Hayate Nakagawa

Intravitreal Ranibizumab and Aqueous Humor Factors/Cytokines in Major and Macular Branch Retinal Vein Occlusion

Aqueous humor levels of cytokines and growth/inflammatory factors were measured in 38 patients with macular edema who had major branch retinal vein occlusion (BRVO) or macular BRVO and were treated with intravitreal ranibizumab injection (IRI). Patients with recurrence of macular edema received further IRI as needed. Aqueous humor levels of vascular endothelial growth factor (VEGF), soluble VEGF receptor-1 (sVEGFR-1), and other cytokines/factors were measured. Compared with major BRVO, macular BRVO was associated with lower aqueous humor levels of sVEGFR-1, its ligands (VEGF and placental growth factor), and other growth/inflammatory factors (platelet-derived growth factor-AA, monocyte chemotactic protein-1, soluble intercellular adhesion molecule-1, interleukin-6, and interleukin-8). The mean number of IRI over 6 months was significantly lower in the macular BRVO group than in the major BRVO group. These findings suggest that macular BRVO requires fewer IRI than major BRVO and is associated with lower aqueous humor levels of various growth/inflammatory factors and cytokines.

Optic neuritis and acute anterior uveitis associated with influenza A infection: a case report

Background A few reports have described ocular complications of influenza A infection, such as impaired ocular movement, parasympathetic ocular nerve, keratitis, macular lesion, and frosted branch angiitis. We encountered a rare case of acute anterior uveitis and optic neuritis associated with influenza A infection. Case presentation A 70-year-old man presented with symptoms of upper respiratory tract infection. A rapid diagnostic test showed a positive result for influenza A. At the same time, he developed ocular symptoms including blurred vision with optic disk edema and hemorrhage in the left eye, and bilateral red eyes. Multiplex polymerase chain reaction performed on aqueous humor sample detected no viral infection. Visual field testing with a Goldmann perimeter showed central and paracentral scotomas in the left eye. In addition to antiviral agent (oseltamivir phosphate 75 mg), the patient was prescribed topical prednisolone acetate ophthalmic suspension eye drops every 5 hours and high-dose intravenous methylprednisolone 1,000 mg daily for 3 days. Two months later, his best-corrected visual acuity improved to 20/50 with regression of visual field defects in his left eye. Conclusion We report a case of bilateral acute anterior uveitis and unilateral optic neuritis concomitant with influenza A infection. Topical and systemic corticosteroids were effective to resolve acute anterior uveitis and neuritis. Analysis of aqueous humor sample suggested that acute anterior uveitis and optic neuritis in this case were not caused by influenza A virus infection per se but by autoimmune mechanism.

Investigation of the Role of Bacteria in the Development of Acanthamoeba Keratitis.

Purpose: Recently, much interest has been shown in bacteria extracted from Acanthamoeba strains isolated from patients with Acanthamoeba keratitis (AK). We hypothesized that the bacteria in Acanthamoeba strains may be a contributing factor in the development of AK. To prove this hypothesis, we investigated the involvement of bacteria harbored by Acanthamoeba in causing progressive ocular infection in rabbit corneas. Methods: One Acanthamoeba strain (T4 genotype) that harbored bacteria was isolated from a patient with AK. The Acanthamoeba strain pretreated or not pretreated with levofloxacin (LVFX) was inoculated into rabbit corneas. We also tested the effect of LVFX eye drops on keratitis induced by the Acanthamoeba strain. The infected rabbit eyes were evaluated for clinical scores, Acanthamoeba 18S rDNA and bacterial 16S rDNA numbers were analyzed by the real-time polymerase chain reaction, and the presence of Acanthamoeba was analyzed by histological examination. Results: Inoculation of nonpretreated Acanthamoeba resulted in severe keratitis. In contrast, inoculation of LVFX-pretreated Acanthamoeba did not induce keratitis (mean clinical score, 17.3 vs. 2.3; P < 0.05). Rabbit corneas inoculated with nonpretreated Acanthamoeba followed by topical LVFX therapy developed severe keratitis. In corneas inoculated with nonpretreated Acanthamoeba followed by LVFX therapy, the number of Acanthamoeba 18S rDNA copies was significantly higher than in other groups (P < 0.05), whereas the bacterial 16S rDNA gene was undetectable. Acanthamoeba cysts were detected by Fungiflora Y staining only in corneas inoculated with nonpretreated Acanthamoeba followed by LVFX therapy. Conclusions: These results suggest that the presence of bacteria in Acanthamoeba may be required for the development of AK.

Non-Descemet's stripping automated endothelial keratoplasty for bullous keratopathy secondary to iridoschisis.

Purpose To report a case of bullous keratopathy secondary to iridoschisis treated by non-Descemet’s stripping automated endothelial keratoplasty (nDSAEK). Case report A 79-year-old woman was referred to our hospital with loss of vision in the left eye. Slit lamp examination of her left eye showed a shallow anterior chamber with cataract and schisis in the inferior quadrant of iris stroma. Bullous keratopathy secondary to iridoschisis was diagnosed. Cataract surgery with iridectomy succeeded to deepen the anterior chamber and remove the floating iris leaf, although corneal edema remained. Four days later, nDSAEK was performed, which resolved corneal edema and restored visual acuity. Conclusion The two-step surgery of cataract surgery plus iridectomy followed by nDSAEK may be an effective strategy for treating bullous keratopathy secondary to iridoschisis.

Cytokines and Recurrence of Macular Edema after Intravitreal Ranibizumab in Patients with Branch Retinal Vein Occlusion

The aqueous humor levels of cytokines and growth/inflammatory factors were measured in 46 branch retinal vein occlusion (BRVO) patients with macular edema (ME) who were treated with intravitreal ranibizumab injection (IRI). Patients with recurrence of ME received further IRI as needed. The number of IRIs was significantly correlated with age, baseline best-corrected visual acuity, and baseline central macular thickness (CMT), as well as the baseline aqueous levels of 5 cytokines/factors (soluble vascular endothelial growth factor receptor-1, platelet-derived growth factor-AA [PDGF-AA], soluble intercellular adhesion molecule-1, interleukin-6 [IL-6], and IL-8). Multivariate linear regression analysis with stepwise selection confirmed that age, baseline CMT, and baseline PDGF-AA level were independent determinants of the number of IRIs. These findings suggest that inflammatory factors may influence the recurrence of ME in BRVO patients, and that PDGF-AA might be a useful indicator of the number of IRIs required to control ME.

Number of bacteria and time of co-incubation with bacteria required for the development of Acanthamoeba keratitis

Purpose: We hypothesized that bacteria may be a factor contributing to the development of Acanthamoeba keratitis (AK). We investigated interactions between Acanthamoeba and Pseudomonas aeruginosa for the development of keratitis in rabbit corneas. Methods: Acanthamoeba castellanii (ATCC50492) and P. aeruginosa (PAO-1) were used. Two densities of P. aeruginosa (high, 1 × 108/mL; low, 3 × 105/mL) and 2 durations of coincubation (long, 6 h; short, 2 h) of Acanthamoeba with 1 × 108/mL of P. aeruginosa were tested. Acanthamoeba alone or Acanthamoeba coincubated with P. aeruginosa was inoculated into rabbit corneas. After inoculation, levofloxacin (LVFX) eye drops were administered. The clinical score of the cornea was evaluated after inoculation. Results: Acanthamoeba alone did not produce keratitis during a 5-day observation period. Rabbit corneas inoculated with Acanthamoeba coincubated with low-density P. aeruginosa followed by topical LVFX were clear with few infiltrates. Corneas inoculated with Acanthamoeba coincubated with high-density P. aeruginosa followed by LVFX treatment developed severe keratitis, and clinical scores were significantly higher compared with high-density P. aeruginosa alone followed by LVFX treatment (scores 7, 9.6, 8.5 vs. 3, 3.5, 3.25 on days 1–3, all P < 0.01). The long (6 h) coincubation time of Acanthamoeba with high-density P. aeruginosa resulted in more severe keratitis compared with short (2 h) coincubation (scores, 9.7, 12.7, 12.1, 9.8, 8.7 vs. 7, 9.6, 8.5, 6.9, 5.6 on days 1–5, all P < 0.01). Conclusions: These results suggest that the presence of bacteria is essential and a critical number of bacteria is required for the development of AK. The time of coexistence with bacteria may be an important determinant of the severity of AK.