Strain specificity of clinical isolates of herpes simplex virus.

Herpes simplex virus (HSV) produces a wide variety of ocular disease in man. Although host factors are important in determining this variation, it is possible that the different clinical patterns of herpetic ocular disease may be attributed at least partially to the differing biological behavior of specific strains of HSV. To test this theory, we compared the anterior segment disease produced by infecting rabbit corneas with seven different strains of HSV. We found that these seven different strains produced different patterns of ocular disease in the rabbit eye. This also may occur in humans, and we hope to define the biological differences that cause one strain to produce disease more severe than that produced by another strain.

An improved method for detection of ganglionic latency in herpes simplex virus type-1 infected guinea pigs.

A simple method was developed which increased the sensitivity and reliability of detecting latent herpes simplex virus type-1 (HSV-1) in trigeminal ganglia of guinea pigs. Animals were infected with the Shealey strain of HSV-1 immediately following scarification of the cornea and maintained for 30-40 days to ensure that true latency was established. Viral latency was defined as the appearance of infectious virus in ganglia only upon cultivation in vitro. Thus, ganglia from similarly infected animals, homogenized immediately upon removal, did not contain infectious virus. Excised ganglia were incubated intact in high glucose medium and yielded maximal positive results (90-100%) by the twelfth day of incubation. This method was compared with the standard cocultivation technique in which minced fragments of ganglionic tissue were explanted onto Vero cell cultures. Cocultivation yielded a considerably lower latency rate and was more variable (29-57%) than the whole ganglion culture method.

Kaposi's varicelliform eruption. Absence of ocular involvement.

The eponym Kaposi's varicelliform eruption (KVE) describes a characteristic syndrome of disseminated vesicopustules that occasionally complicates a number of dermatoses. Among these, the most common is atopic dermatitis, and the inciting agent is most often herpes simplex virus (HSV). Very few reports of ocular herpetic disease exist among the many cases of KVE reported in the literature, despite extensive cutaneous involvement with herpetic lesions. We describe 10 patients with KVE, none of whom have developed evidence of herpetic ocular disease despite widespread facial involvement in all patients. All random conjunctival swab cultures performed in 3 patients were positive for growth of viable HSV. Although ocular exposure to HSV may commonly occur in KVE, ocular pathology due to this virus does not appear to be a common sequela.

Somatotopic distribution of corneal afferent neurons in the guinea pig trigeminal ganglion.

The size and somatotopic distribution of corneal afferent neurons in the guinea pig trigeminal ganglion were determined using a retrograde axonal tracing technique. Wheat germ agglutinin-horseradish peroxidase (WGA-HRP) was applied to the central cornea of the guinea pig and the animals were perfusion-fixed 48 h later. In addition, a preliminary study examined corneal afferent neurons in two animals latently infected with the herpes simplex virus by corneal inoculation. The majority of WGA-HRP-labelled neurons were located in the ophthalmic division of the ipsilateral ganglion. A clear dorsoventral somatotopic arrangement of labelled corneal afferent neurons was noted. The size of the neurons averaged 23 microns and the number of cells per ganglion averaged 205. By contrast, the number of labelled neurons in latently infected ganglia averaged less than 50. No size or morphological distinctions could be made between neurons from uninfected or latently infected ganglia. The results of this study have provided for the first time the precise location and somata diameter of primary afferent corneal neurons within the guinea pig trigeminal ganglion.

Conjunctival involvement in paraneoplastic pemphigus.

Paraneoplastic pemphigus is a recently described autoimmune inflammatory mucocutaneous disease associated with an underlying neoplasm. Although histopathologic and direct immunofluorescence findings of involved skin and mucous membranes are consistent with pemphigus vulgaris, indirect immunofluorescence and immunoprecipitation study results are unique. We treated two patients with non-Hodgkin's lymphoma and paraneoplastic pemphigus. Both patients had bilateral bulbar conjunctival hyperemia and diffuse papillary tarsal conjunctival reactions. One patient had sloughing of conjunctival epithelium and the other had tarsal conjunctival cicatrization and forniceal shortening. Histopathologic findings of conjunctivae obtained from both patients were consistent with pemphigus vulgaris. Diffuse deposition of IgG and C3 in the intercellular substance of the conjunctival epithelium was demonstrated by direct immunofluorescence. Indirect immunofluorescence testing disclosed binding of autoantibodies to rodent bladder and intestinal epithelium. Immunoprecipitation disclosed antibodies reactive to Desmoplakin I (250 kd), bullous pemphigoid (230 kd), Desmoplakin II (210 kd) and 190-kd proteins. Ophthalmologists and pathologists should be aware of the conjunctival changes in paraneoplastic pemphigus.

In vivo corneal and conjunctival epithelial nuclear stain.

Epithelium plays a very important structural and functional role in the cornea and conjunctiva. Evaluation of the epithelium is the first step in diagnosing many pathologic states. We have developed a new technique for the in vivo staining of nuclei of corneal and conjunctival epithelium in rabbits and guinea pigs. Several drops of 0.01%, 0.1%, 0.25%, 0.5%, or 1.0% toluidine blue or 1.0% methylene blue were applied to the conjunctival sac to stain epithelial cells. The cells picked up the vital dye within 5 minutes and could be photographed at 30X with the Keeler-Konan wide-field specular microscope. Cells and nuclei were clearly observable. Photographs could be further enlarged to enhance details. Wash out time was rapid and no toxic effects were observed. This technique adds a new dimension to the study of epithelium in normal and pathologic states in experimental animals. This technique may also be applicable to human eyes for discerning such diseases as carcinoma, herpes simplex, or superior limbic keratoconjunctivitis.

Survival of Streptococcus pneumoniae in corneal storage media.

The Cincinnati Eye Bank had six corneoscleral rims in which Streptococcus pneumoniae was cultured after preservation in corneal storage media. To determine the survival of this organism under conditions common for corneal storage, gentamicin-supplemented McCarey-Kaufman (M-K) medium and chondroitin sulfate/Dextran medium (Dexsol, Ciron Ophthalmics, Irvine, CA, U.S.A.) were inoculated with S. pneumoniae and kept at 4 degrees C. Thioglycollate broth plus 10% rabbit serum (Thio-S) and tryptic soy broth (TSB) served as growth controls. At day 14 after inoculation of 10(5) colony-forming units (CFU)/ml, Dexsol showed a 1-log decrease in bacterial concentration, the M-K medium a 2-log decrease and Thio-S a 4-log decrease, whereas TSB showed no detectable organisms. By day 21 Dexsol had only a 2-log decrease in bacteria. These data suggest that corneal storage medium supplemented with gentamicin does not exert bactericidal activity against S. pneumoniae and may actually support its survival at 4 degrees C.

Appearance of immune cells and expression of MHC II DQ molecule by fibroblasts in alkali-burned corneas.

Corneal alkali burns are characterized by persistent inflammatory response and recurrent epithelial erosions. We examine whether immune cell types, i.e., T-cells and B-cells, play a role in this devastating process. Rabbit alkali-burned corneas that healed for 1-49 days were subjected to immunostaining with monoclonal antibodies (mAb) L11/135 (anti-T-cells), and 2C4 (anti-MHC II DQ). Serum was collected weekly and subjected to Western blot immunostaining to detect antibodies against denatured corneal proteins. Our observations demonstrated that all injured corneas reepithelialized within 3 days but then developed recurrent erosions. Immunohistochemical studies revealed that PMN, monocytes, and B-cells labeled by 2C4 mAb and T-cells labeled by L11/135 mAb appeared in the periphery to the cornea at 1 day after alkali burn. Many of these myeloid and lymphoid cells invaded the central stroma after 2 weeks of injuries when the alkali-burned corneas were heavily vascularized. In addition, some fibroblastic cells also expressed the MHC II DQ molecules in the alkali-burned corneas that had healed for > 2 weeks. Plasma cells appeared in granulation tissue of injured corneas that had healed for > 3 weeks. Western blot analysis demonstrated a production of heterogeneous antibodies in a majority of the rabbits (11 of 14) to various denatured corneal proteins (between 80 kDa and 25 kDa) at 5 weeks of alkali burn. Inflammatory cell types, i.e., PMN, macrophages could be found underneath the detached epithelium. These observations are consistent with the notion that the myeloid and lymphoid cells may participate in and complicate the healing of corneal alkali burns.

Herpes simplex and recurrent corneal disease.

The management of a patient with ocular HSV is a challenge for the ophthalmologist. Attacks may vary in clinical presentation with each episode. Patients should be instructed to contact their ophthalmologist at the first sign of a problem. Because a recurrent attack may be painless, patients may be reluctant to seek medical attention. Therefore, I give patients three easy warning signs to remember. They are instructed to contact me if the eye becomes red or painful or the vision decreases. Those patients with a history of ocular HSV who will undergo immuno-suppression (e.g., renal transplant) must be watched closely (Fig. 5). I often recommend several drops per day of prophylactic trifluridine for these patients while they are on steroid therapy and immunosuppressives. Because of the dangers of corticosteroids without antiviral cover, I instruct patients to emphasize their history of herpetic ocular disease to any physician who may want to treat the patient with corticosteroids. In those patients in whom a trigger mechanism can be identified, I may also recommend prophylactic antiviral agents to be taken at the time that such mechanisms are likely to be activated. Because minor trauma can precipitate a recurrent attack in some patients, I discourage cosmetic contact lens wear in these patients. There has been no form of therapy to date that has decreased the recurrence rate for HSV infections. Research to develop a vaccine that would prevent herpetic latency is ongoing. Such a vaccine theoretically would make herpetic ocular disease nonrecurrent . In our own laboratories at the University of Cincinnati College of Medicine, we have been working with a promising vaccine prepared against the early viral-induced proteins. Thus far, this vaccine has prevented latency in experimental animals. Perhaps it will prevent latency in the human. Further work with newer antiviral agents such as acyclovir may aid in our fight against this disease. Interferon may also find a place in the possible prevention and treatment of recurrent herpetic ocular disease. In the meantime, different forms of recurrence with almost every conceivable complication can occur. The ophthalmologist must, therefore, be diligent in the management of his or her patients with ocular herpetic disease.

Central retinal artery obstruction in herpes zoster ophthalmicus and cerebral vasculopathy.

We present a case of acute central retinal artery obstruction in association with Herpes zoster ophthalmicus and delayed cerebral vasculopathy. Retinal vascular obstruction is rare in zoster, and its occurrence during postherpetic cerebral vasculopathy has not been reported previously to our knowledge. The syndrome of delayed cerebral vasculopathy is discussed as is its possible relationship to central retinal artery obstruction.

The pathogenesis of herpetic ocular disease in the guinea pig.

A detailed study of the pathogenesis of herpetic eye disease in the guinea pig was undertaken to further develop this animal model. Several well-known HSV-1 strains were tested for their ability to produce disease and cause acute and latent infections of the trigeminal ganglion: McKrae, KOS, McIntyre, RE, and Shealey. Two HSV-2 strains failed to cause eye infections. The Shealey strain [HSV-1 (Sh)] produced the most severe eye infections, characterized by epithelial and stromal disease, corneal vascularization and ulcerative blepharitis. Consequently, HSV-1 (Sh) was selected as the prototype strain for this study. The frequency and severity of HSV-1 (Sh) eye disease patterns was determined by a semi-quantitative rating scale, which permitted accurate monitoring of the temporal development of the disease patterns cited above. Virus shedding from infected eyes was also quantified. All of the HSV-1 strains tested established trigeminal ganglionic latency with varying frequency, although HSV-1 (Sh) latency approached 100 percent. The kinetics of acute ganglionic infection by HSV-1 (Sh) was determined, and peak virus titers occurred on the third day after corneal inoculation. This study emphasizes the usefulness of the Guinea pig model for investigations on the pathogenesis, prevention and treatment of herpetic eye infections.

Ophthalmia nodosa caused by tarantula hairs.

A young woman presented with ocular discomfort after handling her pet tarantula. Multiple fine hairs were detected on the eyelids, in the palpebral and bulbar conjunctiva, and in the corneal epithelium and stroma. In addition, foreign body granulomas were found in the conjunctiva. Six months later, peripheral chorioretinal lesions were seen. The clinical and histologic findings in this case closely resemble the findings in ophthalmia nodosa caused by caterpillar hairs.

Living retinal nematode (filarial-like) destroyed with photocoagulation.

A motile worm creating tracks upon the pigment epithelium of the retina was observed in each of two patients. The fundus findings resembled pseudoretinitis pigmentosa. Unilateral macular degeneration resulted in one patient. The worm was a nematode, probably a filaria. This report represents the third and fourth intraocular filariae found in the United States. To our knowledge, it is the first report of living, intraretinal filarial-like worms destroyed by photocoagulation.

Toxicity and tolerance of 9-(2-hydroxyethoxymethyl)guanine.

Acyclovir [9-(2-hydroxyethoxymethyl)guanine] is a new antiviral agent which has specific activity in virus-infected cells. The drug has a high therapeutic index in animal and laboratory models but had not been tested for toxicity in human eyes at the time of this study. A randomized double-blind study on patients requiring antiviral therapy for treatment or prophylaxis of herpetic ocular infections revealed minimal irritation associated with topical administration. Further controlled studies will be necessary to evaluate this compound's clinical efficacy.