Histopathological variation in keratoconus

During examination of 131 penetrating keratoplasty specimens from patients with keratoconus obtained in an 11-year period, we observed two histopathologic variants based on the appearance of Bowman\u27s layer and the corneal epithelium. Typical keratoconus specimens had multiple breaks in Bowman\u27s layer and central epithelial thinning, whereas atypical corneas lacked breaks in Bowman\u27s layer and had less thinning of the central epithelium. Ninety-five corneas were from patients who underwent grafting in only one eye. Seventy-six (80%) of these corneas were typical and 19 corneas (20%) were atypical in appearance. Both variants had similar degrees of central stromal thinning. Patients with typical and atypical corneas differed demographically by race only; 49% of typical and 95% of atypical corneas were from white individuals. Thirty-six corneas were from 18 patients who underwent bilateral penetrating keratoplasty. The histologic appearance of these corneal pairs was concordant in 13 patients and discordant (one typical and one atypical cornea) in five patients. Statistical analysis indicated that this distribution is not significantly different from that predicted by chance and suggests that typical and atypical corneas are manifestations of the same disease process

Corneal argyrosis associated with silver soldering.

We report a patient who developed corneal argyrosis secondary to occupational silver soldering. Clinically, the cornea was notable for a green-brown discoloration localized to Descemet\u27s membrane by slit-lamp biomicroscopy. Silver particles were identified within the anterior three eighths of Descemet\u27s membrane by light and electron microscopy and energy-dispersive x-ray microanalysis. To our knowledge, the association between corneal argyrosis and silver soldering has not been previously reported

The effect of angiostatic steroids and β-cyclodextrin tetradecasulfate on corneal neovascularization in the rat

Folkman and coworkers have described angiostatic steroids that markedly inhibit neovascularization of the rabbit cornea when given topically with β-cyclodextrin tetradecasulfate (β-CD), yet have minimal or no glucocorticoid or mineralocorticoid activity. Our objective was to extend these observations to another species, the rat. We induced neovascularization by cauterizing rat corneas with silver nitrate/potassium nitrate; drugs were applied topically four times per day for 4 days in most experiments. Submicron sized emulsions of lipid-soluble dexamethasone and the angiostatic steroids 17 α-hydroxyprogesterone (1 or 10 mg ml-1) and cortexolone (1 or 10 mg ml-1) were prepared by lecithin encapsulation of drug microcrystals. The vehicle for water-soluble hydrocortisone 21-phosphate (HCP)±β-CD (Molecusol; Pharmatec, Inc) was 10% Tween 20 in Tris-buffered 0·9% saline. Angiogenesis was significantly inhibited only by 1 mg ml-1 dexamethasone (-63·2% when compared with controls), 0·5 mg ml-1 HCP+1 mg ml-1 β-CD (-33·4%), and 1 mg ml-1 HCP (-40·2%). HCP (0·5 mg ml-1) or β-CD (1 or 2 mg ml-1) alone had no significant effect on neovascularization; the inhibition by 1·0 mg ml-1 HCP was not potentiated by 2 mg ml-1 β-CD. We also tested HCP and tetrahydro-S (TH-S) using 1·5% hydroxypropyl methylcellulose vehicle and β-CD from Takeda Chemical Industries. Ltd., to simulate the procedure of Folkman and coworkers. Neovascularization was inhibited by 0·5 mg ml-1 HCP (-45·1%), but this inhibition was not potentiated by 1 mg ml-1 β-CD. TH-S (1 mg ml-1) alone or combined with β-CD (0·5 mg ml-1) did not inhibit angiogenesis when applied for either 4 or 10 days. Our results suggest that inhibition of corneal neovascularization by angiostatic steroids is influenced by species and/or the angiogenic stimulus since we were unable to reproduce the beneficial effect reported for most of these compounds. However, the moderate inhibition of corneal neovascularization by HCP, which has only slight glucocorticoid activity when compared to dexamethasone, supports Folkman\u27s contention that angiostatic, glucocorticoid, and mineralocorticoid activities are separable

Calcific phacolysis

Background and Methods: The authors report the clinical and ocular histopathologic findings in three patients with longstanding unilateral post-traumatic blindness. After one or more decades, acute pain associated with conjunctival hyperemia and apparent keratoprecipitates or a hypopyon developed in the affected eye of each individual. Phacoanaphylaxis was diagnosed preoperatively in two patients. Results: Calcified granular lens fragments were dispersed throughout all three eyes. The anterior chamber in all patients contained extracellular calcified lens particles, but only one eye contained conspicuous macrophages. Two eyes showed elevated intraocular pressure (IOP), and in one patient calcified particles extended into a glaucomatous optic nerve head. Conclusion: To the authors\u27 knowledge, this is the first report describing a rare condition involving the intraocular dispersal of calcified lens particles after disruption of the lens capsule. The authors have designated this entity as calcific phacolysis