Download cme_issue 17_shorten - Singapore National Eye Centre

A PUBLICATION OF
SINGAPORE NATIONAL EYE CENTRE
AUGUST 2010 EDITION
EDITORIAL MESSAGE
02
EDITORIAL TEAM
03
04
RIBOFLAVIN-UVA INDUCED COLLAGEN CROSS-LINKING
TREATMENT FOR KERATOCONUS AND CORNEAL
ECTASIA
FINDINGS FROM THE STARS STUDY : STRABISMUS,
AMBLYOPIA, AND REFRACTIVE ERROR IN SINGAPORE
CHILDREN AGED 6-72 MONTHS OLD
06
EYELID MALPOSITIONS
10
ANSWERS TO PHOTOQUIZ 16
14
QUESTION TO PHOTOQUIZ 17
15
Created in September 2010
Editorial Message (Dr Aliza Jap)
A 37 female Chinese National arrived in Singapore 6 months ago with her son who is studying
in a local school. She came to see me with a complaint of having a sensation that her visual field
was getting smaller in both eyes over the past month. She felt that her superior fields were
shrinking. She had no medical history of note and there was no history of trauma. She was
seeing 6/6 in both eyes. Her intraocular pressures were normal. There was no RAPD. Her ocular
examination was normal with pink healthy discs and the retina was also normal in both eyes. Her
colour vision was normal. Confrontation fields though did suggest bilateral superior field loss
and and this was confirmed on Humphrey field testing. She elected to return to China for
neuroimaging due to cost considerations. However her VDRL and TPA were positive.
Subsequently an 18 year old boy came with a complaint of noticing an inferior field defect in the
right eye for about one month. Again there was no trauma. He did not have any pain on eye
movements , preceding flu or any medical history of note. He didn’t think the field defect had
increased in size over the past one month. He was seeing 6/6 in both eyes. There was no RAPD
and his ocular examination including intraocular pressures, fundal examination, colour vision
and confrontation fields were normal. However in view of his very specific compliants
Humphrey fields were performed and this confirmed the presence of a inferior arcuate field
defect in the right eye. MRI of the anterior visual pathways showed a sellar mass possibly a
craniopharyngioma.
I wonder how many of my other less articulate patients who came with non specific blurring of
vision, but were refracted to 6/6 and had normal ocular examinations had in fact also
neurological abnormalities? Especially if they were young, and may possibly have other issues in
their life to account for their symptoms such as stress or pre-enlistment anxiety? And I just sent
them away with a prescription for artificial tears?
It gets even more scary when you consider that the communication gap between health care
providers and patients can only grow wider and that patient expectations are also increasing. I
wonder if we will come to the point where we MRI all our patients as they register?
| 02
EDITORIAL TEAM
Editor-in-Chief
Dr Ian Yeo
Head, Training and Education
Senior Consultant, Vitreo-Retinal Service, SNEC
Editorial Board
Dr Aliza Jap
Head and Senior Consultant, CGH Eye Service
Assoc Prof Seah Lay Leng
Senior Consultant, Oculoplastic Service
Dr Daniel Su
Consultant, Glaucoma Service, SNEC
Dr Loh Boon Kwang
Associate Consultant, Vitreo-Retinal Service, SNEC
Ms Chia Hui Yien
Secretariat
Ms Daphne Khoo
Creative Designer, Corporate Communications
| 03
Riboflavin-UVA Induced Collagen Cross-linking Treatment for
Keratoconus and Corneal Ectaisa
Presented by Dr Lim Li on 18 November 2009
Written by Dr Laurence Lim
Keratoconus is a bilateral, progressive non-inflammatory corneal ectasia in which the cornea
assumes a conical shape due to central thinning of the corneal stroma. The estimated incidence
amongst Western populations is 1 in 2000, with a higher incidence rate in South Asians of up to
1 in 600 to 1 in 420. The condition is typically seen in young, economically active subjects. Visual
rehabilitation in the early, less severe stages of the disease can usually be effected with
non-invasive modalities like spectacles and rigid contact lenses, but surgery is ultimately
required in approximately 20% of subjects at some point in the course of the disease. Although
surgery in the form of lamellar or penetrating keratoplasty is usually associated with good
outcomes, it is not without its complications and inconveniences.
Riboflavin-ultraviolet-A (UVA) corneal collagen cross-linking (CXL) is a new technique that aims
to arrest keratoconus progression, thereby obviating or delaying the need for surgery. Topically
applied riboflavin is adsorbed to corneal stromal collagen fibres and activated by UVA light, with
the formation of cross-links between collagen fibrils that confer greater corneal rigidity, and
increased resistance to digestion by proteolytic enzymes like collagenase.
The procedure is currently performed for cases with definite keratoconus progression, contact
lens intolerance, good visual potential, and a minimum corneal thickness of 400 m. The last
criterion is required to avoid endothelial toxicity from UVA irradiation, as the corneal stroma acts
to shield the endothelium from UVA light. Subjects are asked to discontinue contact lens wear
3 days before surgery and to discontinue Vitamin C supplements 1 week before surgery.
Pachymetry is performed to ensure a thickness >400 m before the epithelium is removed in
several areas within a central 8-9mm zone. Riboflavin/Dextran solution is instilled as a viscous
eyedrop every 2 minutes for 30 minutes, and corneal penetration is checked by noting
homogenous yellow fluorescence in the anterior chamber at a slit-lamp before proceeding.
UVA light is then focused on the cornea using the UV-X illumination system (IROC, Zurich,
Switzerland) for 30 minutes with continued instillation of riboflavin solution every 2 minutes.
Illumination intensity (3 mW/cm2) is checked with the included light meter prior to each
treatment. Post-operatively, all subjects receive a topical antibiotic-steroid combination and a
bandage contact lens.
To date, data on the clinical outcomes with the procedure have come from a number of small,
uncontrolled studies. In general, most studies have shown modest objective improvements in
refractive error (up to 1-2D reduction) and keratometry (up to 2-3D reduction). A pilot study on
30 subjects led by Dr Lim Li at SNEC has shown similar outcomes, with no changes in visual
acuity, keratometry or corneal thickness at 6 months. Corneal hysteresis, a new measure of
corneal biomechanics, was also found to be unchanged following the procedure.
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Riboflavin-UVA Induced Collagen Cross-linking Treatment for
Keratoconus and Corneal Ectaisa
Presented by Dr Lim Li on 18 November 2009
Written by Dr Laurence Lim
Confocal microscopy is an imaging modality that captures high resolution en-face images of the
cornea in-vivo. Evaluation of the cornea with confocal microscopy after CXL has demonstrated
more dramatic and definite changes. Changes that occur after CXL include increased density
and regularity of the epithelial mosaic, increased subepithelial nerve plexus density, increased
stromal reflectivity, hyperactivated hyperdense keratocyte nuclei (Figure 1, arrowhead) and
spindle-shaped hyper-reflective bands which presumably represent the ‘cross-links’ (Figure 1,
arrow).
Figure 1: Confocal microscopy of
the anterior corneal stroma after
CXL.
Figure 2: Deep stromal scar after CXL
Figure 2: Deep stromal scar after CXL
Initial clinical experience has suggested that the technique is safe. Stromal haze formation is the
most frequently reported complication. In most reports, haze following CXL is relatively mild
and transient, and usually occurs in eyes with advanced keratoconus. In our series at SNEC,
however, 2 of the 30 cases developed dense, deep stromal scars following CXL for relatively mild
keratoconus (Figure 2). Increased astigmatism was induced in one of these cases, although the
best corrected visual acuity was fortunately unaffected. Confocal microscopy in these cases
revealed an exaggerated fibrotic response with sheets of dense hyper-reflective tissue in the
mid- to deep stroma (Figure 3). Riboflavin-UVA exposure typically causes keratocyte apoptosis
in the early post-operative period, and we speculate that a sub-lethal effect in the deep stroma
where the UVA irradiation dose is lower may lead instead to fibroblastic transformation and an
aberrant scarring response. This would explain the delayed reaction seen, and, if proven to be
so with subsequent study, may suggest that longer or higher intensity UVA irradiation is
indicated.
Key Learning Points:
1)
2)
3)
Keratoconus is a progressive corneal ectasia.
CXL may prevent keratoconus progression in early keratoconus.
CXL is generally safe but may rarely be associated with stromal scarring.
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Findings from the STARS Study : Strabismus, Amblyopia, and
Refractive Error in Singapore children aged 6-72 months old
Presented by Dr Audrey Chia on 3 February 2010
Written by Dr Khor Wei Boon
Introduction
The STARS (Strabismus, Amblyopia, and Refractive Error in Singapore) study was a
cross-sectional population study looking at the prevalence of strabismus, amblyopia and
refractive error in young Chinese pre-school children1, 2. The study design was similar to the
Multiethnic Pediatric Eye Disease Study (MEPEDS)3 and the Baltimore Pediatric Eye Disease
Study (BPEDS)4, two large studies conducted in the United States, to allow for comparison with
the STARS findings.
Methods
The study recruited Chinese children aged between 6 to 72 months, living in Housing
Development Board estates in the South-West region of Singapore. Eligible children were
invited to attend two study centres (one at the Singapore National Eye Centre, and the other at
the Jurong Medical Centre) with written consent from parents or guardians to participate in the
study. Children included in the study underwent the following tests:
Visual acuity (VA), with or without glasses
Stereoacuity tests in children aged 30 to 72 months
Orthoptic assessment
Anterior and posterior segment exam
Cycloplegic autorefraction with a table-mounted autorefractor if possible or
handheld autorefractor or streak retinoscopy
Biometry
Parents of these children were also asked to complete a detailed questionnaire on demographic
details, pre-natal / peri-natal / postnatal history, as well as details on relevant family history.
Results
Of the 4126 eligible children, a total of 3009 children were examined (participation rate, 72.3%).
There were no significant differences between participants and non-participants in terms of age
or gender, although participants tended to stay closer to the study centres. There was also a
slightly lower representation of children whose parents were from the lower education and
income groups compared to the national average.
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Findings from the STARS Study : Strabismus, Amblyopia, and
Refractive Error in Singapore children aged 6-72 months old
Presented by Dr Audrey Chia on 3 Feb 2010
Written by Dr Khor Wei Boon
Refractive Error
In all, 2639 children (88%) had cycloplegic refraction, while 370 had non-cycloplegic refraction;
the mean spherical equivalence was lower in the non-cycloplegic refraction (P<0.001).
Conventionally, it is believed that children are more hyperopic at birth, and become more
myopic with age. However, the STARS data revealed that there were more myopic children in the
<36 months age group as compared to those children in the >36months age group; this finding
was present even if only those children with cycloplegic refraction (n=2639) were analysed. In
these 2639 cyclopleged children, the prevalence of myopia <-0.5D was 7.5%, prevalence of
myopia < -2D was 1.1%, and the prevalence of hyperopia > +2 was 6.0%.
Another surprising finding was that the prevalence of astigmatism appeared to higher in older
children. For example, the prevalence of astigmatism (at least -1.5D) in the children aged 60 to
72 months was 11.3%, compared with only 3.6% in the children aged 12 to 23.9 months. In those
aged above 36 months, the overall prevalence of astigmatism > -1.5D was 9.7%, and of
astigmatism > -2D was 3.2%. This is contrary to the belief that astigmatism is high in infancy and
decreases and stabilizes with age.
The number of children with anisometropia was small, with rates of anisometropia >1D being
only 2% in children aged between 36 and 72 months.
Potentially amblyogenic refractive errors were seen in 131 children (4.3%), and included myopia
< -6D (n=9), hyperopic > +4D (n=16), astigmatism > -2.5D (n=96) and anisometropia >1.5D
(n=26). However, the prevalence of amblyopia was found to be much lower than these refractive
errors would suggest.
Amblyopia
In adults, a generally accepted definition for amblyopia is that of a 2-line difference in vision
between the two eyes, with vision worse than 6/12 in the eye with poorer vision, in the absence
of any organic cause for the poor vision. However, there is no universally accepted definition for
amblyopia in small children, especially given the difficulties with VA testing in pre-school
children. With these considerations in mind, only children aged between 30 to 72 months
(n=2015) were assessed for amblyopia in this STARS study. Even so, 333 (16.5%) were excluded
because they could not complete the vision testing, and this ranged from 67% in children aged
30-35 months, to only 1% in those aged 60-72 months old.
The definition of amblyopia used in the study was based on the MEPEDS definition for unilateral
and bilateral amblyopia, which in general consisted of a visual acuity cutoff, and supporting past
or present amblyogenic factor such as strabismus, refractive error, or some obstruction of the
visual axis.
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Findings from the STARS Study : Strabismus, Amblyopia, and
Refractive Error in Singapore children aged 6-72 months old
Presented by Dr Audrey Chia on 3 February 2010
Written by Dr Khor Wei Boon
Unilateral amblyopia was defined, as a 2-line difference in best VA, when <20/30 (logMAR 0.18)
in the worse eye, and with amblyogenic factors such as past or present strabismus,
anisometropia (>1.00 D difference in hyperopia, >3.00 D difference in myopia, or >1.50 D
difference in astigmatism), and past or present obstruction of the visual axis.
Bilateral amblyopia was defined as best VA in both eyes of <20/40 (logMAR 0.3) in children aged
48 to 72 months or <20/50 (logMAR 0.4) in children aged <48 months, in the presence of
amblyogenic factors such as hyperopia > 4 D, myopia > -6.00 D, or astigmatism > 2.50 D, or past
or present obstruction of the visual axis.
In all, 48 children (2.8%) met the VA criteria for amblyopia, but 28 were not considered to have
amblyopia because of the lack of amblyogenic risk factors; 19 (67%) had minimal refractive error
and no past/present strabismus of visual obstruction and 9 children missed refractive error
cutoffs by small margins.
Only 20 children satisfied all the requirements, so that the amblyopia prevalence rate amongst
Singaporean Chinese children aged 30-72 months was 1.15% (95%CI 1.21-1.25). Compared with
children in the MEPEDS and BPEDS, this prevalence was less than that for Hispanic/Latino
(2.6%,95%CI,1.8–3.4) but similar to that found in White (1.8%, 95% CI, 0.9–3.1) and
African-American (0.8%, 95% CI, 0.3–1.6, in the MEPEDS, and 1.5%, 95% CI, 0.9–2.1, in the BPEDS)
children.
Although we found the prevalence of amblyopia to be much lower than the 3% that is usually
quoted in other studies, this may be due in part to the much stricter criteria used in the MEPEDS
study. Using the more liberal definitions suggested by the American Association of Pediatric
Ophthalmology and Strabismus (AAPOS)5, our amblyopia prevalence would increase
dramatically to 3.27%.
Strabismus
Strabismus was much easier to ascertain in the children of the STARS study, and orthoptic
assessment was only not possible in 17 children.
Strabismus was defined as any manifest tropia, and this was found in 24 children, giving an
overall prevalence in children aged 6 – 72 months of 0.80% (95%CI 0.51-1.19).
The ratio between exotropias (XT) and esotropias (ET) was 7:1; there were 12 intermittant XT, 7
constant XT, 3 constant ET, and one patient with a dissociated vertical deviation. The prevalence
of strabismus was much lower than those found in the other racial groups (whites, blacks and
Hispanics/latinos) of the MEPEDS and BPEDS studies, but closer to reports on strabismus in
China and Japan.
| 08
Findings from the STARS Study : Strabismus, Amblyopia, and
Refractive Error in Singapore children aged 6-72 months old
Presented by Dr Audrey Chia on 3 February 2010
Written by Dr Khor Wei Boon
Conclusion
In summary, the findings of the STARS study suggest that in young Singaporean
Chinese children:
-
Children younger than 36 months may be more myopic and less astigmatic
than previously believed.
-
Amblyopia prevalence was low (1.2%) and more likely associated with
refractive error unlike in the West where strabismus was a more significant
associative factor.
-
Strabismus prevalence of esotropia was very low (0.1%), but the prevalence
of XT (0.7%) was also much lower compared with US-based studies.
References
1. Dirani M, Chan YH, Gazzard G et al. Prevalence of refractive error in Singaporean Chinese
children: the strabismus, amblyopia, and refractive error in young Singaporean Children
(STARS) study. Invest Ophthalmol Vis Sci; 51(3): 1348-1355.
2. Chia A, Dirani M, Chan YH et al. Prevalence of amblyopia and strabismus in young
singaporean chinese children. Invest Ophthalmol Vis Sci; 51(7): 3411-3417.
3. Varma R, Deneen J, Cotter S et al. The multi-ethnic pediatric eye disease study: design and
methods. Ophthalmic Epidemiol 2006; 13(4): 253-262.
4. Friedman DS, Repka MX, Katz J et al. Prevalence of decreased visual acuity among
preschool-aged children in an American urban population: the Baltimore Pediatric Eye
Disease Study, methods, and results. Ophthalmology 2008; 115(10): 1786-1795, 1795
e1781-1784.
5. Eye examination and vision screening in infants, children, and young adults. American
Academy of Pediatrics Committee on Practice and Ambulatory Medicine, Section on
Ophthalmology. Pediatrics 1996; 98(1): 153-157.
| 09
Eyelid Malpositions
Presented by Dr Audrey Looi on 7 April 2010
Written by Dr Livia Teo
There are 2 main malpositions of the eyelid: entropion and ectropion.
ENTROPION
Entropion refers to the inward rotation of the lid margin towards the globe. Differential
diagnosis include epiblepharon, lid retraction e.g. in Grave’s disease, trichiasis and dystichiasis.
In all the differentials, the lid margin position is always normal.
Epiblepharon is a congenital lid anomaly whereby a fold of skin and orbicularis muscle
over-rides the lid margin and pushes the lashes against the eye.
In lid retraction, there is a relative posterior lamellar shortening resulting in malrotation of the
lashes inwards in a pseudoepiblepharon manner.
Trichiasis and dystichiasis refer to the misdirection or aberrant posterior lashes against the
globe.
Causes of entropion can be divided into
1) Congenital causes (e.g. tarsal kink syndrome) or
2) Acquired causes
a) Involutional
b) Cicatricial
c) Spastic
Congenital entropion is rare and it usually involves both lower lids. It is usually due to a
maldeveloped distal lower lid retractor with dehiscence near the tarsal plate, hypertrophy of the
marginal orbicularis or levator disinsertion in the upper lid. Lower lid entropion repair involves
excision of the excess skin and orbicularis (3-6mm), lower lid retractor repair and excision of
tarsal kink if present.
Acquired causes
Involution entropion is the commonest cause of acquired entropion locally. The mechanisms of
this include vertical lid laxity (lid retractor dehiscence), horizontal lid laxity (medial and lateral
canthal tendon laxity) overriding of the preseptal orbicularis over the pretarsal orbicularis, tarsal
plate atrophy and enophthalmos (orbital fat atrophy). Management includes temporizing
measures such as lid taping, lubricants, bandage contact lens, or everting sutures. Everting
sutures can be done using a double-armed 6/0 vicryl suture passed from the inferior
conjunctival fornix to the skin just below the lid margin. The aim is to shorten the lower lid
retractors and transfer their pull to the upper border of the tarsal plate. Surgical repair would
include lower lid retractor repair and horizontal lid tightening with a wedge resection or a lateral
tarsal strip procedure.
| 10
Answers to PhotoQuiz 16
| 14
Fig 1. Left optic disc pit with
neurosensory detachment over
macula
Fig 2. Neurosensory
detachment of macula
with intra-retinal schisis
Congenital optic disc pits have a rare occurrence of 1 in 11000 patients and is bilateral in 10-15%
of cases. The affected disc is larger than the fellow eye. There is a 25% to 75% lifelong risk of
developing serous macular detachments. The occurrence of macular detachment is most
common between the ages of 20 and 40. Fenestrations in the diaphanous tissue overlying the
optic pit has been documented. Traction from surrounding attached vitreous allows fluid to enter
the intra and subretinal space via these fenestrations. Schisis-like separation of the inner retinal
layers is thought to be the primary pathology with secondary development of neurosensory
detachment after formation of the schisis cavity. The extent of detachment may be limited by the
small amount of liquefied vitreous in these young patients. There is spontaneous resolution of the
serous detachment in up to 25% of patients. Final vision of 6/60 or worse has been reported in 80%
of patients over a 9-year follow up period. These patients can be observed if vision is reasonably
good with no significant progression. In patients who progress, vitrectomy with complete surgical
posterior vitreous detachment and gas tamponade achieves relief of vitreous traction on the small
fenestrations overlying the pit and is associated with reasonably good anatomical and functional
outcomes. Macular scleral buckling has also been tried. Other novel treatment options include
vitrectomy with partial thickness fenetration of the retina immediately temporal to the pit as well
as the use of autologous platelets as an adjunct to vitrectomy.
Eyelid Malpositions
Presented by Dr Audrey Looi on 7 April 2010
Written by Dr Livia Teo
Mechanical ectropion requires excision of the causative lesion with care being taken to create as
vertical a wound as possible so as to avoid subsequent cicatricial ectropion. Any horizontal lid
laxity can also be addressed at the same time.
Surgical correction in paralytic ectropion also involves the lateral tarsal strip procedure and Tse
procedure +/- lower lid lengthening with auricular cartilage. Medial canthoplasty may be
necessary as well. If lagophthalmos is a feature, lateral tarsorraphy or a gold weight implant
procedure may be performed to reduce exposure keratopathy.
EPIBLEPHARON
Epiblepharon is a congenital anomaly due to a redundant horizontal skin- muscle fold that
results in vertical orientation of the cilia. It is more commonly seen in the oriental population.
The patient may present with chronic eye irritation, redness, tearing, mucoid discharge,
frequent eye rubbing and blepharospasm. In the lower lid, this can be due to a congenital
absence of retractor insertion into the skin and orbicularis or it can be due to insertion of the
retractor being too near to the lid margin. Failure of the retractor muscle to bind skin and
pretarsal orbicularis to the tarsal plate results in the horizontal skin- muscle fold seen clinically.
However, retractor insertion onto the tarsal plate is intact. In the upper eyelid, a lower insertion
of the levator aponeurosis to the anterior surface of the tarsal plate and deficiency of the fibres
to skin and pretarsal orbicularis allows relative overriding of the latter over the lid margin. It
usually resolves by the age of 3 years and can be managed initially with lubricants. Surgery can
be performed for persistent cases.
Methods of repair for the lower lid include the Hotz procedure, Quickert suture or anterior
lamellar reduction and repositioning (Choo). Quickert suture involves passing a 4/0 chromic
catgut suture through the full thickness of the lid just below the tarsus and tying it firmly on the
skin. This creates a tissue adhesion between the anterior and posterior lamellar and reinforces
the action of the retractors on the anterior lamella. Choo’s anterior lamellar reduction and
repositioning includes the excision of excess skin and pretarsal orbicularis with placement of
buried 7/0 vicryl sutures to reposition the anterior lamella. The skin incision is made 2-3 mm
below the lower lid margin and a greater amount of skin is excised on the nasal half of the lower
lid. The aim of this procedure is to debulk the pretarsal orbicularis. A similar approach can be
taken for the upper lid.
| 12
Eyelid Malpositions
Presented by Dr Audrey Looi on 7 April 2010
Written by Dr Livia Teo
Key Learning Points:
1. Entropion refers to the inward rotation of the lid margin towards the globe. Its
causes can be divided as follows:
-
Congenital
Acquired
Involutional
Cicatricial
Spastic
2. Ectropion is the outward rotation of the eyelid margin. Its causes can be divided
as follows:
-
Congenital causes (e.g. blepharophimosis syndrome)
Acquired causes
Involutional
Cicatricial (burns)
Mechanical
Paralytic (e.g. 7th nerve palsy)
3. Management of both conditions includes identification and treatment of the
underlying cause and mechanism as well as ensuring protection of the cornea.
This can include temporizing measures such lid taping, lubricants, bandage
contact lens, botox injections or everting sutures while more definitive
management will require surgical intervention.
| 13
Answers to PhotoQuiz 16
| 14
Fig 1. Left optic disc pit with
neurosensory detachment over
macula
Fig 2. Neurosensory
detachment of macula
with intra-retinal schisis
Congenital optic disc pits have a rare occurrence of 1 in 11000 patients and is bilateral in 10-15%
of cases. The affected disc is larger than the fellow eye. There is a 25% to 75% lifelong risk of
developing serous macular detachments. The occurrence of macular detachment is most
common between the ages of 20 and 40. Fenestrations in the diaphanous tissue overlying the
optic pit has been documented. Traction from surrounding attached vitreous allows fluid to enter
the intra and subretinal space via these fenestrations. Schisis-like separation of the inner retinal
layers is thought to be the primary pathology with secondary development of neurosensory
detachment after formation of the schisis cavity. The extent of detachment may be limited by the
small amount of liquefied vitreous in these young patients. There is spontaneous resolution of the
serous detachment in up to 25% of patients. Final vision of 6/60 or worse has been reported in 80%
of patients over a 9-year follow up period. These patients can be observed if vision is reasonably
good with no significant progression. In patients who progress, vitrectomy with complete surgical
posterior vitreous detachment and gas tamponade achieves relief of vitreous traction on the small
fenestrations overlying the pit and is associated with reasonably good anatomical and functional
outcomes. Macular scleral buckling has also been tried. Other novel treatment options include
vitrectomy with partial thickness fenetration of the retina immediately temporal to the pit as well
as the use of autologous platelets as an adjunct to vitrectomy.
Question to PhotoQuiz 17
Figure 1
| 15
Figure 2
A 45-year-old gentleman, with a known history of high hypermetropia of 17
dioptres spherical equivalent, presented with a decrease in his right visual
acuity for 5 months. The Snellen visual acuity for right and left eye were 6/120
and 6/21 respectively. Fundus photography (Figure 1) and fluorescein
angiography (Figure 2) of the right eye were done.
What is the diagnosis?