Norihiko Itoh

Treatment of retinal detachment resulting from myopic macular hole with internal limiting membrane removal

PURPOSE To examine the efficacy of vitrectomy with internal limiting membrane removal for retinal detachment resulting from a macular hole in highly myopic eyes. METHODS Eleven consecutive highly myopic eyes (11 patients) with retinal detachment resulting from a macular hole were treated by vitrectomy with removal of the internal limiting membrane, which was stained with indocyanine green and sulfur hexafluoride gas injection. Postoperatively, the patients were instructed to remain prone for 2 weeks. The excised specimens were evaluated with transmission electron microscopy. RESULTS The mean postoperative follow-up was 9.2 +/- 2.3 months (range, 7 to 13 months). In 10 of the 11 eyes (91%) the retina was reattached during the initial surgery. Redetachment occurred in one eye, which was successfully treated during the second surgery. Best-corrected visual acuity improved in all eyes and ranged from 20/400 to 20/50. Pathologic examination showed that the internal limiting membrane and epiretinal tissues were present in all specimens. CONCLUSIONS The use of indocyanine green staining can facilitate removal of a macular internal limiting membrane and overlying epiretinal membrane, resulting in complete relief of the macular traction. Primary removal of the internal limiting membrane may contribute to a high initial success rate for retinal reattachment and be an important adjuvant to the treatment of retinal detachment resulting from a macular hole in highly myopic eyes.

High prevalence of herpes simplex virus type 2 in acute retinal necrosis syndrome associated with herpes simplex virus in Japan

PURPOSE To determine the type of herpes simplex virus in acute retinal necrosis syndrome associated with herpes simplex virus. METHODS Herpes simplex virus type 1, herpes simplex virus type 2, varicella-zoster virus, Epstein-Barr virus, and cytomegalovirus were examined by polymerase chain reaction in intraocular specimens from 16 patients with acute retinal necrosis syndrome. Anti-herpes simplex virus type 1 and anti-herpes simplex virus type 2 type-specific antibodies in serum from the patients were detected by enzyme immunoassay. RESULTS Of 16 patients with acute retinal necrosis syndrome, seven were polymerase chain reaction positive for herpes simplex virus type 2 and nine were positive for varicella-zoster virus. Anti-herpes simplex virus type 2 antibody was positive and anti-herpes simplex virus type 1 antibody was negative in the sera of the seven patients with herpes simplex virus type 2 DNA-positive acute retinal necrosis syndrome. In contrast, anti-herpes simplex virus type 2 antibody was absent in all nine varicella-zoster virus DNA-positive acute retinal necrosis syndrome patients. CONCLUSION Herpes simplex virus type 2 has been demonstrated to be the major causative agent in acute retinal necrosis syndrome associated with herpes simplex virus by molecular biological and serological methods. Negative preexisting anti-herpes simplex virus type 1 antibody may play an important role in acute retinal necrosis syndrome associated with herpes simplex virus type 2.

Rapid Diagnosis of Adenoviral Conjunctivitis on Conjunctival Swabs by 10-Minute Immunochromatography

PURPOSE Several methods are available for the diagnosis of acute conjunctivitis, all of which are time-consuming or require the use of a well-equipped laboratory. A new method, immunochromatography (IC), for detecting the presence of adenovirus (Ad) has been developed. Two direct rapid tests to detect Ad antigen, IC and enzyme immunoassay (EIA), were compared with regard to sensitivity, specificity, and technical complexity. METHODS The study materials consisted of 130 swabs from patients with conjunctivitis (95 samples of adenoviral conjunctivitis proven by positive virus DNA on polymerase chain reaction [PCR], 35 samples of nonadenoviral conjunctivitis proven by PCR). IC is a one-step procedure that detects the presence of adenoviral antigen by sandwich EIA on a paper disc. RESULTS In 95 adenoviral DNA-positive samples by PCR, the sensitivity and specificity of IC were 54.7% and 97.1%, respectively, whereas those of EIA were 50.5% and 100%, respectively. By IC, PCR-positive Ad type 3 was recognized in 31%; Ad4 in 100%; Ad7 in 60%; Ad8 in 67%; and Ad37 in 59%, showing similar positivity rates for different serotypes (except Ad7) to those using EIA. Visual determination of the presence of Ad took an average of 10 minutes by IC compared with 70 minutes by EIA. CONCLUSIONS These results indicate that IC is a more rapid and easier test compared with EIA, and it has high specificity. Detection of Ad antigen by this simple and rapid method will serve physicians as a useful tool for early diagnosis and prevention of adenoviral conjunctivitis.

Perifoveal microcirculation before and after vitrectomy for diabetic cystoid macular edema

PURPOSE To quantify the perifoveal microcirculation in diabetic eyes before and after successful vitreous surgery for cystoid macular edema without posterior vitreous detachment, and to determine whether improvement in perifoveal microcirculation is associated with improvement in postoperative visual acuity. METHODS In a prospective study, vitreous surgery was performed on 11 eyes of nine consecutive diabetic patients with cystoid macular edema, and their mean perifoveal capillary blood flow velocity was measured by fluorescein angiography with a scanning laser ophthalmoscope. Visual acuity was measured preoperatively and postoperatively, and the results were converted to the logarithm of the minimum angle of resolution (logMAR). The correlation between changes in logMAR visual acuity and capillary blood flow velocity was evaluated. RESULTS In all nine eyes of seven patients with successful vitreous surgery, the cystoid macular edema resolved within 6 months after surgery, and the mean capillary blood flow velocity was significantly increased compared with that before surgery (2.19 mm per second versus 2.68 mm per second, P =.021); the changes in capillary blood flow velocity were significantly correlated with the changes in the logMAR visual acuity (P =.024). CONCLUSIONS Vitreous surgery may improve perifoveal microcirculation in the eyes of diabetic patients with cystoid macular edema and resolve the macular edema. Improvement of perifoveal microcirculation may be an important factor affecting visual outcome.

Clinical and epidemiological features of acute follicular conjunctivitis with special reference to that caused by herpes simplex virus type 1

BACKGROUND/AIMS It is reported by the national surveillance of ocular infectious diseases in Japan that 4.3% of cases of epidemic keratoconjunctivitis (EKC) diagnosed clinically were caused by herpes simplex virus (HSV). Clinical and virological studies of patients with HSV conjunctivitis were carried out. METHODS The study population consisted of 478 patients with acute follicular conjunctivitis. Virological analysis was carried out for adenovirus (Ad) and HSV by the cell culture method and fluorescein antibody (FA) method. Polymerase chain reaction for Chlamydia trachomatis was also carried out. RESULTS From 23 patients, HSV type 1 was isolated but Ad or C trachomatis was not isolated. 87% of cases were unilateral. Most cases showed clinical resolution within 9 days. Early corneal lesions and preauricular lymphadenopathy were less frequent in HSV conjunctivitis than in adenoviral conjunctivitis, especially that due to subgenus D. No case showed a positive result for HSV by the FA method using conjunctival swabs; however, the FA test was positive in all strains isolated by cell culture. CONCLUSIONS These results indicate that it is difficult clinically to differentiate HSV conjunctivitis from adenoviral conjunctivitis in the acute stage, since the clinical features of adenoviral conjunctivitis are similar to those of HSV conjunctivitis. A biological difference may exist between HSV strains causing keratitis and conjunctivitis.

Ten years’ surveillance of viral conjunctivitis in Sapporo, Japan

Abstract · Background: We set out to establish the epidemiology of viral conjunctivities over a 10-year period in Sapporo, northern Japan. · Methods: A total of 965 patients with clinically suspected viral conjunctivitis during the 10-year period from 1985 to 1994 in Sapporo were evaluated. · Results: Among the 965 patients, cumulative frequency of adenovirus (Ad) was 721 (75%). The dominant serotype of Ad changed with time; each serotype peaked at 3- to 5-year intervals. Adenoviral conjunctivitis occurred most often in July and August each year. Ad3 and Ad4 were predominantly identified in patients 30–39 years old. No enterovirus 70 has been detected. Herpes simplex virus (HSV) and Chlamydia trachomatis had no significant peak. HSV was isolated throughout the year, and C. trachomatis had two peaks of detection: in March and from July to September. HSV and C. trachomatis were predominantly detected in patients 20–29 years old. · Conclusion: In this study, the main etiological agent of viral conjunctivitis in Sapporo, Japan, was Ad; however, attention should be paid to non-adenoviral agents, such as HSV and C. trachomatis, as possible causes of acute conjunctivitis.

Biological adhesive based on carboxymethyl chitin derivatives and chitin nanofibers

Novel biological adhesives made from chitin derivatives were prepared and evaluated for their adhesive properties and biocompatibility. Chitin derivatives with acrylic groups, such as 2-hydroxy-3-methacryloyloxypropylated carboxymethyl chitin (HMA-CM-chitin), were synthesized and cured by the addition of an aqueous hydrogen peroxide solution as a radical initiator. The adhesive strength of HMA-CM-chitin increased when it was blended with chitin nanofibers (CNFs) or surface-deacetylated chitin nanofibers (S-DACNFs). HMA-CM-chitin/CNFs or HMA-CM-chitin/S-DACNFs have almost equal adhesive strength compared to that of a commercial cyanoacrylate adhesive. Moreover, quick adhesion and induction of inflammatory cells migration were observed in HMA-CM-chitin/CNF and HMA-CM-chitin/S-DACNF. These findings indicate that the composites prepared in this study are promising materials as new biological adhesives.

High-Resolution Mapping for Essential Hypertension Using Microsatellite Markers

During the past decade, considerable efforts and resources have been devoted to elucidating the multiple genetic and environmental determinants responsible for hypertension and its associated cardiovascular diseases. The success of positional cloning, fine mapping, and linkage analysis based on whole-genome screening, however, has been limited in identifying multiple genetic determinants affecting diseases, suggesting that new research strategies for genome-wide typing may be helpful. Disease association (case–control) studies using microsatellite markers, distributed every 150 kb across the human genome, may have some advantages over linkage, candidate, and single nucleotide polymorphism typing methods in terms of statistical power and linkage disequilibrium for finding genomic regions harboring candidate disease genes, although it is not proven. We have carried out genome-wide mapping using 18 977 microsatellite markers in a Japanese population composed of 385 hypertensive patients and 385 normotensive control subjects. Pooled sample analysis was conducted in a 3-stage genomic screen of 3 independent case–control populations, and 54 markers were extracted from the original 18 977 microsatellite markers. As a final step, each single positive marker was confirmed by individual typing, and only 19 markers passed this test. We identified 19 allelic loci that were significantly different between the cases of essential hypertension and the controls.

Genetic characterization of adenovirus strains isolated from patients with acute conjunctivitis in the city of São Paulo, Brazil

Genome analysis was carried out on adenovirus strains isolated from patients with acute follicular conjunctivitis in the city of São Paulo, Brazil. Eighteen conjunctival scrapings, collected between December 1993 and March 1994, were analyzed by two methods: a combination of polymerase chain reaction with restriction fragment length polymorphism and viral DNA restriction analysis, carried out using 10 restriction endonucleases: BamHI, BglI, BglII, HindIII, KpnI, SacI, SalI, SmaI, XbaI, and XhoI. Among 11 adenovirus detected by cell culture isolation, nine were Ad8, and two were Ad7. By restriction analysis the Ad8 isolates were typed as two new variants–Ad8/D11 (seven of nine samples) and Ad8/D12 (two of nine samples). Ad7 isolates were identified as a subtype of the widespread genome type Ad7b and the virulent type Ad7h, a predominant genome type circulating in Argentina, Chile, and Uruguay but absent in Brazil until 1991. J. Med. Virol. 61:143–149, 2000.

Favorable effects of superficially deacetylated chitin nanofibrils on the wound healing process.

Previous reports indicate that the beneficial effect of chitin nanofibrils (CNFs), and chitosan nanofibrils (CSNFs) for wound healing. In this study, the wound healing effects of superficially deacetylated chitin nanofibrils (SDACNFs) were evaluated using an experimental model. In the experiments using circular excision wound model, SDACNFs induced re-epithelium and proliferation of the fibroblasts and collagen tissue. In the chitin, CNFs, and CSNFs, on the other hand, the e-epithelium and proliferation of the fibroblasts and collagen tissue were not induced perfectly compared with the SDACNFs group. In particular, re-epithelization was observed on day 4 in the only SDACNF group. Moreover, SDACNFs did not induce severe systemic inflammation in the linear incision wound model. The data indicated that SDACNFs effectively induced the proliferation and re-modeling phases compared with chitin, CNFs, and CSNFs in the wound. These data indicate that SDACNFs can be beneficial as a new biomaterial for wound healing.