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Clinical
Persistent hyaloid arteries
Kirit Patel describes two cases where previous sight loss in one eye
made the prognosis in the other all the more critical
A
Figure 1 Left eye corneal scarring and complete vascularisation
35-year-old
insulin
dependent
diabetic
patient from Nigeria
was advised by her
sister to have a thorough
eye examination. Her
sister was concerned that she needed
thick glasses and a magnifier to read.
Her sister, who was six years older
and one of our patients, also suffered
from diabetes and was very diligent in
controlling her sugar level.
The patient had lost her right eye 10
years ago following a corneal infection
but she could not remember exactly
the cause. Over the past 10-12 years
she had undergone numerous laser
treatments and a successful aphakic
cataract operation. Both eyes had
trabeculectomy operations for glaucoma
and the left eye was treated with topical
Alphagan eye drops as well as Maxitrol
steroid eye drops when necessary.
Figure 2 Greyish white fibrous membrane indicating previous new vessels
well as cotton-wool spot
● Right optic disc had greyish white
fibrous membrane indicating previous
new vessels on the disc (Figure 2)
● Right temporal retina revealed a
much larger fibrous membrane and a
much smaller membrane on the nasal
aspect as well – again remnants of
previous new vessels on the retina
● There were numerous occluded
retinal veins showing cattle track blood
flow
● Inferior branch retinal artery
showing possible occlusion and calibre
change.
● The retina had pan-retinal
photocoagulation and remnants of
laser scars.
Decision taken
The patient was told that owing to
the loss of the left eye she could not
Spectacle prescription
R +11.00DS / -1.00DC X 180 VA 6/36
Add +4.00DS VA N24.
L no light perception.
Ocular findings
● Bilateral intraocular pressures were
22mmHg
● Left eye corneal scarring and
complete vascularisation – no fundus
view possible (Figure 1)
● Right eye cataract extraction and no
intraocular implant (aphakia)
● Right eye revealed R1 retinopathy
consisting of a few haemorrhages as
30 | Optician | 15.10.10
be prescribed an intraocular lens or a
contact lens and her only choice was
a lenticular spectacle lens for distance
and reading. She was also prescribed a
magnifier for reading.
In this patient’s case the new vessels
regressed following treatment and the
regression of the new vessels led to a
fibrous tissue which was noticed on the
disc and elsewhere on the retina. It was
unfortunate that she lost her sight due
to poor diabetes control in her younger
days. How often do we see young
diabetics losing their sight and in some
cases suffering from strokes or cardiac
problems due to their poor compliance
with instructions?
Case 2
Persistent hyaloid artery and
hyaloid membrane
A 76-year-old Russian patient came
for his routine diabetic assessment. He
recalled losing the sight in his right eye
following a karate kick some time in
his youth. He had cataract in his left eye
and had had a right cataract extraction
some 20 years ago. For his diabetes he
took metformin and vitamins A, C and
E plus bilberry.
Spectacle prescription
R count fingers in outside corner.
L -8.75DS / -1.00DC X 40 VA 6/12
and N5 (without specs).
Figure 3 Right vitreous shows the hyaloids membrane
behind the implant
Ocular findings
● Right eye pseudo-aphakia and
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Clinical
Figure 4 The hyaloid artery has a central portion and two extended arms
intraocular implant
● Right vitreous shows the hyaloid
membrane clearly behind the implant.
This is seen as central triangular
membrane and another less clear
membrane on the left to this triangular
piece (Figure 3)
● Right fundus shows a persistent
hyaloid artery extending from the optic
disc. A shiny white bright image is due
to the hyaloid membrane which we
observed on the anterior imaging
● The hyaloid artery is seen in
much greater detail using the retinal
assessment module (RAM) which
shows the membrane much more
clearly. The hyaloid artery has a central
portion and two arms extending from
it (Figure 4)
● The chorioretinal scarring inferior to
the disc is also evident and this could
be related to the myopia or it could be
related to the trauma following the
karate kick
● Macula appears unclear
● Right and left eye showing R0
retinopathy and intraocular pressures
within normal range of 14mmHg in the
right eye and 16mmHg in the left eye
● Left eye early posterior subcapsular
cataract
● Left myopic disc with chorioretinal
changes surrounding
● The left disc appears fairly cupped
and suspect especially when we view
the veins superiorly and inferiorly
bayoneting the edge of the cup
● Left maculr epiretinal membrane
(Figure 5).
Decision taken
The patient was reassured that he had
no diabetic retinopathy in either eye
and his right eye could have been lost
due to myopia or it could have been the
karate kick and the cataract that ensued
32 | Optician | 15.10.10
Figure 5
OCT scan of
macular
area
would have been traumatic. The left eye
cataract was in the early stages so no
intervention was necessary. The patient
was coping well with his high myopic
correction and without for reading. His
optic disc cupping was suspect so it was
suggested that he had visual field test
and nerve fibre analysis to eliminate
glaucoma. The epiretinal membrane
was light and there were no reasons to
expect problems in the future.
Discussion
The hyaloid artery is a branch of the
ophthalmic artery which extends from
the optic disc through the vitreous
humour and to the lens at the front.
This artery supplies nutrients to the
lens in the growing foetus. In the 10th
week of embryological development
the lens starts to grow independently
and the hyaloid artery regresses
while its proximal portion remains as
the central artery of the retina. The
regression of the hyaloid artery creates
a clear zone through the vitreous called
the Cloquet’s or hyaloid canal. In some
patients the hyaloid artery may not
regress fully and the remnant is called
persistent hyaloid artery.
The anterior hyaloid membrane seen
is a layer of collagen separating the
anterior vitreous from the crystalline
lens. The posterior hyaloid membrane
separates the retina from the vitreous.
Hence the hyaloid membrane is a
Figure 6 Hyaloid membrane detachment
thin, delicate coat that runs from the
pars plana to the posterior surface
of the crystalline lens. The posterior
hyaloid membrane is close to the inner
limiting membrane of the retina and
it is common to see posterior hyaloid
membrane detachment occurring
with a ring of Weiss representing
full posterior vitreous detachment
or peri-foveal vitreous detachment
(Figure 6 shows a hyaloid membrane
detachment – author has named this as
a pseudo operculum).
Useful reading
1 Andres B, Jean-Marie Parel, Fabrice
Manns. Evidence for posterior zonular
fiber attachment on the anterior hyaloid
membrane. Investigative Ophthalmology
and Visual Science 2006, 47, 4708-4713.
2 Foos RY. Posterior vitreous detachment.
Trans Am Acad Ophthalmol Otolaryngol
1972; 76: 480.
3 Heegaard S. Structure of the human
vitreoretinal border region. Ophthalmolgica
1994; 208: 82-91.
4 Snead MP, Snead DRJ, Mahmood A, Scott
JD. Vitreous detachment and the posterior
hyaloid membrane: a clinicopathological
study. Eye, 1994; 8: 204-209.
5 Streeten BW. The zonular insertion; a
scanning electron microscopic study. Invest
Ophthalmol Vis Sci, 1977;16:364–375.
● Kirit Patel practises in Radlett, Herts
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