Menu

  1. Home
  2. /
  3. External Disease
  4. /
  5. FP94 : Modified Vertically Split Conjunctival Autograft for Primary Double Head Pterygium – Our Results

Share this post

Dr. Nitin Tiwari, T19511, Dr. Shreesha Kumar K, Dr. Umesh Sharma

ABSTRACT :

INTRODUCTION 

A pterygium is an ocular surfacefibrovascular wing shaped encroachment onto the cornea which is associated with chronic ultraviolet light exposure.[1],[2]Pterygium is seen in all the countries of world but its prevalence  is higher in a country like India which is a part of “pterygium belt”.[3]The main histopathological change in pterygium is elastotic degeneration of conjunctival collagen.[4]Pterygium occurs mostly on nasal side, which can be attributed  to light coming to the temporal cornea being focused on the nasal cornea.[5] Double head pterygium, i.e.  nasal and temporal pterygia in same eye is rare. In studies by Dolezalova(mention Ref number) the incidence was found to be 2.5%.[6]As we know, pterygium excision with conjunctivalautograft is the gold standard  of  management of primary pterygium.[7] However, it may not be sufficient to cover the bare  scleral defect in a double head pterygium. Amniotic membrane transplantation (AMT) has been found to be effective in these cases, however it is not easily available to all surgeons and cost is a limiting factor. Superior and inferior bulbar conjunctivalautografting has been effective,However,it is difficult to obtain a thin graft from inferior bulbar conjunctiva therefore  preferably superior donor site is chosen.

We herein report a novel approach of using the vertically split conjunctivalautograft  without maintaining limbus-limbus orientation which is just large enough to cover the bare scleral defect; and its long term  outcome in patients with primary double head pterygium. 

MATERIAL AND METHODS

Case records of 87 eyes of 87 patients were included in the study. Data from June 2012 to June 2016 wasanalysed retrospectively at a tertiary eye care hospital in south India. All surgeries were performed by a single  surgeon. Data collected included patient’s age, sex, ocular medical and surgical history, visual acuity before and after surgery, surgical technique and complications. Pterygium was graded according to corneal involvement (THIS IS A STUDY ON DOUBLE HEADED PTERYGIUM, SO  DOES THIS GRADING PERTAIN TO BOTH THE SIDES : NASAL AND TEMPORAL; KINDLY SPECIFY THAT THE GRADING WAS DONE FOR BOTH THE SIDES) (grade 1: crossing limbus; grade 2: midway between limbus and pupil; grade 3: reaching up to pupillary margin and grade 4: crossing pupillary margin). Up to grade 3 primary double head pterygium were included in this study. Grade 4 and recurrent pterygium were excluded from this study. The study protocol adhered to the tenets of the Declaration of Helsinki .The study was approved by institutional ethics committee. 

SURGICAL PROCEDURE

A standard surgical technique similar to that described by Raoet al.[8] was followed with few modifications.0.5% Proparacainehydrochloride (Aurocaine, Aurolab, Tamil Nadu, India) was used for topical anesthesia.  Head of the nasalpterygium was avulsed from the corneal surface using a toothed forceps and an iris spatula. The pterygium body and the underlying fibrovascular tissue was then excised using conjunctival forceps. The corneal and limbalareas were scraped clean of residual tissue with crescent blade. Gentle wet field cautery was used to achieve hemostasis. A similar procedure was performed for the temporal pterygium. The superior bulbar conjunctiva was selected as donor site. Balanced salt solution was injected subconjunctivally with 26 gauge (26G )needle, which was useful in good dissection of conjunctiva from Tenon’s capsule. A small nick incision was made at the fornix end using Vannas scissors. A thin conjunctival graft of adequate size was fashioned. Starting from fornix end, the graft was split vertically into two halves till the limbus was reached. Tenon’s attachment was dissected meticulously for each graft. For successful graft take up, thin graft with meticulous dissection of Tenon’s is required.[9] The  grafts were excised from its base using Vannas scissor; and without changing the orientation,  grafts were placed on bare scleral defect of nasal and temporal sides. Adjunctive agents like Mitomycin C or 5 Fluorouracil were not used in this procedure.[10] With epithelium side up, split conjunctivalautografts of adequate size just large enough to cover the bare scleral defects were secured withfibrin glueTisseel VH (Baxter AG, Vienna, Austria). Here limbus-limbus orientation was not strictly maintained and complete covering of bare scleral area with conjunctival graft was ensured. The eye was patched overnight. Postoperatively, topical 0.5% loteprednoletabonate, topical 0.5% moxifloxacinhydrochlorideand tear substitute 0.5% carboxymethylcellulose was started 6 times daily for first week and then gradually tapered over four weeks. Patients were examined on post operative day 1 and later asked for follow up after 1 week, 6 weeks, 6 months, 1 year and every year thereafter. The data of each visit was analysed and documented. Patients with follow up less than six months were not included in the study. Recurrence was defined as fibrovascular tissue growth of 1.5mm or more beyond the limbus onto the clear cornea with conjunctival dragging as described by Singh et al.[11]

STATISTICAL ANALYSIS

Recurrence of pterygium was the primary outcome. Occurrence of Tenon’s granuloma, graft retraction, graft edema, subconjunctival hemorrhage and dellen were considered as other outcome variables. Descriptive analysis of all the variables was done using mean and standard deviation for quantitative variables. MENTION STATISTICAL TEST/TESTS USED 

RESULTS

On retrospective analysis of 87 eyes with primary double head pterygium operated by this technique of vertical split conjunctivalautograftingwithout limbus-limbusorientationthe following results were obtained.Mean age was 54.54±11.51 years; M:Fratio was was 41:46. Overall mean follow up was 17.28±10.28 (months). Patient’s with follow up less than 6 months were not included in the study. A total of 3.45% (3 eyes out of 87) had recurrence, of which 2 eyes had nasal, and 1 eye had temporal recurrence of pterygium.The 3 eyes in which recurrence occurred due to graft loss might have developed excessive graft retraction in the early post operative period. 42.52% (37 eyes out of 87) had postoperative edema. Similarly 36.78% (32 eyes out of 87) had subconjunctival hemorrhage. 31.03% (27 eyes out of 87) had graft retraction in post operative period. 1.15% (1 eye out of 87) developed dellen and 3.45% (3 eyes out of 87) developed Tenon’s granuloma. [Table 1] shows the percentage of various outcome of this study. 

DISCUSSION

Prevention of recurrence is one of the major challenges of pterygium surgery. The operative procedure of choice should aim to minimize the recurrence rate along with better visual cosmetic appearance. In our study we have used vertically split conjunctivalautograft from superior quadrant, and secured the graft with glue without maintaining limbus-limbus orientation on bare scleral defects. Various options available for management of double head pterygium are vertical split conjunctivalautograft(CAG) with limbus-limbus orientation, split CAG with horizontal graft, superior and inferior bulbar CAG, amniotic membrane transplantation(AMT), but none of them have had world-wide acceptance. Conventional bare sclera technique is not done routinely because of high recurrence rate of pterygium.[12] Various adjunctive therapies have been tried with pterygium excision so as to prevent recurrence. Use of beta irradiation or thiotepa eye drops, anti-mitotic drugs (Mitomycin C and 5-Fluorouracil), fibrin glue and amniotic membrane transplantation have been used.[13] Various complications of Mitomycin-C have been noted such as  punctate keratopathy, scleral melt, corneal melting, etc.[14] Amniotic membrane is costly, requires preservation and availability is an issue sometimes. Previous studies have reported higher recurrence rate with AMT compared to conjunctival grafting.[15] Fibrin glue for securing graft possesses the  advantages of easy fixation and better post operative comfort, but it also has the limitation of high cost and risk of transmission of infectious agents such as  parvovirus B19 and prion.[16]Most recently a new technique named ‘Pterygium Extended Removal Followed by Extended Conjunctival Transplant’(P.E.R.F.E.C.T) technique for double head pterygium was published by Hirstet al. and it showed excellent cosmetic results with no recurrence rate in 20 eyes at one year follow up.[17]Generally, the pterygium recurrence occurs within the first 6 months after surgery.[18]

In our study the overall rate of recurrence was 3.45% (3 eyes out of  87) which was comparable to other published studies. Previous studies mentioned suture related complications such as  infection, prolonged operating time, post operative discomfort which can sometimes require second surgery.[19],[20] All 3 eyes which had recurrence might have developed excessive graft retraction at the non-limbal end at 1 week follow up, leading to graft loss at 6 weeks and eventually recurrence at 6 months follow up. In a study by Solomon et al.of pterygium excision with amniotic membrane transplantation, the recurrence rate was 9% (1 eye out of 11).[21] Similarly, double head pterygium excision by using bare sclera technique with  0.02%MMC (5 minutes) was published by Avisaret al.  which showed recurrence rate of  0%(0 out of 10 eyes) in primary pterygium and 33.33%(1 eye out of 3) in recurrent double head pterygium.[22] Using different procedures previously published studies have shown varying degrees of recurrence that ranged from 0% to 71.42%.[17],[21-[25]Previous studies reported that, limbal stem cells act as a barrier between the conjunctiva and corneal epithelium & destruction of this barrier limbal tissue leads to growth of conjunctival tissue on to the cornea.[26],[27] However in our study, adequate size graft;enough to cover the bare scleral defect without maintaining limbus-limbus orientation, had still lower recurrence rate compared to other studies. Graft retraction occurred in 31.03% (27 eyes out of 87) and3 eyes had graft loss which resulted in recurrence. The eyes with retraction at 6 weeks resolved without any intervention at subsequent follow ups. Graft retraction could be due to inclusion of Tenon’s in the graft and can be minimized by meticulous dissection of sub epithelial graft tissue.[20]Graft edema was observed in 42.52% (37 eyes out of 87) which could be due to excessive handling of the graft. Graft edema subsided without any intervention at the end of one to two weeks. Graft edema was the most common outcome of our study. Mutlaet al. (1999) reported that the most frequent complication in limbalconjunctivalautograft transplantation was graft edema.[28]We had 3.45% (3 eyes out of 87) of Tenon’s granuloma , which may be due to inadequate excision ofTenon’s tissue from donor bed. Previously published studies advocated complete excision of Tenon’s tissue since it is the friction of the exposed Tenon’s tissue with upper lid during blinking eventually leadsg to granuloma formation.[29],[30]

[Table 2] shows comparison of different techniques of double head pterygium surgery and their post operative outcomes published in previous studies.

 CONCLUSION:

Our study had certain limitations of being retrospective in nature and non-randomized.  Our study is probably the first reported surgical technique for primary double head pterygium of such a large sample size, where limbus-limbus orientation of conjunctivalautograft was not maintained unlike previous studies; still the cases had low recurrence rate.

In summary, vertical split conjunctival graft without maintaining limbus-limbus orientation, just large enough to cover the bare scleral defect appears to be a successful technique with lower recurrence rate in treating primary double head pterygium.

Table 1:(Outcomes of this Study)
COMPLICATIONS N % (number of cases with complication/87  X 100)
Edema 37 42.52
*SCH 32 36.78
Retraction 27 31.03
Recurrence (temporal) 1 1.15
Recurrence (nasal) 1 1.15
Recurrence (temporal and nasal) 1 1.15
Recurrence (total) 3 3.45
Dellen 1 1.15
Tenon’s granuloma 3 3.45

*SCH – Subconjunctival hemorrhage.

Table 2: (Comparison of outcomes with previously published double head pterygium studies)
Authors Pterygium type Number

Of eyes

(n)

 Surgery technique Mean

Follow up

(months)

 Recurrence

Rate(%)

 Granuloma Sub-conjunctival hemorrhage Edema
Our study Primary 87 Vertical          ⃰ SCG with fibrin gluewithout  limbus-limbus orientation 17.28±10.28 3/87(3.45%) 3/87(3.45%) 32/87 (36.78%) 37/87(42.52%)
Hirstet al[17]

 

 

 

 Primary 20 **PERFECT

Technique

 12 0/20(0%)  

 

—

  

 

—

  

 

—
Solomon et al[21] Primary 11 Extensive pterygium  excision with †AMT 12.8±4.3 1/11(9%)  

_

  

_

 

  

_
Avisaret al [22] Primary 10 Bare sclera technique with 0.02% ‡MMC(5 minutes) 36.3±3.8 0/10(0%) 1/10(10%)  

 

_

 

  

 

_
Recurrent 3 28.4±2.7 1/3(33.33%) 2/3(67.33%)     _         _
Wu et al[23] Primary 20 Conjunctival  rotational autograft combined with CAG 22.6 7/20(35%)  

 

_

 9/20(45%)  

 

_
Maheshwari[24] Primary 7 *SCG with limbus-limbus orientation on nasal side 17.7±6.0 0/7(0%)  

 

_

  

 

_

  

 

_
Lee BH et al[25] Primary(5) 7 Using AMG 21±3.5 5/7(71.42%)       _ 2/7(28.57%)          _
Recurrent(2)
Primary(7) 9 Using  SCG 13.6±2.1 0/9(0%)       _ 2/9(22.22%)          _
Recurrent(2)

 * SCG – Split Conjunctival graft

**PERFECT – Pterygium Extended Removal Followed by Extended Conjunctival Transplant

† AMT – Amniotic membrane transplant

AMG- Amniotic membrane graft

‡ MMC -Mitomycin-C

References

  1. Dushku N, Reid TW. Immunohistochemical evidence that human pterygia originate from an invasion of vimentin-expressing altered limbal epithelial basal cells.CurrEye Res 1994;13:473-81.
  2. Kwok LS, Coroneo MT. A model for pterygium formation.Cornea 1994;13:219-24.
  3. Demartini DR, Vastine DW. Pterygium. In: Abbott RL, editor. Surgical Interventions for Corneal and External Diseases. Orlando, USA: Grune and Straton; 1987. p. 141.
  4. Spencer WH.Ophthalmic pathology: An Atlas and Textbook. 3rd edition. Philadelphia: WB Saunders; 1985. Vol I. p. 174-76.
  5. Maloof AJ, Ho A, Coroneo MT. Influence of corneal shape on limbal light focusing. Invest Ophthalmol Vis Sci1994;35:2592-98.
  6. Dolezalova V. Is the occurrence of a temporal pterygium really so rare? Ophthalmologica 1977;174:88-91.
  7. Kenyon KR, Wagoner MD, Hettinger ME. Conjunctivalautograft transplantation for advanced and recurrent pterygium.Ophthalmology 1985;92:1461-70.
  8. Rao SK, Lekha T, Bickol MN, Sitalaksami G, Padmanabhan P. Conjunctival-limbalautografts for primary and recurrent pterygia: technique and results. Indian J Ophthalmol 1998;46:203-6.
  9. WitD, Athanasiadis I, Sharma A, Moore J, Sutureless and glue-free conjunctivalautograft in pterygium surgery: A case series.Eye2010;24:1474-77.
  10. Kaufman C, Jacob DS, Lee WB, Deng SX, Rosenblatt MI, Shtein RM. Options and adjuvants in surgery for pterygium. Ophthalmology 2013;120:201-208.
  11. Singh G, Wilson MR, Foster CS. Long term follow up study of mitomycin eye drops as adjunctive treatment for pterygia and its comparison with conjunctivalautograft transplantation.Cornea 1990;9:331–4.
  12. Fernandes M, Sangwan VS, Bansal AK, Gangopadhyay N, Sridhar MS, Garg P, et al. Outcome of pterygium surgery: Analysis over 14 years. Eye 2005;19:1182-90.
  13. Kawasaki S, Uno T, Shimamura I, Ohashi Y. Outcome of surgery for recurrent pterygium using intraoperative application of mitomycin C and amniotic membrane transplantation. Jpn J Ophthalmol2003;47:625-6.
  14. Safianik B, BenZion I, Garzozi HJ. Serious corneoscleral complications after pterygium excision with mitomycin C. Br J Ophthalmol 2002;86:357-58.
  15. Luanratanakorn P, Ratanapakorn T, SuwanApichon O, Chuck RS. Randomised controlled study ofconjunctivalautograft versus amniotic membrane graft in pterygium excision. Br J Ophthalmol 2006;90:1476-80.
  16. Foroutan A, Beigzadeh F, Ghaempanah MJ, Eshghi P, Amirizadeh N, Sianati H, et al. Efficacy ofautologous fibrin glue for primary pterygium surgery with conjunctivalautograft. Iran J Ophthalmol2011;23:39-47.
  17. Hirst LW, Smallcombe K. Double headed pterygia treated with P.E.R.F.E.C.T for pterygium. Cornea2017;36(1):98-100.
  18. AdamisAP, Starck T, Kenyon  The management of pterygium. OphthalmolClin North Am 1990;3:611-23.
  19. Allan BD, Short P, Crawford GJ, Barrett GD, Constable IJ. Pterygium excision with conjunctivalautografting: An effective and safe technique. Br J Ophthalmol1993;77:698-701.
  20. Tan D. Conjunctival grafting for ocular surface disease. CurrOpinOphthalmol 1999;10:277-81.
  21. Solomon A, Pires RTF, Tseng SCG. Amniotic membrane transplantation after extensive removal of primary and recurrent pterygia. Ophthalmology 2001;108:449-60.
  22. Avisar R, Snir M, Weinberger D. Outcome of double-headed pterygium surgery. Cornea 2003;22:501-3.
  23. Wu WK, Wong VW, Chi SC, Lam DS. Surgical management of double-head pterygium by using a novel technique: conjunctival rotational autograft combined with conjunctivalautograft. Cornea 2007;26:1056-59.
  24. Maheshwari S. Split-conjunctival grafts for double-head pterygium. Indian J Ophthalmol 2005;53:53-55.
  25. Lee BH, Lee GJ, Park YJ, Lee KW.  Clinical Research on Surgical Treatment for Double-Head Pterygium.   J Korean OphthalmolSoc 2010;51(5):642-650.
  26. Tseng SCG, Chen JJY, Huan AJQ, Kruse FE, Maskin SL, Tsai RJF. Classification of conjunctival surgeries for corneal diseases based on stem cell concept. Ophthalmol Clinics of North Am 1990;3:595-610.
  27. Pfister RR. Corneal stem cell disease: Concepts, categorization, and treatment by auto-and homo transplantations of limbal stem cells. CLAO J 1994;20:64-72.
  28. Mutla FM, Sobaci G, Tatar T, Yildirim EA. Comparative study of recurrent pterygium surgery: limbalconjunctivalautograft transplantation versus mitomycin C with conjunctival flap. Ophthalmology 1999;106(4):817-21.Vrabec MP, Weisenthal
  29. RW, Elsing SH. Subconjunctival fibrosis after conjunctivalautograft.. Cornea 1993;12:181-83.
  30. Starck T, Kenyon KR, Serrano F. Conjunctivalautograft for primary and recurrent pterygia: surgical technique and problem management. Cornea 1991;10:196-202.

 

 

 

 

 

 

Leave a Comment