A rabbit model for herpes simplex virus (HSV) stromal keratitis, produced by intrastromal injection of live virus, was used to evaluate the effects of tunicamycin and 2-deoxy-Dglucose therapy. In vivo and in vitro evidence suggests that HSV strains that produce stromal disease secrete relatively large amounts of highly antigenic glycoproteins. Also, various studies have shown that tunicamycin and 2-deoxy-D-glucose inhibit the production of complete HSV-specific glycoproteins. Thus, these drugs might be capable of mitigating the clinical manifestations of HSV stromal keratitis by reducing the antigenic load. However, when topical therapy with tunicamycin and/or 2-deoxy-D-glucose was begun in rabbit eyes, the day after intrastromal inoculation of live RE strain HSV and several days before the appearance of stromal disease, no difference in the clinical course of herpetic ocular disease was seen between the experimental (treated) and control (untreated) groups. Invest Ophthalmol Vis Sci 25:219221, 1984 Although ocular epithelial herpetic disease does not normally produce permanent damage to the eye, stromal disease often results in irreversible scarring of the cornea, and is therefore a far more serious form of herpes simplex virus ocular infection. Wander et al 1 have shown that experimental ocular herpetic disease produced by different strains of herpesvirus type 1 varies in a consistent and reproducible pattern. Some of these strains produce no epithelial disease or minimal conjunctivitis, some produce minimal epithelial disease, and others produce necrotizing stromal disease. In addition, these variations seem to be relatively independent of the size of the inoculum. Thus, each virus strain appears to have its own biologic properties. Because the pathogenesis of necrotizing stromal keratitis appears to involve a destructive immunologic reaction, many investigators have tried to compare the immune systems of those who get this disease and those who do not. None of these studies has been particularly useful. Some evidence suggests that the HSV strains that produce stromal disease produce relatively large amounts of highly antigenic glycoproteins and that the strains that produce epithelial disease, produce relatively few glycoproteins in relatively small amounts.2 In various in vitro and in vivo studies, tunicamycin and 2-deoxy-D-glucose were found to inhibit the production of herpes simplex specific glycoproteins, and it appears likely that the presence or absence of stromal disease may be determined by the host reaction to the virus-secreted glycoproteins. The present study was designed to evaluate the effect of tunicamycin and 2-deoxy-D-glucose, either separately or in combination, on stromal keratitis in rabbits. Materials and Methods. Virus: RE strain HSV was grown in RK-13 cells. A suspension of infected cells was used to produce the model of stromal keratitis in the rabbit eye. Rabbits: New Zealand white rabbits weighing 2-3 kg were given intramuscular injections of chlorpromazine (Thorazine 25 mg/kg) one hr prior to inoculation of the cornea. Corneas were anesthetized by the topical application of proparacaine HC1 (Ophthaine 0.5%) and injected intrastromally with approximately 0.02 ml of the RE strain of herpesvirus suspension. The injection was given with a 27-gauge needle attached to a tuberculin syringe. Both eyes of all animals were injected with the virus. Drug Therapy: The topically treated rabbits were

This important article1Reynaud C. Rousseau A. Kaswin G. et al.Persistent impairment of quality of life in patients with herpes simplex keratitis.Ophthalmology. 2017; 124: 160-169Abstract Full Text Full Text PDF PubMed Scopus (30) Google Scholar points out the severe reduction in quality of life that herpes simplex keratitis causes, even after initial recovery, and documents the significant likelihood of recurrence. The Herpetic Eye Disease Study2Herpetic Eye Disease Study GroupAcyclovir for the prevention of recurrent herpes simplex virus eye disease.N Engl J Med. 1998; 339: 300-306Crossref PubMed Scopus (309) Google Scholar demonstrated that prophylactic oral acyclovir (a generally nontoxic drug) can reduce the likelihood of recurrence. This suggests that oral acyclovir or valacyclovir should be considered as continuing prophylaxis after recovered keratitis to improve the ultimate quality of life, which has been so clearly demonstrated to be significantly reduced in patients with this disorder. Persistent Impairment of Quality of Life in Patients with Herpes Simplex KeratitisOphthalmologyVol. 124Issue 2PreviewTo evaluate the quality of life (QoL) in patients with quiescent herpes simplex keratitis compared with control patients without ocular herpes. Full-Text PDF

To test and compare in a masked fashion the efficacy of using a parasympathomimetic drug (3% carbachol) and an alpha-2 agonist (0.2% brimonidine) in both combined and separate forms to create optically beneficial miosis to pharmacologically improve vision in presbyopia.

Purpose: To evaluate the importance and practicality of testing for matrix metalloproteinase 9 (MMP-9) in dry eye and ocular surface disease. This enzyme, which can cause tissue damage, seems also to be the most reliable diagnostic indicator of ocular surface disease.Methods: Enzyme-linked immunosorbent assay, polymerase chain reaction, diffusion, and InflammaDry, a new rapid immunoassay by RPS (Rapid Pathogen Screening Inc).Results: MMP-9 measurement is sensitive and accurate for diagnosing dry eye and ocular surface disease and compares favorably in both sensitivity and specificity against the existing methods of dry eye diagnosis. Abnormal elevations of MMP-9 may predict post-laser in situ keratomileusis complications and refractive complications such as epithelial ingrowth and corneal ulceration. The presence of elevated MMP-9 on the ocular surface will identify those patients who should receive antiinflammatory therapy, such as cyclosporine, and may predict those patients who will respond to this therapy.Conclusions: A rapid in-office test that is sensitive for identifying inflammatory dry eye and ocular surface disease may facilitate better preoperative management of the ocular surface. Optimization of the ocular surface perioperatively would be expected to reduce complications from laser in situ keratomileusis and other surgeries that often make the underlying disease worse. This test may also indicate the need for antiinflammatory therapies, such as cyclosporine or steroids, and also may predict those patients who are more likely to respond.

BACKGROUND:Until the availability of ganciclovir ophthalmic gel in 2009, the only option for treating herpes simplex (HSV) keratitis in the USA has been trifluridine (TFT), a compound with tolerability issues related to its nonselective inhibition of DNA replication in both normal cells and virus-infected cells. Ganciclovir has selective pharmacologic activity on viral thymidine kinase and a lower potential for toxicity to healthy human cells. Our objective was to evaluate safety and efficacy findings reported with the use of ganciclovir ophthalmic gel, both for HSV keratitis and other potential clinical indications. METHODS:Clinical and preclinical data with ganciclovir were identified through a comprehensive electronic search of PubMed and Medline, using the search terms ganciclovir, ganciclovir 0.15% ophthalmic gel, acyclovir, acyclovir ointment 3%, herpes simplex keratitis, treatment of herpes simplex keratitis, and adenoviral keratoconjunctivitis. The authors were also granted access to previously unpublished ganciclovir surveillance safety data from Bausch & Lomb, Inc. RESULTS:No clinical data comparing ganciclovir ophthalmic gel to 1% trifluorothymidine (TFT) for HSV keratitis could be identified. Four international, randomized, multicenter clinical trials have demonstrated that ganciclovir gel is at least as effective as acyclovir ointment for the treatment of HSV keratitis. Ganciclovir gel was better tolerated, with lower rates of blurred vision, eye irritation, and punctate keratitis. Recent data also indicate it may hold promise as a treatment for adenoviral keratoconjunctivitis. Worldwide safety surveillance data collected over the past 10-15 years in over 30 countries suggests an extremely low rate of spontaneously reported adverse events with ganciclovir ophthalmic gel. CONCLUSIONS:Current data suggest that ganciclovir ophthalmic gel has similar efficacy as acyclovir ointment for the treatment of HSV keratitis and is better tolerated. Clinical head-to-head studies comparing ganciclovir and TFT would be of great interest, especially for US physicians.

Most humans are infected with herpes simplex virus (HSV) type 1 in early childhood and remain latently infected throughout life. While most individuals have mild or no symptoms, some will develop destructive HSV keratitis. Ocular infection with HSV-1 and its associated sequelae account for the majority of corneal blindness in industrialized nations. Neuronal latency in the peripheral ganglia is established when transcription of the viral genome is repressed (silenced) except for the latency-associated transcripts and microRNAs. The functions of latency-associated transcripts have been investigated since 1987. Roles have been suggested relating to reactivation, establishment of latency, neuronal protection, antiapoptosis, apoptosis, virulence and asymptomatic shedding. Here, we review HSV-1 latent infections, reactivation, recurrent disease and antiviral therapies for the ocular HSV diseases.

Purpose of reviewAdenoviral infection is common, can be severe, and may cause significant morbidity.Recent findingsOphthalmologists and optometrists are often guilty of spreading adenovirus because it is highly contagious and has 53 serotypes with variable morphology. Adenovirus is often difficult to diagnose based on clinical appearance and, in the early stages, is associated with a red eye or superficial keratitis common to herpes and other infections. This difficulty results in the indiscriminate use of antibiotics, which are expensive and of no established value in treating a viral infection. The difficulty of accurate diagnosis also makes the use of newer proposed treatments less valuable and even potentially hazardous.SummaryNew diagnostic tests such as the Rapid Pathogen Screening (RPS) Adeno Detector that are practical, rapid, and inexpensive to use in the office may obviate these problems.

Purpose: To compare the clinical findings and confocal microscopic features of the lamellar interface after 2 types of deep anterior lamellar keratoplasty (DALK): Descemetic with total stromal resection versus pre-Descemetic with deep stromal dissection. Methods: Twenty eyes of 20 patients who had corneal disease with healthy endothelium were treated by DALK using the air technique. Baring of Descemet membrane (DM) was achieved for 12 eyes (Descemetic group). A fine stromal layer was left in 8 eyes (pre-Descemetic group). Visual acuity, interface clarity, corneal topography, confocal microscopy, and endothelial cell count were analyzed. Results: DM microperforation occurred in 2 eyes (10%). No patient required conversion to penetrating keratoplasty (PKP) intraoperatively. Presumed stromal rejection occurred in 1 eye that was excluded from the study. In the Descemetic group, 90.9% achieved final best-corrected visual acuity (BCVA) of 20/30 or better; in the pre-Descemetic group, 75% achieved final BCVA of 20/30 or better. No statistically significant difference in mean visual outcomes was found between groups. The reflectivity of activated keratocytes at the interface was less in the Descemetic than that in the pre-Descemetic group. Ten to 12 weeks after pre-Descemetic DALK and 4 to 6 weeks after Descemetic DALK, keratocyte morphology and reflectivity had returned to normal. Mean combined topographic astigmatism was 2.17 ± 0.75 diopters (D) at 6 months (sutures out). Conclusions: The depth of the lamellar bed, smoothness, and healing process at the interface are the keys to optimal visual acuity. Although dissection to bare DM is more difficult, keratocyte activation and interface haze were less, but differences in final visual acuity were not significant.

PURPOSETo determine whether trifluorothymidine (TFT) and ganciclovir (GCV) are synergistic against herpes simplex virus type 1 (HSV-1).METHODSTFT and GCV activity against 12 strains of HSV-1 (including an acyclovir-resistant strain) was measured by plaque-forming unit (PFU) inhibition. Cellular toxicity was assessed with an MTT dye reduction assay. Synergism was determined by calculating fractional inhibitory concentration (FIC indices) based on PFU reduction.RESULTSConcentrations of TFT resulting in 50% inhibition of PFUs (IC(50)) of acyclovir-susceptible HSV-1 strains ranged from 3.07 ± 0.36 to 12.52 ± 0.61 μM. GCV IC(50) values ranged from 0.40 ± 0.02 to 1.59 ± 0.14 μM. IC(50) values of TFT and GCV against the acyclovir-resistant strain were 15.40 ± 3.17 and 93.00 ± 9.64 μM, respectively. Concentrations of TFT or GCV resulting in 50% cell cytotoxicity (CC(50)) were 0.99 ± 0.01 and 92.91 ± 8.92 μM, respectively. TFT and GCV combined (10:1) were 10 times more potent against all acyclovir-susceptible HSV-1 strains. For 8 of 12 HSV-1 strains, the IC(50) of TFT and GCV combined was lower than the CC(50) of either drug. For acyclovir-susceptible HSV-1 strains, TFT and GCV combined generated a FIC index of <0.5, suggesting strong synergism between the two drugs. The FIC value for TFT and GCV combined against the acyclovir-resistant HSV-1 strain was 0.84, indicating nonantagonism.CONCLUSIONSTFT and GCV are synergistic against acyclovir-susceptible HSV-1 at concentrations significantly less toxic than if each antiviral were used as a sole agent.

OBJECTIVE:To compare wound healing and morphologic characteristics of the host-donor interface in rabbit corneas after maximum-depth and near-Descemet membrane anterior lamellar keratoplasty.DESIGN:Descriptive analysis of confocal microscopy images after 2 types of deep lamellar keratoplasty (deep stromal dissection vs total stromal resection).METHODS:Deep anterior lamellar keratoplasty (DALK) was performed in 16 rabbit eyes, with exposure of the Descemet membrane in 8 eyes (deep group) and deep stromal dissection to near the Descemet membrane in 8 eyes (near group). A full-thickness graft devoid of endothelium and Descemet membrane was sutured in place. Confocal examination of lamellar interface and wound edge was performed throughout 6 months.RESULTS:Four days postoperatively, confocal microscopy revealed numerous highly reflective keratocytes at and adjacent to the interface in all eyes, fewer in the deep than the near group. Keratocyte density and reflectivity returned to normal at 4 to 6 weeks (deep) and 8 to 10 weeks (near) postoperatively.CONCLUSIONS:In the deep group, the smooth interface showed less scarring. In the near group, stroma-to-stroma healing stimulated more activated keratocytes and hence more haze. Successful DALK requires minimal central healing for clarity but significant suture-stimulated healing at the edge to prevent corneal bulge.CLINICAL RELEVANCE:Deep anterior lamellar keratoplasty is rarely accompanied by rejection, avoids entrance into the anterior chamber, and can be performed with tissue that does not have living keratocytes. Interface healing is a determinant of the final visual acuity; depth of the lamellar bed is a major determinant of the healing response. Although dissection to bare the Descemet membrane is more difficult, there is less keratocyte activation and scarring.

PURPOSE To assess the effect of high doses of valacyclovir (VCV) on HSV-1 DNA shedding into tears of latently infected rabbits. METHODS Three oral doses of VCV were tested. Corneas were inoculated with HSV-1, and latent infection was allowed to establish. Starting on postinoculation (PI) day 28, tear swabs were collected once daily for 6 consecutive days before treatment. The rabbits were placed in five balanced groups: group 1 had no treatment, group 2 received placebo, group 3 received 7 mg/kg VCV, group 4 received 70 mg/kg, and group 5 received 140 mg/kg. The treatment was administered by oral gavage twice daily, starting on PI day 36 and continuing for 14 days. The ocular swabs were collected beginning on PI day 40 and continuing for 10 days. RESULTS The mean copy number of HSV-1 DNA before treatment was 370+/-70, 569+/-273, 368+/-86, 408+/-108, and 396+/-91, and the mean HSV-1 DNA copy number after treatment was 232+/-183, 564+/-186, 518+/-122, 67+/-63, and 13+/-7 in groups 1 to 5, respectively. CONCLUSIONS There was no observable toxicity in any group. The 70- and 140-mg/kg doses of VCV significantly reduced the HSV-1 DNA copy number, compared with that of the other three groups. A daily dose of 500 mg (approximately 7 mg/kg) VCV in healthy human volunteers did not suppress HSV-1 DNA shedding in tears and saliva. Thus, higher doses of VCV may be necessary to reduce asymptomatic shedding in healthy human subjects.

Ganciclovir (GCV) is a potent broad-spectrum antiviral with proven efficacy against herpes viruses. As it inhibits viral but not cellular DNA, it is expected to avoid the toxicity associated with trifluridine - the only currently approved treatment for herpes simplex keratitis in the USA. Preclinical studies have demonstrated GCV to be as effective as trifluridine against experimental herpes simplex keratitis. Clinical studies conducted in Europe, Asia, and Africa that compared the efficacy and tolerability of GCV ophthalmic gel with acyclovir (ACV) ophthalmic ointment in patients with herpetic keratitis showed that GCV-treated patients had higher overall healing rates and lower relapse rates than ACV-treated patients. The ganciclovir gel formulation was also much better tolerated than the ACV ointment base. Finally, a controlled, masked, randomized series of 18 patients with adenoviral keratoconjunctivitis compared GCV gel with preservative-free artificial tears. Ganciclovir-treated patients experienced a shorter acute-disease phase and exhibited significantly fewer subepithelial infiltrates.

PURPOSE:To determine changes in host gene expression in HSV-1 latent trigeminal ganglia (TG) after hyperthermic stress. METHODS:Scarified corneas of 6-week-old female BALB/c mice were inoculated with either HSV-1 17Syn(+) (high phenotypic reactivator) or 17DeltaPst(LAT(-)) (low phenotypic reactivator) at 10(4) plaque-forming units/eye. At 28 days after infection, viral reactivation was induced in some of the infected mice with hyperthermic stress, and the mice were killed after 1 hour. Heat-treated uninfected mice served as the control. Labeled cRNA derived from TG-isolated total RNA was hybridized to 430 2.0 chips containing 14,000 mouse genes. Gene expression was confirmed by quantitative real-time PCR. RESULTS:There was no difference in gene expression in the non-heat-treated mice. Gene expression in the TG of each of the heat-treated mouse groups (17Syn(+), 17DeltaPst(LAT(-)) and uninfected) yielded upregulation of more than twofold of a group of the same genes, designated as heat stress-induced gene expression. Twenty-nine genes (0.2%) were significantly upregulated (2- to 17-fold) when the heat stress-induced gene expression was subtracted from the gene expression of 17Syn(+) latent TG relative to 17DeltaPst(LAT(-)) latent TG 1 hour after mouse hyperthermic stress. Nine host adaptive immunity genes comprising Ig molecules, CD83, CD8A, ADA, and CCL8 were the largest subset upregulated, and all were confirmed by real-time PCR. Others identified included genes involved in hypothalamic-pituitary gland functions. CONCLUSIONS:Hyperthermic stress-induced reactivation of the HSV-1 high phenotypic reactivator can upregulate gene expression involved in B-cell function and in T-cell function. CD83 is implicated in HSV-1 latency, suggesting it could also be involved in immune-mediated mechanisms of viral reactivation.

Author(s): Tezel, Gulgun; Fourth ARVO/Pfizer Ophthalmics Research Institute Conference Working Group