Positive pressure during penetrating keratoplasty can be solved with a modified graft-over-host technique.

PURPOSE: To describe a modified graft-over-host (MGOH) surgical technique which was used to prevent serious complications in cases of positive vitreal pressure during penetrating keratoplasty (PKP) and to compare the endothelial cell density (ECD) loss and clinical outcome between eyes undergoing MGOH or standard PKP. METHODS: In the proposed MGOH technique, the donor graft is sutured over the recipient cornea as soon as signs of positive pressure are noticed, even before cutting the recipient cornea, and the surgery is continued by consecutive cutting of the recipient and continuous suturing of the donor cornea, quadrant by quadrant. Donor grafts were prospectively followed up for the graft clarity, ECD loss and the amount of astigmatism. RESULTS: Of 220 cases scheduled for standard PKP in years 2009-2011, eight were operated by MGOH technique. Despite the fact that the donor cornea is situated over the recipient almost throughout the whole MGOH procedure, the ECD loss is equal between eyes operated on by MGOH technique and standard PKP, and none of the grafts had primary graft failure. The only disadvantage was an increased amount of astigmatism that was not as significant once the sutures were taken out. CONCLUSION: Modified graft-over-host technique seems to be a safe and effective method to prevent complications during PKP complicated by positive vitreal pressure.

1-year follow-up study of endothelial cell density loss after penetrating keratoplasty.

High endothelial cell density (ECD) is essential for the corneal graft clarity. We evaluated ECD loss in 120 eyes that underwent penetrating keratoplasty (PK) in Eye Clinic Svjetlost in a one year follow up period. Patients were divided into 3 groups of high (N = 35), intermediate (N = 31) and low risk (N = 54) for graft failure. Postoperative central endothelial density, coefficient of variation in cell area (polymegathism), percentage of hexagonal cells (pleomorphism) in comparison to preoperative donor cell measurements were determined in the following postoperative time-points of 1, 2, 3, 6, 9 and 12 months. There were no significant differences in the preoperative ECD values, storage time, donor age or surgical procedures between groups. Throughout all time points intermediate group had the greatest statistically significant ECD loss as compared to high and low risk groups. There were no significant differences between high and low risk group. After 12 month post PK, intermediate risk group had 28.38% ECD loss as compared to 24.07% in high and 23.03% ECD loss in low risk group. Coefficient of variation in cell area (CV) was for high risk group 0.34, intermediate 0.40 and low risk 0.31 which was not significantly different between groups. Percentage of plemorphism in high risk was 54%, intermediate 58% and in low risk 48% which was significantly different as compared to other two groups. Our study showed that corneal pathology is among others, very important prognostic factor for ECD after PK. However, longer follow up period is needed.

Penetrating keratoplasty and Verisyse iris-claw lens--is it safe for corneal graft?

The loss of the corneal endothelial cells, especially in a first postoperative year, has been observed in patients who underwent penetrating keratoplasty (PK). The implantation of new generation of "iris claw" phakic IOL (Verisyse) in refractive cases has been shown to cause clinicaly insignificant endothelial cell loss. In our prospective case series we investigated the endothelial cell loss and clinical outcome in patients that either underwent PK and implantation of PCIOL or PK and implantation of Verisyse IOL. In the first group of 9 patients scheduled for PK, implantation of Verisyse was performed due to the absence of the posterior capsule support. 2 of these patients had angle supported ACIOL, 4 patients were aphakic and 3 had posttraumatic cataract with ruptured posterior capsule. The second group of 12 patients had standard "triple" procedure (PK + ECCE + PCIOL). BCVA of both groups of patients prior the operation was hand movement in 12 patients, light perception in 7 patients and 0.05 in 3 patients. The preoperative endothelial cell count of the donor grafts obtained from the eye bank was 2800 cells/mm2 on average. The follow up was 6-10 months. Six months after the operation all "Verysise" patients maintained transparent graft. Postoperative visual acuity improvement was recorded in 18 out of 21 eyes (85.7%). Best spectacle corrected visual acuity of > or = 0.3 was achived in 55.5% in the Verisyse group and in 50.0% of "triple procedure" group. The endothelial cell count and morphology were estimated on the specular microscope on a monthly basis. Mean endothelial cells loss in patients with PK and Verysise was 40 +/- 8% and in patients with "triple" procedure was 42 +/- 12% at 10 postoperative months. There was no significant difference in the endothelial cell loss and clinical outcome between the group of patients who had PK and Verysise as compared to those with implanted PCIOL.

Amniotic membrane transplantation in the treatment of persistent epithelial defect on the corneal graft.

It has been shown that amniotic membrane transplantation (AMT) improves healing of the epithelium defects as it serves as a basement membrane for endothelial cells growth, prevents inflammatory cell infiltration and reduces apoptosis in keratocytes. Having in mind the healing properties of AM we investigated the efficacy of AMT in persistent epithelial defect (PED) on the corneal graft. 80 corneal grafts were prospectively followed up for presence of PED 10 months after surgery. PED was detected in 12 cases (15%) having surgery for: rejected graft (n = 4), keratoconus (n = 3), keratoconus following PK on a second eye (n = 3), corneal perforation (n = 1) and Stevens-Johnson keratopathy (n = 1). Epithelial defect (ED) developed 14 +/- 7 days after surgery in 10 cases and 1.5 month in other two. All patients were primarily conservatively treated with subconjuctival steroids and artificial tears for 10 days and systemic steroid therapy if needed after, until the period of 2 weeks. 4 patients were healed. Since ED was unresponsive to all previous treatments for more than 2 weeks, one layer of AM was placed on the corneal lesion in 5 patients, and in 3 cases of deep PED several layers of AM were placed. Healing of the defect was obtained in 7/8 (87.5%) eyes. In 1 patient second AM transplantation was necessary. Mean epithelization time was 2 weeks (range 1-3 weeks) in monolayer and 3 weeks (range 2-4 weeks) for multilayer cases. 5 out of 8 patients retained the same best corrected visual acuity (BCVA) while 3/8 patients improved their vision more than 2 lines. Preoperative corneal thickness of 255 +/- 40 mm increased to 455 +/- 90 mm. AM transplantation facilitates healing of corneal epithelium. PED on the corneal graft unresponsive to conventional treatment can be effectively cured when covered with one or more amniotic membrane layers.