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At least 19 recordsLinked to original sources
PubMed1997

Effect of pterygium morphology on pterygium recurrence in a controlled trial comparing conjunctival autografting with bare sclera excision.

OBJECTIVES: To compare success rates of conjunctival autografting and bare sclera excision for primary and recurrent pterygium in the tropics and to evaluate risk factors for pterygium recurrence. METHODS: A prospective, controlled clinical trial was performed in which 123 primary and 34 recurrent pterygia, matched for age and pterygium morphology, were randomized in 2 separate studies to receive either bare sclera excision or conjunctival autograft. The surgical procedures were performed by one surgeon and reviewed at 1, 3, 6, and 12 months after surgery by an independent observer. Pterygium morphology was clinically graded as atrophic, intermediate, or fleshy according to an assessment of pterygium translucency. Risk factors were assessed using likelihood ratio tests. Weibull curves were used to estimate recurrence rates allowing for the interval censoring. RESULTS: In the group with primary pterygium (mean follow-up, 15.1 months), 38 (61%) of the 62 cases of bare sclera excision (heretofore referred to as the bare sclera group) had pterygium recur in contrast with 1 (2%) of the 61 cases of conjunctival autograft (heretofore referred to as the conjunctival autograph group) (P<.001, likelihood ratio X2 test). Nontranslucency, or fleshiness of the pterygium, and not age was a significant risk factor for recurrence in the bare sclera group (P<.001, likelihood ratio X2 test). In the group with recurrent pterygium (mean follow-up, 13.2 months), 14 (82%) of the 17 bare sclera group had pterygium recur, while no recurrences occurred among 17 cases in the conjunctival autograft group. Nontranslucency was again a highly significant factor for recurrence (P<.001, likelihood ratio X2 test). CONCLUSIONS: Pterygium recurrence is related to pterygium morphology and fleshiness of the pterygium is a significant risk factor for recurrence if bare sclera excision is performed. Conjunctival autografting for primary and recurrent pterygium is effective in reducing pterygium recurrence compared with bare sclera excision.

Adult↗
PubMed2003

Effect of pterygium excision on pterygium induced astigmatism.

Pterygium is known to affect refractive astigmatism, which can have a significant impact on vision. This study was undertaken to evaluate the effect of pterygium excision on refractive astigmatism. Thirty-six eyes with primary pterygium with astigmatism of 2D or more were analysed before and after pterygium excision. Astigmatism increased with the increase in the grade of pterygium (P = 0.000001). The preoperative refractive cylinder decreased from 4.60 +/- 2D to 2.20 +/- 2.04D (P = 0.00001) after pterygium excision.

Astigmatism↗
PubMed1998

[Pterygium and mast cells--expression of basic fibroblast growth factor increase in mast cells of the pterygium].

We examined the expression of basic fibroblast growth factor (bFGF) protein immunohistochemically, and bFGF specific messenger RNA (bFGF-mRNA) by in situ hybridization in the excised tissue of 5 cases of pterygium and 4 cases of normal conjunctiva. Immunohistochemical staining for bFGF showed strong positive staining in metachromatic mast cells stained with toluidine blue in the pterygium and in normal conjunctival specimens. The mean metachromatic mast cell count in pterygium specimens was increased significantly when compared with normal conjunctiva. In mast cells, bFGF positive rate was 84% in pterygium specimens, and 69% in normal conjunctival specimens. In situ hybridization indicated that the bFGFmRNA is located in most mast cells in pterygium specimens, but in only a few mast cells in normal conjunctival specimens. These results suggest that increased bFGF protein produced and stored by mast cells in the pterygium may contribute to its progression.

Female↗
PubMed1994

Management of pterygium with surgery and radiation therapy. The North Florida Pterygium Study Group.

PURPOSE: To compare our results in the management of pterygium using a higher total dose with other reported results. METHODS AND MATERIALS: Between 1971 and 1991, 690 patients were treated with complete surgical excision followed by beta irradiation for primary or recurrent pterygium. Of these patients, 129 had two or more areas involving both eyes for a total of 825 lesions treated. Only 17 patients (2%) had temporal lesions with the rest of the patients having nasal pterygia. All patients underwent complete surgical resection of the pterygium before undergoing radiation therapy. One hundred forty-nine patients had undergone previous surgical resection alone but developed recurrence. After surgical excision, all patients were treated with Strontium-90 applicators starting immediately within 24 hr of surgery. Our standard policy was six weekly applications, each delivering a surface dose of 1000 cGy. The total dose delivered was 6000 cGy. Minimum follow-up was 1 year with a median of greater than 8 years. RESULTS: There were only fourteen recurrences (1.7%) out of a total of 825 lesions treated. Nine of the fourteen patients received suboptimal therapy undergoing less than five applications of Strontium-90. There were no major complications. CONCLUSION: The combination of surgical excision followed by adequate Strontium-90 applications is highly effective in the management of pterygium. The optimal total dose appears to be in the range of 2000 cGy to 6000 cGy.

Adult↗
PubMed2001

Low-dose intraoperative mitomycin C as chemoadjuvant for pterygium surgery.

PURPOSE: To evaluate the efficacy and safety of low-dose intraoperative mitomycin C (MMC) during bare sclera procedure and to compare the rates of pterygium recurrence between recurrent pterygium patients treated with adjuvant MMC and those reconstructed with a conjunctival autograft. METHODS: We studied the recurrence of pterygium, 12-month pterygium-free survival rates, final appearance, and postoperative complications in 96 eyes of 92 patients who received either intraoperative 0.02% MMC for 30 seconds or conjunctival autografting after pterygium excision. Patients were divided into three groups: group 1 included 38 eyes with primary pterygium undergone intraoperative MMC; group 2, 26 eyes with recurrent pterygium treated with intraoperative MMC; and group 3, 32 eyes with recurrent pterygium treated with pterygium excision and conjunctival autografting. RESULTS: Pterygium recurred in 3 (7.9%) of 38 eyes in group 1, 5 (19.2%) of 26 eyes in group 2, and 2 (6.3%) of 32 eyes in group 3. Despite the higher recurrence rate in group 2 compared with that of group 3, the difference between the two was not statistically significant (p = 0.22). The cumulative probabilities of success were 91.6+/-4.6%, 80.8+/-7.7%, and 92.3+/-5.4% at 12 months for groups 1, 2, and 3, respectively. Final appearance of the pterygium excision area was satisfactory in nearly two-thirds of the MMC-treated patients, 71.1% and 65.4% for groups I and 2, compared to 75.1% of patients who had undergone conjunctival autografting. No patients experienced severe complications during a mean postoperative follow-up of 27.3+/-4.1 months, 29.9+/-3.9 months, and 40.9+/-19.1 months for groups 1, 2, and 3, respectively. CONCLUSIONS: A single intraoperative application of 0.02% MMC for 30 seconds after pterygium excision is associated with minimal complication and effectively reduces the recurrence rates after excision of primary or recurrent pterygium. In comparison with conjunctival autografting, low-dose application of MMC after bare sclera procedure is less efficacious in preventing recurrence of pterygium, but simpler and produces a similar proportion of patients with satisfactory final appearance.

Adult↗
PubMed2000

Pterygium-induced corneal astigmatism.

BACKGROUND: Previous work has suggested an association between increasing size of pterygium and increasing degrees of induced corneal astigmatism. OBJECTIVES: To assess the quantitative relation between pterygium size and induced corneal astigmatism using a computerized corneal analysis system (TMS II) and slit-lamp beam evaluation of pterygium size, and to conclude whether corneal astigmatism is an early indication for surgical intervention. METHODS: We evaluated 94 eyes of 94 patients with unilateral primary pterygium of different sizes, using TMS II and slit-lamp beam measurements of the size of the pterygium (in millimeters) from the limbus to assess parameters of pterygium size with induced corneal astigmatism. Best corrected visual Snellen acuity was performed. RESULTS: Primary pterygium induced with-the-rule astigmatism. Pterygium extending > 16% of the corneal radius or 1.1 mm or less from the limbus produced increasing degrees of induced astigmatism of more than 1.0 diopter. Significant astigmatism was found in 16.16% of 24 eyes with pterygium of 0.2 up to 1.0 mm in size, in 45.45% of 22 eyes with pterygium of 1.1 up to 3.0 mm in size (P < or = 0.0004), and in 100% of 3 eyes with pterygium of 5.1 up to 6.7 mm in size (P = 0.0005). We found that visual acuity was decreased when topographic astigmatism was increased. CONCLUSIONS: When primary pterygium reaches more than 1.0 mm in size from the limbus it induces with-the-rule significant astigmatism (> or = 1.0 diopter). This significant astigmatism tends to increase with the increasing size of the lesion. Topographic astigmatism tends to be improved by successful removal of the pterygium. These findings suggest that early surgical intervention in the pterygium may be indicated when the lesion is more than 1.0 mm in size from the limbus.

Astigmatism↗
PubMed2003

[Trefoil factor family gene and peptide expression in pterygium].

PURPOSE: Trefoil factor family (TFF) peptides (formerly P-domain peptides; trefoil factor) are small (7-12 kDa) protease-resistant secreted peptides designated pS2 (or TFF1), SP (TFF2) and ITF (TFF3). Human conjunctival goblet cells (GCs) are known to synthesize TFF, but TFF expression by these cells has not been studied in pathological conditions. We quantified trefoil factor family (TFF) gene transcripts in pterygium, and we immunolocalized TFF protein. METHODS: Eleven pterygium specimens were studied, together with 19 biopsy specimens of normal human conjunctiva as controls. TFF1 (pS2), TFF2 (spasmolytic peptide) and TFF3 (intestinal trefoil factor) mRNA expression was semiquantified by means of reverse-transcription polymerase chain reaction amplification (RT-PCR). TFF1, TFF2 and TFF3 mRNA levels were determined individually, relative to beta2 microglobulin housekeeping gene mRNA (internal standard), by coamplification of the target fragments and beta2 microglobulin in the same tube. Five pterygia and five normal human conjunctival biopsy specimens were also analyzed for TFF1 and mucin (MUC5AC) protein expression by immunostaining with monoclonal antibodies. Anti-PS2 (Zymed Laboratories, San Francisco), a mouse monoclonal antibody (MAb) against the 30 C-terminal amino acids of human TFF1, and P2802 (provided by Doctor Marie-Christine Rio, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM, Strasbourg, France), a mouse MAb directed against a synthetic peptide corresponding to the last 28 amino acids of TFF1, were used at 1/20 dilution. A mouse monoclonal antibody directed against the peptidic core of gastric M1 mucin was used as previously described. M1 immunoreactivity is encoded by the MUC5AC gene. RESULTS: TFF1 and TFF3 mRNA was expressed in all normal conjunctival and pterygium specimens. TFF2 mRNA was not expressed by either sample type, but was expressed by the positive control (human stomach cDNA). TFF1 mRNA expression was stronger in pterygium than in controls (p=0.02). TFF3 mRNA expression was similar in the two sample types (p=0.89). TFF are coexpressed and act in concert with mucins to protect mucous epithelia and trigger wound-healing responses. Inflammation and ulceration of the gastrointestinal tract are associated with increased TFF expression. Conjunctival GCs secrete TFF in both pigs and humans. We found that TFF1 mRNA was overexpressed in pterygium relative to healthy conjunctiva, whereas the TFF1 immunostaining patterns were similar. TFF1 protein expression was confined to goblet cells. However, whereas all GCs were positive for MUC5AC, not all GC were labeled by anti-TFF1 mAbs in either normal conjunctiva or pterygium. The observed TFF1 mRNA overexpression in pterygium was not associated with abnormal TFF1 peptide localization. Increased MUC5AC protein expression would be expected in pterygium, because of increased GC density. Indeed, in conjunctival diseases such as dry-eye syndrome in which GC density is decreased, mucin secretion is also decreased. This could explain the increased expression of TFF1 mRNA in pterygium, although not all GCs expressed TFF1 protein. TFF proteins are copackaged within mucous cell granules; TFF1 preferentially colocalizes with MUC5AC, and TFF3 with MUC2. However, we found some cell granules containing MUC5AC but not TFF1. The proportion of TFF1-negative GCs was similar in pterygium and normal conjunctiva. The normal TFF3 mRNA expression in pterygium was unexpected and suggests that only GCs involved in TFF1 secretion are overrepresented in this pathological tissue. TFF2 mRNA was undetectable in both normal conjunctiva and pterygium, possibly because of its copackaging in mucous cell granules and its preferential cosecretion with MUC6, which is not expressed in the conjunctiva. CONCLUSION: As in normal conjunctiva, the TFF1 and TFF3 genes are expressed by conjunctival goblet cells in pterygium, contrary to the TFF2 gene. Only TFF1 gene expression was elevated in pterygium compared to normal conjunctiva.

Adult↗
PubMed2003

The roles of T-lymphocyte subpopulations (CD4 and CD8), intercellular adhesion molecule-1 (ICAM-1), HLA-DR receptor, and mast cells in etiopathogenesis of pterygium.

PURPOSE: The etiopathogenesis of pterygia is controversial. We wished to explore the effects of inflammatory cells and mediators such as T-lymphocyte subpopulations (CD4 and CD8), mast cells, intercellular adhesion molecule-1 (ICAM-1), and HLA-DR receptors on pterygium development. METHODS: Immunohistochemical stainings were performed for T-lymphocyte subpopulations, mast cells, ICAM-1, and HLA-DR on sections of pterygium specimens. Nasal bulbar conjunctival specimens of patients undergoing cataract or vitrectomy operations were used for comparision. The mean number of mast cells/mm2 was calculated using an ocular grid, and the difference between the numbers derived from pterygium and from normal conjunctival sections was analyzed statistically using the Mann-Whitney U test. CD4 and CD8 lymphocytes in the epithelial and subepithelial regions, and ICAM-1 and HLA-DR expression on pterygium epithelium were compared qualitatively. RESULTS: Increased CD4 and CD8 lymphocytic infiltration in pterygium sections was observed. Only occasional lymphocytes were detected in normal conjunctival sections. The CD4/CD8 ratio was 0.33 for pterygium epithelium and 1.34 for pterygium substantia propria. Increased HLA-DR and scattered ICAM-1 expression were also detected on pterygium epithelium, but not on the normal conjunctival epithelium. The difference in mast cell numbers between the pterygium and control groups was not statistically significant. CONCLUSIONS: The detection of T-lymphocyte infiltration and ICAM-1 and HLA-DR expression in pterygium epithelium strongly supports the suggestion that cellular immunity plays an important role in pterygium formation. Pterygium epithelium also seems to participate actively in the augmentation of this inflammatory process by expressing ICAM-1 and HLA-DR molecules. Mast cells may participate in some stages or subtypes of pterygium during its development.

Adult↗
PubMed2006

Microarray and protein analysis of human pterygium.

PURPOSE: Pterygium is a sunlight-related, ocular-surface lesion that can obscure vision. In order to identify specific genes that may play a role in pterygium pathogenesis, we analyzed the global gene expression profile of pterygium in relation to autologous conjunctiva. METHODS: Oligonucleotide microarray hybridization was used to compare the gene expression profile between human whole pterygium and autologous conjunctiva. Selected genes were further characterized by RT-PCR, western blot, and immunohistochemistry, and comparisons were made with limbal and corneal tissues. RESULTS: Thirty-four genes exhibited a 2 fold or greater difference in expression between human whole pterygium and autologous conjunctiva. Twenty-nine transcripts were increased and five transcripts were decreased in pterygium. Fibronectin, macrophage-inflammatory protein-4 (MIP-4), and lipocalin 2 (oncogene 24p3; NGAL) were increased 9, 5, and 2.4 fold, respectively, while Per1 and Ephrin-A1 were decreased 2 fold in pterygium. Western blots showed that fibronectin and MIP-4 were increased in pterygium compared to limbus, cornea, and conjunctiva. Immunohistochemical analysis showed fibronectin in the stroma; lipocalin 2 in the basal epithelial cells, basement membrane, and extracellular stroma; and MIP-4 in all areas of the pterygium. CONCLUSIONS: These data show both novel and previously identified extracellular-matrix-related, proinflammatory, angiogenic, fibrogenic, and oncogenic genes expressed in human pterygium. Comparisons of selected genes with limbal and corneal tissues gave results similar to comparisons between pterygium and normal conjunctiva. The increased expression of lipocalin 2, which activates matrix metalloproteinases (MMP), is consistent with our previous findings that MMP-9 and other MMPs are highly expressed in pterygium basal epithelium.

Acute-Phase Proteins↗
PubMed2026

Revealing the Association of LIG1 Genetic Variants With Pterygium Susceptibility and Demographic Characteristics in a Taiwanese Population.

BACKGROUND/AIM: Pterygium is a common ocular surface disorder associated with long-term ultraviolet exposure and/or oxidative DNA damage. Accumulated evidence suggests that defects in DNA repair pathways may contribute to pterygium risk. DNA ligase I (LIG1), a key enzyme involved in DNA replication and base excision repair, has been involved in the etiology of several human diseases, including cancers. However, its role in pterygium has never been examined before. This study aimed at exploring the association between the LIG1 genotypes and pterygium risk in a Taiwanese population. PATIENTS AND METHODS: The hospital-based case-control study was conducted including 165 patients with pterygium and 320 age- and sex-matched non-pterygium controls. LIG1 rs20579 genotypes were accessed utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. Stratified analysis and the calculation of odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used for evaluating the associations between genotypes and pterygium risk. RESULTS: Individuals carrying the homozygous variant AA genotype exhibited a significantly elevated risk of pterygium compared with those carrying the GG genotype (OR=2.74, 95% CI=1.17-6.43, p=0.0305). Under the recessive model, the AA genotype conferred a 2.65-fold elevated risk (95% CI=1.14-6.18, p=0.0350). The variant A allele was also associated with increased susceptibility (OR=1.46, 95% CI=1.03-2.07, p=0.0413). Stratified analyses revealed significant associations specifically among individuals aged &#x2265;60 years (OR=5.64, 95% CI=1.67-19.04, p=0.0039) and males (OR=5.23, 95% CI=1.74-15.73, p=0.0034), but not those of younger ages or females. CONCLUSION: The LIG1 rs20579 genotype is significantly associated with pterygium susceptibility in Taiwanese individuals, particularly among elderly and male subjects. These findings support the involvement of impaired DNA repair machinery in pterygium pathogenesis and suggest that LIG1 rs20579 may serve as a novel genetic biomarker for risk assessment and early detection of pterygium.

Humans↗
PubMed2001

[Impact of pterygium size on corneal topography and visual acuity - a prospective clinical cross-sectional study].

PURPOSE: Pterygia may cause topographic changes featuring increase of astigmatism. The purpose of this study was to quantify the impact of the head-limbus-distance (=height) and limbal base length of the pterygium on the anterior corneal curvature and visual acuity before excision. PATIENTS AND METHODS: In 52 eyes (19 female, 33 male) with a mean age of 53 +/- 14 years the pterygium size (height, base length, area) was quantified using projected preoperative clinical slides and was correlated with visual acuity, refractive, keratometric, topographic astigmatism and Surface Regularity Index (SRI), Surface Asymmetry Index (SAI) of the TMS-1 videokeratoscope. RESULTS: The mean height of the pterygium was 3.1 +/- 1.4 (0.8 to 6.7) mm, the mean base length was 5.1 +/- 1.4 (2.9 to 7.8) mm, the estimated mean area was 11.4 +/- 6.9 (2.1 to 29.4) mm(2). The increasing pterygium height and area resulted in a highly significant elevation of the preoperative SRI and SAI values (p </= 0.01). The amount of keratometric (p=0.02) and topographic astigmatism (p=0.001) correlated significantly with height and area of the pterygium. In addition, pterygium size correlated significantly with the differences of zonal corneal power between steepest and flattest hemimeridian in the 3-mm zone or 5-mm zone, respectively (p </= 0.01). Best-corrected visual acuity and height/area of the pterygium correlated significantly inversely (p=0.001). Visual acuity seemed to be mostly unaffected up to a height of 2.5 mm. Overall, the impact of the base length was much less striking. Topographic astigmatism (3.3 +/- 2.8 D) was significantly larger than keratometric astigmatism (2.1 +/- 2.1 D) (p=0.001). The larger the pterygium, the larger was the difference between keratometric astigmatism and subjectively tolerated spectacle cylinder (p </= 0.01). CONCLUSIONS: Increasing distance of the pterygium head from the limbus results in increased amount and irregularity of preoperatively induced corneal astigmatism. This may explain the patient's decrease in visual acuity before the pterygium reaches the optical axis. Our data may help to determine the adequate time point for primary pterygium excision.

Adult↗
PubMed1999

Quantitative analysis of regular and irregular astigmatism induced by pterygium.

PURPOSE: To quantitatively evaluate the influence of pterygium and its removal surgery on both regular and irregular corneal astigmatism. METHODS: In 19 eyes of 19 patients undergoing pterygium surgery, videokeratographic measurements were taken before and 1 month after surgery. Using Fourier harmonic analysis, dioptric data on mire rings were decomposed into spherical, regular astigmatism, and irregular astigmatism (decentration and higher order irregularity) components. The distance between the line of sight and the advancing edge of pterygium was measured, and the eyes were classified into two groups: large pterygium group (the distance <2.0 mm, n = 7) and small pterygium group (> or =2.0 mm, n = 12). Fifteen eyes of 15 subjects served as age-matched normal control eyes. RESULTS: Before surgery, the magnitudes of regular astigmatism and higher order irregular astigmatism showed significant correlation with the size of pterygium. Regular astigmatism, asymmetry, and higher order irregularity in the large pterygium group were significantly greater than those of normal control eyes. The pterygium removal surgery significantly improved these changes, but regular astigmatism and higher order irregularity in the large pterygium group still remained significantly greater than those in the normal control eyes. CONCLUSION: Pterygium induces a significant amount of regular and irregular astigmatism in proportion to its size. The removal surgery can improve these changes, but corneal distortion does not normalize completely in eyes with advanced pterygium.

Aged↗