Ciliary body enlargement and cyst formation in uveitis.

BACKGROUND: Acute anterior uveitis has diverse causes and systemic associations. Inflammation is predominantly localised to the iris and pars plicata. Little is known about the in vivo effects of uveitis on ciliary body anatomy. METHODS: Bilateral, high frequency, high resolution, ultrasound biomicroscopy was performed on consecutive patients with unilateral anterior uveitis to evaluate ciliary body anatomy. Imaging was repeated when possible during the clinical course. The cross sectional area of the anterior ciliary body was measured using image processing and analysis software. Measurements from the uveitic eyes were compared with the fellow eyes and the effect of treatment was evaluated. RESULTS: Fourteen patients were enrolled. Ultrasound biomicroscopy demonstrated a larger ciliary body cross sectional area in the uveitic eyes compared with the fellow, clinically uninvolved eyes (2.45 (SD 0.48) mm2 versus 1.55 (SD 0.15) mm2, (p = 0.0000; paired t test)). A ciliochoroidal effusion was present in one uveitic eye. Epithelial cysts were imaged bilaterally in four uveitic patients (29%) and unilaterally in unaffected eyes of two uveitic patients. Ciliary body cross sectional area decreased following steroid therapy (p = 0.0001; paired t test). New cysts were noted in three uveitic eyes during the follow up period and in none of the fellow, unaffected eyes. CONCLUSION: Ultrasound biomicroscopy offers a new approach to the evaluation of anterior uveitis. The response to treatment can be evaluated objectively and therapeutic efficacy can be more easily assessed. It has the potential to help elucidate the pathophysiology and anatomical changes of this heterogeneous group of disorders.

Alteration of human conjunctival epithelial proliferation.

We used in vitro bromodeoxyuridine to analyze the labeling indexes of conjunctival cells in several external eye diseases. Patients with superior limbic keratoconjunctivitis, squamous cell carcinoma of the conjunctiva, drug-induced pseudopemphigoid, and Stevens-Johnson syndrome had increased conjunctival DNA synthesis.

Varicella-zoster virus retinitis in patients with the acquired immunodeficiency syndrome.

We examined five patients infected with the human immunodeficiency virus who developed a rapidly progressive necrotizing retinitis characterized by early patchy choroidal and deep retinal lesions and late diffuse thickening of the retina. In all but one case, the retinitis began in the posterior pole with little or no clinical evidence of vasculitis. All five patients had relentless progression of disease and were left with atrophic and necrotic retinae, pale optic-nerve heads, and narrowed vasculature. None of the patients developed aqueous or vitreal inflammation or retinal detachment. Clinical and laboratory evidence suggested that varicella-zoster virus was the causal agent in all five cases. First, the onset of retinitis in four cases either succeeded or was coincident with an eruption of dermatomal zoster. Second, varicella-zoster virus was cultured from the two chorioretinal specimens and varicella-zoster virus antigen was detected in the vitreal aspirate from one case. Third, by means of immunocytochemistry, varicella-zoster virus antigen was found in the outer retinae of both enucleation specimens. Fourth, viral capsids with the size and shape of herpesviridae were found in the outer retinae of both enucleation specimens. The clinical features observed in this study are distinct from those described for the acute retinal necrosis syndrome and appear to constitute a new and highly characteristic pattern of varicella-zoster virus-induced disease.

Effects of topical timolol (0.5%) and betaxolol (0.5%) on corneal sensitivity.

There are conflicting reports on the propensity of topical beta blockers to produce corneal anaesthesia. We measured corneal sensitivity thresholds quantitatively for 10 minutes following the administration of one drop of topical timolol maleate (0.5%), betaxolol hydrochloride (0.5%), or saline in 30 eyes of 18 normal subjects in a randomised, double-masked study. Most subjects had insignificant changes in corneal sensitivity thresholds. We identified, however, a subgroup of four subjects (five eyes) that had a marked and prolonged increase of corneal sensitivity threshold (corneal anaesthesia) after timolol (three eyes) and betaxolol (two eyes). The group mean age of these 'responders' (49.0 years) was significantly greater (p less than 0.005) than that of the non-responders (35.0). We recommend periodic measurements of corneal sensitivity in older patients receiving topical timolol or betaxolol, especially when given in higher concentrations, to identify responders, who may be at risk of developing keratitis.

Role of peptidergic neurons in ocular herpes simplex infection in mice.

Peptide-containing nerve fibers (peptidergic fibers) abundantly innervate the mammalian cornea. We investigated their role in ocular herpes simplex infection in mice by using capsaicin, which causes degeneration and permanent loss of peptidergic neurons in neonates and temporary peptide depletion in adult animals. The corneas of neonatally denervated BALB/c mice were observed for capsaicin-induced keratitis at 11-14 wk of age and were then infected bilaterally with herpes simplex virus 1 (HSV-1); trigeminal (TG) ganglia were cocultivated 6 wk later to establish the rate of latent infection. We also applied capsaicin eye drops to adult BALB/c mice that had been infected with HSV-1 6 wk earlier, and measured viral shedding before, and 3 days and 2 months after, administration of capsaicin drops; TG ganglia of these animals were cocultivated at 3 days and 2 months after capsaicin application. Neurotrophic keratitis was found in 81% of neonatally denervated animals; mortality rate due to HSV-1 infection was reduced from 80% in the controls to 24% in the capsaicin-treated group, and recovery of latent virus by cocultivation was reduced by 50%. Viral shedding could not be produced by capsaicin eye drops in adult animals infected with HSV-1. However, recovery of latent virus was significantly reduced in TG ganglia sampled 3 days and 2 months after capsaicin drops were instilled. Our findings suggest 1) that peptidergic fibers play a crucial role in the establishment of trigeminal HSV-1 latency and 2) that reactivation of latently infected ganglia can be inhibited by topical capsaicin.

An experimental model of carotid artery occlusive disease.

To develop an animal model for acute carotid artery occlusion suitable for studying the retinal sequelae of this disease, we performed bilateral and unilateral common carotid artery ligations on mature pigmented rats. Bilateral ligation consistently resulted in a characteristic pathologic retinal appearance, paralleling the retinopathy of carotid artery occlusive disease in humans, demonstrated by fundus photography and fluorescein angiography. Any abnormalities found in the rats with unilateral ligations were inconsistent and less severe, although fluorescein angiography proved to be more sensitive than ophthalmoscopy for detecting these subtle changes. Pepsin-trypsin retinal digests disclosed extensive disruption of the microvasculature in the eyes of bilaterally ligated animals. This model should prove to be useful in examining the reversibility of the ocular findings as well as evaluating central nervous system abnormalities after carotid artery occlusion.

Experimental carotid occlusion: funduscopic and fluorescein angiographic findings.

A characteristic fundus picture was consistently produced following acute bilateral common carotid artery ligation in mature rats, reminiscent of human carotid occlusive disease. Two days after ligation it consisted of dilatation and tortuosity of retinal veins, blurring and swelling of the optic disc, retinal whitening primarily along the venous distribution, and straightening of retinal arteries. Fluorescein angiography showed hyperfluorescence of the disc, delay in the rate of retinal arterial and venous filling, venous dilatation, disc oedema, disruption of the retinal capillary bed pattern, and late peripapillary staining/leakage. This pattern was not seen in rats which underwent acute unilateral ligation, although some mild changes were seen on fluorescein angiography. The vascular alterations seemed to regress spontaneously within one week. A peripapillary 'halo' and a granular-appearing nerve fibre layer developed later, exclusively in bilaterally ligated animals.