrimal river impairment. In the local residents, most patients were classified as minimal or moderate degree. The location of inferior lid margin and the tension of inferior lid may be related factor of conjunctivochalasis.