Zanco Journal of Medical Sciences
 
Skip Navigation Links
Home
Available Issues
Search
Editorial Board
Information for Authors
Review Process
Copyright
Links and Contacts
  Zanco J Med Sci:  Aug. 2018; 22 (2): 141–147

The relation between pterygium size and refractive astigmatism among a group of patients in Erbil city

Hawzhin M. Abdussamad *, Ahmed Kareem Joma **

 

* Erbil Directorate of Health, Erbil, Iraq.

** Department of Surgery , College of Medicine, Hawler Medical University, Erbil, Iraq.
 


Abstract

Background and objective: A pterygium is a triangular fibrovascular subepithelial ingrowth of degenerative bulbar conjunctival tissue over the limbus onto the cornea. Excision is indicated if the pterygium approaches the visual axis, causing loss of vision from irregular astigmatism or in cases of considerable irritation. This study aimed to determine the percentage of astigmatism in patients presented with pterygium and measure the effect of size (width and height) of pterygium on a degree of astigmatism and indication of early surgery.

Methods: A hospital based cross-sectional study using non-probability convenience sampling was conducted in the ophthalmology department of Rizgary and Erbil teaching hospital in Erbil city from June 2015 to February 2016. Ninety-six eyes of eighty patients with pterygium were included in this study.

Results: The mean age ± SD of the 80 patients included in the study was 37.5 ± 9.62 years ranging from 22-58 years. There were 45 male and 35 female patients. Two-thirds of eyes (72.6%) had with-the-rule astigmatism while 12.6 % of eyes had against-the-rule astigmatism. A highly significant strong correlation was seen between a fraction of corneal area encroached by pterygium with induced astigmatism (r = 0.727, P <0.001). A highly significant strong correlation was found between the area of pterygium and corneal astigmatism in a case of severe pterygium (pterygium encroaching > 4 mm area on the cornea) (r = 0.802, P <0.001).

Conclusion: Pterygium size has a significant correlation to the amount of induced astigmatism. The correlation is stronger in the pterygia of severe degree (>4 mm) as in this group they are encroaching on the visual axis.

Keywords: Pterygium; Size; Refractive astigmatism; Erbil.

PDF

Reference

1. Kanski JJ, Bowling B. Clinical Ophthalmology: A Systematic Approach. 8th ed. Philadelphia: Elsevier/Saunders; 2016. P.162.

2. American Academy of Ophthalmology. Basic and Clinical Science Course. External Disease and Cornea. San Francisco, CA: American Academy of Ophthalmology; 2015. P.317.

3. Shoja M, Besharati M. Pterygium: Risk factors and the effect on corneal Astigmatism. The Journal of the Iranian Society of Ophthalmology 2004; 1(17):19–25.

4. Lin A, Stern GA. Correlation between pterygium size and induced corneal astigmatism. Cornea 1997; 17:22–7.

5. Tasman W, Jaeger EA. Duane’s ophthalmology. London: Lippincott Williams & Wilkins; 2007.  

6. Oldenburg JB, Garbus J, McDonnell JM, McDonnell PJ. Conjunctival pterygia. Mechanism of corneal topographic changes. Cornea 1990; 9:200–4.

7. Fong KS, Balakrishnan V, Chee SP, Tan DT. Refractive change following pterygium surgery. CLAO J 1998; 24:115–7.

8. Maheshwari S. Effect of pterygium excision on pterygium induced astigmatism. Indian J Ophthalmol 2003; 51:187–8.

9. Shelke E, Kawalkar U, Wankar R, Nandedkar V, Khaire B, Kosavi V. Effect of Pterygium Excision on Pterygium Induced Astigmatism and Visual Acuity. Int J Adv Health Sci 2014; 1:2–3.

10. Tomidokoro A, Oshika T, Amano S, Eguchi K, Eguchi S. Quantitative analysis of regular and irregular astigmatism induced by pterygium. Cornea1999; 18:412–5.

11. Maguire LJ. Computerized corneal analysis. Vocal Points 1996; 14:2.

12. Spalton DJ, Hitchings RA, Hunter PA. Atlas of Clinical Ophthalmology. 3rd ed. Philadelphia: Elsevier Mosby; 2005. P.152.

13. Shelke E, Kawalkar U, Wankar R, Nandedkar V, Khaire B, Kosavi V. Effect of Pterygium Excision on Pterygium Induced Astigmatism and Visual Acuity. Int J Adv Health Sci 2014; 1:2–3.

14. Devika P, Lakshmi K, Rajani K, Sudhir H, Achar A, Kudva A. Astigmatism in Primary Pterygium and its Effect on Visual Acuity. J Evidence Based Med Healthcare 2015; 2: 6036–40.

15. Aidenloo1 NS, Mikaili P, Farajpour S. Studying the Type of Astigmatism I Patients with Corneal Pterygium Referring to Ophthalmology Clinics of Northwestern Iran. Life Sci J 2013; 10(1):782–4.

16. Nema N, Jain J, Ishrat S.Conjunctival limbal autograft with stem cells transplantation for primary pterygium. Asian J Med Cli Sci 2013; 2:14.

17. Lin A, Stern GA. Correlation between pterygium size and induced corneal astigmatism. Cornea 1997; 17:22–7.

18. Salih PM, Sharif AF. Analysis of pterygium size and induced corneal astigmatism. Cornea 2008; 27:434–8.

19. Faisal AKh, Shafaq PKh, Dilshad AKh. The Impact of Pterygium Excision on Corneal Astigmatism. JCPSP 2014; 24(6):404–7.

20. Qasim KF, Alya´a AK. Pterygium and induced astigmatism. Kufa Med J 2012; 15:341–4.

21. Jaffar S, Dukht U, Rizvi F. Impact of pterygium size on corneal topography. RMJ 2009; 34:145–7.

22. Lin A, Stern GA. Correlation between pterygium size and induced corneal astigmatism. Cornea 1998; 17:18–30.