Effectiveness of laser pulsed irradiation for antimicrobial photodynamic therapy.

The aim of this study was to compare two types of light irradiation devices for antimicrobial photodynamic therapy (aPDT). A 660-nm light-emitting diode (LED) and a 665-nm laser diode (LD) were used for light irradiation, and 0.1 mg/L TONS 504, a cationic chlorin derivative, was used as the photosensitizer. We evaluated the light attenuation along the vertical and horizontal directions, temperature rise following light irradiation, and aPDT efficacy against Staphylococcus aureus under different conditions: TONS 504 only, light irradiation only, and TONS 504 with either LED (30 J/cm2) or LD light irradiation (continuous: 30 J/cm2; pulsed: 20 J/cm2 at 2/3 duty cycle, 10 J/cm2 at 1/3 duty cycle). Both LED and LD light intensities were inversely proportional to the square of the vertical distance from the irradiated area. Along the horizontal distance from the nadir of the light source, the LED light intensity attenuated according to the cosine quadrature law, while the LD light intensity did not attenuate within the measurable range. Following light irradiation, the temperature rise increased as the TONS 504 concentration increased in the order of pulsed LD < continuous LD < LED irradiation. aPDT with light irradiation only or TONS 504 only had no antimicrobial effect, while aPDT with TONS 504 under continuous or pulsed LD light irradiation provided approximately 3 log reduction at 30 J/cm2 and 20 J/cm2 and approximately 2 log reduction at 10 J/cm2. TONS 504-aPDT under pulsed LD light irradiation provided anti-microbial effect without significant temperature rise.

Rapid Corneal Calcification Following Endothelial Keratoplasty: A Case Report.

Corneal calcification typically progresses slowly but can occasionally advance rapidly. This report details severe stromal calcification following repeat Descemet's stripping automated endothelial keratoplasty (DSAEK) in a 75-year-old patient with diabetes, hypertension, and prior ocular surgeries, including cataract surgery, intraocular lens extraction with suturing, and trabeculectomy. Persistent epithelial defects after the surgery led to rapid central stromal calcification within four weeks, significantly reducing visual acuity. Management included switching from betamethasone sodium phosphate to fluorometholone, facilitating complete epithelial recovery within two months. However, persistent stromal opacity necessitated a subsequent penetrating keratoplasty. Infrared absorption spectrophotometry identified calcium phosphate as the primary component of the calcification. This case highlights the importance of vigilant monitoring and proactive management of epithelial defects to prevent rapid calcification following endothelial keratoplasty.

Efficacy of azithromycin hydrate ophthalmic solution for treatment of internal hordeolum and meibomitis with or without phlyctenular keratitis.

PURPOSE: To evaluate the efficacy of azithromycin hydrate ophthalmic solution for the treatment of internal hordeolum and meibomitis with or without phlyctenular keratitis. STUDY DESIGN: Retrospective study. METHODS: Patients diagnosed with internal hordeolum or meibomitis were prescribed azithromycin hydrate ophthalmic solution twice daily for 2 days and then once daily for 12 days. Depending on the presence of meibomitis-related keratoconjunctivitis (MRKC), we further divided the patients with meibomitis into three subgroups: meibomitis alone (non-MRKC group), meibomitis with non-phlyctenular MRKC (non-phlyctenular group), and meibomitis with phlyctenular MRKC (phlyctenular group). Inflammatory findings (eyelid redness and conjunctival hyperemia) were scored before and after treatment. Some patients also underwent culture testing fluids discharged by the meibomian gland orifices. RESULTS: Three patients (3 eyes) had internal hordeolum and 16 patients (16 eyes) had meibomitis. After treatment, the inflammatory findings disappeared in all eyes with internal hordeolum. Among the patients with meibomitis, three eyes were in the non-MRKC, six in the non-phlyctenular, and seven in the phlyctenular group. The inflammatory findings were significantly improved only in the phlyctenular group. Among seven eyes with positive culture results, Cutibacterium acnes was detected in five, and treatment improved the inflammatory findings in all of these eyes. CONCLUSION: Azithromycin hydrate ophthalmic solution is effective for the treatment of inflammatory meibomian gland diseases, including internal hordeolum and meibomitis. In particular, the agent is highly efficient in patients with phlyctenular MRKC.

Inflammatory Cells and Lipid Deposits Detected by in Vivo Confocal Microscopy in Brimonidine Tartrate Ophthalmic Solution-Related Corneal Disorders: A Case Series.

We reviewed the medical charts of five patients diagnosed with brimonidine tartrate (BT)-related corneal disorders. A fan-shaped corneal opacity was present in four patients and limbal corneal infiltrations were present in one patient. In vivo confocal microscopy revealed dendritic cells and lipid deposits in the fan-shaped opacity as well as neutrophils in limbal infiltrations. BT instillation was discontinued and topical administration of a corticosteroid was initiated for all patients. The limbal infiltrations improved after BT discontinuation. Conversely, the fan-shaped opacity remained in all affected patients. After a fan-shaped opacity has developed in a patient with a BT-related corneal disorder, the lesion is difficult to resolve. However, limbal infiltrations respond well to treatment. Therefore, BT should be discontinued and anti-inflammatory treatment initiated before a fan-shaped opacity forms.

Corneal Copper Deposition Secondary to Monoclonal Gammopathy in a Patient With Chronic Lymphocytic Leukemia: A Case Report.

Hypercupremia-induced corneal copper deposition secondary to monoclonal gammopathy is rare and shows a characteristic corneal opacity quite different from other causes of hypercupremia, such as Wilson's disease. This report describes a case of corneal copper deposition in a patient with monoclonal gammopathy associated with chronic lymphocytic leukemia. An 84-year-old man with slowly progressive corneal opacity was referred to our hospital. The corneal opacity was present at least five years ago. The patient's best-corrected visual acuity was 20/25 OU (in both eyes) at the initial visit to our hospital. Slit-lamp examination and anterior segment optical coherence tomography revealed bilateral brown-colored opacity localized to deep layers of the central cornea. In vivo confocal microscopy (IVCM) showed indistinct corneal stromal cells in the deep layer and endothelial cells. The possible differential diagnoses were corneal dystrophy and Wilson's disease, but the color, shape, or site of corneal opacity was inconsistent with the disease. As the patient had a history of chronic lymphocytic leukemia, which is often associated with monoclonal gammopathy, we suspected that the corneal opacity was copper deposition in association with the hematologic diseases. Laboratory examinations showed elevated serum copper and normal ceruloplasmin. Serum protein electrophoresis revealed significantly high IgG levels with depression of IgA, IgE, and IgM. These results supported our diagnosis. Followingly, we consulted the patient's attending hematologist, and the doctor initiated treatment for hypercupremia. In conclusion, hypercupremia secondary to monoclonal gammopathy should be considered a possible cause of central brown-colored corneal opacity.

Technical Report: Automatic Measurement of Corneal Nerve Fiber Area Using Versatile Software.

SIGNIFICANCE: In vivo confocal microscopy has become a popular method to observe the details of corneal structures. We consider the area of corneal structures to be a versatile index and have measured the areas of various corneal structures using a commercially available software. PURPOSE: This study aimed to evaluate the accuracy of software used to measure the corneal nerve fiber area. METHODS: The corneal structures of 11 healthy volunteers were visualized using in vivo confocal microscopy. The image that most clearly depicted the corneal nerve fibers of each participant was selected for analysis. The corneal nerve fiber area was automatically measured by the software. An experienced ophthalmologist then manually measured the corneal nerve fiber area in each image assessed by the software. The Pearson correlation test was used to determine the correlation coefficient between the corneal nerve fiber areas measured automatically and those measured manually. The correlation between the corneal nerve fiber area and the participant's age was also evaluated. RESULTS: A strong correlation was found between the corneal nerve fiber area measured automatically and the corneal nerve fiber area measured manually ( r = 0.98, P = 2.4 × 10 -7 ). The corneal nerve fiber area was not correlated with participant age, regardless of whether the area was measured automatically ( r = -0.26, P = .44) or manually ( r = -0.13, P = .71). CONCLUSIONS: The software used in this study automatically measures the corneal nerve fiber area with accuracy similar to that of manual measurement by an experienced ophthalmologist. This software has potential for use in quantifying the areas of various corneal structures.

Synergistic effect of TONS504-mediated photodynamic antimicrobial chemotherapy and additives widely contained in ophthalmic solutions: benzalkonium chloride and ethylenediaminetetraacetic acid.

TONS504 (C51H58N8O5I2), a chlorine derivative, effectively generates singlet oxygen by light activation and exhibits photodynamic antimicrobial effects (PAEs) on various pathogens. However, this photosensitizer has some limitations: a high tendency to self-aggregate and a relatively weak PAE for Gram-negative bacteria compared with Gram-positive bacteria. To overcome these limitations, the present study investigated the synergistic effects of the PAE of TONS504 and two additives commonly contained in ophthalmic solutions: benzalkonium chloride (BAC) or ethylenediaminetetraacetic acid (EDTA). Staphylococcus aureus and Pseudomonas aeruginosa were exposed to TONS504 and/or each additive. Photodynamic antimicrobial chemotherapy was performed with light irradiation centered at a wavelength of 665 nm with a total light energy of 30 J/cm2. Following incubation, the number of colonies formed was counted. Additionally, we examined the inhibitory effects of the additives on TONS504 self-aggregation by observing its absorption spectrum. Consequently, the PAEs of TONS504 on S. aureus were enhanced by both additives, and BAC displayed stronger synergistic effects on the bacteria than EDTA. By contrast, only EDTA increased the PAE on P. aeruginosa. The peak of the TONS504 absorption spectrum shifted to a longer wave length and the absorbance increased in the presence of BAC, suggesting that BAC inhibited the self-aggregation of the photosensitizer. In conclusion, the combination of BAC or EDTA and TONS504-mediated photodynamic antimicrobial chemotherapy exhibits a synergistic antimicrobial effect on S. aureus and P. aeruginosa. The optimal additive to enhance the PAE may differ between bacterial strains.

Vernal keratoconjunctivitis with a limbal mass lesion developing independently of severe papillae formation at the tarsal conjunctiva: a case report.

BACKGROUND: A hypertrophic limbal mass lesion is an uncommon finding of vernal keratoconjunctivitis; it normally occurs in eyes with severe papillae formation in the tarsal conjunctiva. We present a case with a limbal mass lesion in a patient with relatively mild allergic findings in the tarsal conjunctiva. CASE PRESENTATION: A 12-year-old Japanese boy displaying allergic conjunctivitis presented with a mass lesion at the inferior limbus in the left eye. Relatively mild papillae formation was found on the tarsal conjunctiva in both eyes. We diagnosed that the mass lesion resulted from limbal vernal keratoconjunctivitis and resected it for therapeutic purposes. Histopathological examination showed that eosinophils, lymphocytes, and fibroblasts were present in the subepithelial lesion and the substantia propria of the mass lesion. Immunohistochemical staining detected diffuse and rich infiltration of CD3-positive T lymphocytes and a relatively small number of CD20-positive B lymphocytes and CD138-positive plasma cells that tended to aggregate. The histopathologic features suggested that the limbal mass lesion had similar structures to the papillae at the tarsal conjunctiva of vernal keratoconjunctivitis. CONCLUSION: The limbal mass lesion as a finding of vernal keratoconjunctivitis can occur even if the papillae formation at the patient's tarsal conjunctiva is mild.

Long-Term Observation of Deep Anterior Lamellar Keratoplasty in Patients with Post-LASIK Granular Corneal Dystrophy Type 2: Two Case Reports.

INTRODUCTION: Laser-assisted in situ keratomileusis (LASIK) exacerbates granular corneal dystrophy type 2. Post-LASIK granular corneal dystrophy type 2 is treated by several surgical techniques. To the best of our knowledge, no report has addressed the results of deep anterior lamellar keratoplasty in affected patients. Here, we report our experience regarding deep anterior lamellar keratoplasty treatment of patients with post-LASIK granular corneal dystrophy type 2. METHODS: We describe two Japanese women who underwent deep anterior lamellar keratoplasty to treat corneal opacities that worsened after LASIK. RESULTS: One patient had a family history of corneal dystrophies. During the initial visit to our clinic, numerous fine opacities were found at the LASIK flap interface in both patients. The clinical findings were compatible with post-LASIK granular corneal dystrophy type 2. Both patients underwent deep anterior lamellar keratoplasty by one of the authors (T.C.). In both procedures, the surgeon used a visco-dissection technique and successfully removed the whole corneal stroma. Histopathological examination of the excised corneal button from each eye revealed amyloid and hyaline deposits at the LASIK flap interface. Neither patient experienced recurrent corneal opacity during the follow-up visit at 8 years (patient 1) and 6 years (patient 2). CONCLUSION: Deep anterior lamellar keratoplasty can be used for the treatment of post-LASIK granular corneal dystrophy type 2. Removal of the entire host stroma may be important for the prevention of recurrent corneal opacity.

Molecular characteristics of the photosensitizer TONS504: Comparison of its singlet oxygen quantum yields and photodynamic antimicrobial effect with those of methylene blue.

TONS504 (C51H58O5I2) is a chlorin derivative that exhibits a photodynamic antimicrobial effect (PAE) on various infectious keratitis pathogens. However, the molecular characteristics of TONS504 are not well understood. This study aimed to investigate the molecular characteristics of TONS504 by comparing its singlet oxygen (1O2) quantum yields and PAE with those of methylene blue (MB). To measure the 1O2 quantum yields, TONS504 and MB were dissolved in phosphate-buffered saline and phosphate-buffered saline containing 1% Triton X-100. The solutions were then activated by a Nd:YAG laser with an average output power of 8 mW. Near-infrared 1O2 luminescence was detected as an indicator of the 1O2 quantum yields. To evaluate the PAE, TONS504 and MB were activated by a light-emitting diode with a total light energy of 30 J/cm2. We compared the minimum molar concentration of each photosensitizer to show apparent PAEs on Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. TONS504 exhibited higher 1O2 quantum yields than MB in PBS/Triton X-100 but not in PBS. S. aureus and C. albicans were reduced by TONS504 at lower concentrations than by MB, but this was not the case for P. aeruginosa. Our results provide insight on the molecular characteristics of TONS504 and suggest that TONS504 has excellent 1O2 quantum yields and PAE. Compared with MB, TONS504 in PBS has stronger efficacy toward some infectious keratitis pathogens but not others.