1) The document discusses several conditions that can mimic or masquerade as other conditions based on their clinical presentation. These include restrictive myopathy mimicking superior rectus palsy, rhabdomyosarcoma mimicking orbital cellulitis, Cogan-Reese syndrome mimicking iris melanoma, and various conditions that can cause vitritis mimicking intermediate uveitis. 2) It also provides examples of APMPPE mimicking sarcoidosis, orbital inflammation in retinoblastoma mimicking orbital cellulitis, uveitis mimicking retinoblastoma, and neurological lesions causing visual field defects mimicking glaucoma. 3) Buried optic disc drusen can mimic

1. MiMiC !
By
Ahmed Alsherbeny
MD, CABOphth, MRCSEd Ophth, FRCS Ophth (Glasg), FICO

2. Chapter IV

3. In TED restrictive myopathy, Elevation
defect caused by fibrotic contracture of
the inferior rectus, may mimic superior
rectus palsy and is the most common
motility deficit.
Lt fibrotic contracture
of the inferior rectus in TED
Rt elevation defect due to
Rt isolated superior rectus palsy

4. In Rhabdomyosarcoma, rapidly progressive unilateral proptosis is usual,
and may mimic an inflammatory condition such as orbital cellulitis.
Rhabdomyosarcoma Orbital cellulitis
N.B.
Most common cause of acute unilateral proptosis in
a child is orbital cellulitis while the most dangerous
cause to be excluded is rhabdomyosarcoma

5. In ICE syndrome, Iris naevus (Cogan–Reese) syndrome is
characterized by either a diffuse naevus that covers the anterior
iris, or by iris nodules. Iris atrophy is absent in 50% of cases and in
the remainder it is usually mild to moderate, although corectopia may
be severe. The appearance may be mimicked by a diffuse iris
melanoma.
Cogsn-Reese syndrome in ICE Diffuse iris melanoma

6. Other conditions that may give vitritis mimicking IU
include Fuchs uveitis syndrome, intraocular lymphoma
(older patients), Toxocara granuloma, Whipple disease,
endogenous Candida endophthalmitis (risk factors such as
IV drug use) and toxoplasmosis. These will commonly be
suspected on the basis of the history and specific clinical
findings.
Snowballs in IU Endogenous candida endophthalmitis

7. The clinical picture of APMPPE can be
mimicked by other entities such as
sarcoidosis and tuberculosis.
APMPPE Sarcoidosis choroiditis

8. N.B.
Syphilis is often known as the “Great
Imitator”. Ocular syphilis being
particularly challenging to diagnose as
it can mimic any form of uveitis

9. In Lymphoproliferative lesions of the conjunctiva , A
slowly growing salmon-pink or flesh-coloured mobile
infiltrate is seen on the epibulbar surface or in the
fornices . Rarely, a diffuse lesion may mimic chronic
conjunctivitis.
Conjunctival lymphoma Chronic conjunctivitis in SLK

10. In ciliary body melanoma , erosion through the iris root may mimic
iris melanoma, extraocular extension through scleral vessels a
conjunctival melanoma.
Extraocular extension of
ciliary body melanoma
Conjunctival melanoma
Iris root erosion of
ciliary body melanoma
Iris melanoma

11. In Retinoblastoma, Orbital inflammation
mimicking orbital or preseptal cellulitis
may occur with necrotic tumours
Orbital inflammation in retinoblatoma Orbital cellulitis

12. OOPS !
You have been tricked 😛
Both figures are for orbital inflammation in
retinoblastoma !
Orbital inflammation in retinoblastoma

13. Uveitis may mimic the diffuse infiltrating
type of retinoblastoma seen in older
children. Conversely, retinoblastoma may be
mistaken for uveitis, endophthalmitis or
orbital cellulitis
Retinoblastoma presented with
anterior uveitis
Anterior uveitis in JIA
Note : The eye in both figures is white and quite

14. N.B.
In JIA , you must exclude Masquerade syndromes
such as anterior segment involvement by
retinoblastoma (older onset).

15. N.B.
Posterior segment
examination should
always be performed to
detect a masquerading
cause of anterior uveitis
(e.g. retinal
detachment, tumour),
primary intermediate or
posterior segment
inflammation, and
complications of
anterior uveitis such as
cystoid macular
oedema.

16. N.B.
In leukaemia, retinal and choroidal infiltrates
may occur, most commonly posterior to the
equator and may masquerade as posterior
uveitides
Leukaemic chorioretinal deposit Tuberculous choroidal granuloma

17. In macular pseudohole , lesion mimics the clinical appearance of
a FTMH, but is caused by distortion of the perifoveal retina
into heaped edges by ERM, without any loss of retinal tissue,
and near-normal foveal thickness; there is a central defect in
the membrane. VMT may be present
Macular pseudohole
FTMH

18. In degenerative myopia, (Peripapillary) intrachoroidal cavitation (ICC), formerly described
as peripapillary detachment of pathological myopia (PDPM), may occur adjacent to the
nerve, commonly inferiorly. Clinically, it may be evident as a small yellowish-orange
peripapillary area typically inferior to the disc. Visual field defects are common and
frequently mimic glaucoma
Myopic degenerative disc in OAG
ICC
Field change in a case of ICC Mild glaucomatous damage
(not related to the above case)

19. N.B.
In optic disc pit, Visual field defects are
common and may mimic glaucoma
Case report: Optic disc coloboma with pit treated as glaucoma

20. N.B.
Neurological lesions causing optic nerve or chiasmal
compression can produce visual field defects that may
be misinterpreted as glaucomatous, and neuroimaging
should be performed if there is any suspicion; some
practitioners routinely perform a cranial MRI in all
cases of NTG.
Miscellaneous optic neuropathies including inflammatory,
infiltrative and drug-induced pathology will often be
clinically obvious, but can occasionally masquerade as
NTG

21. Buried optic disc drusen in
children can mimic papilloedema
Buried optic disc drusen Grade II Papilledema

22. Sclerosing BCC can mimic a localized area of
unilateral chronic blepharitis.
Extensive sclerosing BCC Unilateral chronic blepharitis

23. The appearance of myelinated
nerve fibres can be mimicked by
neoplastic infiltration
Myelinated nerve fibres Diffuse infiltrating retinoblastoma

24. Congenital glaucoma may masquerade as neonatal conjunctivitis &
Cong NLD obstruction and should always be considered, particularly
in monocular cases
Rt eye shows lacrimation/epiphora as in Cong NLD obstruction
Lt eye shows pink eye and sticky discharge as in neonatal conjunctivitis

25. Myasthenia gravis may mimic
intermittent pupil-sparing
third nerve paresis
Lt third nerve palsy Ocular myasthenia

26. Lt third nerve palsy Ocular myasthenia
OOPS !
You have been tricked again 😉 , The
right diagnosis between figures is
replaced !!

27. Thank You