Pterygium (conjunctiva)

Jump to: navigation, search
Pterygium (conjunctiva)
Pterygium.jpg
Pterygium
ICD-10 H11.0
ICD-9 372.4
DiseasesDB 10916
MedlinePlus 001011
eMedicine oph/542 
MeSH D011625

WikiDoc Resources for Pterygium (conjunctiva)

Articles

Most recent articles on Pterygium (conjunctiva)

Most cited articles on Pterygium (conjunctiva)

Review articles on Pterygium (conjunctiva)

Articles on Pterygium (conjunctiva) in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Pterygium (conjunctiva)

Images of Pterygium (conjunctiva)

Photos of Pterygium (conjunctiva)

Podcasts & MP3s on Pterygium (conjunctiva)

Videos on Pterygium (conjunctiva)

Evidence Based Medicine

Cochrane Collaboration on Pterygium (conjunctiva)

Bandolier on Pterygium (conjunctiva)

TRIP on Pterygium (conjunctiva)

Clinical Trials

Ongoing Trials on Pterygium (conjunctiva) at Clinical Trials.gov

Trial results on Pterygium (conjunctiva)

Clinical Trials on Pterygium (conjunctiva) at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Pterygium (conjunctiva)

NICE Guidance on Pterygium (conjunctiva)

NHS PRODIGY Guidance

FDA on Pterygium (conjunctiva)

CDC on Pterygium (conjunctiva)

Books

Books on Pterygium (conjunctiva)

News

Pterygium (conjunctiva) in the news

Be alerted to news on Pterygium (conjunctiva)

News trends on Pterygium (conjunctiva)

Commentary

Blogs on Pterygium (conjunctiva)

Definitions

Definitions of Pterygium (conjunctiva)

Patient Resources / Community

Patient resources on Pterygium (conjunctiva)

Discussion groups on Pterygium (conjunctiva)

Patient Handouts on Pterygium (conjunctiva)

Directions to Hospitals Treating Pterygium (conjunctiva)

Risk calculators and risk factors for Pterygium (conjunctiva)

Healthcare Provider Resources

Symptoms of Pterygium (conjunctiva)

Causes & Risk Factors for Pterygium (conjunctiva)

Diagnostic studies for Pterygium (conjunctiva)

Treatment of Pterygium (conjunctiva)

Continuing Medical Education (CME)

CME Programs on Pterygium (conjunctiva)

International

Pterygium (conjunctiva) en Espanol

Pterygium (conjunctiva) en Francais

Business

Pterygium (conjunctiva) in the Marketplace

Patents on Pterygium (conjunctiva)

Experimental / Informatics

List of terms related to Pterygium (conjunctiva)

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [2] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.

Overview

Pterygium usually refers to a benign growth of the conjunctiva. A pterygium commonly grows from the nasal side of the sclera. It is associated with, and thought to be caused by ultraviolet-light exposure (e.g. sunlight), low humidity, and dust. The predominance of pterygia on the nasal side is possibly a result of the sun's rays passing laterally through the cornea where it undergoes refraction and becomes focused on the limbic area. Sunlight passes unobstructed from the lateral side of the eye, focusing on the medial limbus after passing through the cornea. On the contralateral side, however, the shadow of the nose medially reduces the intensity of sunlight focused on the lateral / temporal limbus.[1]

Pathology

Pterygium in the conjunctiva is characterized by elastotic degeneration of collagen and fibrovascular proliferation. It has an advancing portion called the head of the pterygium, which is connected to the main body of the pterygium by the neck. Sometimes a line of iron deposition can be seen adjacent to the head of the pterygium called Stocker's line. The location of the line can give an indication of the pattern of growth.

The exact cause is unknown, but it is associated with excessive exposure to wind, sunlight, or sand. Therefore, it is more likely to occur in populations that inhabit the areas near the equator, as well as windy locations. Additionally, Pterygium are twice as likely to occur in men than women.

Some research also suggests a genetic predisposition due to an expression of vimentin, which indicates cellular migration by the keratoblasts embryological development, which are the cells that give rise to the layers of the cornea. These cells also exhibit an increased P53 expression likely due to a deficit in the tumor suppressor gene. These indications give the impression of a migrating limbus because the cellular origin of the pterygium is actually initiated by the limbal epithelium. [2]

Occasionally it is found as an incidental finding in middle aged patients who spend a lot of time in the sun. Pterygiums are also among younger men and women who surf, wakeboard, and kiteboard due to excessive exposure to UV rays bouncing off of the water. Skiiers and snowboarders protect their eyes on the snow so athletes participating in water sports also need to take heed of the UV rays and protect their eyes. Some patients may also choose surgery if the growth becomes too unsightly. The exact cause is unknown, but it is associated with excessive exposure to wind, sun, or sand.

Anatomically, the pterygium is composed of several segments:

  • Fuchs' Patches (minute gray blemishes that disperse near the pterygium head).
  • Stocker's Line (a brownish line composed of iron deposits).
  • Hood (fibrous nonvascular portion of the pterygium).
  • Head (apex of the pterygium, typically raised and highly vascular).
  • Body (fleshy elevated portion congested with tortuous vessels).
  • Superior Edge (upper edge of the triangular or wing shaped portion of the pterygium).
  • Inferior Edge (lower edge of the triangular or wing shaped portion of the ptyerygium).

As it is a benign growth, it requires no treatment unless it grows to such an extent that it covers the pupil, obstructing vision.

While patients can be symptomatically treated w/ artificial tears, no reliable medical treatment exists to reduce or even prevent pterygium progression. Definitive treatment is achieved only by surgical removal. Long term follow up is required as pterygium may recur even after complete surgical correction.

Wearing protective sunglasses with side shields and/or wide brimmed hats and using artificial tears throughout the day may help prevent their formation or stop further growth. For surfers and other water-sport athletes, they should wear eye protection that block 100% of the UV rays from the water.

Symptoms

Symptoms of pterygium include persistent redness, inflammation, foreign body sensation, dry and itchy eyes. In advanced cases the pterygium can affect vision as it invades the cornea with the potential of induced astigmatism and corneal scarring.[3][4][5]

Treatment

Today a variety of options are available for the management of pterygium, from β-irradiation, to conjunctival auto-grafting or amniotic membrane transplantation, along with glue and suture application. As it is a benign growth, pterygium typically does not require surgery unless it grows to such an extent that it covers the pupil, obstructing vision or presents with acute symptoms. Some of the irritating symptoms can be addressed with artificial tears. However, no reliable medical treatment exists to reduce or even prevent pterygium progression. Definitive treatment is achieved only by surgical removal. Long-term follow up is required as pterygium may recur even after complete surgical correction.

If there is recurrence after surgery or if recurrence of pterygium is thought to be vision threatening, it is possible to use strontium (90Sr) plaque therapy. 90Sr is a radioactive substance that produces beta particles which penetrate a very short distance into the cornea at the site of the operation. It suppresses the regrowth of blood vessels that occur with return of the pterygium. The treatment requires some local anaesthetic in the eye and is best done at the time of, or on the same day as the pterygium excision.

The 90Sr plaque is a concave metal disc about 1-1.5cm in diameter which is hollow and filled with an insoluble strontium salt. The side placed on the eye is a very thin and delicate silver film that will contain the strontium but allow the beta particles to escape. The dose of radiation to the conjunctiva is controlled by the time that the plaque is left in contact with the surface. The integrity of the plaque surfaces is paramount to prevent exposure to patients and so is wipe tested to see if radioactive matter is escaping. Obviously this test must be done very very gently.

Conjunctival auto-grafting is a surgical technique that is effective and safe procedure for pterygium removal. When the pterygium is removed the tissue that covers the sclera known as the conjunctiva is also extracted, auto-grafting replaces the bare sclera with tissue that is surgically removed from the inside of the patients’ upper eyelid. That “self-tissue” is then transplanted to the bare sclera and is fixated using sutures, tissue adhesive, or glue adhesive.

Amniotic membrane transplantation is an effective and safe procedure for pterygium removal. Amniotic membrane transplantation offers practical alternative to conjunctival auto graft transplantation for extensive pterygium removal. Amniotic membrane transplantation is tissue that is acquired from the innermost layer of the human placenta and has been used to replace and heal damaged mucosal surfaces including successful reconstruction of the ocular surface. It has been used as a surgical material since the 1940s, and has been shown to have a strong anti-adhesive effect. [6] [7] Using an amniotic graft facilitates epithelialization, and has anti-inflammatory as well as surface rejuvenation properties. Amniotic membrane transplantation can also be fixated to the sclera using sutures, or glue adhesive.[8] [9] [10] [11] [12] Amniotic membrane transplantation with Tisseel glue application and Mitomycin-C has shown excellent cosmetic outcomes with a surface free of redness, stitching, or patches which makes the ocular surface suitable for vision correction surgery sooner.[13] [14] [15]

References

  1. Coroneo, MT (November 1993). "Pterygium as an early indicator of ultraviolet insolation: a hypothesis". Br J Ophthalmol. 77 (11): 734–9. PMID 8280691.
  2. Gulani A, Dastur YK. Simultaneous pterygium and cataract surgery. J Postgrad Med 1995; 41:8-11. http://www.jpgmonline.com/article.asp?issn=0022-3859;year=1995;volume=41;issue=1;spage=8;epage=11;aulast=Gulani
  3. Gulani A.C.Extended Sun Exposure Increases Risk of Eye Pterygium Release March 24, 2005. http://www.prweb.com/releases/2005/3/prweb221035.htm
  4. Gulani AC. "Dry Eye Matrix." Innovator's Lecture, ASCRS, 2002. http://www.gulani.com/doc-seminars.html
  5. Gulani AC. Irregular Astigmatism: Management in Unstable Corneas. Slack Inc 2007, 28.
  6. Trelford JD, Trelford-Sauder M. The amnion in surgery, past and present, American Journal Obstetrics and Gynecology1979; 134: 833-845.
  7. Tayyar M, Turan R, Ayata D. The use of amniotic membrane plus heparin to prevent postoperative adhesions in the rabbit, Tokai J Exp Clin Med 1993; 18:57-60.
  8. .Gulani AC. "Corneoplastique™” SASRCS, Durban. August 2005.
  9. Gulani AC. Advanced Corneal Surgery Course: AAO, California, Oct 2006
  10. Gulani AC. Corneoplastique. Techniques in Ophthalmology 5(1): 11-20, 2007.
  11. Gulani AC. “Corneoplastique”, Video Journal of Cataract and Refractive Surgery. Volume XXII. Issue 3, 2006.
  12. Gulani AC. "A New Concept for Refractive Surgery", Ophthalmology Management 2006; 10 (4). 57-63.
  13. Gulani AC. Vision Corrective Surgeries: Past Techniques, Present Trends and Future Technologies, North East Florida Medicine. 2007; 2 (58) 41-44.
  14. Gulani AC, Holladay J, Belin M, Ahmed I. Future Technologies in LASIK- Pentacam Advanced Diagnostic for Laser Vision Surgery. In Experts Review of Ophthalmology, 2008- London
  15. Gulani AC. “ Corneoplastique: Art of Laser Vision Surgery”- Corneal Refractive Surgery in Video Atlas of Ophthalmic Surgery. XXXVIII. (2) 2008

See also

External links


Cost Effectiveness of Pterygium (conjunctiva)

| group5 = Clinical Trials Involving Pterygium (conjunctiva) | list5 = Ongoing Trials on Pterygium (conjunctiva) at Clinical Trials.govTrial results on Pterygium (conjunctiva)Clinical Trials on Pterygium (conjunctiva) at Google


| group6 = Guidelines / Policies / Government Resources (FDA/CDC) Regarding Pterygium (conjunctiva) | list6 = US National Guidelines Clearinghouse on Pterygium (conjunctiva)NICE Guidance on Pterygium (conjunctiva)NHS PRODIGY GuidanceFDA on Pterygium (conjunctiva)CDC on Pterygium (conjunctiva)


| group7 = Textbook Information on Pterygium (conjunctiva) | list7 = Books and Textbook Information on Pterygium (conjunctiva)


| group8 = Pharmacology Resources on Pterygium (conjunctiva) | list8 = AND (Dose)}} Dosing of Pterygium (conjunctiva)AND (drug interactions)}} Drug interactions with Pterygium (conjunctiva)AND (side effects)}} Side effects of Pterygium (conjunctiva)AND (Allergy)}} Allergic reactions to Pterygium (conjunctiva)AND (overdose)}} Overdose information on Pterygium (conjunctiva)AND (carcinogenicity)}} Carcinogenicity information on Pterygium (conjunctiva)AND (pregnancy)}} Pterygium (conjunctiva) in pregnancyAND (pharmacokinetics)}} Pharmacokinetics of Pterygium (conjunctiva)


| group9 = Genetics, Pharmacogenomics, and Proteinomics of Pterygium (conjunctiva) | list9 = AND (pharmacogenomics)}} Genetics of Pterygium (conjunctiva)AND (pharmacogenomics)}} Pharmacogenomics of Pterygium (conjunctiva)AND (proteomics)}} Proteomics of Pterygium (conjunctiva)


| group10 = Newstories on Pterygium (conjunctiva) | list10 = Pterygium (conjunctiva) in the newsBe alerted to news on Pterygium (conjunctiva)News trends on Pterygium (conjunctiva)


| group11 = Commentary on Pterygium (conjunctiva) | list11 = Blogs on Pterygium (conjunctiva)

| group12 = Patient Resources on Pterygium (conjunctiva) | list12 = Patient resources on Pterygium (conjunctiva)Discussion groups on Pterygium (conjunctiva)Patient Handouts on Pterygium (conjunctiva)Directions to Hospitals Treating Pterygium (conjunctiva)Risk calculators and risk factors for Pterygium (conjunctiva)


| group13 = Healthcare Provider Resources on Pterygium (conjunctiva) | list13 = Symptoms of Pterygium (conjunctiva)Causes & Risk Factors for Pterygium (conjunctiva)Diagnostic studies for Pterygium (conjunctiva)Treatment of Pterygium (conjunctiva)

| group14 = Continuing Medical Education (CME) Programs on Pterygium (conjunctiva) | list14 = CME Programs on Pterygium (conjunctiva)

| group15 = International Resources on Pterygium (conjunctiva) | list15 = Pterygium (conjunctiva) en EspanolPterygium (conjunctiva) en Francais

| group16 = Business Resources on Pterygium (conjunctiva) | list16 = Pterygium (conjunctiva) in the MarketplacePatents on Pterygium (conjunctiva)

| group17 = Informatics Resources on Pterygium (conjunctiva) | list17 = List of terms related to Pterygium (conjunctiva)


}}

de:Pterygium it:Pterigio nl:Pterygium pms:Pterygium



Linked-in.jpg