Indian Journal of Ophthalmology

ARTICLES
Year
: 1986  |  Volume : 34  |  Issue : 1  |  Page : 7--10

Pterygium--evaluation of management


RG Dash, MS Boparai 
 Department of Ophthalmology, A.F.M.C. Pune, India

Correspondence Address:
R G Dash
A.F.M.C Pune -411040
India




How to cite this article:
Dash R G, Boparai M S. Pterygium--evaluation of management.Indian J Ophthalmol 1986;34:7-10


How to cite this URL:
Dash R G, Boparai M S. Pterygium--evaluation of management. Indian J Ophthalmol [serial online] 1986 [cited 2020 Apr 5 ];34:7-10
Available from: http://www.ijo.in/text.asp?1986/34/1/7/26458


Full Text

Pterygium, according to Duke Elder[1] is a common ophthalmic disease in the tropical countries. Though considered to be trivial, this disease still stands as a challenge to the ophthalmologists all over the world in view of high recurrence following surgery. Various authors[2],[3] have reported 30 to 69 % recurrence after the standard excision and transposition operations. The surgery for recurrent ptery­gium is extremely difficult, necessitating the utmost care in dissection. In the quest for a technique which could reduce the recurrence rate, excision of pterygium has been combin­ed with carbolisation, irradiation, mucosal transplantation, lemellar corneal grafting and the use of antimitotic agents. The present study was conducted to compare the result of five different techniques-in the management of pterygium with a special reference to the role of Mitomycin-C.

 MATERIAL AND METHODS



The present study includes 250 cases of pterygium including 45 recurrent cases. Indi­cation for surgery in all these cases was either the problem of recurrent ocular irrita­tion or a rapid growth of the lesion threaten­ing vision. Cases of atrophic or static pterygium, where surgery was undertaken only for cosmetic reason were not included in this study because of their less likelihood for recurrence. All our cases were kept admitted in the hospital for at least two weeks after surgery to ensure the postoperative medica­tion and to prevent their exposure to dust, smoke, sun and other atmospheric hazards in the immediate postoperative period. The criteria used by us to label a recurrence were either the re-invasion of the cornea with blood vessels or the growth of a conjunctiva­like tissue onto the cornea.

The following five techniques were adopt­ed.

Technique I-D' Ombrain's excision with bare sclera technique.

Technique II-D' Ombrain's excision followed by carbolisation of the bare cornea and sclera.

Technique III-D' Ombrain's excision followed by six-hourly instil­lation of Mitomycin-C in the strength of 0.4 mg/ml for two weeks.

Technique IV-D' Ombrain's excision followed immediately by single sitting irradiation of 2,000 rads of Beta rays.

Technique V-Excision of pterygium follow­ed by buccal mucose trans­plantation.

Post-operative follow-up was made at weekly intervals upto one month and then once in three months for at least one year.

 OBSERVATIONS



Majority of the patients were males (92.8%) and the maximum incidence of the disease was recorded in the age between 20 to 39 years [Table 1].

No recurrence was recorded after Techni­ques III, IV and V. However, from the cos­metic point of view Technique III (Mitomy­cin-C treated group) provided the best result with only 20% cases being left with a promi­nent co.i.,unctival scar [Table 2].

The only side effect reported of Mitomy­cin-C therepy was a mild irritation during the course of administration of the drug. The irritation was more pronounced in patients who spent more time in the bright sunshine during its therepy. However, the irritation promptly subsided on cessation of the therepy.

There was no advantage of treating the bare cornea and sclera with carbolic acid over simple excision [Table 2].

 DISCUSSION



In evaluating the efficacy of a procedure for treating pterygium one has to consider the post-treatment recurrence rate and the ultimate cosmetic outcome. Considering these two factors Technique I and II of this study fall far behind the desired goal. Both these techniques achieved desirable result only in about 48% cases.

There was no recurrence in Techniques III, IV and V. Use of Beta irradiation after the excision of the pterygium has been recog­nised to be significantly effective in minimis­ing recurrence. Camaron[4], using two differ­ent types of Beta ray applicators had unsatisfactory result in 12.1% cases of pri­mary pterygium and in 25% cases of recurrent pterygium. Lentino et a1[5] had 3.6% recur­rence, Cooper ssub had 11.7% recurrence and Vanden Brenk 7sub had 5% recurrence with Beta ray application. Most of these workers feel that the administration of about 5000 rads of Beta rays in single or divided doses is required to achieve the best result. Careful follow up by Cameron[8] of the cases, where higher dose of Beta irradiation has been used shows a host of complications like sectorial posterior cortical lens opacities, scleral ulceration, conjunctival telenge­ctasia, indolent corneal ulcer, localised iris atrophy, perforation of the globe and endophthalmitis. Severity of these complica­tions weighs heavily against the trivial nature of the original disease process. We used only 2000 rads of Beta irradiation and understand­ably none of our cases showed any compli­cation. However, the cosmetic achievement in the 40 cases treated with Beta irradiation remained below the desired level. A conspi­cuous conjunctival scar resulted in 27.5% cases. This corroborates Cameron's observa­tions.

Buccal mucosal grafting is not a procedure which can be routinely performed for ptery­gium. The pain at the donor site causes some discomfort to the patient. Lack of care while raising the mucosal graft could produce complication at the donor site as reported by Neuhaus et a1 9sub . All the 9 cases of the present series treated with buccal mucosal transplantation were cases of recurrence. Though none of these cases showed recurrence, the cosmatic result was not good in 33.4% cases.

Antimitotic agents like Thio-TEPA and Mitomycin-C inhibit capillary endothelial proliferation and prevent vascularisation of the bare sclera after exision of the pterygium. The disadvantage of Thio-TEPA on Mitomy­cin-C is that it has to be used for 6 to 8 weeks postoperatively whereas Mitomycin-C is used only for 2 to 4 weeks The frequency of instil­lation of Thio-TEPA is 3 hourly, whereas Mitomycin-C is instilled 6 hourly. Recurrence after the use of Thio-TEPA has been reported to be 6.2% by Partneyi[10] and 6.8% by Asrega­doo[11]. Khanna et al[12] using Mitomycin-C in 20 cases had no recurrence.

We observed 25% recurrence and 27% cosmetically undesirable result in cases treated by D'Ombrien's excision. Where simple excision was followed by carbolic acid cauterisetion of the; bare area the recurrence rate was 30.6% and the cosmetically undesi­rable result was in 22.2% cases. Thus both these procedures yielded good result in less than 50% of the cases.

The cases treated by Mitomycin-C after surgery yielded the best result. There was not a single recurrence and the result was good in 80% and satisfactory in 20% of the cases. This result is slightly below the 100% good result reported by Khanna et al. This could be because of a larger number of cases in our series.

There was no recurrence in our cases treat­ed with post-operative Beta irradiation, but 27.5% cases showed only a satisfactory result. Probably this result would have been better if the dose of Beta irradiation was increased to around 4000 rads. We restricted the dose to only 2000 rads to avoid ocular complica­tions of Beta rays.

We treated only a small number of cases with Buccal mucosal transplantation even in this small group 33.4% cases failed to achieve the desired cosmetic outcome.

We have limited experience of lamellar keratoplasty in the management of pterygium. This procedure is claimed to be best suited for recurrrent pterygium. A high success rate with this procedure has been reported by Mohan[13] and Sharma et al[14].

 SUMMARY



250 cases of progressive pterygium includ­ing 45 recurrent cases were treated by five different techniques. Excision of the lesion followed by 6 hourly instillation of Mitomy­cin-C drops for two weeks yielded the best result. Excision followed by single dose irra­diation of 2000 rads of Beta rays yielded almost a similar result. Simple excision and excision followed by carbolisation fell far behind a desired result.

References

1Duke Elder, S., 1965 System of Ophthalmology, Vol. VIII, Henry Kimpton. London, p. 574.
2Zauberman, Z., 1967, Amer J. Ophthalmol., 63: 1780.
3Tarr, K. H. and Constable, I. J., 1980, Brit. J. Ophthalmol., 64: 496.
4Cameron, M. E., 1968, Brit J, Ophthalmol., 52:582.
5Lentino, W., Zaret, M.M., and Rossignol, B., 1959, Amer J. Roentgenol, 81 : 93.
6Cooper, J. S., 1978, Radiology, 128 : 753.
7Vanden Brenk, H.A.S., 1968, Amer J. Roengeo­nol., 103 : 723.
8Cameron, M. E,, 1972, Brit. J. Ophthalmol., 56: 52.
9Neuhaus, R. W., Baylis, H. I., Shorr, N, 1982, Amer. J. Ophthalmol. 93(5) : 643.
10Partney, G. L., 1969, Amer J. Ophthalmol, 67 : 759.
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12Khanna, K. K., Nirankari, M. S., Nair, K. G. R., and Singh, M., 1971, Orient. Arch. Ophthalmol. 10: 114.
13Mohan, M., 1976, Afro Asian Cong. Ophthal­mol. 6 : 95.
14Sharma, S. L., Singh, M. M. and Manocha, M. C., 1979, Ind. J. Ophthalmol., 27 (IV) : 133, 93(5) 643.