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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.

Background:The theoretical benefits of synthetic keratc,nhakia over conventional corneal lamellar proceciiires arc the elimination of donor concerns and superior rcfractive predictability. Additionally, synthetic material can be inspected for optical quality and power, and it can be sterilized. Furthermore, visual recovery should be more rapid since epithelium is not removed from the central part of the cornea and the need for keratocyte repopulation is eliminated.Bb$zctive: To present results on patients who received an intracorneal implant (Kerato-Gel, Allergan Medical Optics, Irvine, Calif) that was made from lidofilcon A, a glucose-permeable hydrogel with an equilibrium water content of 68%. Methods:The intracorneal implants were implanted in 35 adult patients for correction of aphakia. Inclusion cri-\c:-ia excluded patients with aphakia who were candidates for intraocular lenses.Results: A total of 19 patients were followed up through 2 years postoperatively. For 16 patients with 2-ye~r postoperative refractive data, the average spherical equivalent was -0.63?2:07 diopters (D). At 2 years, 88% of patients were within k3.00 D of plano and 50% were within 2 1.00 D. The mean change in Snellen's line for corrected visual acuity was -3.25 lines at 2 years for all patients and -2.0 lines for a subgroup of five patients who were free of vision-limiting preoperative disease.Conclusions: Results suggest that this intracorneal implant is well tolerated by the cornea and can provide predictable refractive results in patients with high-nsk aphakia. Limitations of the procedure are uneven microkeratome resections, loss of best-corrected visual acuity, and irregular astigmatism in some patients. Although these data show good evidence of bioco~patibility of theimplant material, technical surgical progress is needed to advance this procedure into clinical therapeutic practice.

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In a retrospective study the rate of rejection and clouding of the donor cornea for other reasons was investigated in 230 penetrating keratoplasties performed between 1984-1986. Donor corneas were stored in McCarey-Kaufmann Medium (MK) at 4 degrees C or in a modified Minimal Essential Medium (MEM) at 31 degrees C. No statistical differences in rejection rate, cloudiness due to other causes or visual acuity was found between MEM- and MK-stored donor corneas.