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[Eye Reports 2011; 1:e1] [page 1]

Bilateral pterygium 
in the two siblings
Suleyman Ciftci,1 Leyla Ciftci2
1Department of Ophthalmology,
Diyarbakir Training and Research
Hospital; 2Department of Cardiology,
Faculty of Medicine, Dicle University,
Diyarbakir, Turkey

Abstract 

Pterygia are fibrovascular connective tissue
overgrowths of bulbar conjunctiva onto the
cornea. There is a worldwide distribution of
pterygium, but it occurs more commonly in
warm, dry climates. Patients younger than the
age of 15 rarely acquire a pterygium. We report
a case of bilateral nasal pterygium in two sib-
lings. A 10-year-old boy and a 12-year-old girl
who are siblings presented with bilateral nasal
pterygium. While pterygium is a common dis-
order, its bilaterality in young people is not a
common condition. This report is the first
known report in the peer-reviewed medical lit-
erature of patients with bilateral nasal ptery-
gium in siblings younger than the age of 15.

Introduction

Pterygia are fibrovascular connective tissue
overgrowths of bulbar conjunctiva onto the
cornea. They are horizontally located in the
interpalpebral fissure on either the nasal or
temporal side of the cornea. Histopathologic
examination reveals that the subepithelial tis-
sue exhibits elastotic degeneration of colla-
gen, resulting from breakdown of the collagen
and destruction of Bowman’s membrane.
Patients younger than the age of 15 rarely
acquire a pterygium.1

Case Report

A 10-year-old boy and a 12-year-old girl who
are siblings presented with bilateral nasal
pterygium. On examination, the anterior seg-
ments in both eyes of both patients were oth-
erwise normal, as were the posterior segments
as well as the intraocular pressures (Figures 1
and 2). The visual acuity of the boy was 8/10 in
the right eye and 9/10 in the left eye without
correction. The visual acuity of the girl was
9/10 in each eye without correction. There was
no evidence of other functional impairments
in either of the two siblings. None of their par-

ents or their first-degree relatives, who live
under the same environmental and geographi-
cal conditions, had any pterygia.

Discussion

There is a worldwide distribution of ptery-
gium, but it is more common in warm, dry cli-
mates. The association between ultraviolet
radiation and formation of pterygia is strong.
In addition, local drying of the cornea and con-
junctiva in the interpalpebral fissure from tear
film abnormalities may lead to fibroblastic
growth.1 There is also some evidence that
hereditary factors play a role in the develop-
ment of pterygium. Several case reports sug-
gest a possible autosomal dominant pattern of
occurrence.2-4 Our knowledge of the pathogen-
esis of pterygium has increased in recent
years. Recently, Jaworski et al.5 studied some
of the genes that play a role in cell migration.
These gene products include spermidine/sper-
mine N1-acetyltransferase 1, clusterin, S100
protein, and keratins. Among migration-relat-
ed genes present in pterygia is the gene SAT1,
which encodes for the enzyme spermidine/
spermine N1-acetyltransferase 1. SAT1 is
abundant particularly at the body of the ptery-
gium. One polyamine analogue, IPENSpm, a
potential inhibitor of SAT1, significantly
reduces migration in primary cultures of ptery-
gium.5 Another of the more abundantly
expressed gene products in pterygia is clus-
terin. Clusterin has many functions and is
known by several synonyms:  apolipoprotein J,
testosterone-repressed prostate message 2,
sulfated glycoprotein 2, and complement-asso-
ciated protein SP-40. Clusterin is abundant

particularly at the fibrovascular body of the
pterygium.5

S100 proteins comprise a multitude of low
molecular weight, calcium-binding proteins
that interact with other proteins to modulate
biological processes.6,7 S100A8 and S100A9 are
present at higher levels in pterygia than in
uninvolved conjunctiva, and present in tear
fluids of patients with pterygia. S100A9 (also
known as calgranulin B) is abundant particu-
larly at the leading edge of the pterygium body.
S100A9 may be a pterygium and/or conjunctiva
marker5,6 and may also serve as an especially
useful indicator for predicting recurrent ptery-
gium.8 Kerkhoff et al. have showed that S100A8
and S100A9 are released from neutrophils by a

Eye Reports 2011; volume 1:e1

Correspondence: Suleyman Ciftci, Diyarbakir
Eğitim ve Araştirma Hastanesi Göz Hastalikları
Polikliniği, 21000 Diyarbakir, Turkey. 
Tel: +90.412.2570206 - Fax: +90.0412.2245267. 
E-mail: ciftci1977@hotmail.com

Key words: bilaterality, pterygium, sibling, young
patients.

Conflict of interest: the authors report no con-
flicts of interest. 

Received for publication: 6 April 2011.
Accepted for publication: 30 May 2011.

This work is licensed under a Creative Commons
Attribution NonCommercial 3.0 License (CC BY-
NC 3.0).

©Copyright S. Ciftci and L. Ciftci, 2011
Licensee PAGEPress, Italy
Eye Reports 2011; 1:e1
doi:10.4081/eye.2011.e1

Figure 2. Nasal pterygia (arrows) in the
right and left eyes of the 12-year-old girl.

Figure 1. Nasal pterygia (arrows) in the
right and left eyes of the 10-year-old boy.

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microtubule-dependent mechanism and may
induce inflammation by influencing leukocyte
trafficking.9

Jaworski et al. suggested the hypothesis
that a pterygium may spread across the corneal
surface by migration of cells bearing conjunc-
tival and limbal markers into the corneal
epithelium.5 They observed migration-related
transcripts of the following proteins: keratin
19, found in limbal stem cells; keratins 4 and
13, found in conjunctiva and limbal cells; and
aldehyde dehydrogenase, found in corneal
epithelial cells.5

Matrix metalloproteinases (MMPs) also play
a role in the development of pterygium. The
pterygial cells which invade over Bowman’s
layer were found to have produced increased
matrix metalloproteinases. MMP-1, MMP-2,
and MMP-9 are likely the main MMPs respon-
sible for dissolution of Bowman’s layer, by acti-
vating fibroblasts at the head of the pterygium,
nearest to intact Bowman’s layer.10 The finding
of increased MMPs at the leading edge of a
pterygium led to a more recent study on the
effect of doxycycline, an MMP inhibitor on
pterygium growth. Doxycycline was shown to
reduce migration of pterygial epithelial cells in
culture.11

Tong et al. concluded that aberrant wound
healing processes play a role in pterygium
pathogenesis. They compared expression of
primary pterygia, recurrent pterygia, and unin-
volved conjunctiva, and observed increased
expression of adhesion molecules and extra-
cellular matrix and structural proteins
(fibronectin; collagen and keratin family mem-
bers). Expression of epithelial-mesenchymal
transition (EMT), with down-regulation of E-
cadherin and up-regulation of β-catenin and
lymphoid-enhancer-factor-1, has also been pro-
posed as a mechanism for the origin of ptery-
gial fibroblasts.16

Vascular endothelial growth factor (VEGF)
plays an important role in fibrovascular compo-
nent of pterygia. Recently Tsai et al. evaluated
potential associations between pterygium for-
mation and the VEGF gene-460 polymorphism.
They observed no significant differences seen
between pterygium and control groups in age
and sex, but found that VEGF-460C polymor-
phism is associated with pterygium formation
in young female patients.17

Dushku and Reid found that there is
increased expression of p53 in all pterygia they
studied. The increased amount of p53 protein
in pterygial cells does not cause apoptosis or
block cell proliferation, suggesting that the
normal p53 functions are inactivated in ptery-
gia.10 Despite the increased amount of p53 pro-
tein in pterygial cells, pterygium has been
described by some as a benign neoplastic
lesion.13-15

Conversely, the small leucine-rich proteogly-
can (SLRP) family is highly expressed in the

cornea and is believed to contribute to corneal
transparency. Members of this family include
decorin, keratocan, lumican, and mimecan
(also called osteoglycin). SLRPs are collective-
ly down-regulated in pterygium. Furthermore,
there are no transcripts for any of these SLRPs
in the pterygium library.5,12

Conclusions

Pterygium is a common disorder; however, it
is not common in childhood.4 Few cases of
pterygia in childhood have been reported. In a
series of 95 patients with pterygia, Ajayi and
Bekibele18 reported the youngest was a 10-
year-old child with a pterygium. Islam and
Wagoner2 reported a family with pterygia. One
member of the family was a 4-year-old child.
Belliveau and Ali19 reported a 3-year-old child
with a pterygium due to xeroderma pigmento-
sum; pterygia are a common finding in xero-
derma pigmentosa. In the cases in children
reported, all except one patient, which report-
ed by Islam and Wagoner, were unilateral. In
none of the cases reported was there a history
of a sibling with a pterygium. Our case is
unique in that it is a sibling pair with pterygia,
that are also bilateral. I have previously report-
ed a boy with bilateral nasal pterygium.20 This
report is the first known report in the peer-
reviewed medical literature of patients with
bilateral nasal pterygium in siblings younger
than the age of 15.

References

1. Stephen G. Waller, Anthony P. Adamis.
Pterygium. Chapter 35. In: William
Tasman, eds. Duane's Clinical
Ophthalmology on CD-ROM. 1st ed.
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Wilkins, 2006. 

2. Islam SI, Wagoner MD. Pterygium in
young members of one family. Cornea
2001;20:708-10.

3. Zhang JD. An investigation of aetiology
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4. Saw SM, Tan D. Pterygium: prevalence,
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5. Jaworski CJ, Aryankalayil-John M, Campos
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6. Riau AK, Wong TT, Beuerman RW, Tong L.
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in pterygium. Mol Vis 2009;15:335-42.
7. Tu CL, Chang W, Bikle DD. The extracellu-

lar calcium-sensing receptor is required
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8 Zhou L, Beuerman RW, Ang LP, et al.
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9. Kerkhoff C, Klempt M, Kaever V, Sorg C.
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10. Reid TW, Dushku N. What a study of ptery-
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11. Cox CA, Amaral J, Salloum R, et al.
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12. Kao WW, Liu CY. Roles of lumican and ker-
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13. Dushku N, Reid TW. Immunohisto -
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expressing altered limbal epithelial basal
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14. Weinstein O, Rosenthal G, Zirkin H, et al.
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15. Tan DT, Tang WY, Liu YP, et al. Apoptosis
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normal conjunctiva and pterygium. Br J
Ophthalmol 2000;84:212-6.

16. Tong L, Chew J, Yang H, et al. Distinct
gene subsets in pterygia formation and
recurrence: dissecting complex biological
phenomenon using genome wide expres-
sion data. BMC Med Genomics 2009;2:14.

17. Tsai YY, Chiang CC, Bau DT, et al. Vascular
endothelial growth factor gene 460 poly-
morphism is associated with pterygium
formation in female patients. Cornea
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18. Ajayi BG, Bekibele CO. Evaluation of the
effectiveness of post-operative beta-irradi-
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19. Belliveau MJ, Ali A. Pterygium resection
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Cornea 2008;27:1174-5.

20. Ciftci S. Bilateral pterygium, symmetrical
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Can J Ophthalmol 2009;44:713.

Case Report

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