Saudi Journal of Ophthalmology (2014) 28, 262–267

Original article

Safety profile and complications of autologous limbal conjunctivaltransplantation for primary pterygium

Peer review under responsibilityof Saudi Ophthalmological Society,King Saud University Production and hosting by Elsevier

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Received 17 August 2013; received in revised form 17 November 2013; accepted 11 March 2014; available online 21 March 2014.

J.S.S. Medical College & Hospital, M.G. Road, Mysore 570004, India

⇑ Address: 57, 8th Cross, 4th Main, Vinayaka Nagar, Mysore 570012, Karnataka, India. Tel.: +91 08212524999 (Office)/08212410360 (Resimobile: +91 9880074529.e-mail address: svp_pbk1947@yahoo.co.in

Srinivasapuram Krishnachary Prabhakar, MBBS, DO, DNB (Ophthalmology) ⇑

Abstract

Purpose: Primary pterygium is a fibrovascular proliferation over the nasal cornea, probably resulting from the limbal stem celldeficiency. Intraoperative mitomycin-C application seems to associate with reduced recurrences, however produced ocular surfaceproblems and vision threatening complications. The present clinical study investigated the safety profile of autologous limbalconjunctival transplantation in terms of recurrence rate, as the main outcome measure and complications as the secondary outcome.Methods: The present study was randomised, interventional and prospective clinical study conducted from a tertiary Hospital.Pterygium excision was performed with limbal conjunctival autograft availed from the affected eye. Secondary pterygia resultingfrom inflammation, trauma and other diseases were excluded. Patients were followed up for 18 months for recurrence and othercomplications. Microsoft Office Excel 2007 was used for statistical analysis.Results: A total of 71 eyes of sixty-eight patients with primary pterygia included between November 2007 and October 2010. Thestudy recruited 35 (51%) males and 33 (49%) females with mean age of 36.9 with ±12.82 years standard deviation (mean, SD)ranging from 19 to 75 years. Age grouped by range intervals categorised into six groups. Pterygium was diagnosed in 32(45%) right eyes and 39 (55%) left eyes. There were 65 (91.55%) nasal and 4 (5.63%) temporal pterygium and no case of doublehead pterygia found. Average horizontal extension of the pterygium measured was 1.67 mm (±4.23) from the apex to the corneallimbus. Graft oedema in 1 (0.71%) patient, graft bleed in 2 (1.42%) cases and 1 (0.72%) case of granuloma observed. Norecurrences encountered during 18 months follow up.Conclusions: Pterygium occurred predominantly in the younger population group 36.9 mm (±12.82) probably due to theincreased outdoor activity with high exposure to sunlight and dusty atmosphere. Absence of recurrences was probablyattributable to the smaller pterygium size of 1.67 mm (±4.23), use of the autologous limbal conjunctival graft and treatable intraand post operative complications successfully.

Keywords: Limbal stem cells (LSC), Conjunctival autograft (CG), Limbal conjunctival autograft (LCAG)

� 2014 Production and hosting by Elsevier B.V. on behalf of Saudi Ophthalmological Society, King Saud University.http://dx.doi.org/10.1016/j.sjopt.2014.03.006

Introduction

Proprioception from the ocular surface is not normally per-ceived, firstly because of lack of proprioceptors and secondlydue to the smooth and regular surface pattern. Blinking reflexhelps in the lubrication of the ocular surface with precorneal

tear film. Therefore any irregularities that alter the corneo-conjunctival surface produce foreign body sensation. Theexact pathophysiology of primary pterygium remains elusivein spite of its characteristic clinical appearance and floridrecurrence after simple excision. It is proposed that normallythe limbal stem cells provide anatomical and physiological

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dence),

Limbal conjunctival stem cell autografting for primary pterygium 263

barrier to the growth of conjunctiva blood vessels over thecornea. Hence, local or diffuse limbal stem cell deficiency isprobably the accepted hypothesis for primary pterygiumevolution.

Simple excision by ‘bare sclera’ technique alone resulted inincreased incidence rates of recurrent pterygium.1 Meta-analytical study following bare sclera method revealed, asixfold increase in recurrence if no conjunctiva grafting wasperformed and twenty-five times higher incidence wasreported without intraoperative/postoperative mitomycin-Cuse.2 Although mitomycin-C proved to be an excellentadjuvant in terms of decreasing the incidence of recurrentpterygium, unfortunately caused ocular surface problemsnamely dry eye, persistent photophobia and chronic irritation.Bare sclera technique without the use of adjuvant carried ahigh risk of pterygium recurrences and sight threatening com-plications, commonly surgically induced necrotising scleritis.3

Conjunctival autografting yielded acceptable limits ofrecurrences with no reports of long term vision threateningcomplications.4–7 Limbal conjunctiva contains stem cellsdemarcated externally by palisade of Vogt’s that normallyvisualised as longitudinal wavy brownish striations runningperpendicular to the corneal surface at the superior andinferior llimbus.8 This prospective study was undertaken toinvestigate the anatomical, physiological and cosmeticallyacceptable ocular surface reconstruction by autologouslimbal epithelium/stem cell transplantation in terms of itssafety profile and post operative complications.

Patients and methods

Data collection included patient demographics of age, sexand laterality of the primary pterygium. Patients of all agegroups with true progressive primary pterygium whoattended outpatient Department of Ophthalmology from atertiary hospital were enrolled in the present prospectiveand interventional randomised clinical study from 2007 to2010. The data collection and sampling method done byidentifying the patients with the primary pterygium afterobtaining informed consent from the patients with the per-mission granted from the Institutional ethics committeeboard. Seventy-one eyes of 68 patients were enrolled in thestudy who presented with classical primary pterygium.

The patients with the primary pterygium were classifiedinto unilateral and bilateral pterygium. Pterygium present inthe nasal and temporal side of the limbus was categorisedinto nasal and temporal pterygium respectively. When thepterygium was seen on both the sides of the limbus (nasalor temporal) in the same eye, then it was classified as doubleheaded pterygia. The inclusion criteria consisted of allpatients with primary pterygium and the secondary ptery-gium due to trauma, inflammation, chemical burns; thermaland autoimmune conditions were excluded.

Primary pterygium was diagnosed by the presence of thickreddish fibrovascular growth encroaching upon the cornea,either on the nasal (in most of the cases) or on the temporalbulbar aspect of the conjunctiva present in the interpalpebralarea, characterised by the wing shaped configuration consist-ing of the superior and inferior margins with rounded apexand the body. Bowman’s probe test was helpful in differenti-ating the true pterygium from the pseudopterygium by theinability of the probe to insinuate freely underneath the body

of the primary pterygium, due to its adherence to underlyingepisclera and the sclera throughout the extent of the growth.The morphological features of the pterygium were studiedunder the slit lamp microscopy with photographic documen-tation and by measuring the horizontal growth extension bymeans of a simple transparent scale graduated in millimetresfrom the apex of the pterygium to the corneal limbus.

Regarding the history of pterygium presence, primarypterygium was seen most commonly in the agriculturistsand the teachers who regularly travelled in dusty and hot cli-mates throughout the year. There was history of constantexposure to sunlight in the male patients although the femalepatients remained indoors. Patients were unaware of ptery-gium probably due to the negligence or the lack of educationin the initial stages of the natural course of the condition andto the benign nature of the growth. Younger patients com-plained of increase in the size of the growth and presentedafter 6 months to 1 year when the pterygium started invadingthe cornea and sought surgical treatment for the restorationof the cosmetic appearance. In older patients surgical exci-sion was indicated due to the recurrent inflammation, infec-tion and pain.

Ocular examination included the best corrected visual acu-ity recordings performed by the Snellens vision chart and therefractive state of the eyes with the pterygium was assessedby the TOPCON AR RM-8000B autorefractor made in Japan.Preoperative and intraoperative photography of the ptery-gium was taken in the operation theatre through the eyepiece of the surgical microscope by placing 10 pixels resolu-tion Sony camera.

Procedure

All the patients were admitted to the hospital and oper-ated by single surgeon. Pre operative measures includedeyelash trimming and topical gatifloxicin and dexametho-sone to decrease the pre operative inflammation. All thepatients were operated under the peribulbar anaesthesiausing 3 ml of 2% Lignocaine hydrochloride with adrenaline1:10,000 and 2 ml of 0.5% Sensocain. By using 26 Gaugeinsulin needle, a nick was made to enter the subtenons spacenear the upper and lower borders at the centre of the bodyof the pterygium.9 Underlying scleral adhesions werereleased by passing the Tooke’s knife through and throughthe nicks. Using conjunctival scissors, the main mass of thepterygium was designed in a semicircular fashion about5 mm from the limbus to avoid injuring the medial rectusinsertion. The dissected part of the pterygium was reflectedover the cornea for further advancement. The dissectionwas continued tangentially towards the limbus by using the15 number Bard Parker’s knife until the limbus is free of anypterygial tissue. At this time no cauterisation was done andthe dissection was further extended towards the apex ofthe pterygium. Excision was completed by forming a smoothand transparent area at its site of corneal encroachment. Anyresidual remnants are shaved by means of the Tooke’s knifeparallel to the corneal surface.

The excised raw area of the bare sclera was measured byCastrovejo’s callipers and the approximate size of the con-junctival graft was demarcated by gentle markings made bythe points of the callipers on the superolateral bulbar aspectof the same eye. The eye ball was rotated downwards by the

36.76%

0

5

10

15

20

25

30

35

40

19-29 30-40 41-51 52-62 63-73 74-84

No. of patientspercentage

Figure 2. Graph showing age grouped by range intervals.

0 (0%)

1 (0.71%)

1 (0.71%)

2 (1.42%)

recurrence

odema

granuloma

graft bleed

Figure 3. Incidence of intraoperative and postoperative complications.

264 S.K. Prabhakar

use of corneal stay suture at 6 o clock by 8-0 Ethicon suturefor free dissection of the superior conjunctiva. The superficialpart of the conjunctiva was lifted by the smooth forceps with-out injecting the conjunctiva with Ringers Lactate and a smallnick was made in the demarcation area that was always awayfrom the limbus. The nick was extended and meticulous andgentle dissection carried forward up to its insertion into thecornea without the tenons capsule inclusion. Dissection car-ried out from the fornix towards the limbus and lastly the con-junctiva carrying the limbal portion was closely disinserted atits attachment by Vannus scissors. The limbal border wasidentified by its brownish colour that was tough and firm,somewhat characterised by wavy margin. The epithelial sur-face was recognised from the stromal side by its smoothand shiny surface, and slippery in nature without adherenceto the wicks. By maintaining the limbus to limbus polarity,the graft was rotated on the excised area, initially anchoringand fixing the graft at the limbal margin and then proceedingtowards the other sides by suturing to the normal healthyconjunctival margin with 8-0 Ethicon silk sutures (6–8 sutures).The corneal stay suture was removed and Tobramycin-dex-amethosone eye ointment was instilled into the conjunctivalsac and the eye was patched.

Post operative regimen included topical installation ofTobramycin-dexamethosone 4 times a day for four weeksand the same mixture was used as ointment at bed time forone week. The sutures were removed by the 10th day of sur-gery. The patients were reviewed subsequently in the first,third, sixth, twelfth and eighteenth month for any recurrencesand other complications.

Results

A total of 71 eyes of sixty-eight patients with the primarypterygium were investigated in the present study with 35(51%) males and 33 (49%) females. Microsoft Office Excel2007 was used for statistical analysis. The mean age of thesample was 36.9 years (±12.8) (mean, standard deviation)ranging from 19 to 75 years with a median age value of35 years (Fig. 1). The age grouped by range intervals werecategorised into 6 divisions shown in the bar diagram.Between 19 and 29 year interval category there were 25(36.76%) patients, there were 20 (29.41%) patients in30–40 year group, between 41 and 51 year intervals therewere 12 (17.65%) cases, between 52 and 62 range intervalsthere were 9 (13.24%) patients and one (1.47%) each between

0

5

10

15

20

25

30

35

40

Males Females Right eyes Left eyes

35 (51%) 33 (49%)

32 (45%)

39 (55%)

Figure 1. Demography of the population size and laterality of thepterygium.

52–62 years and 74–84 years category respectively. Predilec-tion observed more frequently for the left eyes 39 (55%) thanthe right eyes 32 (45%). There were 65 (91.54%) nasal ptery-gium cases and 4 (5.63%) temporal pterygium patients andno case of double head pterygium found. The horizontalextension of the pterygium was measured by an average of1.67 mm (±4.23) from the apex to the corneal limbus(Fig. 2). There were no recurrences observed in the presentstudy, although one patient had graft oedema (0.71%), onecase presented with granuloma (0.71%) and graft bleedingwas noticed in two patients (1.42%) (Fig. 3).

Discussion

The present prospective study included a total of seventy-one eyes of 68 patients composed of 35 (51%) males and 33(49%) females with a mean age of 36.9 (±12.8) years charac-terised into 65 (91.54%) nasal and 4 (5.63%) temporal ptery-gium that investigated the safety profile in terms ofrecurrence rate, as the main outcome measure and complica-tions as the secondary outcome.

Although the exact aetiology of the pterygium is elusive, itis hypothesised that the ultraviolet induced stem cell disrup-tion might be one of the factors.10 Several predisposing fac-tors were implicated in its causation that included exposureto the heat, dust and prolonged outdoor activity (Fig. 4). Atone time ‘bare sclera’ technique was the most widelyadopted procedure for the management of the pterygiumdespite the high recurrence rates (30–70%) and complica-tions.11 With the introduction of the simple conjunctival graftand the amniotic membrane transplantation with or withoutintraoperative use of mitomycin-C as adjuvant the recurrencerates were decreased. The successful results with mitomycin-C encouraging for the routine adoption, unfortunately the

Figure 4. Preoperative image of the left eye pterygium.

Figure 5. Postoperative appearance of graft integration to globe withsutures (10th day).

Limbal conjunctival stem cell autografting for primary pterygium 265

procedure was heralded by the sight threatening complica-tions and ocular surface disruption in the long run. In a previ-ous comparative study, a recurrence rate of 15.9% with themitomycin-C group and 1.9% in the limbal conjunctival groupsuggested that the latter procedure showed acceptablerecurrence rate.12

The present study investigated the efficacy and safety ofthe autologous limbal stem cell conjunctival transplantationfor the ocular surface reconstruction in primary pterygium.The age of onset observed in this study ranged from 19 to75 years suggesting that the tendency of pterygium develop-ment seen in all the age groups. The mean age of the patientsobserved in the present study was 36.9 years (±12.8) thatincluded the younger population compared to the previousstudies on the pterygium surgery that showed higher meanage groups.9–11 (Table 1) Another retrospective review studyreported no specific predisposing factors like environmentalor familial were detected that contributed to pterygiumdevelopment in children less than 16 years of age suggestingthe idiopathic nature of the disease. Surprisingly most of thecases were amenable for conservative management withoutresorting to pterygium excision and grafting procedures.13

The younger to middle age seem to be vulnerable for thedevelopment of pterygium, probably because of theirincreased outdoor occupations for prolonged time. Therewas almost equal preponderance noticed between the malesand the females in the present study, since both the sexeswere agriculturists and teachers. In comparison to the otherstudies the left eye showed more predilections for the ptery-gium than the right eye, the reason was not known.

The mean horizontal extension of the pterygium measured1.67 mm (±4.23) compared to the previous report of thestudy of the factors influencing the success of pterygium sur-gery that reported pterygium less than 5 mm of base width

Table 1. Comparative analysis of the previous study results with the presentstudy.

Study Numberof eyes

Mean age (range)in years

Sex

Abdalla WM11 40 Range 21–51 M 22 F 18Young AL12 52 60.04 (39–81) M 19 F 33G. Mery15 16 56 (31–81) M 11 (69%) FMahdy MA16 42 43.4 (21–66) M 30 (71%) FPresent study 71 36.9 (19–75) M 35 F 39

had weak positive correlation with the recurrence rates andreported 8 recurrences out of 36 patients during one year fol-low up. They concluded that the male gender and continuousexposure to the sunlight were strongly and independentlyassociated with the pterygium surgery success rates whichwere closely associated with the present study results.14

The previously reported method differed from the presentstudy in that trephination demarcation was used to includethe apex of the pterygium and the body. The author usedhydro dissection for the conjunctival graft preparation, how-ever a smooth conjunctival forceps with its tips slightlyopened, secure only the conjunctiva sparing the tenons cap-sule inclusion.15 In another study pterygium was dissectedfrom the body towards the corneal side to find out the cleav-age plane that was correlated with the methods followed inthe present investigation. The same study reported 100%success rate with follow up for 19 months similar to theresults of the current study with no recurrences observed in18 months follow up.16

A study on pterygium excision with conjunctival graft wasinvestigated for long term survival rate in a retrospectivecohort study that invited patients for interrogation aboutthe pterygium recurrence 10 years after the surgical proce-dure. There were 20 (11.4%) recurrences out of 176 patientsduring a mean follow up time of 34.4 years and concludedthat worse prognosis could be expected for younger patientswith the use of thicker sutures and probably in lesser invadingpterygium.17 The present study found no recurrences duringthe 18 months follow up possibly due to the use of limbalconjunctival graft and thin sutures. In the present study 8-0Ethicon-silk suture was used to minimise the post operativeocular irritation that might be more pronounced with

Laterality Follow upin months

Recurrence rates(percentage)

RE 19 LE 20 12.15 7.5RE 31 LE 21 16.73 1.9

5 (31%) No data 19 012 (29%) No data 18.26 4.75

RE 32 LE 39 18 0

Figure 6. Restored limbal architecture at two months postoperativeperiod.

266 S.K. Prabhakar

absorbable or monofilament nylon sutures (Fig. 5). Harvestingof a thin conjunctiva that was free of any tenons facia, use ofnon-irritating suture material and minimal post operativeinflammation might account for no recurrences in the presentstudy that correlated with 0% recurrence rate reported byMery et al.

Previous prospective study on recurrence and complica-tions after 1000 extended conjunctival transplants that wasfollowed up for 1 year showed only one pterygium recur-rence (0.1%), nevertheless with some postoperative compli-cations unlike the present study that had a small samplesize, however no sight threatening complications observedduring the follow up of the patients.18 Young et al. observedthree conjunctival cysts, three symblephara, one granulomaand one delllen as post operative complications.12 In thisstudy two cases had graft bleeding that subsided in threeweeks and the delay in suture removal incited granuloma for-mation in another patient that settled after its excision. Onepatient had graft oedema that resolved with the conservativemanagement. The donor site observation revealed conjuncti-val epithelialisation with no signs of limbal stem cell defi-ciency. All the patients had comfortable ocular surfacereconstruction with the absence of irritation, dry eye andphotophobia during eighteen months supervision with satis-factory postoperative vision (Fig. 6).

Primary pterygium was observed in the younger patientsmore often than seen in the old aged population, mostlyattributable to their increased outdoor activity due to theiroccupational liabilities in their most active productive periodof life. The risk factors in the present study were younger agegroup, high constant continuous exposure to sunlight anddusty field atmosphere. No other specific risk factors werefound. The pterygium was more fleshy and reddish with moreprominent vascular component than the fibrous componentin the younger patients compared to thin and membrane likeappearance with decreased vascular component that wasmore commonly observed in elderly patients. The meanage found was higher than 45 years in most of the publishedliterature compared to the present study that found a lowermean age group. The contributing factors may be multifacto-rial in the development of pterygium with only known risk fac-tor as prolonged sunlight exposure. The lower mean age of

the sample (36.9 ± 12.8, mean ± SD) found in the presentstudy might be taken into account of the preventive aspectsof the primary pterygium which may include the use of theumbrellas and the brimmed hats that may not be practicalwhen the patients compliance is concerned.

Conclusion

In conclusion, the present study revealed a lower meanage sample of 36.9 (±12.8) years compared to the highermean age found in most of the published literature. The con-tributing factors may be multifactorial in the development ofpterygium with only known risk factor as prolonged sunlightexposure and dusty atmosphere. The plausible factors attrib-utable to no recurrence in the present study might be ptery-gium extension less than 1.67 mm and meticulous surgicalmethods followed with the use of autologous limbal conjunc-tival autograft that contained stem cells and thin suture mate-rial for graft anchorage.

Sources of support

J.S.S. Medical College & Hospital, Mysore 570004, Karna-taka, India.

Conflict of interest

The authors declared that there is no conflict of interest.

Acknowledgements

We profusely thank the Head of the Institution and theDepartment of Ophthalmology for the cooperation extendedin pursuing the clinical data for the completion of the study.

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