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Sir,

Meningococcal meningitis is a medical emergency with numerous possible ophthalmic manifestations. We present an unusual story of unilateral visual loss associated with meningococcal meningitis.

Case report

An 18-year-old man presented with a 36 h history of headache, rigors, and malaise. There were signs of meningism and a widespread petechial rash. There was no focal neurological deficit. He was treated with intravenous cefotaxime (2 g q.i.d.). The cerebrospinal fluid showed a white cell count of 3680 per mm3 (90% polymorphonuclear leucocytes) with Gram-negative diplococci seen on microscopy. There was no bacterial growth on culture of the CSF; however, polymerase chain reaction confirmed the presence of Neisseria meningitides group B DNA.

He made a good recovery; however, on the 10th day following admission he complained of blurring of the vision of the right eye with a ‘ghost’ image and pain in the right ankle. The visual acuity was 6/60 on the right and 6/9 on the left. There was a mild cellular reaction in the right anterior chamber. Fundoscopy showed a focal pale yellow, raised chorioretinal lesion on the right macula just superotemporal to the fovea (Figure 1a). There was no clinical effusion in the right ankle and the range of movement appeared normal.

Figure 1
figure 1

(a) On presentation the right macula showed a raised pale yellow chorioretinal lesion. (b) After 18 months, the macula showed a poorly defined flat chorioretinal pigmentary disturbance.

Full size image

The vision in the right eye improved gradually with no further treatment. His Snellen's acuity on the right was 6/18- after 2 weeks and continued to improve to 6/9 at 6 months. He had mild metamorphopsia on Amsler's grid testing with a small positive scotoma inferonasal to fixation. At the latest review at 18 months, he was seeing 6/5 with a pinhole on the right eye and the scotoma was unchanged. The fundus shows distortion of the foveal reflex and a small, flat, poorly defined parafoveal chorioretinal pigmentary disturbance (Figure 1b).

Comment

Ophthalmic manifestations of meningococcal meningitis include ocular motility abnormalities due to third, fourth, and sixth nerve palsies and nystagmus. Raised intracranial pressure associated with meningitis may cause papilloedema and secondary optic atrophy. Optic neuritis and papillitis are potential causes of visual loss in patients with meningitis.1

Meningococcal septicaemia may result in vascular obstruction secondary to disseminated intravascular coagulation with ocular features including retinal haemorrhages and infarcts; iris infarction has also been described.2

Meningococcus normally causes systemic infection via the nasopharynx; however, the conjunctiva may provide an alternative sight of entry for the bacteria. A few reports of meningococcal conjunctivitis associated with meningitis have been described, predominantly in children.3, 4 Endogenous endophthalmitis is the most serious sight-threatening complication, although very rare, it is often bilateral.5

Our patient presented with an isolated chorioretinal focus of inflammation that caused symptoms due to the close proximity to the fovea. There was only a mild cellular reaction in the anterior chamber that did not cause any ocular discomfort. The inflammation could have resulted from metastatic spread of the organisms or possibly an immune-mediated hypersensitivity reaction.6

Evidence exists for the crossreactivity between antibodies to the polysaccharide capsule of group B meningococci and neural cells expressing embryonic neural cell adhesion molecules (N-CAM),7 and other human glycolipid/glycosphingolipid antgens.8 Immune complex depostition has been postulated as a cause of ‘allergic’ meningococcal arthritis.9

Features of the case report that supports an immune-mediated event include the timing of the presentation of visual loss following 10 days of intravenous cefotaxime and the simultaneous complaint of monoarticular arthralgia of the right ankle. Both the ankle and the visual complaint improved without further intravenous antibiotics. Alternatively, haematogenous spread of organisms already rendered sterile by the antibiotics may have caused a self-limiting focal chorioretinitis.

Although the exact pathogenesis is unclear, we believe this to be the first case of a focal chorioretinitis associated with meningococcal meningitis, illustrated with fundus photographs, in the English literature.