Biomedical subjects

Hiroko Bissen-Miyajima

Publications and source records attributed to Hiroko Bissen-Miyajima.

7 recordsLinked to original sources

PubMed2006

In vitro behavior of ophthalmic viscosurgical devices during phacoemulsification.

PURPOSE: To evaluate the behavior and aspiration of several ophthalmic viscosurgical devices (OVDs) during phacoemulsification. SETTING: Department of Ophthalmology, Tokyo Dental College Suidobashi Hospital, Tokyo, Japan. METHODS: Cohesive OVDs (sodium hyaluronate 1.0% [Healon and Provisc]), dispersive OVDs (sodium hyaluronate 3.0%-chondroitin sulfate 4.0% [Viscoat]), and new-generation OVDs such as viscoadaptive (sodium hyaluronate 2.3% [Healon5]) and viscodispersive (hyaluronic acid 1.65%-chondroitin sulfate 4.0% [DisCoVisc]) OVDs, were stained with fluorescein sodium. The movement of the OVDs during simulated cataract surgery was recorded in porcine eyes under an operating microscope and with a side-view video camera. The initial and complete aspiration times of each OVD during phacoemulsification using 20 and 40 mL/min flow rates and sleeves and the removal times using the irrigation and aspiration (I/A) tip at the end of surgery were evaluated from the recorded videos. RESULTS: The complete aspiration time of the cohesive OVDs was less than 3 seconds but up to 20 seconds with a low flow rate of 20 mL/min with a smaller sleeve. Other OVDs remained in the anterior chamber during phacoemulsification with both flow rates. The removal time for cohesive OVDs was less than 4 seconds and for new-generation OVDs, 10 to 15 seconds. The dispersive OVD required a significantly (P<.05) longer removal time than other OVDs. CONCLUSIONS: Cohesive OVDs are removed easily during phacoemulsification; however, the aspiration rate can be affected by fluidics. New-generation OVDs, such as Healon5 and DisCoVisc, remained in the anterior chamber during phacoemulsification and were removed easily by I/A at the end of surgery. The behavior of these OVDs is preferable during phacoemulsification.

Animals↗

PubMed2005

Experimental observation of intraocular pressure changes during microkeratome suctioning in laser in situ keratomileusis.

PURPOSE: To observe changes in intraocular pressure (IOP), the manner in which the eye is suctioned, and the effect of the number of suction ports. SETTING: Department of Ophthalmology, Tokyo Dental College, Suidobashi Hospital, Tokyo, Japan. METHODS: Suction rings with single or dual ports were made of transparent acrylic acid resin to facilitate observation with a digital video camera. The IOP and the duration of the IOP increase (time to reach 90% of the maximum IOP) were measured in 6 porcine eyes with an intra-vein pressure-sensor catheter in the vitreous cavity. The IOP changes were recorded using a personal computer. RESULTS: Suctioning with single- and dual-port suction rings was similar. The IOP increases with single- and dual-port suction rings were similar (99.1 mm Hg +/- 6.1 [SD] and 99.0 +/- 6.5 mm Hg, respectively) (P=.987). The duration of the IOP increase was also similar (4.21 +/- 0.24 seconds and 4.12 +/- 0.33 seconds, respectively) (P=.190). CONCLUSIONS: The number of ports did not affect suctioning and changes in IOP. This technique is useful in developing the ideal shape and setting of the suction ring.

Animals↗

PubMed2005

Observation of the corneal flap interface with metal particles in a rabbit model.

PURPOSE: To observe changes, such as diffuse lamellar keratitis, at the corneal interface when metal particles from microkeratome blades were left in rabbit eyes. SETTING: Department of Ophthalmology, Tokyo Dental College, Suidobashi Hospital, Tokyo, Japan. METHODS: Following the creation of a corneal flap with microkeratome, metal particles from a microkeratome blade were placed at the corneal interface in 14 rabbit eyes. Microscopic and histopathologic changes were compared with those in the control eyes (n = 4), which did not receive any metal particles. Each examination was conducted at 3 days, 2 weeks, and 1 and 3 months postoperatively. The change in the depth of the metal particles was also measured. RESULTS: Slitlamp examination did not show an inflammatory reaction or corneal opacification in any eye (100%) with metal particles at the flap interfaces. Histopathologic examinations showed no obvious changes at the flap interfaces or around the metal particles in any eye. CONCLUSION: Inflammatory reactions, such as diffuse lamellar keratitis, do not appear to be induced by metal particles from the microkeratome blade itself.

Animals↗

PubMed2005

Microkeratome-assisted phacoemulsification.

This study reports a technique in which phacoemulsification and intraocular lens (IOL) insertion are performed in conjunction with a microkeratome flap in a patient with ocular surface disease. Microkeratome-assisted phacoemulsification was performed in a 72-year-old woman with a history of trachoma during childhood. A 130 microm corneal flap was made using a microkeratome prior to phacoemulsification and IOL insertion. Lifting the flap during surgery allowed a clear view of the anterior chamber through the smooth lamellar interface created by the microkeratome blade. The flap was washed and repositioned without sutures at the end of surgery. There were no complications associated with the microkeratome flap following surgery. Visual acuity improved from hand motion to 20/200. Microkeratome-assisted phacoemulsification is a safe technique for cataract patients with diseases of the ocular surface.

Aged↗

PubMed2004

Role of the endothelial pump in flap adhesion after laser in situ keratomileusis.

PURPOSE: To investigate the role of the endothelial pump in the attachment of the corneal flap during the early period after laser in situ keratomileusis (LASIK). SETTING: Department of Ophthalmology, Tokyo Dental College, Tokyo, Japan. METHODS: The study comprised 30 porcine eyes. In all eyes, a corneal flap was made with a microkeratome. Five minutes after the flap was placed over the bed, the adhesion strength was measured with a load-testing machine. To inhibit the endothelial pump, ouabain was injected into the anterior chamber (10 eyes) or the endothelium was mechanically scraped (10 eyes). The control group included 10 eyes. RESULTS: The load needed to lift the flap was significantly lower in the ouabain group (0.21 gram force [gf]; P<.01) and the endothelial scrape group (0.22 gf; P<.01) than in the control group (0.61 gf). CONCLUSION: The endothelial pump plays an important role in flap attachment in the early postoperative period after LASIK.

Animals↗

PubMed2004

Clinical comparison of Healon5 and Healon in phacoemulsification and intraocular lens implantation; Randomized multicenter study.

PURPOSE: To compare the overall clinical performance during phacoemulsification and intraocular lens (IOL) implantation, the effect on intraocular pressure (IOP), and the effect on corneal endothelium of Healon5 (sodium hyaluronate 2.3%) and Healon (sodium hyaluronate 1.0%) ophthalmic viscosurgical devices (OVDs). SETTING: Multicenter study. METHODS: In this randomized prospective clinical study, the performance of Healon5 (viscoadaptive; dispersive and cohesive) and Healon (cohesive) during cataract surgery was evaluated in 157 patients, 79 with Healon5 and 78 with Healon. Surgeons evaluated the following on a 5-point scale: retention during phacoemulsification (primary endpoint), ease of injection, anterior chamber maintenance during continuous curvilinear capsulorhexis (CCC), facilitation of IOL implantation, and ease of removal from the eye. Masked examiners other than the surgeon performed the following measurements: IOP preoperatively and 5 and 24 hours, 7 days, and 3 months postoperatively; corneal thickness before and 24 hours, 7 days, and 3 months postoperatively; and corneal endothelial cell count preoperatively and 3 months postoperatively. RESULTS: Intraocular retention during phacoemulsification was assessed as good or very good in 77% in the Healon5 group and 8% in the Healon group; the difference was statistically significant (P<.0001, Wilcoxon rank sum test). The Healon5 group had significantly better scores for anterior chamber maintenance during CCC (P<.0001) and facilitation of IOL implantation (P =.032), and the Healon group had significantly better scores for ease of injection (P<.0001) and ease of removal (P<.0001). There were no statistically significant between-group differences in IOP, corneal endothelial cell count, or corneal thickness. CONCLUSIONS: Surgeons rated Healon5 better than Healon in retention during phacoemulsification, anterior chamber maintenance during CCC, and facilitation of IOL implantation. They assessed Healon as easier to inject and remove. There was no difference in safety-related parameters between the 2 OVDs. These findings indicate that Healon5 is effective in cataract surgery.

Aged↗

PubMed2002

Cataract surgery combined with ocular surface reconstruction in patients with severe cicatricial keratoconjunctivitis.

PURPOSE: To present the technique and outcome of cataract surgery combined with ocular surface reconstruction in patients with severe cicatricial keratoconjunctivitis. SETTING: Department of Ophthalmology, Tokyo Dental College, Chiba, Japan. METHODS: Phacoemulsification with transplantation of a limbal allograft and an amniotic membrane was performed in 4 eyes of 3 patients with cataract and end-stage cicatricial keratoconjunctivitis. The surgical technique and the improvements in visual acuity were reviewed. The follow-up ranged from 13 to 27 months. RESULTS: Phacoemulsification and intraocular lens implantation were performed in all cases without intraoperative complications. In 3 of the 4 eyes, the best corrected visual acuity improved from hand motions to 20/100, hand motions to 20/30, and counting fingers to 20/50. The visual acuity recovered to 20/60 postoperatively in 1 eye in which the preoperative visual acuity was light perception; at 1 year, the visual acuity decreased to hand motions because of recurrent fibrous tissue over the cornea. CONCLUSION: Small-incision phacoemulsification was performed safely in combination with ocular surface reconstruction in patients with cataract and end-stage cicatricial keratoconjunctivitis.

Cataract↗