Takeshi Ohguchi

Novel Human Adenovirus Causing Nosocomial Epidemic Keratoconjunctivitis

ABSTRACT In 2000, we encountered cases of nosocomial infections with epidemic keratoconjunctivitis (EKC) at a university hospital in Kobe, in the western part of Japan. Two human adenovirus (HAdV) strains, Kobe-H and Kobe-S, were isolated from patients with nosocomial EKC infection. They were untypeable by existing neutralizing antisera; however, the isolate was neutralized with homologous antisera. We then encountered several cases of EKC due to nosocomial infections in eye clinics in different parts of Japan. A total of 80 HAdVs were isolated from patients with EKC at eight different hospitals. The partial hexon gene sequences of the isolates were determined and compared to those of the prototype strains of 51 serotypes. All isolates had identical partial hexon nucleotide sequences. Phylogenetic analysis classified these isolates into species of HAdV-D. The isolates showed 93.9 to 96.7% nucleotide identity with HAdV-D prototype strains, while all 32 HAdV-D prototype strains ranged from 93.2 to 99.2% identity. The sequences of the loop 2 and fiber knob regions from the representative strain, Kobe-H, were dissimilar in all prototype strains of 51 serotypes. We believe that this virus is a novel serotype of HAdV that causes EKC.

Analysis of the complete genome sequence of epidemic keratoconjunctivitis-related human adenovirus type 8, 19, 37 and a novel serotype.

We determined the complete genome sequence of epidemic keratoconjunctivitis (EKC)-related human adenoviruses (HAdVs). We analysed a total of 12 HAdV strains; three prototype strains and two HAdV-8, three HAdV-19 and three HAdV-37 clinical isolates from EKC patients in Japan, and one novel serotype of HAdV. Genome organization of these serotypes was identical to those of the recently determined HAdV-19 and HAdV-37. The identities of the whole genome were over 99 % among strains from the same serotype, except for HAdV-19p, which is not associated with conjunctivitis, resulting in the formation of a distinct cluster in the phylogenetic analysis. The penton, loop 1 and loop 2 of hexon, early region 3 (E3) and fiber were hypervariable regions between serotypes. Results suggest that the HAdV-19 clinical strain is a recombinant of HAdV-19p-like and HAdV-37-like strains, and that the acquisition of the penton, E3 or fiber may be related to ocular tropism.

Epidemic Keratoconjunctivitis Due to the Novel Hexon-Chimeric-Intermediate 22,37/H8 Human Adenovirus

ABSTRACT In a 2-month period in 2003, we encountered an outbreak of epidemic keratoconjunctivitis (EKC) in Japan. We detected 67 human adenoviruses (HAdVs) by PCR from eye swabs of patients with EKC at five eye clinics in different parts of Japan. Forty-one of the 67 HAdV DNAs from the swabs were identified as HAdV-37 by phylogenetic analysis using a partial hexon gene sequence. When the restriction patterns of these viral genomes were compared with that of the HAdV-37 prototype strain, one isolate showed a never-before-seen restriction pattern. Within 1 year, we encountered three more EKC cases caused by a genetically identical virus: two nosocomial infections at two different university hospitals and a sporadic infection at an eye clinic. We determined the nucleotide sequences of the full-length hexon and fiber genes of these isolates and compared them to those of the 51 prototype strains. Surprisingly, the sequence of the hexon (ε determinant) loop-1 and -2 regions showed the highest nucleotide identity with HAdV-22, a rare EKC isolate. However, the nucleotide sequence of the fiber gene was identical to that of the HAdV-8 prototype strain. 22 We propose that this virus is a new hexon-chimeric intermediate HAdV-22,37/H8, and may be an etiological agent of EKC.

The possibility of human adenovirus detection from the conjunctiva in asymptomatic cases during nosocomial infection.

Purpose: To prevent outbreaks of nosocomial adenoviral conjunctivitis, proper management for transmission control must be performed. We collected conjunctival samples from asymptomatic inpatients and an ophthalmologist in an ophthalmology ward and attempted to detect the human adenovirus (HAdV) pathogen for infection control. Methods: One inpatient was diagnosed with adenoviral conjunctivitis on the basis of typical, acute, and severe symptoms and virologic testing by using an immunochromatography (IC) kit. To survey nosocomial infection, conjunctival swabs from 17 other inpatients and 1 ophthalmologist without obvious symptoms of adenoviral conjunctivitis were sampled and analyzed for HAdV pathogens with an IC kit, viral isolation, nested polymerase chain reaction (PCR), and real-time PCR. Results: HAdV antigens and DNA were detected from 1 and 8 of the 18 samples collected for nosocomial survey by IC kit and nested PCR method, respectively. Moreover, infectious HAdV was isolated in the cell culture from only 1 antigen-positive sample. All PCR-positive samples had identical nucleotide sequences of the partial hexon gene and were determined to be HAdV type 37 by phylogenetic analysis. No inpatients tested showed any symptoms of typical adenoviral conjunctivitis, but slight conjunctival infection caused by postoperative reaction and/or mild conjunctivitis that did not resemble HAdV infection was observed. No one developed typical adenoviral conjunctivitis over the 2-month follow-up. Conclusions: The clinical course of adenoviral conjunctivitis varies from inapparent infection to severe conjunctivitis. Mild or inapparent HAdV conjunctival infection could be common during conjunctivitis outbreaks and might play a role in the spread of nosocomial adenoviral conjunctivitis.

Clinical features of adenoviral conjunctivitis at the early stage of infection

PurposeBecause adenoviral conjunctivitis is a contagious disease, prompt and accurate diagnosis in the early stage of infection is necessary to prevent epidemics. We evaluated and compared the clinical features of adenoviral conjunctivitis at the first medical examination with those of nonadenoviral follicular conjunctivitis.MethodsThe clinical features of 102 patients with suspected adenoviral conjunctivitis at the first medical examination were retrospectively reviewed. Human adenovirus (HAdV) DNA in samples from the patients was detected by polymerase chain reaction, and HAdV DNA-positive and HAdV DNAnegative patients were respectively assigned to adenoviral and nonadenoviral follicular conjunctivitis groups. The two groups were compared for bilaterality, intrafamilial infection, multiple subepithelial corneal infiltrates (MSI), preauricular lymphadenopathy, and severity of conjunctivitis.ResultsAdenoviral conjunctivitis and nonadenoviral conjunctivitis were diagnosed in 68 and 34 patients, respectively. Bilaterality, intrafamilial infection, and MSI showed significant intergroup differences. Remarkably, MSI was observed in 42.6% of the patients in the early stage of infection. There were no significant intergroup differences in preauricular lymphadenopathy or severity of conjunctivitis at any stage.ConclusionsTo accurately diagnose adenoviral conjunctivitis in the early stage, bilateral conjunctival conditions, history of intrafamilial infection, and MSI should be checked, even in cases of mild or moderate follicular conjunctivitis.

Nucleotide sequence variation in the hexon gene of human adenovirus type 8 and 37 strains from epidemic keratoconjunctivitis patients in Japan.

Human adenovirus type 8 (HAdV-8) and 37 (HAdV-37) cause epidemic keratoconjunctivitis (EKC) associated with community-acquired and nosocomial infections. The nucleotide sequences of the entire hexon and fiber genes of eight HAdV-8 and 26 HAdV-37 strains were analysed and the transition mutations in each gene were compared among strains. Compared with prototype strains, the hexon gene of HAdV-8 and -37 strains showed between two and seven and one and twelve variations at nine and 21 different positions, respectively. All of these, except one position in HAdV-37, were located in the conserved region 4 (C4). There were only three polymorphisms in the fiber gene of both HAdV-8 and HAdV-37, fewer than those in C4. The nucleotide sequence of HAdV-8 and -37 C4 might be readily modified during EKC epidemics.

Corneal hyperalgesia in patients with short tear film break-up time dry eye

PURPOSE To evaluate corneal tactile and pain sensations in patients with short tear film break-up time dry eye (sBUT DE). METHODS This study enrolled 60 patients with sBUT DE and 46 healthy volunteers from Japan. We evaluated corneal tactile and pain sensations using a modified method with the Cochet-Bonnet corneal esthesiometer. RESULTS Patients with sBUT DE had higher corneal pain sensitivity (26.3 ± 23.1 mm) than healthy subjects (6.9 ± 16.4 mm), but similar corneal tactile sensation (52.0 ± 15.5 mm and 52.9 ± 14.9 mm, respectively). In patients with sBUT DE and corneal hyperalgesia (n = 22, 36.7%), defined as a pain sensitivity ≥40 mm (i.e., the cutoff value at the 95th percentile of corneal pain sensitivity in healthy subjects), a strong significant correlation was found between the subjective pain score and objective corneal pain sensation (R = 0.79). However, for the entire cohort, we found a weak positive correlation between the subjective pain score and objective corneal pain sensation. CONCLUSIONS Patients with sBUT DE were hypersensitive to corneal pain, which suggested that corneal hyperalgesia partly accounted for subjective symptoms in patients with sBUT DE.

Histological Findings in the Trabecular Meshwork of a Patient with Atopic Glaucoma

Purpose: The aim of this study was to report a case of atopic dermatitis showing elevated intraocular pressure (IOP) beyond the baseline levels followed by a modified 360-degree suture trabeculotomy, and to analyze the histological findings in the trabecular meshwork. Methods: A 40-year-old male suffered from blurred vision in the right eye (OD). He had a medical history of severe atopic dermatitis and intraocular lens implantation OU due to atopic cataract. At the initial presentation, the visual acuity was 0.03, and IOP was 35 mmHg OD. Slit-lamp examination demonstrated corneal epithelial edema OD. Increased IOP was refractory to several topical medications. The patient underwent a modified 360-degree suture trabeculotomy. The visual field defect, however, deteriorated with persistently high IOP. The patient underwent trabeculectomy together with drainage implant surgery. In the outflow routes, although there seemed to be an opening of Schlemm’s canal into the anterior chamber, there was no endothelium of the canal in the region of its opening. The fibrotic changes were conspicuous around Schlemm’s canal. Conclusion: The histological results indicated that trabeculotomy might not be an appropriate treatment for patients with atopic glaucoma, possibly because of excessive repair to the newly created uveoscleral outflow in addition to the increased postoperative fibrosis in the trabecular meshwork and Schlemm’s canal.

Evaluation of the Safety and Tolerability of Conjunctival Ring for Posterior Segment of the Eye

ABSTRACT Purpose: To evaluate the safety and tolerability of conjunctival rings (CRs), a novel device for drug delivery to the posterior segment of the eye. Methods: In animal studies, CRs containing 5% dexamethasone sodium phosphate (DSP) or vehicle solution were placed on the right and left eyes of C57BL/6J mice, respectively. Contact lenses (CLs) containing vehicle solution were used as a control. Twenty-four hours after placement of the CRs, corneal fluorescein staining was graded based on the McDonald-Shadduck scoring system, ranging from 0 to 4. In humans, CRs containing vehicle solution were placed on the right eye of healthy volunteers for 9 hours. The corneal curvature, corneal thickness, intraocular pressure, visual acuity, tear production (Schirmer I test), tear film break-up time and fluorescein staining scores of the cornea (scores ranging from 0 to 3) and conjunctiva (scores ranging from 0 to 6) were assessed before and after wearing the CRs. The release characteristics of DSP from CRs were also evaluated. Results: In animal experiments, corneal fluorescein staining scores were 1 or less in all the groups, and there was no significant difference between the CR group and the CL group. In the preclinical safety evaluation of CR for humans, ophthalmic examination revealed that CR caused no significant changes in all the parameters investigated including corneal curvature (p = 0.77), corneal thickness (p = 0.96), intraocular pressure (p = 0.59), visual acuity (p = 0.14), Schirmer I test results (p = 0.76), tear film break-up time (p = 0.68), corneal fluorescein staining scores (p = 0.64), and conjunctival fluorescein staining scores (p = 0.52). The DSP release from CRs occurs within a few hours, which is similar to the drug-release property of medicated CL, as reported previously. Conclusions: The current data showed the safety and tolerability of CR as a drug delivery device for the treatment of posterior segment diseases.

Catastrophic Thermal Corneoscleral Injury Treated with Transplantation of Donor Scleral Graft

Background: The aim of this study is to report a patient with senile cataract developing severe thermal corneoscleral injury during phacoemulsification, which was treated with a donor scleral graft. Case: Severe thermal corneoscleral injury occurred during phacoemulsification in the right eye of a 74-year-old male. His medical history was prostate hypertrophy. Visual acuity was hand motion and the intraocular pressure was 3 mm Hg OD. There was heavy corneal stromal opacity with intraocular fluid leakage. The patient underwent transplantation of a donor scleral graft to the burn site. Histologically, the injured sclera showed coagulation necrosis without inflammatory cell infiltration. An intraocular lens was eventually fixed in the ciliary sulcus 7 months later. His visual acuity remains at 2/20 OD. Conclusions: Transplantation of the donor scleral grafts is useful to close the wound in catastrophic thermal injury.