Page 113 - NAME OF CONDITION: REFRACTIVE ERRORS

increased injection. The upper lid becomes edematous and the cornea shows variable
degree of edema. The anterior chamber shows increased flare and cells, and hypopyon is

often present in the inferior angle. Fundus view is obscured by focal or diffuse vitritis which
manifests as a yellow glow. In more extreme cases the anterior chamber is filled with
exudates and the cornea is white. If the infection has spread to orbit, restriction of
extraocular motility and proptosis may occur.

b)Investigations:
i) When measuring visual acuity, the technique of differentiating light perception from
hand motions vision is most important, since this is a major factor in determining
candidates most likely to benefit from vitrectomy in postoperative endophthalmitis.

Hand motions vision should be determined no closer than 2 feet from the patient with
light illumination originating from behind the patient.
ii) A diligent clinical examination with slit lamp biomicroscopy should be done to look for
certain risk factors which influence the management. These include wound leak or
dehiscence, suture abscess and vitreous incarceration in the wound in postoperative
endophthalmitis. Additionally, presence of intraocular foreign body and lens disruption
should be recognized in post-trauma endophthalmitis.
iii) Ultrasound evaluation of the globe should be performed if significant media
opacification prevents an adequate view of the fundus. Findings consistent with
endophthalmitis include dispersed vitreous opacities from associated vitritis and in
advanced cases, chorioretinal thickening. The ultrasound examination should rule out

associated retinal or choroidal detachment, dislocated lens material, or intraocular
foreign bodies.
iv) Ocular samples should be obtained for microbial identification. As there are no
significant differences in yield of positive cultures among the needle tap, vitreous
biopsy, or pars plana vitrectomy techniques, the surgeon may decide the best possible
sampling method based on the resources available. Retrobulbar anesthesia may be
necessary but must be administered cautiously in the presence of recent ocular
surgical wound or open globe injury. The eye is surgically prepared with povidone

iodine 5% solution and rinsed thoroughly with sterile balanced salt solution or normal
saline to remove residual antiseptic from the ocular surface. A surgical drape, lid
speculum and operating microscope may be used. A 30 gauge needle attached to a
tuberculin syringe is inserted through the limbus into the anterior chamber and an
aqueous specimen is aspirated without collapsing the anterior chamber. A quantity of
approximately 0.1ml can usually be obtained. A vitreous specimen may be obtained
either by vitreous needle tap or by vitreous biopsy with a vitreous cutter. After
conjunctival incision, a vitrectomy probe attached to a tuberculin syringe is inserted
into the vitreous cavity through a sclerotomy incision placed 3mm posterior to the

limbus. Approximately 0.1-0.3ml of vitreous is removed from the anterior vitreous

cavity by using the automated cutting mechanism of the probe and slow, manual
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