Tyrosinemia type II: nine cases of ocular signs and symptoms.

PURPOSE: To report nine cases of tyrosinemia type II, with ocular signs and symptoms. METHODS: Participants included nine patients (18 eyes) who were followed for a mean follow-up period of 6.5 years (range, 2 to 8 years). Intervention included dietary restriction of tyrosine and phenylalanine, which led to resolution of ocular and cutaneous lesions, improved behavior in one patient, and may have prevented developmental delay in others. The main outcome measures were visual acuity and serum tyrosine levels to determine the response to dietary therapy. Intelligence testing and developmental screening were performed when appropriate. RESULTS: All patients presented with ocular signs and symptoms as the primary manifestation of disease and serve to illustrate the typical ocular findings of this syndrome. Three patients presented with cutaneous manifestations, and one patient had mild mental impairment at the time of diagnosis. CONCLUSIONS: Recalcitrant pseudodendritic keratitis may be the presenting sign in tyrosinemia type II. Awareness of the presenting signs and symptoms may accelerate the diagnosis and dietary intervention. Initiation of a tyrosine-restricted and phenylalanine-restricted diet in infancy is most effective in preventing cognitive impairment.

The management of corneal trauma: advances in the past twenty-five years.

Over the past quarter century, advances in our understanding of corneal anatomy, physiology, and wound healing have all played an integral role in the management of corneal trauma. As the etiologies of corneal trauma have changed, so has our understanding of the impact of injury on corneal function as it relates to visual rehabilitation. Numerous new classes of antibiotics, antiinflammatory agents, and tissue adhesives have emerged. Occlusive therapy has advanced from simple pressure patching bandage soft contact lenses and collagen shields. Surgical instrumentation, operating microscopes, viscoelastic substances, and suture materials have all improved the outcomes of corneal trauma repair. Improved understanding of the refractive properties of the cornea through topography and alternative suture techniques has helped us restore the natural corneal curvature and visual outcomes. Consequently, in the last quarter of this century our therapeutic approaches to cornea trauma, both medical and surgical, have improved.

Management of oculus fragilis in Ehlers-Danlos type VI.

PURPOSE: To describe an alternative, novel surgical approach to the repair of a ruptured globe in the second reported patient with keratoglobus, Ehlers-Danlos type VI, and normal lysyl hydroxylase. METHODS: Under general anesthesia, a 360 degrees conjunctival peritomy was performed and the epithelium was removed from the keratoglobus cornea. Descemet's membrane and endothelium were removed from a fresh donor corneoscleral ring. An onlay epikeratoplasty was then performed and the entire donor corneoscleral button was secured to the sclera with 9-0 nylon suture. The conjunctiva was brought into position and tacked down over the edge of the donor graft. After 4 months, a full-thickness penetrating keratoplasty was then performed. RESULTS: The patient ultimately had a ruptured globe in the fellow eye and thus required the identical procedure OU. Both eyes were successfully repaired with a final visual acuity OU of 20/100. CONCLUSION: The described surgical approach allowed successful surgical repair of bilateral ruptured globes in a patient with keratoglobus, Ehlers-Danlos type VI, and normal lysyl hydroxylase levels. In the previous report of such a patient by Judisch et al. (1), the attempt at surgical repair was unsuccessful and ended in enucleation. The described surgical technique may be used to treat advanced keratoglobus or oculus fragilis.

Obesity as a factor in penetrating keratoplasty.

PURPOSE: We reviewed the clinical data on 10 obese patients to define the role of obesity as a factor for consideration in planning penetrating keratoplasty. METHODS: We performed a retrospective case series review of penetrating keratoplasty in obese patients. RESULTS: In our series of 10 patients, spontaneous extrusion of lens and vitreous (three patients) and choroidal hemorrhage (one patient) were intraoperative complications. Wound leakage, wound dehiscence (two patients), iridocorneal synechia formation, and graft rejection (one patient) were postoperative complications. Despite these complications, seven of the 10 patients achieved a final postoperative visual acuity of > or =20/30. CONCLUSION: Cornea surgeons must consider obesity as a potential risk factor that may be mitigated partially by careful preoperative patient evaluation, anesthesia planning, and meticulous attention to patient positioning and comfort during surgery.

Staphylococcal endophthalmitis following cataract extraction in a patient with Darier's disease.

PURPOSE: To report staphylococcal endophthalmitis following cataract extraction in a patient with Darier' s disease. METHODS: A 67-year-old man presented with decreased visual acuity OD and hypopyon 3 days status post-cataract extraction with intraocular lens placement. The patient was hospitalized and placed on topical and intravenous antibiotics. A diagnostic vitreous tap, pars plana vitrectomy, and intravitreal antibiotic installation were performed. RESULTS: Vitreal tap cultures indicated Staphylococcus epidermidis. His clinical status improved after vitrectomy and antibiotic therapy. The same bacteria was cultured from the patient's eyelids. CONCLUSIONS: The source of the S. epidermidis was the skin lesions on the patient's face and eyelids. Darier's disease is an exfoliative hyperkeratotic skin disease that affects all areas on the body except the buttocks. Although clean, sterile surgical techniques were followed, the risk of endophthalmitis following intraocular surgery in a patient with Darier's disease may be increased due to his or her dermatologic condition.

Repair of Descemet's membrane detachment with perfluoropropane (C3F8)

PURPOSE: To report the use of perfluoropropane (C3F8) gas in the repair of Descemet's membrane detachments. METHODS: Descemet's membrane detachments after cataract surgery in three eyes and pars plana vitrectomy in a fourth underwent anterior-chamber gas-exchange descemetopexy with an isoexpansile 14% mixture of C3F8 to facilitate reattachment of Descemet's membrane. RESULTS: Descemet's membrane detachment was successfully reattached after anterior-chamber gas exchange with 14% C3F8 in three of the four eyes treated. The fourth eye treated with 14% C3F8 probably failed Descemet's membrane reattachment because of an unrecognized viscoelastic bleb situated anterior to Descemet's membrane. No corneal decompensation or fluctuations in intraocular pressure were believed to be attributable to isoexpansile C3F8 gas exchange. CONCLUSION: Early recognition and repair of Descemet's membrane detachments may prevent complications, such as corneal decompensation, corneal opacities and edema, and an overall decline in visual acuity. Isoexpansile C3F8 is demonstrated as a safe and efficacious alternative for the repair of Descemet's membrane detachment.

Bilateral corneal ulcers in primary vitamin A deficiency.

PURPOSE: To report a case of bilateral corneal ulcers and perforations resulting from hypovitaminosis A in an alcoholic patient. METHODS: A 38-year-old cachetic man presented with bilateral corneal ulcerations and severe visual loss. He was hospitalized, developed bilateral corneal perforations, and was treated with bilateral corneal transplants. RESULTS: Serum vitamin A level was 0.01 microg/dL (normal, 0.30-0.75). The electroretinogram was consistent with vitamin A deficiency. His clinical status improved after vitamin A replacement. CONCLUSIONS: Although rare in developed countries, the ophthalmologist must consider avitaminosis A in the differential diagnosis of corneal ulcerations in cachetic, alcoholic, or chronically ill patients. Early diagnosis and treatment can prevent unwanted outcomes.

Small-diameter, round, eccentric penetrating keratoplasties and corneal topographic correlation.

PURPOSE: The purpose of the study is to report the outcome and postoperative topographic analysis of seven patients who underwent small-diameter, round, eccentric penetrating keratoplasty. METHODS: Seven patients underwent small-diameter, round, eccentric penetrating keratoplasty for a variety of corneal disorders (cataract wound necrosis and dehiscence or fistula, three patients; penetrating keratoplasty wound infection, two patients; corneal rheumatoid melt and perforation, one patient; localized fungal keratitis, one patient). Full-thickness corneal transplants ranged in size from 3.0 to 5.5 mm. The graft wound and sutures spared the visual axis in all cases. Patients were observed for 7 to 42 months (mean, 21 months). All patients had postoperative topographic analysis. One of these also had preoperative analysis. RESULTS: All grafts tectonically were effective in treating the intended condition. Best-corrected visual acuity was 20/30 or better in the four patients without pre-existing corneal transplants or dry eyes; 20/60 and 5/200 in the patients with previous central penetrating keratoplasties; and 20/40 in the patient with rheumatoid melt. There was no clinically significant regular or irregular astigmatism induced centrally by the eccentric graft in the four patients where visual acuity was 20/30 or better. Irregular astigmatism was noted in the other three patients. CONCLUSION: Small-diameter, eccentric penetrating keratoplasties may be used successfully to treat various peripheral corneal disorders. In some cases, this can be performed without inducing high or irregular astigmatism or both centrally.

OptiSol corneal storage medium and transmission of Treponema pallidum.

This study was conducted to provide experimental information on the probability of syphilis transmission resulting from corneal transplantation. To determine the effects of commonly employed corneal storage conditions on the survival and infectivity of Treponema pallidum, T. pallidum subsp. pallidum (Nichols) was inoculated into OptiSol storage medium or a T. pallidum survival medium at a concentration of 10(6)/ml and incubated in cornea viewing chambers for 24 h at 4 degrees C. When inoculated intradermally into rabbits (0.1 ml per site), none of the 10 sites developed lesions from suspensions incubated in OptiSol in the presence or absence of 100 microgram/ml gentamicin; T. pallidum incubated in the survival medium yielded lesions at one of 10 sites, whereas freshly extracted organisms produced lesions at all 10 sites. In another set of experiments, the infectivity of corneal tissue from rabbits inoculated intratesticularly with 2 x 10(7) T. pallidum 10 days earlier was determined. Corneas from five T. pallidum-infected rabbits were excised, extracted, and tested for infectivity either immediately after removal or after 24-h storage in OptiSol. Recipient rabbits developed lesions at five of 50 intradermal sites when the corneas were neither stored in OptiSol nor rinsed before extraction. Corneas from 10 donor rabbits that were rinsed with phosphate-buffered saline to remove blood and aqueous humor before extraction did not yield lesions at any of 200 sites in the recipient animals. The results of this study indicate that retention of T. pallidum infectivity is poor under typical corneal storage conditions and that rabbit corneal tissue contains few, if any, infectious T. pallidum organisms under the experimental conditions employed.

Clinical pathologic correlation of superficial corneal opacities in X-linked ichthyosis.

X-linked ichthyosis is a relatively common oculodermal disorder. Characteristic corneal opacities are small punctate or filiform lesions and are located in the deep corneal stroma. In an unusual case, a 73-year-old man with X-linked ichthyosis and steroid sulfatase deficiency had superficial corneal opacities. The corneal opacities were granular in nature, involving the subepithelial and anterior stromal layers. The opacities resulted in irregular overlying corneal epithelium and were white-gray in color in direct illumination. Histopathologic and electron microscopic studies demonstrated abnormalities of the corneal epithelial basement membrane. The epithelial basement membrane was thickened with irregular extensions into Bowman's layers. Abnormal depositions of basement membrane protein were seen in the anterior stroma. These abnormalities may have resulted from increased production of basement membrane proteins by the corneal epithelium, resulting from hyperactive turnover of the basal layer.

Tetanus prophylaxis following ocular injuries.

The administration of prophylaxis against tetanus following a corneal abrasion is routinely performed in many acute care facilities, despite a lack of support in the literature for its necessity. The risk of developing clinical tetanus from three different types of injuries to the eye was evaluated in an animal model. Clinical tetanus was induced in unimmunized mice by injecting Clostridium tetani organisms or toxin into the anterior chamber. Immunized mice injected intracamerally did not develop signs of tetanus. Tetanus was not induced by topical inoculation of either live organisms or toxin following corneal epithelial debridement or stromal scarification of unimmunized and immunized mice. The results of this study support the administration of prophylaxis against tetanus following perforating ocular injuries. However, our results do not support its routine use following uncomplicated corneal abrasions or other types of nonperforating ocular injuries.

Deposition of ciprofloxacin, prednisolone phosphate, and prednisolone acetate in SeeQuence disposable contact lenses.

We noted opaque deposits in SeeQuence disposable contact lenses in three patients with persistent epithelial defects who were being treated with topical ciprofloxacin and prednisolone acetate. In each patient, the contact lenses with deposits were removed and replaced. High performance liquid chromatography analysis revealed the deposits to be precipitates of ciprofloxacin and prednisolone acetate. We incubated new SeeQuence disposable contact lenses in ciprofloxacin, prednisolone phosphate, and prednisolone acetate alone and in combination. Precipitates did form when ciprofloxacin was combined with either prednisolone acetate or prednisolone phosphate. We recommend removal and replacement of contact lenses should these deposits develop to prevent the possibility of corneal toxicity.

The results of penetrating keratoplasty for pellucid marginal corneal degeneration.

Over a 14-year period from 1974 to 1988, 12 eyes of 11 patients with pellucid marginal corneal degeneration underwent penetrating keratoplasty. Peripheral corneal thinning required a large eccentric graft in each case. Follow-up ranged from one to eight years (mean, three years). One graft failed because of a persistent epithelial defect with keratolysis of the wound. Although endothelial allograft rejection was common, occurring in seven of 11 (64%) clear grafts, no graft failed because of rejection. Other complications included retinal detachment and a bacterial corneal ulcer. Suture erosion and vascularization of the graft were not problems. Postoperative spectacle correction was dispensed an average of 11 months after surgery. Visual acuity in seven patients without amblyopia, retinal disease, or a previous corneal ulcer at the time of spectacle correction ranged from 20/20 to 20/40 (mean, 20/30). Average final keratometric astigmatism in these patients was 2.46 diopters (range, 0.00 to 5.25 diopters). We believe that penetrating keratoplasty offers an excellent surgical result for patients with pellucid marginal corneal degeneration.

Development of keratoconus after contact lens wear. Patient characteristics.

A retrospective review of 398 eyes of 199 patients with keratoconus revealed 106 eyes of 53 patients with an association between contact lens wear and the development of keratoconus. The absence of keratoconus at the time of contact lens fitting was confirmed by slit-lamp examination, keratometry readings, and manifest refraction. Keratoconus was diagnosed after a mean of 12.2 years of contact lens wear. This group was compared with patients with sporadic keratoconus with either no history of contact lens wear or a history of contact lens wear after the diagnosis. They were older at the time of diagnosis, had central vs decentered cones, and had a tendency toward flatter corneal curvatures. We believe that these patients suggest that long-term contact lens wear is a factor that can lead to keratoconus.

Cell-to-cell fusion of lens fiber cells in situ: correlative light, scanning electron microscopic, and freeze-fracture studies.

We have discovered cell-to-cell fusion between fiber cells of adult frog lenses in situ. Stereo scanning electron microscopy (SEM) revealed fusion between neighboring fiber cells in radial cell columns (RCCs) and in the same growth ring, respectively. Cell-to-cell fusion of fiber cells in the lens produced fusion zones that in cross-section were larger and of different polygonal shapes than unfused fiber cells. The shape and sizes of fiber cells surrounding fusion zones and the alignment of RCCs were also altered. Serial sectioning through fusion zones confirmed that they were areas of cell-to-cell continuity established by the union of neighboring fiber cells as seen by SEM. Fusion zones represent a previously unrecognized intercellular pathway in the adult frog lens. Although numerous fusion zones were seen throughout the lens cortex and nucleus, cell-to-cell fusion was rarely observed to have occurred between elongating fiber cells. Interestingly, communicating junctions with an unusual ultrastructure that closely resembles the appearance of membranes in the process of fusion demonstrated in other systems were frequently seen in the region of the superficial cortex where fusion zones were most numerous. The fact that such unusual communicating junctions were not found in any other region of the lens leads us to speculate that structural changes in fiber cell communicating junctions may herald the formation of fusion zones and that the initial site of cell-to-cell fusion between fiber cells may be within communicating junctional plaques.

Sutures of the crystalline lens: a review.

The sutures of the crystalline lens have previously been studied by light microscopy (LM). While the gross suture patterns (umbilical, line, y-shaped and star) of lenses are readily visualized by LM, fiber cell shape, curvature, length and the morphology of fiber cell ends cannot be adequately resolved by this technique. We have used scanning electron microscopy (SEM) to examine the sutures of crystalline lenses. SEM has revealed that in lenses with line, y-shaped or umbilical sutures, the anterior and posterior ends of fiber cells curve away in opposite directions from the polar axis of the lens before interlocking at suture branches. The degree of curvature decreases as a function of the number of suture branches. This relationship was not resolved by LM. SEM has revealed that the relationship of fiber cell taper to suture type was underestimated by previous LM studies. The reduction in fiber cell width from the equator to the sutures is 3:1 and 2:1 respectively, in lenses with line and y-shaped sutures. Furthermore, in lenses with star sutures, fiber cells are flared (1:1.7) rather than tapered, a fact not reported by previous LM studies. SEM also revealed that the offsetting of anterior and posterior suture branches does not result in equal fiber cell length in any growth ring as reported by LM studies. Rather, fiber cell length in any one growth ring varies as a sine wave function according to fiber cell location at the equator. Furthermore, the range of fiber cell length decreases as a function of the number of suture branches. Finally, SEM has revealed that the distal ends of fiber cells are expanded in both width and thickness prior to interlocking at suture branches and that these ends overlap rather than simply abut end-to-end to form a three dimensional suture plane extending down from the lens surfaces to the primary fiber cell mass.