|
 |
| LETTER TO EDITOR |
|
| Year : 1999 | Volume
: 47
| Issue : 2 | Page : 143-144 |
|
Author's reply
Srinivas K Rao, T Lekha, G Sitalakshmi, Prema Padmanabhan
Medical Research Foundation, 18 College Road, Chennai - 600 006, India
Correspondence Address:
Srinivas K Rao
Medical Research Foundation, 18 College Road, Chennai - 600 006
India
 Source of Support: None, Conflict of Interest: None  | Check |
How to cite this article:
Rao SK, Lekha T, Sitalakshmi G, Padmanabhan P. Author's reply. Indian J Ophthalmol 1999;47:143-4 |
| Dear Editor: | |  |
We appreciate Dr. Gopal's comments. He has raised several important issues pertinent to the surgical management of pterygia. Contrary to Dr Gopal's statement, we have not used vascularization as the sole criterion for classifying pterygium severity in our study. Other indices included extent of pterygium onto the cornea and recurrence of the pterygium. Vascularization of the pterygium was graded subjectively; we are not aware of any objective grading system of vascularization in pterygium. It is however, important to quantify the extent of vascularization since this is an index of pterygium activity. A similar subjective system of classification, namely, atrophic, noninflamed and inflamed, has been used by Chen et al.[1]
With regards to the issue of recurrence, different studies in literature have used differing definitions. The definition used by Singh et al,[2] a fibrovascular ingrowth of 1.5 mm or more beyond the limbus with conjunctival drag, has been adopted in a recently published study.[3] We, however, chose a more stringent definition of pterygium recurrence as the occurrence of any fibrovascular tissue crossing the corneoscleral limbus onto clear cornea in the area of previous pterygium excision. Since the purpose of the conjunctival-limbal autograft is to reconstruct the limbal barrier at the site of pterygium excision, we feel that any recurrence of fibrovascular tissue constitutes a failure of this approach, irrespective of vessel orientation with respect to the limbus. We agree with Dr Gopal's comments that vessels seen under the graft and at the sides constitute a healing response, attempting to revascularize the graft.
During surface reconstruction, an effort should be made to achieve a precise apposition of the margins of the conjunctival graft and the host conjunctiva.[3][4]
Matching graft dimensions with the scleral bed improves post-operative cosmesis and reduces the risk of conjunctival inclusion cysts. While we feel that it is unnecessary to excise a graft 2 mm larger than the size of the bare sclera we agree with Dr. Gopal that undersizing of the graft should be avoided.
The use of topical mitomycin-C during or after surgery following bare sclera excision of the pterygium addresses a major disadvantage of the conjunctival autograft technique, that is, disturbance of the superior bulbar conjunctiva. This can worsen the prognosis of future antiglaucoma surgery, should this be required. However, the optimal concentration, frequency of application and duration of postoperative mitomycin-C drops are still being refined. Serious complications have been reported after the use of mitomycin-C eye drops, as late as 3 years after treatment.[5] The success rate of conjunctival-limbal autografting for pterygium surgery is excellent (90-96.2%)[4],[6],[7] as is the case with use of topical or intra-operative low dose mitomycin-C after bare sclera excision (78.9-95.8%).[8][9][10][11] Hence, a combination of the two approaches, with a potential for complications and disadvantages of both techniques, would need to have a very high success rate.
| References | | |
| 1. | Chen PP, Ariyasu RG, Kaza V, La Bree LD, Mc Donnell PJ. A randomized trial comparing mitomycin-C and conjunctival autograft after excision of primary pterygium. Am J Ophthalmol 1995;120:151-60.  |
| 2. | Singh G, Wilson MR, Foster CS. Long-term follow-up study of mitomycin eye drops as adjunctive treatment for pterygium and its comparison with conjunctival autograft transplantation. Cornea 1990;9:331-34. [ PUBMED] |
| 3. | Figueiredo RS, Cohen EJ, Gomes JAP, Rapuano CJ, Laibson PR. Conjunctival autograft for pterygium surgery: How well does it prevent recurrences? Ophthalmic Surg Lasers 1997;28:99-104. |
| 4. | Kenyon KR, Wagoner MD, Hettinger ME. Conjunctival autograft transplantation for advanced and recurrent pterygium. Ophthalmology 1985;92:1461-70. [ PUBMED] |
| 5. | Yamanouchi U, Takaku I, Tsuda N, Kajiwara I, Mine M, Ueno Y. Scleromalacia presumably due to mitomycin-C instillation after pterygium excision. Jpn J Clin Ophthalmol 1979;33:139-44. |
| 6. | Koch JM, Mellin JB, Wauble TN. The pterygium Autologous conjunctival limbus transplantation as treatment. Ophthalmology 1992;98:143-46. |
| 7. | Guler M, Sobaci G, Likei S, Ozturk F, Muthi FM, Yildirim E. Conjunctival autograft transplantation in cases with recurrent pterygium. Acta Ophthalmol 1994;72:721-26. |
| 8. | Lam DS, Wong AK, Fan DS, Chew S, Kwok PS, Tso MO. Intraoperative mitomycin-C to prevent recurrence of pterygium after excision a 30 month follow-up study. Ophthalmology 1998;105:907-909. |
| 9. | Caliskar S, Orhan M, Irkec M. Intraoperative and postoperative use of mitomycin-C in the treatment of primary pterygium. Ophthalmic Surg Lasers 1996;27:600-604. |
| 10. | Manning CA, Kloess AM, Diaz MD, Yee RW. Intraoperative mitomycin in primary pterygium excision (C A prospective randomized trial. Ophthalmology 1997;104:844-48. |
| 11. | Kraut A, Drnovsek OB. Instillation of mitomycin-C after recurrent pterygium surgery. Eur J Ophthalmol 1996;6:264-67. |
|
.png "Santen")
Search Pubmed for