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Murata Eye Clinic product

Self medical care in posterior eye segment during COVID-19 pandemic　（ARVO, 2023）

Purpose: During COVID-19 pandemic, it is desirable for ophthalmologists, to remotely examine patients. However, accurate tests and diagnoses are difficult to be performed remotely, and even when a disease is found, it is difficult to treat the disease remotely. As a means to solve these problems, methods are being sought for the examination, diagnosis, and treatment of posterior segment eye diseases (PSED), by patients themselves.

Methods: Recording of human self-fundus image (SFI): SFIs were obtained using two smartphones and then, the SFIs were evaluated. Self-diagnosis of PSED: The prepared fundus image was provided into an automatically constructed deep-learning model to determine whether or not the vitreous opacity was found to evaluate the method for self-diagnosis. Human 24 fundus images were divided into two groups: 12 control group and 12 vitreous opacity group. Self-treatment of PSED: To investigate the effectiveness of PSED self-treatment, whether the injection of dexamethasone (DEX) in/on the choroid through a tube suppresses inflammatory vitreous opacity due to endotoxin-induced uveitis was examined in a rabbit model. The tube was inserted in/on the choroid near the optic disc. The tip of tube on the conjunctival side was exposed on the skin through the subconjunctiva and subcutaneous. One hundred ng of the lipopolysaccharide solution was injected intravitreally in 8 eyes. Then 4 eyes were simultaneously injected the DEX solution through the tube on the skin side using the wireless injector (DEX group). Residual 4 eyes were used as controls. On days 2, vitreous opacity was evaluated by clinical observation and protein measurement of vitreous humor.

Results: For five subjects, clear SFIs were obtained. The deep-learning model was determined whether each of fundus images was vitreous opacity with 100% sensitivity, 100% specificity, and 100% accuracy. Clinical grading scores of the DEX group were significantly lower those of the control group on days 2 (p<0.05). The eyes in DEX group significantly suppressed mean protein concentrations at 2 days compared with the eyes in control group (p<0.05).

Comclusions: Self-medical care for PSED might be useful to increase patient’s access, decrease the cost, and avoid the infection during COVID-19 pandemic.

Resources Implant Insertion System (ARVO, 2020 & 2017)

2020 ARVO
Purpose Dexamethasone (DEX) is widely used for the treatment of severe macular diseases. However, it is difficult to deliver effective doses of DEX to the posterior eye segment for long periods. We have generated a simple insertion technique of intra-choroidal sustained DEX implant through posterior scleral   approach. This procedure would be helpful to increase the DEX level in the posterior retina.
Methods An implant was prepared by dissolving poly(DL-lactide)(PLA) and DEX. In vitro release of DEX was measured at 1, 7, and 28 days by mass spectrometry. In vivo, 20G needle was shallowly stabbed the sclera of Japanese white rabbit and moved ahead in the choroid. After that, the implant in 20G needle, was inserted to the choroid at 2 disc diameter inferior to the optic disc by using an injector. After the implantation, the DEX level in the retina was determined at 1, 7, and 28 days by mass spectrometry. Possible adverse effects of the implant, were evaluated by ophthalmoscopy and light microscopy.
Results The implant showed an initial burst within 24 hours, and then the DEX was gradually released at least for 4 weeks in vitro. In vivo, the intra-choroidal implant at 24 hours effectively delivered the DEX into the posterior retina. After that, this implant released the DEX constantly at least for 4 weeks. DEX implant showed no retinal abnormalities except the implantation site in ophthalmoscopy and light microscopy.
Conclusions We have demonstrated a simple methodology of intra-choroidal sustained drug delivery system in posterior eye segment. This new drug delivery system may be possible to insert an implant near the optic disc-macular lesion, and useful in adjusting the most effective and minimum medication to individual patient.

2017 ARVO
Purpose.  To investigate the feasibility of retro-ocular implantation for an intrachoroidal sustained dexamethasone (DEX) delivery system as a potentially useful therapy for adjusting the most effective drug level to posterior segment eye diseases.
Methods.  A gelatin implant was prepared by incorporating DEX or fluorescein. A DEX or fluorescein implant was inserted into a rabbit vitreous, sclera, or choroid. The retina was extracted at 1, 3, or 24 hours, and the DEX level was measured by mass spectrometry. The fluorescein image was examined by ophthalmoscopy at 1 hour. An implant was also prepared by dissolving poly(DL-lactide)(PLA) and DEX. The DEX-PLA implant was inserted into a rabbit choroid using the retro-ocular implantation technique, and the retinal DEX level was measured at 24 hours, 1 week, and 3 weeks. The toxicity of the implant was evaluated by ophthalmoscopy and light microscopy. Endotoxin-induced uveitis (EIU) was induced after DEX-PLA implantation, and anti-inflammatory activities were evaluated by histopathological studies.

Resources Tube Insertion System (ARVO, 2017)

Tube insertion has a long history of medical use, including ophthalmology. The intrachoroidal tube placement by using retro-ocular insertion through scleral approach would be useful to decrease tissue damages and increase the DEX level in posterior eye segment, especially disc-macula area locally. In addition, the intrachoroidal tube near the disc might be possible to maintain drug level by repeating drug injections through the tube.

This time, we have invented a simple procedure of a tube insertion through sclera for the intrachoroidal DEX delivery in posterior eye segment. This procedure would be helpful to increase DEX level in disc-macula area, and to maintain effective retino-choroidal DEX level by repeating the DEX injections. Therefore, in this study, we assessed whether this procedure was useful to maintain the DEX level in the posterior eye segment near the disc.

Resources Laser-induced intrachoroidal dexamethasone drug delivery (IOVS, 2013)

Purpose. To investigate the feasibility of laser-induced intrachoroidal dexamethasone (DEX) delivery as a potentially useful therapy for adjusting the most effective drug level to posterior segment eye diseases.

Methods. The implant was prepared by dissolving poly(DL-lactide) and DEX. In vitro release of DEX was evaluated at 7, 14, and 28 days by ELISA. In vivo, the DEX implant was inserted into the rabbit choroid, and then 10, 50, or 200 burns of photocoagulation were applied at the implant lesion, respectively. After treatment, the vitreous humor was immediately aspirated and the DEX level was measured by LC/MS/MS. Furthermore, the vitreous DEX level was measured at 1, 7, 14, and 28 days after the implantation and 50 burns of photocoagulation. The toxicity of laser-induced DEX implant was evaluated by ophthalmoscopy and light microscopy.

Endotoxin-induced uveitis (EIU) was induced after the DEX implantation and photocoagulation, and the anti-inflammatory activities were evaluated by grading clinical signs, protein concentrations, and histopathologic studies, respectively.

Resources Feasibility of biodegradable intra-choroidal implantation (2011,ARVO)

Purpose: To understand the possible roles of intra-choroidal implantation, we investigated the in vivo release of betamethasone phosphate (BP) from the intra-choroidal implant. Furthermore, we sought to evaluate the effect of intra-choroidal implantation of basic fibroblast growth factor (bFGF)–impregnated gelatin in promoting choroidal neovascularization (CNV).

Methods: 1) The intra-choroidal implant was made of poly(DL-lactide) containing 50% BP(0.15mg). The implant prepared as above was inserted into a choroidal pocket in the rabbit’s eye. The concentration of BP in the choroid sample at 4 weeks after implantation was determined by high-performance liquid chromatography (HPLC).

2) The intra-choroidal implant was made of gelatin impregnated 1μg of bFGF. The implant was placed into a choroidal pocket in the rabbit’s eye. The treated eye was examined by fluorescein angiography and light microscopy at weeks 2.

ContactUs

Murata Eye Clinic
5-8-30 Mitake, Morioka city, JAPAN 020-0122
murata-ganka@cap.ocn.ne.jp

Murata Eye Clinic

盛岡市みたけの眼科 むらた眼科クリニック