Background and Purpose-Chronic ocular ischemia is a rare form of ischemia of the eye in patients with carotid artery occlusion (CAO). The early and often asymptomatic stage of chronic ocular ischemia is referred to as venous stasis retinopathy (VSR). The aim of this study was to gain insight into the prevalence, cause, and outcome of VSR in patients with symptomatic CAO. Methods-In 110 patients with symptomatic CAO, we prospectively investigated the frequency of VSR, the association between the presence of VSR and impaired cerebral blood flow, and the proportion of patients who developed clinically manifest chronic ocular ischemia with ischemia of the anterior eye segment or blindness. Results-At study entry, VSR was found in 32 patients (29%; 95% CI, 21 to 38), particularly in those with symptoms classically associated with a hemodynamic cause, such as limb shaking (relative risk, 2.4; 95% CI, 1.0 to 5.9). Patients with VSR had lower pulsatility indexes in the ophthalmic artery in case of reversed flow, lower cerebral CO 2 reactivity, and lower cerebropetal blood flow than patients without VSR. On follow-up (mean, 29 months), clinically manifest chronic ocular ischemia developed in 4 patients (annual rate, 1.5%; 95% CI, 0.4 to 3.8); it tended to occur more often in patients in whom VSR was present at study entry (relative risk, 7.3; 95% CI, 0.8 to 68).
Conclusions-One
We retrospectively evaluated the factors which might have caused excessive corneal astigmatism after penetrating keratoplasty (PKP) in 29 eyes, in which surgical correction of astigmatism was indicated. In 18 eyes high astigmatism (5 diopters or more) existed before suture removal probably due to graft elevation (3x), wound dehiscence (3x), wound configuration abnormalities such as ovality/overcut (8x), and a thin recipient cornea (2x). The cause was unknown in 2 eyes. In 19 eyes the astigmatism considerably increased after all sutures were removed; astigmatism increased an average of 8.8 diopters (range, 5 to 16.5 D). Ten of these 19 patients showed graft elevation, despite the fact that the sutures were only removed after an average 22.9 months. In 3 other patients the astigmatism gradually increased over the years, long after suture removal; two of these showed graft elevation. The study demonstrates the possible instability of keratoplasty wounds, the change in astigmatism after suture removal, and the late apparently spontaneous changes in astigmatism after PKP in some eyes.
We retrospectively evaluated 41 corneal wedge resections, performed for the correction of high astigmatism in 40 patients who were spectacle and contact lens intolerant. Keratometric astigmatism decreased from an average of 11.7 diopters (range 5 to 22.5 D) preoperatively to 3.5 diopters (range 0 to 10 D) postoperatively, representing a mean reduction of 8.2 D (range 0 to 16.5), or 70%. The length of follow-up averaged 11 months. Twenty-five, 15 and 9 cases had a follow-up of at least 3, 5 and 10 years, respectively. In 16 cases the keratometry readings remained stable over the years. However, in 1 case of Fuchs' endothelial dystrophy (follow-up 13 years) and 5 cases of keratoconus (follow-up 3, 4, 12, 13 and 14 years) the astigmatism gradually increased during the various follow-up periods. In 3 other cases the astigmatism gradually decreased over the years. Corneal wedge resection is an effective technique for managing high corneal astigmatism. The results remain stable over the years except in some patients with keratoconus.
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