Search

Our clinical study was designed to determine whether "through-and-through" corneal sutures would prevent the postoperative intraocular pressure rise that occurs in 70% of aphakic eyes after uncomplicated penetrating keratoplasty. Twenty-five aphakic patients received the same operative procedure except that the corneal buttons of ten of them were sutured into place with "through-and-through" sutures. The intraocular pressures of patients with the "through-and-through" sutures were significantly lower than those of the other patients during the entire postoperative course.

The technique of using two continuous sutures of different caliber and relative tightness, running in the same direction, is described for penetrating keratoplasties. The primary purpose of the technique is to allow visual correction earlier in the postoperative period. In addition, graft slippage with override and posterior wound gape, both occurring at suture removal with resultant functional loss, have been eliminated.

A patient experienced marked visual distortion following myopic keratomileusis, despite the presence of a clear graft and an apparently smooth corneal surface. A color coded topographic map of corneal surface power generated by computer analysis of a keratoscope photograph of the operated eye identified a degree of irregular astigmatism and asphericity not readily apparent from simple visual inspection of the keratoscope photograph. Contour map graphics display of corneal surface power is a useful clinical tool in the evaluation of visual distortion complications following myopic keratomileusis.

Histological examination of primate corneas with hydrogel lenses implanted in intrastromal pockets showed the corneal lamella posterior to the implant protruding into the anterior chamber; these eyes had shown no increase in anterior corneal curvature. In an attempt to obtain a dioptric increase without removing a corneal lamella, relaxing incisions were made in Bowman's layer followed by intrastromal implantation of hydrogel lenses. However, no refractive increase resulted, although six of the seven eyes were optically clear eight months postoperatively.

The shaping of swollen, abnormally hydrated donor corneal tissue on the cryolathe for use in keratorefractive surgery yields lenticules of insufficiently predictable dioptric powers. The irregular nature of this abnormal hydration precludes the use of mathematical compensating factors. To improve control over the shape of the lenticule, we have developed a cornea press which restores normal hydration and dimensions to the donor tissue by mechanical dehydration.

Following penetrating keratoplasty, aqueous hyposecretion results in marked thickening of the cornea identical to that seen when the donor endothelium is unsatisfactory. The lack of secretion is accompanied by hypotony, and the persistence of fluorescein in the anterior chamber can be measured by fluorophotometry or observed clinically 24 hours after the instillation of topical fluorescein. An eye with aqueous hyposecretion will usually recover in seven to ten days, and additional surgery is not only unnecessary, but harmful to an already damaged eye. However, poor donor tissue can often be replaced promptly and successfully with repeated penetrating keratoplasty. Therefore, clinical differentiation of these conditions is important in management decisions.

Gore-Tex (polytetrafluoroethylene) grafts have been used in a variety of surgical procedures, particularly vascular, plastic, and reconstructive surgery. As suggested by previous animal studies, Gore-Tex soft tissue patches (expanded polytetrafluoroethylene) may have application in ocular surgery for scleral buckling and support procedures. We buckled the scleras of 14 rabbit eyes using strips of polytetrafluoroethylene soft tissue patches and monitored ocular tissue reaction and histologic changes in response to this material.

A through-the-lid keratoprosthesis in a patient with severe Stevens-Johnson syndrome resulted in 20/20 vision for one year, at which time the patient experienced a sudden and painless loss of vision. Surgical exploration revealed a Staphylococcus aureus intraocular abscess and a 10-mm-thick cyclitic membrane. Electrophysiology had shown normal retinal function by ERG and VER at the time of this surgery. Vision has since deteriorated to no light perception.

Five patients required secondary surgical procedures after receiving epikeratophakia grafts. A neonate underwent epikeratophakia in combination with extracapsular cataract extraction, followed one week later by peripheral iridectomy and nine months later by strabismus surgery. A 53-year-old male had surgery to correct retinal detachment 4-1/2 months after epikeratophakia surgery for the correction of aphakia. A five-year-old male had epikeratophakia after removal of a traumatic cataract; five weeks later, retinal detachment necessitated vitrectomy, 360 degrees buckle, and cyclocryotherapy. A 4-1/2-year-old female had epikeratophakia for aphakia, followed nine months later by strabismus surgery. A 38-year-old female with keratoconus received a plano epikeratophakia graft, in combination with an extracapsular cataract extraction and anterior vitrectomy, followed two weeks later by an Ocutome vitrectomy. In all cases, the epikeratophakia grafts and interfaces remained clear, and in four of the five patients in whom secondary procedures were successful, vision continued to improve with time.

There are three basic needs for a vitrector or vitreophage. One is for the anterior segment surgeon so that he may have a machine available when vitreous is lost during anterior segment surgery and may spare himself the hazards and potential complications of doing vitrectomy solely with cellulose sponges. The simplified vitrector which is disposable, sterile, and rapidly made ready ideally serves this need in a way which is not served by any other technique. Two, the removal of normal vitreous may be necessary in patients with vitreous contact, and any type of vitreous removing machine may be useful for this. The vitrector we have worked with is simple and satisfactory, and has the potential advantage of having blades which are always sharp and always pushed firmly against the cutting edge of the hole since they are disposable and inexpensive. An infusor as well as simple cutting tips are available. Three, vitrectomy for serious vitreous pathology can be done with the simple vitrector through the anterior segment approach if the lens is absent or will be removed, and if heavy pre-retinal and vitreous bands are not present. For the handling of diabetic retinopathy and sheets of vitreous membranes which appear organized, other equipment may be superior.

We used autogenous periosteum to reinforce scleral defects in two patients with necrotizing scleritis. This technique produced good anatomical results and maintained useful vision in each case. Autogenous periosteum offers advantages over other tissues as a tectonic graft for necrotizing scleritis, since it is easy to harvest and handle, it is strong and vascular, and is not subject to immunologic rejection.

Dimensional changes in the Barraquer cryolathe , resulting from contraction due to refrigeration, can exert a considerable effect on the dimensions of the lathed lenticule . We have devised a simple technique for re- zeroing the cryolathe after freezing. This procedure negates the effects of the dimensional changes and thereby improves the accuracy of shaping the lenticules .

A specially-designed diamond fraise was used on three cats in an attempt to change the anterior corneal surface. After controlled grinding at 30,000 revolutions per minute, healing was rapid. By specular microscopy, there was no evidence of endothelial damage. Examination revealed areas with a defect in the anterior stroma and slightly thickened epithelium. Some superficial vascular ingrowth did occur in the three eyes when healing was slow. This study shows the feasibility of corneal grinding; a prototype instrument is suggested for superficial keratectomy.

This report describes three patients who have in common an occurrence of ocular epithelial herpes infection following a penetrating keratoplasty for a corneal opacity unrelated to herpesvirus infection. It may be that patients undergoing episodes of graft rejection are at increased risk for the reactivation of herpesvirus latent in the trigeminal ganglia, and corticosteroids should be used with this in mind. Because virtually all adults have been exposed to herpes and therefore harbor latent virus, a viral etiology should be considered for lesions in post-penetrating keratoplasty patients. Although the occurrence of this possibly rejection-related reactivation of herpes simplex virus is undoubtedly rare, management of potential cases of this nature should take this possibility into account.

Two primate corneas were analyzed histologically 22 and 25 months after epikeratophakia surgery. Keratocytes had migrated from the host cornea into the lenticule through the surgical disruption of the host Bowman's membrane; the lenticule with the wider connection to the host cornea appeared to have more complete keratocyte repopulation. The lenticule stroma and host Bowman's membrane were continuously apposed along the interface, with a basement membrane-like material composed of collagen fibrils and amorphous matrix filling the interstices.