|
A 48 year-old man has had recurrent
attacks of painful right eye. The vision was 6/36 and there was
significant cataract. Previously, he required periocular steroid
injection to control the attacks. The eye was poorly dilated with
mydriatics.
a. What do the pictures show?
Posterior synechiae and granulomatous
keratic precipitates in the inferior cornea. The signs are features
of anterior uveitis.
b. Is it necessary to carry out
further investigations?
Large keratic precipitates in the
inferior cornea are suggestive of granulomatous uveitis. This
condition is associated with systemic conditions such as
tuberculosis, sarcoidosis, syphilis, toxoplasmosis and Vogt-Koyanagi-Harada
syndrome. Therefore, it is important to investigate the patient
further by detailed examination of the patient (looking for any
toxoplasmosis scar in the posterior segment, signs of Vogt-Koyanagi-Harada
syndrome such as vitiligo and white forelock), performing the
relevant blood tests (auto-immune screening, angiotensin converting
enzyme concentration and VDRL/TPHA) and chest X-ray (for bilateral
hilar lymphadenopathy in sarcoidosis and pulmonary tuberculosis)
c. How would you prepare the patient
for cataract surgery?
The control of inflammation prior to cataract surgery is
critical. Total control of active inflammation for at least 3 months
must be attempted and this is defined by the absence of any
inflammatory cells in the anterior chamber (aqueous flare is not a
reliable indicator of inflammation as it only indicates vascular
incompetence).
According to the Intraocular Inflammation Society (IOIS), uveitis
patients with cataract can be divided into two groups: complicated
cases and uncomplicated. Complicated patients are those that require
systemic or periocular therapy to keep the uveitis quiescent or
those in which the cataract surgery itself is expected to be
difficult. Uncomplicated patients are those in which the uveitis is
controlled with topical steroids and the operation is expected to be
straightforward.
Pre-operative management begins one week before the planned surgery.
In the complicated cases, the patient is given 1mg/kg/day of oral
prednisolone (as in this patient). In the uncomplicated cases, the
patient is given a topical corticosteroid (prednisolone acetate 1%
or dexamethasone alcohol 0.5%) one drop four times daily.
d. How would you approach the
cataract if you were to perform phacoemulsification on him?
Enlargement of the pupil aperture can be achieved by several
approaches which may be used in combination:
• Injection of viscoelastic throughout the circumference of the
pupillary margin. This is the simplest method but may not be
adequate if the pupil is too small.
• The pupillary sphincter can be stretched open using two
diametrically opposed instruments such as Sinskey hooks with
opposing vector forces at multiple locations around the pupillary
border.
• Creating multiple small sphincterotomy incisions at the pupillary
margin using a pair of Vannas scissors followed by stretching as
described above. Alternatively, a small pupil may be enlarged by
advancement of a surgical peripheral iridectomy to the pupillary
margin. After IOL insertion, the pupil can be reformed by closure of
the pupillary margin with a polypropylene suture (pupilloplasty).
• Using iris hooks or iris protector ring.
Reference:
Anterior Segment Intraocular Inflammation (Published in 2000).
International ocular inflammation Society (IOIS)
|
