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Outcome of
pterygium surgery:
analysis over
14 years
M Fernandes
1
, VS Sangwan
1
, AK Bansal
1
,
N Gangopadhyay
1
, MS Sridhar
1
, P Garg
1
,
MK Aasuri
1
, R Nutheti
2
and GN Rao
1
Abstract
Aim To report the outcome of pterygium
surgery performed at a tertiary eye care centre
in South India.
Methods Retrospective analysis of medical
records of 920 patients (989 eyes) with primary
and recurrent pterygia operated between
January 1988 and December 2001. The
demographic variables, surgical technique
(bare sclera, primary closure, amniotic
membrane transplantation (AMT),
conjunctival autograft (CAG), conjunctival–
limbal autograft (CLAG), or surgical
adjuvants), recurrences and postoperative
complications were analysed.
Results A total of 496 (53.9%) were male and
69 (7.5%) had bilateral pterygia. Bare sclera
technique was performed in 267 (27.0%) eyes,
primary conjunctival closure in 32 (3.2%),
AMG in 123 (12.4%), CAG in 429 (43.4%), and
CLAG in 70 (7.1%). Adjuvant mitomycin C
was used in 44 (4.4%) cases. The mean
duration of follow-up was 8.9717.0 and
5.978.8 months for unilateral primary and
recurrent pterygia, respectively. The overall
recurrence rate was 178 (18.0%). Following
primary and recurrent unilateral pterygium
excision respectively, recurrences were noted
in 46 (19.4%) and 1 (33.3%) eyes after bare
sclera technique, five (16.7%) and 0 after
primary closure, 28 (26.7%) and 0 with AMG,
42 (12.2%) and five (31.3%) with CAG, and
nine (17.3%) and two (40%) with CLAG.
Recurrences were significantly more in males
with primary (23.3 vs 10.7%, Po0.0001) and
recurrent (26.7 vs 0%, P ¼ 0.034) pterygia, and
in those below 40 years (25.2 vs 14.8%,
P ¼ 0.003).
Conclusion CAG appears to be an effective
modality for primary and recurrent pterygia.
Males and patients below 40 years face greater
risk of recurrence. Bare sclera technique has an
unacceptably high recurrence. Prospective
studies comparing CAG, CLAG, and AMG for
primary and recurrent pterygia are needed.
Eye (2005) 19, 1182–1190. doi:10.1038/sj.eye.6701728;
published online 29 October 2004
Keywords: pterygium surgery; conjunctival
autograft; conjunctival–limbal autograft;
amniotic membrane transplant; bare sclera
excision
Introduction
A pterygium is a wing-shaped growth of
fibrovascular conjunctiva onto the cornea. Its
incidence varies across geographical locations.
Several hypotheses have been ascribed to its
aetiology.
1
Currently, it is believed that the
pterygium is a growth disorder characterised by
conjunctivalisation of the cornea due to
localised ultraviolet induced damage to the
limbal stem cells.
2
Aggressive pterygial
fibroblasts are also responsible for corneal
invasiveness.
3
The indications for surgery
include reduced vision due to encroachment of
the visual axis and irregular astigmatism,
4
chronic irritation and recurrent inflammation,
restriction of ocular motility, and cosmesis.
Numerous surgical techniques including bare
sclera excision with or without the use of
adjuncts like beta irradiation, thiotepa eye
drops, intra- or postoperative mitomycin C
(MMC) or antineoplastic agents, amniotic
membrane transplantation, conjunctival
autograft (CAG) with or without limbal stem
cells have been described.
5
Despite these
innovative procedures, recurrence continues to
be a complication. Reported rates of recurrence
range from 2% for excision with CAG to 89% for
bare sclera excision.
5
Differences in study
methodology, patient characteristics, nature of
pterygium, geographic area, definition of
recurrence, duration of follow-up, and loss to
follow-up are some of the factors responsible for
Received: 9 February 2004
Accepted in revised form:
2 September 2004
Published online:
29 October 2004
Financial or proprietary
interest: None.
1
Cornea and Anterior
Segment Service,
LV Prasad Eye Institute,
Hyderabad, India
2
Department of Biostatistics,
LV Prasad Eye Institute,
Hyderabad, India
Correspondence:
M Fernandes,
LV Prasad Eye Institute,
LV Prasad Maarg,
Banjara Hills,
Hyderabad 500 034, India
Tel: þ 91 40 23548267;
Fax: þ 91 40 23548271.
E-mail: fernandes@lvpei.org
Eye (2005) 19, 1182–1190
& 2005 Nature Publishing Group All rights reserved 0950-222X/05 $30.00
www.nature.com/eye
CLINICAL STUDY
widely varying rates of recurrence.
6
Since pterygium has
a moderate to high prevalence 301 above and below the
equator,
1
pterygium surgery is fairly common in our
country, which is located within the tropics. We decided
to determine the outcome of various surgical techniques
for pterygium performed at our Institute over a period of
14 years.
Methods
A retrospective analysis was performed of medical
records of all patients with primary and recurrent
pterygia who underwent surgery between January 1988
and December 2001. We assessed the demographic
variables, previous history of recurrences and prior
pterygium surgeries (if data were available). The
duration of follow-up, type of surgery performed (bare
sclera excision, primary closure, amniotic membrane
transplantation (AMT), CAG, conjunctival–limbal
autograft (CLAG), or concomitant use of surgical
adjuvants), recurrences with respect to the type of
surgery performed and postoperative complications
were analysed.
Surgical technique
The analysis of pterygium surgery outcome spanned
14 years during which time, we have witnessed the
evolution of several techniques performed by multiple
surgeons. Bare sclera excision and primary closure were
performed in the early to mid nineties. Subsequently
these were replaced by either CAG or CLAG or human
amniotic membrane (HAM). The specific surgical
techniques followed for each procedure have remained
consistent over the years, and are briefly described
below. All patients were anaesthetised with a peribulbar
block using 2% lignocaine hydrochloride and 0.001%
adrenaline tartarate.
(a) Pterygium excision
The pterygium head was taken off the cornea by blunt
dissection with a No. 15 Bard-Parker blade or a crescent
knife. The pterygium was then resected from the
underlying sclera. Fibrous adhesions, if any, between the
underlying muscle and the pterygium were carefully
dissected before the pterygium was excised. Minimal wet
field cautery was applied to maintain hemostasis. The
corneal and limbal surfaces were smoothed by scraping
with a Bart Parker blade.
(b) Bare sclera
Following excision of the pterygium, the sclera was
left bare.
(c) Primary closure
The surrounding conjunctiva was undermined and
mobilised to cover the bare sclera. The conjunctiva was
then sutured with 8–0 vicryl sutures.
(d) Amniotic membrane transplant
The human amniotic membrane was prepared and
preserved according to the technique described by
Kim and Tseng.
7
After excision of the pterygium, the
HAM was removed from the nitrocellulose paper and
placed over the bare sclera and cornea with the
epithelial side up. The stromal side was identified
by its stickiness to a surgical sponge. It was secured in
place with 10–0 monofilament nylon beyond the
edges of the corneal defect and at the limbus, and
to the surrounding conjunctiva with 8–0 vicryl sutures.
The excess membrane was trimmed. One of the
authors (VSS) prefers to cover the donor site with
HAM as well.
(e) CAG
After pterygium excision, the eyeball was rotated down
and an area of the superior bulbar conjunctiva adjacent to
the limbus, measuring 1 mm greater than the bare sclera,
was demarcated. Blunt dissection of the conjunctiva
without the Tenon’s capsule was carried out. The
limbal tissue was not included. The autograft was
slid into place over the bare sclera in its correct
anatomical orientation, and was secured in position at
the limbus by 10–0 monofilament nylon sutures and
peripherally to the surrounding conjunctiva by 8–0
vicryl sutures.
(f) CAG with AMT
In some cases, HAM was spread on the corneal epithelial
defect, epithelial side up and was secured in place with
10–0 monofilament nylon sutures in the normal cornea at
the edge of the defect, avoiding placement of sutures in
the visual axis, and at the limbus. The knots were
trimmed and buried. The excess amniotic membrane was
trimmed. The CAG harvested as described above was
transferred to the recipient bed over the HAM and
anchored along with the HAM to the surrounding
conjunctiva with 8–0 vicryl sutures.
(g) CLAG
Harvesting of the CLAG was similar to the CAG in all
respects except that on reaching the limbus, the tissue
was reflected onto the cornea and the dissection was
continued 0.5 mm beyond the limbus. The donor tissue
was excised and slid onto the recipient bed ensuring
accurate orientation of the limbal edge of the graft
with the limbus.
Outcome of pterygium surgery
M Fernandes et al
1183
Eye
(h) CLAG with AMT
The technique for pterygium excision, harvesting of
CLAG and securing HAM was as described above.
Postoperatively, all patients were started on topical
steroids, tapered over 6 weeks, and topical antibiotics for
a week. Patients were followed up after 1 week, 1 month,
every 3 months for the first year, and annually thereafter.
We defined progressive pterygium as any pterygium
wherein over a period of 3–6 months, there was an
increase in the size as observed by the patient or as
documented in the medical record. Vascular pterygium
was defined as any fleshy vascularised pterygium, which
obscured the view of the underlying episcleral vessels.
We defined recurrence as any fibrovascular growth
extending across the limbus onto the cornea at the site of
surgical excision. The onset of recurrence was recorded
as the date on which the recurrence was first noted,
irrespective of the duration between that visit and the
previous visit.
All the data were analysed separately for primary and
recurrent groups using SPSS (SPSS for Windows, version
11.0; SPSS, Chicago, IL, USA) statistical package.
Between-group differences were evaluated for
continuous variables using the two-sample t-test and for
categorical variables using Fisher’s exact test/w
2
test.
Cumulative success probability of recurrence was
determined for each group using Kaplan–Meier survival
analysis. Risk factors for recurrence were identified in a
univariate analysis (log-rank test). The factors having P
value less than 0.15 were subjected to a forward selection
procedure using a multivariate Cox proportional hazards
model. A P-value of less than 0.05 was considered
statistically significant.
Results
In total, 920 patients (989 eyes) of whom 496 (53.9%) were
male underwent surgery between January 1988 and
December 2001. There was a statistically significant
difference in the mean age of patients with primary
pterygia compared to those with recurrent pterygia
(50.7713.4 vs 40.6714.4 years, Po0.0001, independent
sample t-test). The characteristics of the pterygia are
presented in Table 1. More than two-thirds of the
pterygia were progressive and vascular. Figure 1 shows
the indications for pterygium surgery, the main
indication being visual impairment in more than half the
patients.
We analysed patients with unilateral (n ¼ 851) and
bilateral (n ¼ 69) pterygia separately. The demographic
and clinical data is presented in Table 2. The mean
duration of follow-up was 6.478.8 and 9.8717.8 months
for primary and recurrent pterygia, respectively.
Unilateral recurrent pterygium was significantly more
common in younger individuals (mean age, 41.6714.4
years).
The different surgical procedures and the recurrences
with each technique performed for unilateral primary
and recurrent pterygia are presented in Table 3. Three
Figure 1 The indications for pterygium surgery in unilateral and
bilateral primary and recurrent pterygia. NA ¼ not available.
Table 1 Morphological characteristics of unilateral pterygia
and other associated features
Clinical features Unilateral
Primary
pterygia n ¼ 821
Recurrent
pterygia n ¼ 30
Progressive (%) 516 (62.9) 24 (80)
Vascular (%) 578 (70.4) 27 (90)
Atrophic (%) 46 (5.6) 1 (3.3)
Nasal þ temporal (%) 11 (1.3) 1 (3.3)
Symblepharon (%) 21 (2.6) 7 (23.3)
Ocular motility
restriction (%)
42 (5.1) 3 (10)
Table 2 Demographic and clinical data of patients with
unilateral pterygia
Unilateral P-value
Primary
pterygia n ¼ 821
Recurrent
pterygia n ¼ 30
Age
Mean7SD 50.6713.5 41.6714.4 o0.0001
Range 3–94 10–83
Gender
Male (%) 399 (48.6) 20 (66.7) 0.063
Female (%) 422 (51.4) 10 (33.3)
Duration of
follow-up (months)
Mean7SD 8.86716.97 5.9278.78 0.347
Median 2.49 2.93
Range 0.75–150 0.75–48.63
SD ¼ standard deviation.
Outcome of pterygium surgery
M Fernandes et al
1184
Eye
patients underwent a combination of either CAG or
CLAG with AMT and MMC. Of 821 patients with
unilateral primary pterygium, recurrences were noted in
138 (16.8%) on an average 6.078.2 months (0.66–
59.9 months) after surgery. Of 159 patients below the age
of 40 years, 40 (25.2%) developed recurrences as
compared to 98 (14.8%) of 662 patients older than
40 (P ¼ 0.003). Recurrences were significantly more
common in males operated for primary pterygium (93
(23.3%) of 399 male patients, Po0.0001) compared to
female (45 (10.7%) of 422 female). In those with recurrent
pterygia (n ¼ 30), eight (26.7%) had recurrences, all of
whom were male (P ¼ 0.034). The average onset of
recurrence was 3.173.1 (0.98–10.33) months. There was
no statistically significant difference in the failure rates
between eyes with primary and recurrent pterygia
(P ¼ 0.212, Fisher’s exact test).
Of 69 patients with bilateral pterygium, only one
patient had recurrent pterygia in both eyes. In all,
40 (58.8%) patients had surgery in the right eye first
and 28 (41.2%) patients had surgery in the left eye first.
Eight (11.6%) patients underwent bilateral simultaneous
surgery. The mean duration between surgery of both eyes
in the remaining patients was 11.06 months (range 0.03–
98.97 months). In 41 (60.3%) patients the same surgery
was performed in both eyes. In total, 25 (61%) patients
underwent CAG, eight (19.5%) had bare sclera excision,
three (7.3%) underwent CLAG, three (7.3%) had adjuvant
MMC application, and two (4.9%) received an AMT. The
remaining patients underwent different surgeries in each
eye. Table 4 shows the surgical procedures performed in
these patients. Recurrences were noted in 32 eyes of 24
patients. In 23 patients with bilateral primary pterygia,
the mean onset of recurrence in 14 patients with
recurrence in the eye operated on first was 17.2721.5
(1.6–52.9) and 11.6717.9 (1.4–59.1) months in 16 patients
with recurrence in the eye operated on second. In six
patients, recurrences were seen in both eyes. One patient
with bilateral recurrent pterygia developed recurrences
in both eyes, at 11.3 months following surgery in the eye
operated on first and at 6.3 months in the eye operated on
second.
We analysed several risk factors for recurrence
including age, gender, laterality, occupation (whether
indoors or outdoors), the morphological characteristic of
the pterygium, and the type of surgical technique
performed. Table 5 shows the results of a univariate and
multivariate analysis of these factors for recurrence of
pterygium. Since the sample size of those with recurrent
pterygium developing another recurrence was small,
analysis was not carried out between subsets within this
group. A P-value o0.002 was considered significant after
adjusting the level of significance using Bonferroni’s
correction, for multiple comparisons among the various
groups with unilateral primary pterygium undergoing
different surgical procedures. A statistically significant
difference was noted in the recurrence between bare
sclera excision (P ¼ 0.019) and amniotic membrane
transplantation (P ¼ 0.006) compared to pterygium
excision with CAG. There was no statistically significant
difference among any of the other surgical procedures.
Figure 2 shows the probability of success as a function
of time (Kaplan–Meier survival analysis curves) for
primary and recurrent pterygia. The mean survival
time for primary pterygia was 81.3875.44 months
(95% CI; 70.73–92.04) and 28.9375.48 months (95%
Table 3 Different surgical procedures, frequency of first recurrence and median time of onset of first recurrence following these
procedures for unilateral primary and recurrent pterygia
Surgical procedure Primary Recurrent
Total no.
of eyes (%)
No. of
recurrences (%)
95% CI Median time
to recurrence
(months)
Total no.
of eyes (%)
No. of
recurrences (%)
95% CI Median time to
recurrence (months)
Bare sclera 237 (28.7) 46 (19.4) 14.4–24.4 2.07 3 (10) 1 (33.3) 0–86.7
Primary closure 30 (3.7) 5 (16.7) 3.3–30.0 2.72 1 (3.3) 0 0–100
AMT 105 (12.8) 28 (26.7) 18.2–35.1 4 4 (13.3) 0 0–46.1
CAG 345 (42.1) 42 (12.2) 8.7–15.6 2.64 16 (53.3) 5 (31.3) 8.5–54 1.9
CAG þ AMT 20 (2.5) 3 (15) 0–30.6 3.7 0 0 0
CLAG 52 (6.3) 9 (17.3) 7–27.6 5.88 5 (16.7) 2 (40) 0–82.9 1.78
Bare sclera þ MMC 25 (3.1) 5 (20) 4–35.7 8.92 0 0 0
Primary closure þ MMC 5 (0.6) 0 (0) 0 0 0
CAG þ AMT þ MMC 2 (0.2) 0 (0) 0 0 0
CLAG þ AMT þ MMC 0 (0) 1 (3.3) 0 0–100
Total 821 (100) 138 (16.8) 30 (100) 8 (26.7)
No. ¼ number, CI ¼ confidence intervals, AMT ¼ amniotic membrane transplantation, CAG ¼ conjunctival autograft, CLAG ¼ conjunctival limbal
autograft, MMC ¼ mitomycin C.
Outcome of pterygium surgery
M Fernandes et al
1185
Eye
CI; 18.19–39.66) for recurrent pterygia. At 1, 3, 6 months,
and 1 year, 4.9% (8), 44.2% (72), 68.7% (112), and 82.2%
(134), respectively, of recurrences (n ¼ 165) had occurred.
The postoperative complications are shown in Table 6.
Graft odema (1.3%), conjunctival granuloma (0.8%), and
Tenon’s cyst (0.2%) were the minor complications noted.
Microbial keratitis was seen in three (0.3%) eyes 2–
4 weeks postoperatively. Two had undergone pterygium
excision and CAG, and one had AMT. All three patients
were on topical steroids at the time of presentation and
did not have any other predisposing factors. All patients
resolved within 3–6 weeks on topical antibiotics. Scleral
melt was seen in two (0.2%) eyes of patients who had
undergone pterygium excision with CAG 2 and 3 weeks
earlier. Neither of the patients had evidence of collagen
vascular disorders and resolved within 6 weeks on
topical and oral steroids.
Discussion
Pterygium surgery should ideally have a low or no
recurrence, minimal complications and be cosmetically
acceptable. The evolution of several surgical techniques
over the years with recurrence rates varying from 2 to
88%
5
indicates that we are yet to find the ‘ideal’
procedure.
The risk factors for recurrence include geographic
location,
8
age,
9
and morphology of pterygium.
10
We have
noted that recurrence was significantly higher in males
with primary (23.3 vs 10.7%, Po0.0001) and recurrent
pterygia (26.7 vs 0%, P ¼ 0.034). It was also higher in
patients below 40 years of age (25.2 vs 14.8%, P ¼ 0.003)
as has been described previously.
9,11,12
The lipoid
degeneration in the peripheral cornea in elderly
individuals may be an inhibiting factor to pterygium
progression.
13
The commonest morphological characteristics of the
primary pterygia were vascular in 578 (70.4%) and
progressive in 516 (62.9%). Among those with recurrent
pterygia, vascular pterygia comprised 27 (90%) and
progressive pterygia 24 (80%). A significantly higher
number of patients with recurrence following surgery for
unilateral primary pterygium were noted to have
vascular pterygia (18.9 vs 11.9%, P ¼ 0.026). The
pterygium morphology has been described as a
significant risk factor for its recurrence.
10
Symblepharon
was more common in those with recurrent pterygium
and was seen in seven (20.6%) eyes compared to 21
(2.6%) of eyes with primary pterygium.
Bare sclera
Although this appears to be the quickest and easiest
technique, unacceptable recurrence rates ranging from
Table 4 Surgical procedure and outcome of eyes operated first and second in patients with bilateral pterygia
Surgical procedure of
eye operated first
Surgical procedure of eye operated second No. of recurrences
in eye operated first (%)
Bare
sclera
Primary
closure
AMT CAG CAG þ AMT CLAG Bare
sclera þ MMC
Primary
closure þ MMC
CLAG þ AMT þ MMC Total
Bare
sclera
8 0 0 4 0 2 1 1 0 16 3 (18.8)
Primary closure 0 0 0 1 0 0 0 0 0 1 1 (100)
AMT 1 0 2 2 0 1 0 0 1 7 4 (57.1)
CAG 2 0 4 24 1 2 1 0 0 34 2 (5.9)
CAG þ AMT 0 0 0 0 1 1 0 0 0 2 0
CLAG 0 0 0 1 0 3 0 0 0 4 2 (50)
Bare sclera þ MMC 0 0 0 1 0 0 2 0 1 4 2 (50)
Primary closure þ MMC 0 0 0 0 0 0 0 0 0 0
CLAG þ AMT þ MMC 0 0 0 0 0 0 0 0 0 0
Total 11 0 6 33 2 9 4 1 2 68
No. of recurrences in
eye operated second (%)
4 (36.4) 0 2 (33.3) 6 (18.2) 0 2 (22.2) 2 (50) 0 0 30
a
AMT ¼ amniotic membrane transplantation, CAG ¼ conjunctival autograft, CLAG ¼ conjunctival limbal autograft, MMC ¼ mitomycin C, No. ¼ number.
a
Total number of recurrences.
Outcome of pterygium surgery
M Fernandes et al
1186
Eye
30 to 82%, with the exception of two reports,
5
have forced
it into oblivion. Our experience is similar with
recurrences of 46 (19.4%) for primary and one (33.3%) for
recurrent pterygia among those with unilateral
pterygium. We have stopped doing bare sclera excision
with the advent of newer, more acceptable techniques
with lower recurrence rates.
Primary closure
With this procedure for primary pterygium, recurrences
of 16.7% (n ¼ 5) were noted. There are only three recent
studies describing results of this technique with widely
varying recurrence rates ranging from 2 to 69%.
14–16
Two
of these
15,16
used a small sample with extremely high
recurrences of 45
16
and 69%.
15
In the third retrospective
study despite a large number of patients,
14
the
description of the surgical technique and the number lost
to follow-up were inadequate. Hence, the efficacy of
primary closure has not been substantiated in literature
and needs further study.
AMT
Amniotic membrane anatomically consists of epithelium,
basement membrane, and avascular stroma. Its unique
properties have promoted its use in several ocular
surface disorders.
17
The basement membrane promotes
Table 5 Risk factors for pterygium recurrence
N R (%) P-value
a
Univariate Multivariate
HR 95% CI HR 95% CI
Age (years)
o40 159 40 (25.2) o0.0001 2.12 1.43–3.14 2.13 1.41–3.2
440 662 98 (14.8) 1
Gender
Male 399 93 (23.3) 0.002 1.82 1.35–2.66 1.76 1.19–2.58
Female 422 45 (10.7) 1
Occupation
Indoor 232 31 (13.4) 1
Outdoor 260 40 (15.4) 0.25 1.34 0.81–2.22 n/a
Progressive
P 516 84 (16.3) 1
NP 305 54 (17.7) 0.935 1.01 0.71–1.45 n/a
Vascular
V 578 109 (18.9) 0.026 1.63 1.06–2.51 1.63 1.05–2.53
NV 243 29 (11.9) 1
Symblepharon
Present 21 4 (19) 0.958 1.03 0.38–2.78 n/a
Absent 800 134 (16.8) 1
Laterality
Unilateral 821 138 (16.8) 1
Bilateral 66 24 (36.4) 0.08 1.49 0.95–2.33 n/a
Surgical technique
BS 237 46 (19.4) 1 1
PC 30 5 (16.7) 0.103 1.51 0.92–2.49 1.15 0.45–2.93
AMT 105 28 (26.7) 0.185 0.74 0.48–1.15 1.37 0.83–2.27
CAG 345 42 (12.2) 0.975 0.99 0.39–2.49 0.67 0.43–1.05
CAG þ AMT 20 3 (15) 0.662 0.73 0.18–3.02 0.54 0.13–2.27
CLAG 52 9 (17.3) 0.989 0.99 0.47–2.13 0.83 0.39–1.78
MMC 32 5 (15.6) 0.541 0.75 0.3–1.89 0.64 0.25–1.61
N ¼ no. of patients, R ¼ no. of recurrences (first recurrence), HR ¼ hazards ratio, CI ¼ confidence interval, P ¼ progressive, NP ¼ nonprogressive,
V ¼ vascular, NV ¼ nonvascular, BS ¼ bare sclera, PC ¼ primary closure, AMT ¼ amniotic membrane transplantation, CAG ¼ conjunctival autograft,
CLAG ¼ conjunctival limbal autograft, MMC ¼ mitomycin C.
a
Univariate Cox regression analysis.
Outcome of pterygium surgery
M Fernandes et al
1187
Eye
epithelial growth and differentiation and reinforces the
adhesion of basal epithelial cells. The stromal matrix
reduces scarring by suppressing TGF-b signalling,
proliferation, and myofibroblast differentiation in
cultured human corneal and limbal fibroblasts
18
and by
suppressing normal conjunctival and pterygium body
fibroblasts.
19
Recurrence rates of 10.9 and 37.5% were
reported with the use of amniotic membrane following
excision of primary and recurrent pterygia respectively.
16
These rates were significantly higher than those for CAG
transplant.
18
The same group subsequently described a
modification of the surgical technique and reported
recurrences of 3 and 9.5% for primary and recurrent
pterygia respectively.
20
The high recurrence rate of 26.7%
noted in our study could be attributed to inadequate
excision of the subconjunctival fibrous tissue. There is a
lack of descriptive literature on this technique and
prospective randomised controlled trials are needed.
AMT will be useful in cases with extensive conjunctival
defects or in those patients who may require glaucoma
filtering procedures in the future.
CAG transplantation
The relatively lower recurrences with this technique
could be due to transplantation of normal conjunctiva
that forms a barrier to the proliferation and advancement
of residual abnormal tissue (both conjunctival and
episcleral tissues) towards the limbus and the
noninclusion of episcleral tissue in the graft.
15
In
addition, scleral dessication and subsequent melting is
prevented,
20
and there is restoration of normal anatomic
appearance.
16
Our results with CAG reflect those of other
groups.
5
Recurrences of 12.2% (n ¼ 42) were noted in
those with primary pterygium and 31.3% (n ¼ 5) in those
with recurrent pterygium. Results of prospective
randomised clinical trials performed in geographical
areas with a higher prevalence of pterygium have shown
higher recurrences of 21% and 39%
11
with CAG:
however, these values are still lower than those following
bare sclera excision. The recurrences following CAG
reported in the English language literature range from 0
to 40%.
5
The variable results among several groups could
be due to
1. different study populations, some within the tropics
with higher exposure to UV
2. variations in surgical technique, that is, inadequate
excision of episcleral tissue, graft retraction due to
undersizing or inclusion of Tenon’s tissue
3. diverse definitions of recurrence
4. small sample size
5. pterygium morphology.
Compared to bare sclera excision, the risk of
recurrence following CAG was significantly lower
(hazards ratio 0.67; 95% CI 0.43–1.05). Despite the
retrospective nature of this study, this is the largest series
of patients in whom CAG has been done and it appears
to be a safe and effective procedure for primary
Follow up Duration (months)
16
0
140120100806040200
Cum Survival Probability
1.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.0
Primary pterygium
Recurrent pterygium
Figure 2 Kaplan–Meier survival analysis curves for primary
and recurrent pterygia.
Table 6 CLAG outcome
Year No. of eyes
(Prim;rec)
Rec %
(Prim;rec) (eyes)
Ave FU
(months) (range)
Surgery Nature of study Control
(Prim;rec)
Surgery Rec% (eyes)
1994
21
31 (0;31) 13.3 (4) 10 (3–18) CLAG Prospective 18 (0;18) Czermak 50
1996
22
27 (16;11) 6.25;9.1 (1;1) 10.87 (1–34) CLAG Prospective
noncomp
FF F
1998
23
4 (0;4) 25 (1) NA CLAG þ AMG Prospective
noncomp
FF F
1998
6
53 (36;17) 3.8;0 (2;0) 18.972.1 (1.5–43) CLAG Retro FF F
2000
24
7 (0;7) 0 F (14–24) CLAG Prospective
noncomp
FF F
2003
25
34 (0;34) 0 F min. 18 months CLAG þ MMC Mixed
a
FF F
2003
26
15 (0;15) 20 (3) 16.75 CLAG þ AMG F 12 CAG þ AMG 8.3 (1)
No. ¼ number; Rec ¼ recurrence; Ave FU ¼ average follow-up; Prim;rec ¼ primary;recurrent; CLAG ¼ conjunctival limbal autograft;
noncomp ¼ noncomparative; AMG ¼ amniotic membrane graft; retro ¼ retrospective; min ¼ minimum; MMC ¼ mitomycin C.
a
retrospective (n=18) þ Prospective (n=16).
Outcome of pterygium surgery
M Fernandes et al
1188
Eye
pterygium. Most studies have not described their results
of CAG for primary and recurrent pterygia separately.
5
A report by Riordan-Eva et al
15
in a retrospective study
described recurrences of 6% in 17 of 47 eyes with
recurrent pterygium. Recurrence rates of 0 and 9.1% have
been described in prospective studies comprising of 17
and 44 eyes with recurrent pterygia each.
10,16
We noted a
higher recurrence rate of 31.3% (five of 11 eyes) with a
small series of patients with recurrent pterygium. Larger
prospective trials are needed to determine the efficacy of
this technique for recurrent pterygia.
CLAG
Localised stem cell deficiency has been hypothesised to
be a cause of pterygium.
2
Based on this concept, a CLAG
including limbal stem cells from a healthy site of the
affected eye has been shown to be effective following
pterygium excision with recurrences ranging from 0 to
25%. The results with this technique have been described
in Table 7.
21–26
A combination of AMT and CLAG has
also been tried for recurrent pterygia.
26
Excision of
recurrent pterygia results in excessive fibrovascular
regrowth. Multiple surgeries at the limbus result in
destruction of limbal barrier function. Thus, a
combination of CLAG for restoration of limbal barrier
function, and AMT for suppressing the fibrous growth,
have demonstrated good results (Table 7). We noted
recurrence in nine (17.3%) of 52 eyes with primary
pterygia with this combined procedure. The recurrences
were higher compared to the published literature. This
may be attributed to inadequate excision of the
subconjunctival tissue or due to an inadvertent selection
bias in this retrospective analysis resulting in this
procedure being performed for progressive, vascular
pterygia in younger patients; however, this was assessed
and there was no difference noted. When compared to
CAG, there was no statistically significant difference in
the recurrence rate. Of five eyes with recurrent pterygia,
recurrences were seen in two (40%). Conclusive evidence
cannot be drawn regarding the use of this procedure for
recurrent pterygia considering the small number of
patients operated upon.
Adjuvant therapy
A total of 32 (3.9%) patients with unilateral primary
pterygia undergoing surgery received adjuvant
intraoperative MMC therapy in doses varying from 0.2 to
0.4 mg/ml for varying durations from 1 to 4 min.
Recurrences were noted among those who underwent
bare sclera excision (Table 3). This high rate of recurrence
compared to what has been described in literature,
5
may
be due to lack of uniformity in the surgical procedure
and the relatively small sample size confounding the
results. The major drawback of antimetabolites is the
potential risk of scleral necrosis and perforation.
Hence, the concomitant use of adjuvants has been
recommended with caution for aggressive recurrent
pterygium until adequate follow-up information has
been obtained from those receiving MMC for primary
pterygium.
5
We agree that this study, although comprising the
largest series of cases describing outcome of various
surgical techniques for pterygium, has all the limitations
of a retrospective study. Prospective randomised case
control studies comparing AMT, CAG and CLAG for
primary pterygia and CAG and CLAG with and without
the use of MMC for recurrent pterygia are needed.
Conclusion
CAG with or without AMG appears to be the safest and
most effective modality for primary and recurrent
pterygia. Males, patients below the age of 40 years, and
those with vascular pterygia face greater risk of
recurrence. Bare sclera excision and primary closure have
high recurrence rates.
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