Long-term viability of allogenic donor stroma.

We report the clinical history and histopathology of the longest known postoperative course of a myopic cornea lenticule implanted via epikeratoplasty that also had been subjected to excimer laser and mitomycin. Despite the mechanical and photochemical processes the allogenic cornea stroma had sustained, it is notable that it retained structural integrity and clarity. This report affirms the potential long-term clarity and resilience of allogenic stromal cornea and supports its use as a potential stabilizing option in cornea allogenic intrastromal ring segments for keratoconus and variations thereof for other cornea disorders.

Tectonic epikeratoplasty with ethanol-stored donor corneas.

To evaluate the efficacy and outcomes of tectonic epikeratoplasty with use of ethanol-preserved corneal grafts for the management of perforated corneal melts. The present retrospective case series includes 10 eyes which underwent tectonic epikeratoplasty for perforated corneal melts. The stromal remainders of Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK) graft preparation were stored in 95% ethanol and used as emergency tectonic grafts for restoring globe integrity after sterile and infectious perforated corneal melts. In 6 cases with subtotal corneal melt, DMEK remainders (endothelium-denuded corneoscleral buttons) were used for 'limbus to limbus' tectonic epikeratoplasty and in 4 cases DSAEK remainders (anterior stroma) were used to seal focal perforated melts. Graft storage time was 5.1 ± 4.9 (ranging from 0.5 to 17) months. The surgeries were successful in all cases with restitution of the globe integrity. During the postoperative course 4 cases developed a graft melt (corneoscleral button for limbus to limbus tectonic epikeratoplasty, n = 3; lamellar patch, n = 1) within 2-6 months after the initial procedure. Three patients underwent successful repeat tectonic epikeratoplasty. In the fourth case of graft melt the globe was enucleated due to underlying expulsive haemorrhage and severe pain. The short-term results of the present case series suggest that the use of ethanol-stored stromal remainder of donor corneas after endothelial keratoplasty is an efficient temporary measure for tectonic restoration of perforated corneas.

Congenital keratoglobus with multiple cardiac anomalies: a case presentation and literature review.

Keratoglobus is a rare condition of bilateral corneal ectasia, which results in high myopia, irregular astigmatism, scarring, and rarely spontaneous globe rupture. Globoid protrusion of a clear, diffusely thin cornea is the pathology. The congenital form has been associated with blue sclera in which there is a systemic connective tissue disorder with abnormal collagen synthesis like Ehlers-Danlos syndrome, Marfan syndrome, and osteogenesis imperfecta. Some concomitant abnormalities reported with kertoglobus include joint hypermobility, dental and skeletal abnormalities, osteal fragility, and deafness. Acquired forms have been reported to be associated with vernal keratoconjunctivitis and thyroid ophthalmopathy. We report the case of a 16-year-old boy with keratoglobus who presented with a history of photophobia and a low vision in both eyes since birth. He has been followed up by our pediatric cardiology department due to multiple cardiac anomalies. He had hypermobility of large joints, easy bruising, thin and hyperextensible skin with visible veins, which were also described in his elder brother. We aimed to discuss the etiology and the association of keratoglobus with some systemic abnormalities caused by collogen tissue disturbance, and make a brief review about the recent literature concerning the management of keratoglobus patients.

The Effects of Epikeratoplasty & Laser in Situ Keratomileusis(LASIK) for Correction of High Myopia

In order to compare the clinical results of Epikeratoplasty (EPK) with Laser in situ keratomileusis(LASIK) to be corrected of high myopia above -9 diopters, the effect of the procedure on 74 patients following EKP and 63 patients following LASIK who were followed up at least 1 year were analyzed retrospectively. Postoperative mean uncorrected visual acuity was reached 0.56 until 3 month in EKP group and 0.53 until 1 month in LASIK group. LASIK group recovered and stabilized more rapidly than EKP guoup(p<0.01). Also LASIK group had more rapid recovery in keratometryp(p<0.01) and mean refractive error than EKP group(p<0.01). But there was no significant difference between two groups in uncorrected visual acuity(p=0.62), keratometry(p=0.41) and mean refractive error(p=0.32) at postoperative 1 year. LASIK seems to have more rapid and effective visual recovery than EKP for high myopia treatment.

Epithelial healing time and rate of the cornea after myopic epikeratoplasty

This study was performed to investigate the corneal epithelial healing time and rate according to the method for promoting the reepithelization after myopic epikeratoplasty. A prospective study was conducted on 30 myopic epikeratoplasties which were divided into 3 groups according to the method for promoting the epithelial healing. The groups consisted of 10 eyes with pressure patches, 10 eyes with Acuvue(R) disposable contact lens (CL) and 10 eyes with SeeQuence(R) disposable CL. The cornea epithelial healing time were 3.4, 3.5 and 3.4 postoperative days for the pressure patch, Acuvue(R) CL and SeeQuence(R) CL groups, respectively. The corneal epithelial healing rates during postoperative 1, 2, and 3 days were 0.33, 0.78, and 0.44 mm2/hour for the pressure patch group; 0.24, 0.92 and 0.37 mm2/hour for the Acuvue(R) CL group; and 0.30, 0.79 and 0.38 mm2/hour for the SeeQuence(R) CL group. These results suggest that a disposable contact lens may not hinder epithelial healing compared with a pressure patch.

The Effect of Disposable Bandage Contact Lenses on Time and Velocity of Corneal Epithelial Healing after Myopic Epikeratoplasty

To investigate the effect of disposable contact lenses (CL) on the corneal epithelial healing, a prospective study of 30 myopic epikeratoplasties which were divided into 3 groups according to the method for promoting the corneal epithelial healing was conducted. The groups are consisted of 10 eyes with pressure patch, 10 eyes with Acuvue(R) disposable CL and 10 eyes with SeeQuence(R) disposable CL. Corneal epithelial healing was completed in the pressure patch, Acuvue(R) CL and SeeQuence(R) CL group at 3.4, 3.5 and 3.4 postoperative days, respectively. Corneal epithelial healing rate during postoperative 1, 2 and 3 days are 0.33, O.78, and O.44mm2/hour in pressure patch group, O.24, O.92 and O.37mm2/hour in Acuvue(R) CL group, and O.30, O.79 and O.38mm2/hour in SeeQuence(R) CL group respectively. From the above results, it is concluded that there was no statistically significant difference of the corneal epithelial healing time and rate between the pressure patching and disposable bandage CL wearing after myopic epikeratoplasty.

Trephination Effect After Epikeratoplasty

Trephination was performed for the purpose of correction of undercorrection after epikeratoplasty. We classified two group-Delayed regression group represented regression toward myopia more than 3D again after spherical equivalant become stable. Undercorrection group represented remained myopia after epikeratoplasty. Thirteen trephinations were performed on eleven eyes. Mean follow-up period was 22.4 weeks. In skiascopy, totally 1.15D myopia was decreased. In delayed regression group myopia was increased 0.5D, while in undercorrection group, myopia was dereased 3.5D, The results of three eyes in eleven eyse were satisfactory. Those 3 cases were from undercorrection group. The results suggest that trephination might be effective method for correction of remained myopia in undercorrection group.

The Morphologic Changes of Epikeratoplasty Lenticule In a Case

The patients initially underwent epikeratoplasty for keratoconus but a penetrating kerato plasty was required due to the opacity in the cornea. By using of this specimen, which was obtained by trephination the healing process of the host-Ienticule cornea could be examined by electron microscopy and immunofluorescence method. Epithelial ingrowth over the lenticule was well formed by the regeneration of the basement membrane over the Bowman's membrane. However, the poor attachment of the lenticule over the host corneal stroma made the interface easily separated during the sectioning processes. Electron microscopic study revealed the keratocytes in the lenticule stroma vacuolized with large number of degenerated microorganelles. These results suggest that it may take a long time to complete the wound healing of the host-Ienticule interface despite the epithelial ingrowth onto the lenticule was well formed.

Trephination with vacuum trephine in undercorrection of myopic epikeratoplasty

For the treatment of undercorrection after myopic epikeratoplasty, early suture removal, scar revision, retrephination, replacement of lenticule and, recently, excimer laser photorefractive keratoplasty have been employed. We performed trephination with Hessburg-Barron vacuum trephine on 11 eyes of 11 patients whose post-epikeratoplasty myopic power was over -4.00 diopters for 3 consecutive months. Patients were followed up on post-trephination 1 month, 3 months and 6 months. The mean duration from epikeratoplasty to trephination was 14.27 months, the mean pre-trephination spherical equivalent was -8.50 D and the mean keratometric reading was 40.87 D. The mean reduction of spherical equivalent was -4.07, -5.99, -8.02 D at post-trephination 1, 3, 6 months, respectively. The mean keratometric reading was 37.60 diopters at 1 month and 41.53 diopters at 6 months. At 1 and 3 months, there were significant reductions of myopic power in refraction and keratometry (p 0.05). There was no change of uncorrected and best corrected visual acuity between baseline and post-trephination 6 months.

The Clinical Report on Seven Cases of Epikeratoplasty

After the first description of epikeratoplasty for the correction of aphakia, it has been widely used in high myopia and keratoconus for improvement of visual acuity. Seven epikeratoplasties were performed on five high myopia and two keratoconus patients showing intolerance to eye-glasses and contact lens, with the mean follow-up period of 9.7 months. In high myopia, mean spherical equivalent decreased from -15.90D to -2.05D postoperatively. In keratoconus, mean keratometric value decreased more than 4.94D postoperatively and the progression of disease stopped. All patients showed an imporvement in thei uncorrected visual acuity and best corrected visual acuity. In all cases, reepithelialization completed in 4-23 days (mean 14 days).

Clinical Results of Epikeratoplasty for Myopia, Keratoconus and Aphakia

We have performed epikeratoplasty to correct the visual acuity in high myopia who are more than -8.0D and intolerant to the wearing of contract lens, and for the aphakic eyes. It has been also applied to supress the progression of keratoconus. Of 118 eyes performed from january 1989 to july 1992, a total of 90 eyes which could be followed up were subject to the review, including 66 high myopic eyes, 18 keratoconus, and 6 aphakic eyes. In myopic patients, uncorrected visual acuity was stable from a proeperative mean of 0.04 to 0.58 at 4 months. Spherical equivalent was stable from a preoperative mean of -13.99 to -2.01 at 4 months. In keratoconus patients with mean 10.1 months follow-tp, uncorrected visual acuity was changed from 0.05 to 0.33 Corrected viaual acuity was changed from 0.15 to 0.60, keratometry reading was changed from 55.87D to 45.92D. Of 6 aphakic eyes, spherical equivalent of 3 pediatric: aphakic eyes under the age of 3 was changed from +15.0D to +3.41, for the other 3 adult aphakic eyes, spherical equivalent was changed from +9.5D to +1.83D and uncorrected visual acuity was changed from 0.03 to 0.32. Epikeratoplasty is effective surgery applicable to the correction of myopia more than -8.0D, keratoconus, and aphakia.

Progressive Loss of Power After Myopic Epikeratoplasty

It has been widely accepted due to its simplicity, safety and effectiveness to correct high myopia by epikeratoplasty. We evaluated clinical results of 23 cases of myopic epikeratoplasty over one year follow up. The uncorrected visual acuity improved in all cases and corrected visual acuity improved in 20 cases (91%). But, in 5 cases (22%), we experienced progressive loss of lenticular power more than 4 diopter of emmetropia and their clinical courses were also reviewed Two cases were both eyes of the same patient. The loss of lenticular power appeared as early in 5th week and even in 6th month postoperatively. We could not find any differences between this grolp of power loss and that of remained well corrected within 4 diopter of emmetropia, except preoperative spherical equivalent (-19 diopter vs -15 diopter), period of reepithelization (8.2 days vs 5.9 days), and mean age (25.8 years vs 31.1 years). But, only the difference of mean age was statistically significant (p<0.05). In addition, the surgical techniques the process of manufacturing tissue lenticule, and postoperative care might be document2d as possible factors.

Epikeratoplasty for Correction of High Myopia

Epikeratophakia was first described in 1980 by Kaufman, the correction of aphakia in adults. Since then, epikeratoplasty has been emploed for the correction of high myopia, keratoconus and most often. We have operated on high myopic eye, for which spectacles or contact lenses were no good enogh to correct myopia. 32 epikeratoplasty for 26 patients of high myopia were operated on and followed up to reveal the effect of the epikeratoplasty. The cases with 6 months or more followed up are reviewed. The cases reviewed are followed up at least 6 month or more. All cases improved their uncorrected visual acuity 20/40 or better. The mean keratometric reduction after surgery was 11.2D. Mean preoperative spherical equivalent of -12.8D was corrected to average -0.4D postoperatively. This study has revealed that epikeratoplasty has a couple of unique advantatges; a wide range of the correction of visual acuity and no postoperative complications. And these advantages were us to make epikeratoplasty a first choice method for the correction of high myopia.

Epikeratoplasty for keratoconus

The 6 eyes of 6 patients operated on using keratoconic epikeratoplasty are evaluated, and the mean 11-month postoperative results are reported. Uncorrected visual acuities improved in 4 patients and were maintained in 1 patient. One patient revealed a decrease of uncorrected visual acuity in the postoperative 6th month. Two patients showed an improvement of over 2 Snellen lines. Two patients showed the same corrected visual acuity, and that of 2 patients decreased within the postoperative 6-months follow-up. There was a significant decrease of myopia in terms of spherical equivalent. As a result, 4 cases showed a postoperative refractive error from +1.0 to -2.5D. Two cases were myopic deviated, -4.0 and -5.0D, and need further observation. In all cases, there was an effective flattening of the protruding cone with a mean decrease of over 11D of keratometry readings. Complete reepithelization occurred within 12 days, (average 7.5 days) and a moderate pressure patch was used as a routine procedure to promote the reepithelization.

The Clinical Report on Six Cases of Epikeratoplasty

After the first description of epikeratoplasty for the correction of aphakia by Kaufman in 1980, the application of epikeratoplasty has been extended further to keratoconus and high myopia. Six epikeratoplasty for 5 eyes of high myopia and 1 eye of keratoconus were performed and followed upto average 4.9 months. All cases improved their uncorrected visual acuity and the preoperative best corrected visual acuity improved or had no change postoperatively except one case on the last visit. In the cases of high myopia, the mean preoperative spherical equivalent of -19.4D was corrected to average -0.23D with the range of -1.75D to +2.5D postoperatively. In the case of keratoconus, there was the mean decrease in 12.0D of myopia in terms of spherical equivalent and the cornea was flattened by over 8D in keratometry readings.

The clinical report on six cases of epikeratoplasty

After the first description of epikeratoplasty for the correction of aphakia by Kaufman in 1980, the application of epikeratoplasty has been extended further to the treatment of keratoconus and high myopia. Six epikeratoplasty for five eyes of high myopia and one eye of keratoconus were performed and followed up for an average of 4.9 months. All cases improved their uncorrected visual acuity, and the preoperative best corrected visual acuity improved or had no change postoperatively except for one case. In the cases of high myopia, the mean preoperative spherical equivalent of -19.4 D was corrected to an average -0.23 D with a range of -1.0 D to +2.5 D postoperatively. In the case of keratoconus, there was a mean decrease in 12.0 D of myopia in terms of the spherical equivalent, and the cornea was flattened by over 8 D in keratometry readings.