Inflammation of the iris – iritis, also referred to as anterior uveitis, can be associated with a number of systemic conditions, the most common being the sero-negative spondyloarthropathies. In uveitis, the signs include ciliary injection, anterior chamber cells, keratitic precipitates on the posterior surface of cornea, and posterior synechiae (adhesion between the lens and iris, Figure 1). A slit lamp is required to detect anterior chamber cells. But for posterior synechiae, it can often be detected by just using a torch.
Posterior synechiae refers to abnormal adhesions between the lens and iris. This sign can be detected without a slit lamp, whereas the hallmark of uveitis – the presence of cells in the anterior chamber – requires a slit lamp.
When there is a severe anterior chamber reaction, hypopyon can be seen (Figure 2). When hypopyon is seen, endophthalmitis must be ruled out. Etiologies include post-intraocular surgery, trauma and endogenous causes.
This is a key feature of endophthalmitis and is an ophthalmic emergency. In this patient there is significant corneal injection, corneal oedema and also pus seen in the anterior chamber (hypopyon).
For endogenous endophthalmitis, it is classically associated with Klebsiella sepsis. The infection will progress rapidly, and aggressive systemic and intra-vitreal antibiotics are required to control the infection. Otherwise, the patient may need an evisceration (removal of all intraocular contents, only leaving a scleral shell) if the infection is uncontrolled.