Epikeratoplasty for pellucid marginal corneal degeneration.

Two patients with advanced pellucid marginal corneal degeneration (PMCD) received bilateral epikeratoplasty grafts ranging in diameter from 9 to 12 mm. Corneal astigmatism was greatly reduced in every case and the possibility of resuming contact lenses for daily wear, obtained after surgery, provided patients with a satisfactory best corrected visual acuity. Peculiarities of surgical procedure and clinical experience are reported.

Relaxing incisions for postkeratoplasty astigmatism.

We report 100 cases of postkeratoplasty astigmatism, ranging from 4 to 20.5 diopters, treated with the following procedures: relaxing incisions, relaxing incisions with augmentation sutures, and repeated relaxing incisions with augmentation sutures according to the degree of astigmatism. Patients were divided into three study groups (group 1 for preoperative defects ranging from 4 to 10 diopters, group 2, from 10.5 to 15 diopters, and group 3 for defects exceeding 15 diopters). Mean preoperative astigmatism was 7.15 +/- 1.67, 12.56 +/- 1.37, and 17.50 +/- 1.51 diopters in each group, respectively. The net decrease in astigmatism after surgery was 5.53 +/- 1.44, 9.68 +/- 1.80, and 14.87 +/- 1.69 diopters in each group, respectively. Postoperatively, spectacle-corrected visual acuity improved by two Snellen lines in the group 1, five in the group 2, and nine in the group 3. The mean time to achieve stable results after surgery was 2.2 +/- 0.3, 2.7 +/- 0.4, and 4.2 +/- 0.7 months in each group, respectively (two patients in group 2 and all patients in group 3 underwent a two-step procedure). The relaxing incisions procedure, eventually modified by either adding compression sutures or repeating the incisions after 8-10 weeks, offers the possibility of a wide range of corrections for postkeratoplasty astigmatism with acceptable postoperative periods for visual rehabilitation.

Comparison of epikeratoplasty and penetrating keratoplasty for keratoconus.

We report the results obtained in two groups of 30 eyes surgically treated for keratoconus. The eyes in the first group underwent epikeratoplasty, and those in the second group, penetrating keratoplasty. All eyes had sutures removed and a follow-up period ranging from 3 to 6 years. In the epikeratoplasty group, mean postoperative uncorrected visual acuity was 20/52 +/- 0.25; spectacle corrected, 20/23 +/- 0.18; and contact lens corrected, 20/21 +/- 0.17. In the penetrating keratoplasty group, mean postoperative uncorrected visual acuity was 20/63 +/- 0.23; spectacle corrected, 20/22 +/- 0.11; and contact lens corrected, 20/20.5 +/- 0.07. In the epikeratoplasty group, astigmatism (2.18 +/- 1.48) and astigmatism reduction (-4.16 +/- 2.98) were comparable to the penetrating keratoplasty group (astigmatism; 3.16 +/- 1.43 and astigmatism reduction; -4.2 +/- 2.56). Among the advantages offered by epikeratoplasty were both the absence of immunologic complications and reduction of operative risk. Penetrating keratoplasty provided patients with higher reduction of the myopic defect and earlier improvement in both visual acuity and contrast sensitivity.

Relaxing incisions with compression sutures to reduce astigmatism after epikeratoplasty.

Relaxing incisions with compression sutures were performed in seven eyes with high astigmatism following epikeratoplasty for keratoconus and in one case of posttraumatic aphakia. Mean preoperative keratometric astigmatism was 7.64 +/- 2.51 diopters (range 5.50 D to 13.00 D) in the epikeratoplasties for keratoconus and about 10.00 D in the hyperopic epikeratoplasty. The surgical procedure consisted of a free-hand dissection perpendicular to the steeper meridian along the scar between the edge of the epikeratoplasty lenticule and the recipient cornea, with an additional incision into the recipient stroma to an approximate depth of 80%. Following the incisions, compression sutures were added 90 degrees away in the flatter meridian. After surgery, the net decrease in keratometric astigmatism was 6.50 D +/- 2.90 D (range 5.00 to 13.00 D) in the eyes with epikeratoplasty for keratoconus and 6.50 D in the eye with hyperopic epikeratoplasty. Uncorrected visual acuity improved in six eyes and remained unchanged in two eyes. Spectacle-corrected visual acuity improved in every eye and contact-lens-corrected visual acuity improved in seven eyes and was unchanged in one eye. This procedure, already employed for astigmatism correction after penetrating keratoplasty, was effective in decreasing astigmatism after epikeratoplasty.

Epikeratoplasty for keratoconus. Report of 40 cases.

Forty cases of keratoconus were surgically treated with epikeratoplasty. The surgical technique is aimed at reducing the degree of high irregular myopic astigmatism of keratoconus and providing the ectatic cornea with a permanent mechanical support. Nearly all patients showed a satisfactory improvement in uncorrected and best corrected visual acuity. This reduction of preoperative astigmatism and spherical equivalent with a regularization of the corneal surface permitted the fitting of contact lenses for daily wear in patients who were preoperatively intolerant of them.

The effect of diet on the ophthalmological, clinical and biochemical aspects of Richner-Hanhart syndrome: a morphological ultrastructural study of the cornea and the conjunctiva.

Type II tyrosinemia (Richner-Hanhart syndrome) is a familial aminoacid disorder, clinically characterized by ocular changes (keratitis), palmo-plantar hyperkeratosis, no constant mental changes with mental deterioration, abnormal urinary excretion and high serum tyrosine level in consequence of the absence of tyrosine-aminotransferase. Almost 20 families have been described in the literature of which 50% are of Italian origin, suggesting that this disorder is particularly frequent in our country. We report a family with 2 affected members with typical clinical and biochemical findings (keratitis, palmo-plantar hyperkeratosis, abnormal urinary and serum tyrosine concentrations), not suffering from mental retardation. Clinical symptoms completely disappeared after the decrease of urinary and serum tyrosine levels following a tyrosine- and phenylalanine-free diet. These cases are compared with those reported in literature, and the usefulness of diet for the improvement of clinical and metabolic symptoms is discussed.

[Evaluation of donor corneas by means of a computerized image analysis]. / Beurteilung der Spenderhornhaut durch ein computerisiertes Bildanalysegerät.

The authors compare two groups of patients and specify characteristics of possible cornea donors for penetrating keratoplasty. Donors are selected by examining several parameters of the corneal endothelium: cellular density, average cell area, form factor, polymegetism quotient. These parameters are studied using an endothelial microscope and an image analysis system. The data thus obtained are then used for statistical analysis.