Yoshinori Oie

Regenerative Medicine for the Cornea

Regenerative medicine for the cornea provides a novel treatment strategy for patients with corneal diseases instead of conventional keratoplasty. Limbal transplantation has been performed in patients with a limbal stem cell deficiency. This procedure requires long-term immunosuppression that involves high risks of serious eye and systemic complications, including infection, glaucoma, and liver dysfunction. To solve these problems, ocular surface reconstruction using cultured limbal or oral mucosal epithelial stem cells has been successfully applied to patients. However, cell sheets must be fabricated in a cell processing center (CPC) under good manufacturing practice conditions for clinical use, and the expenses of maintaining a CPC are too high for all hospitals to cover. Therefore, several hospitals should share one CPC to standardize and spread the application of regenerative therapy using tissue-engineered oral mucosal epithelial cell sheets. Consequently, we developed a cell transportation technique for clinical trial to bridge hospitals. This paper reviews the current status of regenerative medicine for the cornea.

Relation of Posterior Staphyloma in Highly Myopic Eyes with Macular Hole and Retinal Detachment

PurposeTo investigate whether the type of posterior staphyloma (PS) affects the development of macular hole and retinal detachment (MHRD) in high myopia.MethodsIncluded in this retrospective study were 28 highly myopic eyes with MHRD (MHRD group) and 47 highly myopic eyes without MHRD (control group). The presence or absence of PS and the type of PS according to the classification of Curtin, the postoperative visual acuity, and the retinal reattachment rate were investigated.ResultsThe percentage of eyes with PS was significantly higher in the MHRD group than in the control group (P < 0.001). The rate of type II PS was significantly higher in the MHRD group (P = 0.01). There were no significant differences among the types of PS regarding the retinal reattachment rates and visual outcome.ConclusionsEyes with type II PS have a higher risk for the development of MHRD. However, the type of PS did not seem to affect the anatomic and visual outcome. Jpn J Ophthalmol 2005;49:530–532© Japanese Ophthalmological Society 2005

Effect of diquafosol ophthalmic solution on the optical quality of the eyes in patients with aqueous-deficient dry eye

To investigate the short‐ and long‐term effects of diquafosol ophthalmic solution on the optical quality of the eyes in patients with aqueous‐deficient dry eye.

Effect of non-invasive tear stability assessment on tear meniscus height.

To investigate the effect of non‐invasive tear stability assessment with forced eye opening on the lower tear meniscus.

Ocular forward light scattering and corneal backward light scattering in patients with dry eye.

PURPOSE To evaluate ocular forward light scattering and corneal backward light scattering in patients with dry eye. METHODS Thirty-five eyes in 35 patients with dry eye and 20 eyes of 20 healthy control subjects were enrolled. The 35 dry eyes were classified into two groups according to whether superficial punctate keratopathy in the central 6-mm corneal zone (cSPK) was present or not. Ocular forward light scattering was quantified with a straylight meter. Corneal backward light scattering from the anterior, middle, and posterior corneal parts was assessed with a corneal densitometry program using the Scheimpflug imaging system. RESULTS Both dry eye groups had significantly higher intraocular forward light scattering than the control group (both P<0.05). The dry eye group with cSPK had significantly higher values in anterior and total corneal backward light scattering than the other two groups. Moderate positive correlations were observed between the cSPK score and corneal backward light scattering from the anterior cornea (R=0.60, P<0.001) and corneal backward light scattering from the total cornea (R=0.54, P<0.001); however, no correlation was found between cSPK score and ocular forward light scattering (R=0.01, P=0.932). CONCLUSIONS Ocular forward light scattering and corneal backward light scattering from the anterior cornea were greater in dry eyes than in normal eyes. Increased corneal backward light scattering in dry eye at least partially results from cSPK overlying the optical zone.

Effect of instillation of eyedrops for dry eye on optical quality.

PURPOSE To investigate the effects of viscosity and suspensibility of eyedrops for dry eye by evaluating an eyedrop with one of the solutions or no solution (0.3% sodium hyaluronate ophthalmic solution, 3% diquafosol ophthalmic solution, and 2% rebamipide ophthalmic suspension) on ocular higher-order aberrations (HOAs) and forward light scatter. METHODS We evaluated ocular HOAs and forward light scatter before and 1, 5, and 10 minutes after instillation of three eyedrops for dry eye in 15 healthy subjects. Saline served as the control. The HOAs were measured for a 4-mm pupil using a wavefront sensor. The obtained aberration data were analyzed in the central 4-mm diameter for total HOAs up to the sixth-order Zernike polynomials. Forward light scatter was quantified with a straylight meter. RESULTS A significant increase was seen in the HOAs 1 minute after instillation of the three eyedrops for dry eye; the HOAs recovered to the baseline level thereafter. When 0.3% sodium hyaluronate was compared with 2% rebamipide and 3% diquafosol, the HOAs increased significantly (P < 0.01 for both comparisons) immediately after instillation. A significant increase in forward light scatter occurred 1 minute after instillation of rebamipide suspension and returned to the preinstillation level 5 minutes after instillation. No significant changes in forward light scatter occurred after instillation of 3% diquafosol or 0.3% sodium hyaluronate. CONCLUSIONS Quantitative serial measurement of HOAs and forward light scatter showed that the temporal reduction in optical quality may be attributed mainly to increased HOAs after instillation of highly viscous 0.3% sodium hyaluronate ophthalmic solution and to increased forward light scatter after instillation of 2% rebamipide ophthalmic suspension in healthy subjects.

Maintenance and Distribution of Epithelial Stem/Progenitor Cells after Corneal Reconstruction Using Oral Mucosal Epithelial Cell Sheets

We assessed the maintenance and distribution of epithelial stem/progenitor cells after corneal reconstruction using tissue-engineered oral mucosal cell sheets in a rat model. Oral mucosal biopsy specimens were excised from green fluorescent protein (GFP) rats and enzymatically treated with Dispase II. These cells were cultured on inserts with mitomycin C-treated NIH/3T3 cells, and the resulting cell sheets were harvested. These tissue-engineered cell sheets from GFP rats were transplanted onto the eyes of a nude rat limbal stem cell deficiency model. Eight weeks after surgery, ocular surfaces were completely covered by the epithelium with GFP-positive cells. Transplanted corneas expressed p63 in the basal layers and K14 in all epithelial layers. Epithelial cells harvested from the central and peripheral areas of reconstructed corneas were isolated for a colony-forming assay, which showed that the colony-forming efficiency of the peripheral epithelial cells was significantly higher than that of the central epithelial cells 8 weeks after corneal reconstruction. Thus, in this rat model, the peripheral cornea could maintain more stem/progenitor cells than the central cornea after corneal reconstruction using oral mucosal epithelial cell sheets.

Surgical Excision of Retinal Macroaneurysms with Submacular Hemorrhage

PurposeTo report the visual outcome following the surgical excision of retinal macroaneurysms with submacular hemorrhage.MethodsTwo patients presented with decreased vision caused by submacular hemorrhage from retinal macroaneurysms. In the first case, the macroaneurysm was too large to be treated by photocoagulation, and in the second case the direct photocoagulation during the first vitrectomy did not prevent the recurrence of hemorrhages. Vitrectomy with surgical excision of the retinal macroaneurysm using scissors and diathermy with a drainage of the submacular hemorrhage was then performed.ResultsIn the first patient, the visual acuity was light perception before treatment and 2/200 16 months after the excision. In the second patient, the visual acuity was 20/667 before treatment and 20/40 11 months after the excision. No hemorrhage has recurred in either case after the second vitrectomy.ConclusionsThe surgical excision of retinal macroaneurysms might be an effective procedure in cases where the macroaneurysm is too large or cannot be treated by photocoagulation during vitrectomy.

A Novel Method Using Quantum Dots for Testing the Barrier Function of Cultured Epithelial Cell Sheets.

PURPOSE The corneal epithelium provides a barrier to protect the deeper structures of the eye from any particles or pathogens. Cultured epithelial cell sheets are used in transplantation surgery for corneal repair or regeneration. The purpose of this study was to develop a novel method using fluorescent quantum dot nanoparticles for validating the quality and barrier function of cultured epithelial cell sheets. METHODS Human function epithelial cell sheets, cultured from oral mucosal or corneal limbal cells, were incubated in either normal calcium-containing medium or medium containing no calcium with a calcium chelator. Also contained in the media were suspensions of two different sizes of quantum dots. Following incubation, analysis of quantum dot penetration was carried out using confocal microscopy. RESULTS In contrast to the cell sheets incubated in calcium-containing medium, removal of extracellular calcium resulted in the disruption of tight junctions, compromising the cell sheets barrier function. This caused a reduction in transepithelial electrical resistance and deeper, more ubiquitous penetration of the quantum dots into the paracellular space and interior of the cell sheet. CONCLUSIONS This method provides easy to interpret qualitative and quantitative data on the functionality of a cell sheets tight junctions, as well as nanoscale and microscale structural information on its surface and interior morphology, and any localized areas of damage or abnormality. This novel technique could be used as part of the validation system for cultured epithelial cell sheets for use in transplantation.

Corneal topographic analysis of patients with Mooren ulcer using 3-dimensional anterior segment optical coherence tomography.

Purpose: To investigate the corneal topography and visual function of patients with Mooren ulcer using 3-dimensional anterior segment optical coherence tomography (3-D AS-OCT). Methods: Fourteen eyes of 9 patients with Mooren ulcer were studied. Pachymetric and axial power maps were obtained by 3-D AS-OCT. The axial power maps were classified into 3 patterns by visual inspection. The distribution of the corneal dioptric power was analyzed by Fourier harmonic expansion. The magnitudes of the spherical component, asymmetry, regular astigmatism, higher-order irregularity, and radial distance from the corneal vertex to the thinnest point of the lesion were determined. Results: The axial power maps of 9 eyes were classified into arcuate patterns, 4 into crab-claw patterns, and 1 eye into an intermediate pattern. The radial distance from the corneal vertex to the thinnest point of the lesion was significantly shorter in the crab-claw pattern group than in the arcuate pattern group (P = 0.007). The magnitudes of asymmetry, regular astigmatism, and higher-order irregularity of the crab-claw pattern group were significantly greater than those of the arcuate pattern group (P = 0.017, P = 0.011, and P = 0.030, respectively). Conclusions: Three-dimensional AS-OCT is able to evaluate the corneal topography of opacified peripheral lesions in eyes with Mooren ulcer, and the results showed that irregular astigmatism is higher when the lesion is closer to the center of the cornea.