The Role of Serum Calcium in the Development of the Acute Red Eye in Chronic Renal Failure

In patients with chronic renal failure treated by long-term dialysis, inflammatory reactions occasionally develop in the bulbar conjunctiva; the episcleral tissue is only rarely involved. Diffuse congestion of both the conjunctiva and episclera was present in 5.3% of our patients and was associated with a sudden, marked rise in serum calcium. Histopathological examination suggests that this form of hyperemia, clinically preceded by a marked shedding of calcific precipitates, is the result of a neurogenic-driven inflammatory reaction in which mast cell degranulation is mediated by the axon reflex. Focal hyperemia associated with elastosis ("pingueculitis") was present in 6.7% of the patients. This type of hyperemia was observed after an extended period of increasing levels of BUN and seemed independent of both serum calcium and phosphorus. Diffuse hyperemia of the conjunctiva, being clinically distinctly different from the combined diffuse conjunctival and episcleral hyperemia, was also observed in 6.7%. Diffuse conjunctival hyperemia seemed to be associated with low BUN. Here, again, there was no association with serum calcium and phosphorus levels.

Sclerochoroidal calcification: clinical manifestations and systemic associations

BACKGROUND

Sclerochoroidal calcification is an unusual ocular condition that is believed to be idiopathic in most cases.

OBJECTIVES

To describe the clinical manifestations of sclerochoroidal calcification and to investigate its possible systemic associations.

METHODS

This noncomparative consecutive case series included patients diagnosed as having sclerochoroidal calcification based on clinical characteristics and diagnostic test findings. We analyzed the demographic, systemic, and ocular features of 27 such patients. Systemic evaluation included tests for calcium-phosphorus metabolism in 19 patients and renal tubular hypokalemic metabolic alkalosis syndromes (Bartter or Gitelman syndrome) in 13.

RESULTS

All the patients were asymptomatic older (mean age, 70 years) white individuals, incidentally noted as having a choroidal lesion on routine examination. Among 38 eyes, the main referral diagnoses were choroidal metastasis in 10 eyes (26%), choroidal melanoma in 8 (21%), and choroidal nevus in 4 (11%). Sixteen patients (59%) had unilateral clinical findings, while 11 (41%) had bilateral. The Snellen visual acuity was 20/50 or better in 37 eyes (97%). Cogan scleral plaque was visible anterior to the insertion of horizontal rectus muscles in 10 eyes (26%). Among 77 foci, there were a mean of 2 foci of sclerochoroidal calcification in each eye, 41 yellow (53%), 32 yellow-white (42%), 2 white (3%), and 2 orange (3%), measuring a mean 2.6 mm in diameter and 1.1 mm in thickness. The most common locations were postequatorial in 45 (58%), along the temporal vascular arcades in 30 (39%), and in the superotemporal quadrant in 43 (56%). A-scan and B-scan ultrasonography revealed dense echoes compatible with calcium, with orbital shadowing. All the lesions remained stable in size and configuration during a mean follow-up of 38 months. One patient developed a choroidal neovascular membrane over the area of sclerochoroidal calcification. Investigations for abnormal calcium-phosphorus metabolism in 19 patients revealed primary hyperparathyroidism in 1 patient (5%). Clinical and biochemical evaluation of 13 patients demonstrated hypomagnesemia in 6 (46%). Four patients (31%) met the criteria for the diagnosis of Gitelman syndrome.

CONCLUSIONS

Sclerochoroidal calcification usually manifests as multiple discrete yellow placoid lesions in the midperipheral fundus of asymptomatic older white individuals. Although most cases may be idiopathic in nature, some patients may have underlying systemic disorders involving abnormal calcium-phosphorus metabolism or renal tubular hypokalemic metabolic alkalosis syndromes. All patients with sclerochoroidal calcification should be tested for these treatable systemic associations.

Diffuse and focal hyperaemia of the outer eye in patients with chronic renal failure

In 8 of 57 patients with chronic renal failure that all had deposition of calcium salts in the limboconjunctival area, a focal hyperaemia of the conjunctiva was observed. This focal hyperaemia developed gradually around one or more greyish, slightly elevated, areas situated in the bulbar conjunctiva in the interpalpebral fissure. Clinically these lesions are very much alike inflamed pingueculae. Three patients showed a diffuse inflammatory reaction of the eye that was characterized by a waxy red episcleral and conjunctival hyperaemia extending beyond the palpebral fissure. The average value of the serum calcium concentration in these patients was particularly high and statistically significantly higher than in patients with calcification but without inflammatory signs and also higher than in patients that showed focal hyperaemia. In addition to the focal hyperaemia and the diffuse hyperaemia, we observed another diffuse hyperaemia located principally in the conjunctival tissue. This conjunctival redness often followed the focal hyperaemia associated with pingueculae or preceded the more acute fiery red episcleral hyperaemia, but it could also be present in isolation.