Lawrence W. Hirst

Possible Mechanisms for the Loss of Goblet Cells in Mucin-deficient Disorders

By studying the pathological changes in human conjunctival flaps and the conjunctival transdifferentiation in rabbits, we have identified and correlated two pathological processes with the loss of goblet cells: (1) loss of vascularization, and (2) intense inflammation. Loss of vascularization may be correlated with the loss of goblet cells in the chronic cicatricial stage of various mucin-deficient disorders, whereas inflammation may be responsible for their absence in the acute inflammatory stage. The exact interrelationship between these two processes remains unknown. The loss of goblet cells appears to be an early sign of a spectrum of squamous metaplasia, an abnormality of epithelial differentiation. We therefore speculate that loss of vascularization and intense inflammation may have an important effect on epithelial differentiation.

Hereditary Fuchs' Dystrophy

We studied 102 individuals from 25 families in which at least one member was known to have Fuchs endothelial dystrophy. We used slit-lamp examination, corneal pachymetry, and specular microscopy. We also examined pathology records which contained 79 cases of penetrating keratoplasties done solely for phakic Fuchs dystrophy between 1940 and 1978. Although there was a marked predominance of females in our review of pathology records, our clinical study provided a more even sex distribution. There was a close correlation between the number of expected and observed affected first-degree relatives based on an autosomal-dominant mode of inheritance. We observed a fairly typical corneal pattern, beginning as a circumscribed area of central or paracentral cornea guttata, and thereafter expanding more horizontally than vertically with progression of severity. Fuchs dystrophy appears to be a true corneal dystrophy with autosomal-dominant inheritance, a high degree of penetrance, and variable expressivity, with generally increased severity among females.

Specular Microscopy of Hard Contact Lens Wearers

Wide-field specular microscopy, slit-lamp examination, and pachometry were performed on 22 successful hard contact lens wearers and 22 controls matched for age, race, sex, and refractive error. A minimum of 600 cells per control and 1200 per contact lens wearer were manually digitized from the specular photomicrographs. Frequency distributions of cell areas were compared between the two groups using the parameters of mean, median, standard deviation, coefficient of variation, skewness and kurtosis. Slit-lamp examination was normal and there was no significant difference in corneal thickness between the patient group and the control group. Comparison of mean, median, and standard deviation also revealed no significant difference, but skewness (P less than .001), kurtosis (P less than .001) and coefficient of variation (P less than .004) were greater in the hard contact lens wear group. Hard contact lens wearing time correlated with increasing pleomorphism (P less than .05). Specular microscopy also revealed morphologic changes including deep stromal striae, intra- and extracellular blackout areas, and clustering of extremely small and large cells. The possible relationship between endothelial hypoxia and structural stromal changes are discussed.

Quantitative Corneal Endothelial Evaluation in Intraocular Lens Implantation and Cataract Surgery

We analyzed pre- and postoperative corneal endothelial photographs of 33 intraocular lens patients and found an average endothelial cell density loss of 14%. Twenty-six cataract patients, similarly examined, showed a 13% mean endothelial cell loss. In 14 of the intraocular lens patients, a second postoperative evaluation of the central endothelium, at a later date, revealed a trend toward continuing cell loss. Our results indicate fewer endothelial cells were lost after intraocular lens implantation than has been previously reported. This may be accounted for by our considering only patients with normal corneas for lens implantation, and by our constant maintenance of the anterior chamber with an air bubble during lens implant surgery.

Corneal Perforations: Changing Methods of Treatment, 1960–1980

One hundred four nontraumatic corneal perforations or descemetoceles in patients admitted to the Wilmer Institute from 1960 to 1980 were studied retrospectively, with follow-up data obtained from records or from referral physicians for 87 of these perforations. Forty-nine percent of the cases were caused by bacterial corneal ulcers, 13% by exposure, 12% by chemical burns, 6% by fungal keratitis, 5% by herpes simplex keratitis, and 15% were undiagnosed. Since the start of tissue adhesive use at the Wilmer Institute in 1974, there has been an apparent trend towards a lower enucleation rate (6%) in corneal perforations treated with tissue adhesive as compared to 19% in perforations treated by other therapies, although the cases may not be entirely comparable. An improved visual result of 20/200 or better was achieved in 29% of patients treated with tissue adhesive as compared to 19% with other treatment.

Management of Acanthamoeba Keratitis: A Case Report and Review of the Literature

A recalcitrant corneal ulcer resulted in an extensive corneal opacity requiring penetrating keratoplasty. Histopathologic studies and subsequent cultures established the diagnosis of Acanthamoeba keratitis. A second transplant was performed due to a culture-proven recurrence of the keratitis in both the recipient and the graft, with progressive thinning. This has remained clear for six months on systemic ketoconazole and topical miconazole drops. This case demonstrates the difficulty in initial diagnosis of Acanthamoeba keratitis and the apparent successful medical control of the infection despite transplantation into an infected recipient bed.

Ocular BB Injuries

Data from the United States Consumer Product Safety Commission indicate that air-powered guns were responsible for 22,800 injuries treated in emergency rooms during 1981, of which 1255 were eye injuries. From 1970 to 1981, 32 patients have undergone surgical intervention at the Wilmer Eye Institute for airgun-related eye injuries. Of the 22 patients with penetrating injuries from the pellets, 19 eyes were enucleated; final vision in the three remaining eyes was worse than 5/200. Of seven patients with nonpenetrating injuries, six had final vision of 20/40 or better. All three patients with penetrating injuries from shattered spectacle lenses had final vision of 20/40 or better. Histopathologic examination of the enucleated specimens demonstrated severe disruption of intraocular contents, particularly posteriorly. Despite the potential ocular dangers of airguns, only 11 states have enacted legislation that regulates their sale or use. BB injuries represent a devastating form of ocular trauma which can be prevented by adoption and enforcement of appropriate legislation.

Clinicopathologic features of Chandler's syndrome

The clinicopathologic features of Chandlers syndrome are elucidated based on a study of nine patients. Keratoplasty, trabeculectomy and/or iris specimens were studied by light, electron and, in six cases, specular microscopy. The prominent pathologic features were abnormalities of the endothelially-derived cells lining the posterior corneal surface, the inner surface of the trabecular meshwork, and the anterior iris surface. In all four corneal buttons, the endothelium was diffusely attenuated and focally absent, and posterior collagen layers were present. Extension of the endothelial cell layer and Descemets membrane deposition over the trabecular meshwork were observed in two trabeculectomy specimens, and similar proliferation onto the anterior surface of the iris was evident in four iris specimens. Other abnormalities of the endothelial cells included increased intracytoplasmic filaments. These pathologic alterations are consistent with the concept of Chandlers syndrome as representing one variant of the iridocorneal endothelial (ICE) syndrome. Interestingly, although both endothelial proliferative and degenerative responses can be observed in Chandlers syndrome, their occurrence within the same eye is apparently not simultaneous.

Diagnosing and treating Phthirus pubis palpebrarum

Phthiriasis palpebrarum is an uncommon cause of blepharitis and conjunctivitis and may easily be overlooked. A high index of suspicion and careful examination of the patients lid margins and eyelashes will lead to the proper diagnosis. Treatment is best accomplished by careful removal of the lice and nits (louse eggs) from the patients lashes. Local application of a pediculocide such as yellow mercuric oxide N.F. 1% ophthalmic ointment applied twice daily for one week or 0.25% physostigmine (Eserine) ointment applied twice daily for a minimum of ten days, to the lid margins should be considered when the total removal of Phthirus pubis and nits is not possible mechanically. Body hair should be examined for infestation with lice and treated with gamma benzene hexachloride shampoo. This medication should be used with caution in infants, children and pregnant women. Family members, sexual contacts, and close companions should be examined and treated appropriately; clothing, linen and personal items should be disinfected with heat of 50 degrees C for 30 minutes.

Prevalence of map-dot-fingerprint changes in the cornea.

Map-dot-fingerprint basement-membrane abnormalities of the cornea are common in the general population, affecting as many as 76% of persons over age 50 and 42% of persons of all ages. The prevalence of this condition in the general population is not significantly different from that found in families of patients with recurrent corneal erosions and map-dot-fingerprint corneal changes. Despite this extremely high prevalence of basement-membrane changes the incidence of recurrent erosive symptoms in total groups of patients with basement-membrane changes is quite rare, suggesting that these 2 entities are possibly not related. Although previous observers have suggested an autosomal dominant mode of inheritance of these basement-membrane changes, our data raise the possibility that map-dot-fingerprint basement-membrane changes represent an age-dependent, degenerative condition of the cornea. We were unable, however, to prove either hypothesis.