Infections of the lacrimal system.

Deficiency of the tears or obstruction to the free flow of tears predispose to infections of the lacrimal system. The relevant anatomy of the lacrimal system and the pathologic conditions leading to obstruction are outlined. The clinical manifestations of infections of the lacrimal gland, the canaliculus, and the lacrimal sac are described, and the basis for medical and surgical treatment is discussed.

Recurrence of posterior polymorphous corneal dystrophy after penetrating keratoplasty.

Recurrence of a corneal dystrophy after keratoplasty can occur in multiple dystrophies, including macular, granular, and lattice dystrophies. We treated two unrelated patients who had documented posterior polymorphous dystrophy and who, in previously clear grafts, developed haziness in the zone of Descemet's membrane, which led to graft failure. Histologic examination of the keratoplasty specimen showed changes typical of posterior polymorphous dystrophy.

Factors influencing predilection and outcome in bacterial keratitis.

Complete records from 175 patients with 176 episodes of culture-proven bacterial keratitis treated over a 4-year period at the Massachusetts Eye and Ear Infirmary in Boston were analyzed. Sixty-three percent of the infections involved gram-positive organisms, and 40% involved gram-negative organisms; 15% were polymicrobial. There was a high incidence of infection with Staphylococcus aureus (28%), coagulase-negative staphylococci (14%), diphtheroids (14%), Pseudomonas aeruginosa (14%), and Streptococcus pneumoniae (12%). Gram stain correlation was achieved in 55%. Potential predisposing factors, usually multiple, were identified in 97% of the patients. Fifty percent of the ulcers were associated with such iatrogenic factors as prior topical corticosteroid therapy, penetrating keratoplasty, and contact lens use. Trauma occurred in only 16%. Several statistically significant associations of epidemiologic factors and outcome variables were revealed. Ninety-five percent of the ulcers resolved with therapy, but only 44% of the patients had visual acuity better than the level at admission, and 13% developed major complications.

Idiopathic bilateral lipid keratopathy.

A 52-year-old Mexican man presented with asymptomatic, bilaterally symmetrical lipid infiltrates of the cornea and adjacent limbus. No evidence of previous ocular disease or systemic disorder of lipid metabolism could be detected. Penetrating keratoplasty of the right eye was required. The cornea was rigid and thick, with posterior bulging into the anterior chamber. Light microscopy revealed deep corneal lipid granules, foamy histiocytes, vascularisation, and chronic non-granulomatous inflammation. Transmission electron microscopy showed extracellular lipid spaces and numerous intracytoplasmic lipid vacuoles in histiocytes, keratocytes, conjunctival epithelium, and the endothelium of blood vessels in the corneal stroma and adjacent limbal conjunctiva. Histochemical analysis revealed the presence of neutral fats, free fatty acids, cholesterol, and phospholipids.

Microbial keratitis associated with contaminated ocular medications.

We studied seven cases of severe gram-negative microbial keratitis associated with the use of contaminated topical ocular medications. Five cases involved Pseudomonas aeruginosa, one involved Serratia marcescens, and one involved Proteus mirabilis. In each case the same organism was cultured from corneal scrapings and from the medication. Either prednisolone acetate (one case) or timolol maleate (seven cases) was implicated in all instances.

Clinically atypical granular corneal dystrophy with pathologic features of lattice-like amyloid deposits. A study of these families.

Four patients from families in Pennsylvania, Massachusetts, and Argentina were diagnosed clinically as having granular dystrophy. Results of pathologic examination of the corneal buttons from each patient after penetrating keratoplasty confirmed granular deposits in the anterior third of the stroma. Amyloid was demonstrated within some of these granular deposits by Congo red staining with birefringence and dichroism and by electron microscopy. In addition to the morphologically granular deposits, numerous fusiform deposits identified as amyloid by histochemistry and electron microscopy and morphologically identical to those seen in lattice corneal dystrophy were detected deep to the granular deposits. It was further shown that the histochemical pattern of staining of the granular material by a series of lectins was similar to that present in corneas with lattice dystrophy. Although a relationship between these patients cannot be definitively proven, each family traces its origins to the Italian province of Avellino.

Topical fibronectin in the treatment of persistent corneal epithelial defects and trophic ulcers.

Six patients with persistent corneal epithelial defects that failed to improve with standard therapy were treated with topical fibronectin in a phase I uncontrolled trial. Fibronectin was purified from autologous plasma by affinity chromatography and administered topically, 0.5 mg/ml five times a day, for three weeks. Complete reepithelialization was achieved in five patients: three healed three to 17 days after initiation of treatment while two healed one to two weeks after discontinuation of topical fibronectin. No side effects were observed. Over a follow-up period of three to 18 months, two recurrences were noted.

Corneal hydrops in Terrien's marginal degeneration.

We present four cases of Terrien's marginal degeneration that developed spontaneous ruptures in Descemet's membrane resulting in corneal hydrops. In all cases, the hydrops was characterized by a clear intracorneal pocket of aqueous humor rather than by stromal clouding. In two cases, the pocket extended peripherally to form a conjunctival filtering bleb. Although a lamellar corneal patch graft was used in one case for severe astigmatism, hypotony, and impending perforation, most cases were merely observed without treatment.

Corneal epithelial dysplasia.

Corneal epithelial dysplasia is a rare clinical problem. It is not known whether the corneal epithelial cells undergo dysplastic changes in situ or in the region of the limbal or conjunctival epithelium with subsequent centripetal migration onto the cornea. We obtained an intact, dysplastic corneal epithelial sheet and samples of conjunctival tissue from a 75-year-old patient. Light and transmission electron microscopic examination of the dysplastic corneal epithelium showed histologic evidence of conjunctival, limbal, and corneal epithelium. The adjacent conjunctiva appeared normal except for a possible slight decrease in goblet cells. The 3H-thymidine uptake indicated a normal mitotic index for the conjunctiva. Glycogen content of the dysplastic sheet showed high values seen with corneal and not conjunctival epithelium. The dysplasia recurred despite wide conjunctival resection. Although no final conclusions can be made, we feel our studies support the hypothesis that the dysplastic process in our patient arose de novo in the corneal epithelium.

Corneal hematoma.

Two cases of corneal hematomas initially manifested as corneal blood staining, but were further complicated by the presence of persistent epithelial defects and stromal thinning. Both cases occurred following cataract surgery. Scanning electron and light microscopic examination in the second case demonstrated a loss of keratocytes, stromal collagen breakdown, and epithelial cell degeneration over the center of the hematoma. Large corneal hematomas may cause epithelial degeneration by functioning as barriers to nutrients and metabolic factors from the anterior chamber. Unlike corneal blood staining, conservative treatment is often insufficient therapy for corneal hematomas with associated persistent epithelial defects. Complications from epithelial defects, including corneal thinning, descemetocele, and perforation, may necessitate more aggressive treatment, even surgery. An epithelial defect overlying blood staining should suggest the presence of a corneal hematoma.

Pre-keratoplasty potential acuity evaluation. Laser interferometer and potential acuity meter.

Twenty-three patients who underwent penetrating keratoplasty were evaluated preoperatively for potential retinal acuity utilizing the Randwal Laser Interferometer and the Mentor Potential Acuity Meter. When compared with Snellen visual acuity during the early postoperative period (1-6 months), both instruments were useful as qualitative predictors of macular function when used in the presence of mild to moderate corneal edema. The laser interferometer was somewhat more accurate in the severe cases of corneal edema.

Morphologic characteristics of posterior polymorphous dystrophy. A study of nine corneas and review of the literature.

Based on their own study of nine corneas with clinically documented posterior polymorphous dystrophy and a review of the literature, the authors describe the morphologic features of this entity. Study by phase contrast light microscopy and transmission and scanning electron microscopy found that changes were primarily in the endothelium and consisted of endothelial cell degeneration and loss with focal fibroblastic and epithelial-like cell transformation. Secondary alterations of Descemet's membrane were seen; they consisted of abnormal lamination with deposition of abnormal collagen material, particularly in the posterior collagen layer, and formation of guttate excrescences and pits.

The fellow eye of patients with aphakic bullous keratopathy.

The fellow normal-appearing eyes of 23 patients with unilateral aphakic bullous keratopathy were examined by wide-field specular microscopy and pachymetry. All patients had: pseudophakic or aphakic bullous keratopathy in one eye; unoperated fellow eye on no medication; no other ocular disease; and no endothelial guttata seen by slitlamp biomicroscopy or specular microscopy. Three of 23 patients had endothelial cell counts less than 1,000 cells/mm2. There was no correlation between cell density and corneal thickness, but a negative correlation existed between age and endothelial cell density. Preoperative specular microscopy is indicated in patients who have developed bullous keratopathy in the fellow eye after cataract surgery.

Endothelial guttata and facility of aqueous outflow.

Thirty-eight eyes of 22 patients with corneal endothelial guttata were examined by slit lamp, tonometry, tonography, and wide-field specular microscopy. The mean value for facility of outflow (C55) was 0.23, and it was not statistically different from reported values for a normal population. Also, there was no correlation between extent of guttata as seen with wide-field specular microscopy and facility of outflow. Thus, contrary to a previous report, endothelial guttata does not seem to predispose to impaired facility of outflow.

Posterior subcapsular cataracts induced by topical corticosteroids following keratoplasty for keratoconus.

Posterior subcapsular cataracts studied in 86 eyes of 86 patients transplanted for keratoconus were retrospectively studied. The follow-up period ranged between one and four years with a median of 18 months. Twenty-eight eyes developed posterior subcapsular cataracts. The development of posterior subcapsular cataracts was significantly related to the total cumulative steroid dose and the total time steroids were administered (p less than 0.01). Age, surgical technique, and rejection episodes could not be significantly correlated with development of a posterior cataract. The progression of the cataract appeared to be slow, and if topical steroids were discontinued the lens changes appeared to stabilize and progressed in only one patient. The effect of an early posterior subcapsular cataract on visual acuity was minimal in the early stages.

Epithelial cyst of the iris following penetrating keratoplasty.

In a 35-year-old patient with keratoconus a cyst of the iris was first observed 22 months after routine penetrating keratoplasty. The lesion was completely excised and shown by light and transmission electron microscopy to be composed of conjunctival epithelium organised as a single large cyst containing serous material and occasional free epithelial cells. The management of epithelial implantation cysts is discussed. When indicated, complete surgical excision without ruputure is preferred to avoid possible intraocular dissemination of viable epithelial cells that might result in further complications.

Effect of bilateral and unilateral grafts on the incidence of rejections in keratoconus.

We studied results of 124 keratoplasties in 100 keratoconus patients; 61 men and 39 women varying in ages from 11 to 69 years with an average age of 30 years. Twenty-four patients had bilateral grafts with a 27% incidence of rejection, and 76 patients had unilateral grafts with a 13% incidence of rejection (P less than .01). Data analysis of the first year after the graft of first eyes and subsequent years after the graft of first and second eyes, however, revealed a nearly fourfold increase of rejections following second grafts, with a 17% increased chance of rejection for the first graft after the second was implanted. Only two of the bilateral and two of the unilateral grafts were irreversibly lost because of graft reaction. The major complication was the formation of posterior subcapsular cataract, which occurred in approximately 32% of the patients. The final postkeratoplasty visual acuities were significantly improved. In the patients who did not develop a cataract, 86% achieved visual acuity of 6/12 (20/40) or better. In the patients who did develop cataracts, 68% achieved visual acuity of 6/12 (20/40) or better.

Keratinization of the bulbar conjunctival epithelium in superior limbic keratoconjunctivitis in humans. An electron microscopic study.

A prominent histological feature of superior limbic keratoconjunctivitis is the presence of keratinization of the superior bulbar conjunctiva. Ultrastructurally the affected conjunctival epithelium shows all of the characteristics of keratinization as described in skin. There is a superficial layer of horny cells with reduced organelles and thickened cell membrane. In the intermediate layers, the cells contain an increased number of cytoplasmic filaments which are sometimes aggregated into dense masses, keratohyalin granules, both in the cytoplasm and in the nucleus, membrane coating granules, lysosomes and various other types of membranous structures.