A human lens containing a cataract has been visualized in vivo by a computer transformation of a rotated set of Scheimpflug digital-image slices through the three-dimensional volume of the lens. At each angular position (incremented 3 degrees about the optical axis) of the camera a digital image of the ocular lens in vivo was acquired. Data acquisition was made with a series of 60 Scheimpflug images. The set of optical sections were aligned to correct for small eye movements during the data-collection process prior to computer transformation into a new set of slices, which are orthogonal to the optical axis of the eye. The use of slices orthogonal to the optical axis to visualize lenticular light scatter represents a new, simple technique, which can be performed on a personal computer to visualize in vivo human cataracts in three dimensions.

This investigation was done to evaluate in vivo changes in corneal micromorphology occurring after laser in situ keratomileusis. By means of confocal microscopy, nine eyes of eight patients showing uncomplicated wound healing at 2-16 weeks after surgery and one eye of one patient at 30 weeks after initial surgery who had to undergo two retreatments because of a central island were examined. Video recording was used to register the data. The distribution of scattered light in the treated corneae was registered with the z-scan of the microscope. Slit-lamp findings obtained several weeks postoperatively showed only minor corneal alterations. Confocal microscopy revealed morphological changes as a result of the surgery, especially in the epithelium and in the anterior stroma. With the z-scan an additional peak determined by higher reflectivity in the anterior stroma was found. The retreated patient showed marked folds in the area of the interface and flap. Confocal in vivo microscopy is suitable for the noninvasive detection of micromorphological alterations following refractive corneal surgery and for observation of the postsurgical wound-healing phase, including nerve regeneration.

The purpose of this study was the determination of morphological changes in the corneal epithelium and the keratocyte network in keratoconus. In all, 33 eyes of 19 patients were examined in vivo using the confocal slit-scanning microscope Microphthal. After penetrating keratoplasty, recipients' trephanates were stained with the Live/Dead kit and examined using the confocal laser-scanning fluorescence microscope Diaphot 300/Odyssey. The fluorescence images were reconstructed three-dimensionally. All findings were compared with data from healthy corneas. Morphological alterations were found only in the area of the corneal apex; obviously elongated superficial epithelial cells arranged in a whorl-like fashion were found. Near Bowman's membrane, highly reflective changes and fold-like structures were visible. The anterior stroma also showed an increased reflectivity. In the posterior stroma, typical findings were Vogt's striae and keratocytes with extremely long processes arranged nearly in parallel. In scarred stroma the keratocytes were spindle-shaped and arranged irregularly. The spatial organization of the living keratocyte network could be demonstrated through three-dimensional reconstructions.

Thus far assessment of corneal reinnervation after penetrating keratoplasty has been possible only by esthesiometry techniques. Since the introduction of confocal microscopy, we have been capable of performing structural corneal in vivo examinations. The purpose of our study was to correlate esthesiometry results with confocal microscopy findings. We used a Cochet-Bonnet esthesiometer and a Microphthal confocal microscope to investigate corneal grafts in vivo. A total of 46 eyes were examined preoperatively and for up to 3 years after penetrating keratoplasty. At 8 weeks after keratoplasty the first stromal nerves were detected in the periphery of the graft. The first nerves in the middle and superficial stroma of the graft center were observed at 7 months after surgery. Reinnervation of the central basal epithelium was found at 2 years after keratoplasty. The highest level of sensitivity was detected in young patients with reinnervation of the basal epithelium. Confocal microscopy enables us to correlate morphologically and functionally corneal reinnervation after surgery. The present study shows that corneal reinnervation is influenced by the amount of time elapsing after surgery, the patient's age, and the preoperative diagnosis. In none of our patients was normal nerve morphology or sensitivity observed during the follow-up period. Comparison of the morphology of nerves seen in eyes after nonsurgical trauma with that observed in corneal grafts indicates that surgically induced scar formation may limit nerve regeneration in grafts.

The purpose of this study was to compare the regeneration of corneal nerves after photorefractive keratectomy (PRK) versus laser in situ keratomileusis (LASIK) in vivo with a confocal videomicroscope. In all, 15 eyes that had undergone PRK and 15 eyes that had been subjected to LASIK were compared with a confocal in vivo slit-scanning video-microscope. The subepithelial nerves were observed preoperatively and at 3, 6, and 12 months postoperatively. In all eyes, good microscope images of the subepithelial nerve plexus could be obtained preoperatively. Because of postoperative light reflection and scattering in the treated area, subepithelial nerve-fiber regeneration could be followed satisfactorily only in seven eyes after PRK and in five eyes following LASIK. In the eyes treated with PRK, recovery of subepithelial reinnervation started from the margin of the ablation zone, being directed toward the center of the cornea. At 8 weeks postoperatively, rarefied subepithelial nerve fibers were visible at the edges, and after 3 months, single nonbranched nerve fibers could be visualized in the center of the ablation zone. At 6-8 months following PRK, subepithelial nerve regeneration seemed to be completed; however, abnormal branching and accessory thin nerve fibers were present without exception. After LASIK, corneal nerve-fiber regeneration followed the same course described for PRK except that regenerated subepithelial nerve fibers were barely visible in the center after 6 months. Further changes in nerve structure were visible for up to 12 months postoperatively. Recovery of corneal sensitivity in humans has been reported to start at 4-6 weeks after PRK and is said to be completed within 6-12 months of surgery. Slit-scanning videomicroscope findings were in accordance with these observations.

A series of 60 reflected-light, rotating slit images of the human cornea in vivo are acquired with a rotating Scheimpflug camera. Each single acquired optical slice on a single meridian contains the shape of the anterior and posterior surfaces of the cornea. These 60 images are mathematically transformed into a three-dimensional volume that can be visualized on any meridian, including those images on meridians that have not been selected during the image-acquisition process. The optical distortions and aberrations of both the camera system and the eye are not included in this study using a rotating slit camera to determine the shape of both anterior and posterior corneal surfaces. The method presents the view of the anterior and posterior cornea (out to the midperipheral region) and a reference plane of the iris reflection. Further development of this technique may find clinical applications in corneal refractive surgery.

The evolution of confocal microscopy for in vivo qualitative analysis of the cornea seems to follow a path similar to that followed by specular microscopy after its reintroduction almost 20 years ago. The purpose of this report is to present the evolution of our own research data, starting with speculation concerning the attribution of morphological features and finishing with cell-to-cell correlation with special techniques. We present representative clinical but mainly experimental data from relocation studies using flat preparation, especially developed sequential vital staining techniques, and scanning electron microscopy as compared with specular microscopy. Starting from speculative attribution of the observed morphological features, we were capable of classifying morphological data on the endothelium and the surrounding structures into preendothelial, endothelial, retroendothelial, and non-endothelial features. Specular microscopy allows the detailed study of cellular and even intracellular structures and is probably one of the most spectacular ways of doing noninvasive in vivo microscopy in humans.

In cases of malignant diseases situated within the orbit and threaten to extend beyond it, removal of the orbit and periorbital contents may be indicated, followed by adjuvant chemotherapy or irradiation. An effective radiotherapy device for treatment of residual or suspicious cancer in the enucleated orbit consists of an external-beam radiation source (60Co) and an intraoperatively fitted mould as a guide for the flexible afterloading tubes using a 192Ir source. Considering the physical dose distribution and the local situation, this therapy permits a high dose with homogeneous dose distribution to the target area of the orbit but also allows significant dose reduction to adjunctive critical structures. Four patients with different orbital malignancies were treated by means of a combination of percutaneous radiotherapy with afterloading brachytherapy following orbital exenteration. The individual mould of the orbital cavity is modeled at the end of the operation. The technique of radiotherapy, dose distribution, and follow-up of the disease are demonstrated. Orbital malignancies with an extremely poor prognosis may profit from the application of this combined radiotherapy to avoid supraradical surgical intervention.

We studied the effect of intraoperative fibrinolysis prior to surgical evacuation of subretinal hemorrhage, which has been recommended as a valuable adjunct in the surgical treatment of submacular hemorrhage. We analyzed retrospectively the records of eight patients who underwent pars plana vitrectomy combined with subretinal injection of tissue plasminogen activator (TPA). The duration of symptoms ranged from 2 h to 14 days (median 1.5 days). During vitrectomy, TPA (6-75 micrograms) was injected subretinally through a retinotomy. After 20 min the liquified blood was surgically drained. The residual clot had to be extracted mechanically through an enlarged retinotomy site. In all patients, fibrinolysis was incomplete and an additional mechanical clot extraction was necessary. The postoperative visual acuity improved slightly in four patients, stabilized at the preoperative level in three patients, and worsened in one patient. During follow-up, one patient suffered from retinal detachment. In four patients a cataract developed. In all eyes, large defects of the retinal pigment epithelium resulted. In contrast to other authors, we did not find an acceptable liquefaction of the subretinal clot that would have facilitated surgical extraction of the hemorrhage. Therefore, a therapeutic benefit from the injection of TPA before removal of a subretinal hemorrhage was not distinct.

The cornea is a physiologically capillary-free and optically transparent tissue that subserves optimal visual function. In frequent pathological situations of diverse natural or experimental etiologies (lesions, burns, denervations, dystrophies, ulcers, infections) that involve long-lasting epithelial defects, vascular capillaries invade the cornea, resulting in opacity and reduction or loss of visual function. In view of the relative insensitivity of animal models, of the need for large numbers of animals to perform experiments, and, not least, of the painful interventions due to the very dense trigeminal innervation of the cornea in situ, we searched for alternative experimental setups to study mechanisms of corneal pathophysiology. As a first goal we developed a new slice-culture model and examined interactions between in-vitro-differentiated corneal epithelial cells and cocultured vascular endothelial cells. Corneas from enucleated eyes, from donor eyes retrieved for keratoplasty, or from animal eyes were dissected and cut along the optical axis to produce slices containing all three corneal layers. Corneal epithelial cells developed well-differentiated histotypical monolayers whose sizes were comparable with the size of the corneal surface in situ. When examined by electron microscopy, the epithelial cells formed tight contacts with each other and formed typical villous protrusions at the growing front. As a second goal we studied interactions between corneal epithelium and cocultured capillary endothelial cells. Upon encountering cocultured vascular endothelial cells, corneal epithelium exerted a strong, contact-mediated repulsion. The morphological correlates of repulsion were collapse of lamellipodial protrusions, immobilization, and cell death. These responses resulted in the inability to penetrate the corneal epithelium. The repulsive activity was exclusively localized in the epithelium, whereas stromal keratocytes were permissive for ingrowth of vascular cells. The angiorepulsive features of the cornea could be partially neutralized with aprotinin, indicating that membrane-linked proteolytic systems are involved in the interactions between corneal and vascular tissue. This coculture system may be used to characterize further the cell-signaling mechanisms and the interactions between cornea and vascular endothelial cells during pathological situations associated with angiogenesis.

The purpose of the present study was to elucidate the origin and spectrum of the yellow-orange fluorescence observed during standard argon-ion laser irradiation of the eye. The possibility that the fluorophores were induced by the laser was investigated. The 514.5-nm line of an argon ion laser was used to induce thermal coagulation on frozen sections of human and rabbit eyes. Specifically, the spectrum and retinal site of the fluorescence were analyzed. The fluorescence was measured with a microspectrofluorometer apparatus. The excitation wavelength was 514 nm. At the level of the retinal pigment epithelium (RPE) and choroid a fluorescence was induced that had an emission spectrum that was comparable with that of lipofuscin yet was far more intense. The fluorophores are induced by laser irradiation. Further research to identify the fluorophores and determine their biological behavior is necessary.