Pterygium Group Research Articles

Postoperative irradiation of primary or recurrent pterygium: results and sequelae

Purpose: To evaluate the efficacy of postoperative beta irradiation and to analyze treatment sequelae in patients with primary and recurrent pterygium. Methods and Materials: From June 1986 to June 1998, 94 patients corresponding to 100 eyes received postoperative beta irradiation. Two groups of patients were treated: 37 eyes with primary pterygium (Group I) and 63 eyes with recurrent pterygium (Group II). Terson technique surgery was used in the majority of patients. Time between surgery and beta irradiation ranged from 2 to 48 h. Radiation doses and fractionation consisted of 30 Gy/3 fractions/5 days in 17 cases, 60 Gy/6 fractions/6 weeks in 80 cases, and 20 Gy/1 fraction in 3 patients. Results: Fourteen of the 100 cases (14%) treated with surgery and adjuvant irradiation recurred. The overall crude local recurrence rates were 5.4% for Group I and 19% for Group II patients. The 5-year probability of local tumor control was 83.5% for the whole group of patients, 94% for Group I, and 76.9% for Group II ( p = 0.04). The early sequelae related to surgery or irradiation were self limited and disappeared by 6 months after the end of the treatment: ocular irritation (14 cases), scleral atrophy (5 cases), and neovascularization (7 cases). A greater incidence of sequelae was observed in Group II patients, but the difference between the groups was not statistically significant ( p = 0.15). No significant correlation between treatment sequelae and treatment dose was noted: 29% sequelae with 30 Gy vs. 18.7% sequelae with 60 Gy ( p = 0.32). No late complications have been observed. Conclusion: Adjuvant beta irradiation provides effective therapy for primary pterygium, is somewhate less effective in patients with recurrent pterygium, and is associated with a moderate rate of early and transient sequelae.

Epidemiological Survey of Ocular Diseases in K Island, Amami Islands: Prevalence of Cataract and Pterygium

Purpose: An epidemiological survey of ocular disease was performed in a town of the Amami Islands in southwestern Japan. Object and Methods: A total of 339 participants over 40 years joined the survey. Among the 339 participants, the lens findings of 602 eyes of 301 subjects were analyzed. Results: The prevalence of lens opacification was 32.0, 54.0, 83.1, 96.9%, and 100% among subjects in their 40, 50, 60, 70s, and over 80 years. Lens opacification over grade II was 4.0, 12.7, 26.2, 60.0%, and 83.3%. The cataract type most frequently seen was cortical (96.1%), followed by 48.5% with nuclear opacity and 14.7% with subcapsular type. A high prevalence was seen of pterygium at 25.4%. Although the prevalence of lens opacification was higher in the group with pterygium in their 70s, no significant difference was noticed in persons in their 40, 50, 60s, and over 80 years old between the pterygium and non-pterygium groups. Conclusions: Similarly to the results of a previous survey in Okinawa, Noto, and Hokkaido, the main type of lens opacification was cortical in Amami. The prevalence of nuclear opacification and pterygium was higher than in Noto and Hokkaido, and close to that seen in Okinawa.

Tear functions in patients with pterygium.

In the etiology of pterygium abnormalities in tear functions have also been emphasized. In this study, tear function tests are evaluated in patients with pterygium. Schirmer's test 1, tear film break-up time and mucus fern patterns were evaluated in 70 eyes with pterygium and in 70 eyes of the age matched control group. Marginal tear films were also assessed. Tear film break-up time was significantly reduced in the pterygium group. Mucus fern patterns and marginal tear films were found to be markedly abnormal in the eyes with pterygium, however, there was no significant difference in Schirmer's test 1. Tear function tests disclosed disrupted tear film stability which is more likely to be due to the altered mucin. This change may either be the primary factor inducing pterygium formation or reflect an existing pathology in the cells lining the ocular surface.

The Effect of Pterygia on Contrast Sensitivity and Glare Disability

To detect subtle changes in visual acuity, we measured spatial contrast sensitivity in 12 patients with pterygium (Group 1) and compared their results with those from an age- and sex-matched control population (Group 2). Glare disability was also measured in each group. Measurements of contrast sensitivity were lower in Group 1 at all spatial frequencies than those of Group 2, independent of the testing device used. Glare disability was significantly increased in Group 1 compared to Group 2. Our studies indicate that contrast sensitivity and glare disability testing may provide additional objective methods for documenting impaired vision in patients with pterygium when Snellen visual acuity is minimally affected.