• Current Optics and Photonics
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• v.6 no.2
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• pp.196-201
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• 2022

Collagen fibers tens of nanometers in size, which constitute most of the corneal volume of the human eye, are layered in a uniform direction, and adjacent fiber layers are arranged at an angle of 90° to each other. According to the results of this study, the transmittance at 45° of interlayer rotation angle is highest, and higher than that of the 90° body structure. The transmittance is examined, concerning the polarization state of the incident light; circularly polarized light case shows higher transmittance than linearly polarized. Through this, a simulation to confirm the deformed structure of collagen fibers, which show higher transmittance than the anatomical structure of the cornea, is attempted.

• Journal of Veterinary Science
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• v.24 no.2
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• pp.30.1-30.6
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• 2023

A 4-year-old Chihuahua dog was referred for bilateral corneal ulcers. Slightly raised white fluorescein-positive plaque-like corneal lesions in both eyes appeared as intense hyperreflective areas with posterior shadowing on optical coherence tomography (OCT). Based on corneal cytology and culture, Candida albicans-induced fungal keratitis was diagnosed. Despite treatment, on OCT, endothelial plaques, increased stromal infiltration thickness, vertical shapes of the ulcer edge, and necrotic stromal space were judged to be aggravation of the disease, and surgery was performed. Conjunctival grafting surgery with topical 1% voriconazole effectively resolved fungal keratitis. OCT can provide detailed and objective information related to the disease prognosis.

• Journal of Veterinary Clinics
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• v.40 no.3
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• pp.221-224
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• 2023

A two-year-old spayed female Maltipoo dog was presented with a two-month duration of glaucoma in the right eye. On the first presentation, menace response and dazzle reflex were absent in the right eye, but it was present in the left eye. Slit-lamp biomicroscopy showed buphthalmia, mild corneal edema, and conjunctival and episcleral hyperemia in the right eye. The intraocular pressures were 70 mmHg and 30 mmHg in the right and left eyes, respectively. On the gonioscopic and high-resolution ultrasound examinations, both the iridocorneal angle and ciliary cleft were completely closed in the right eye. However, gonioscopy revealed an opened iridocorneal angle even with some broader base of pectinate ligament fiber, but high-resolution ultrasound showed a narrowed ciliary cleft and increased contact of the iris base with the limbal cornea in the left eye. Based on these results, a diagnosis of primary angle-closure glaucoma was made in both eyes. This case report highlighted the importance of evaluating the ciliary cleft with high-resolution ultrasound as a critical diagnostic and prognostic role in canine glaucoma.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.223-232
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• 2012

Purpose: Validating a new research method to determine posterior corneal curvature and asphericity(Q) in vivo, based on measurements of anterior corneal topography and corneal thickness. Methods: Anterior corneal topographic data, derived from the Medmont E300 corneal topographer, and total corneal thickness data measured along the horizontal corneal meridian using the Holden-Payor optical pachometer, were used to calculate the anterior and posterior corneal apical radii of curvature and Q. To calculate accurate total corneal thickness the local radius of anterior corneal curvature, and an exact solution for the relationship between real and apparent thickness were taken into consideration. This method differs from previous approach. An elliptical curve for anterior and posterior cornea were calculated by using best fit algorism of the anterior corneal topographic data and derived coordinates of the posterior cornea respectively. For validation of the calculations of the posterior corneal topography, ten polymethyl methacrylate (PMMA) lenses and right eyes of five adult subjects were examined. Results: The mean absolute accuracy (${\pm}$standard deviation(SD)) of calculated posterior apical radius and Q of ten PMMA lenses was $0.053{\pm}0.044mm$ (95% confidence interval (CI) -0.033 to 0.139), and $0.10{\pm}0.10$ (95% CI -0.10 to 0.31) respectively. The mean absolute repeatability coefficient (${\pm}SD$) of the calculated posterior apical radius and Q of five human eyes was $0.07{\pm}0.06mm$ (95% CI -0.05 to 0.19) and $0.09{\pm}0.07$ (95% CI -0.05 to 0.23), respectively. Conclusions: The result shows that acceptable accuracy in calculations of posterior apical radius and Q was achieved. This new method shows promise for application to the living human cornea.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.2
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• pp.91-98
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• 2016

Purpose: This study investigated the masking effect of the hydrogel lens and silicone hydrogel lens on the cornea with refractive surgery and without surgery. Methods: 24 university students (means age: $23.48{\pm}2.89years$) without refractive surgery (12, control group) and with refractive surgery (LASIK: 8, LASEK: 4, experimental group) participated in the study. Mean refractive errors of right eyes were -2.73 D for control group and -0.24 D for experimental group. The differences in the refractive power and corneal topography map between pre- and post-wearing the -3.00 D lenses were compared, and 2 kinds of hydrogel contact lenses (0.89 Mpa, 0.49 Mpa) and 2 kinds of silicone hydrogel lenses (1.5 Mpa, 0.8 Mpa) were used for -3.00 D lenses. NVision-K5001 (Shin nippon, Japan) was used to measure the refractive power and Keratograph 5M (Oculus, Germany) to measure the corneal topography map change. Results: Variations in the refractive power increased to the plus direction in the experimental group after wearing soft contact lenses. The corneal topography map showed significant changes on the both groups after wearing soft contact lenses (p<0.05). However there were no significant differences in the refractive power and corneal topography map variations by lens materials. Conclusions: Wearing soft contact lenses showed corneal topography map changes. Especially wearing soft contact lenses on the flat cornea after corneal refractive surgery showed greater corneal power changes. Therefore, it should pay attention to refractive change in case of prescribing soft contact lenses to patients with corneal refractive surgery.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.449-456
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• 2013

Purpose: The present study aimed to investigate the effects of corneal eccentricity and shape on the rotational pattern of toric soft lens by the postural change of lens wearers. Methods: The corneal eccentricity of 41 eyes (aged 20s) having -1.0 D with-the-rule corneal astigmatism (WRCA) was measured, and then toric soft lenses were fitted with the amount of total astigmatism. In lying and straight postures, the rotation of toric soft lenses was recorded by a camera attached to slitlamp and analyzed. Results: Most toric soft lens designed with accelerated stabilization rotated to the temporal direction, which was the lying position direction, regardless of corneal eccentricity, and some lenses rotated to the nasal direction for high corneal eccentricity and corneal type of asymmetric bowtie. There was no correlation between the amount of rotation and corneal eccentricity right after of contact lens wearing in straight and lying posture, however, the amount of rotation was the greater for the cornea with the higher eccentricity after the subjects laying down for some period. The speed of lens rotation started to decrease after the subjects laying down, but the speed was not different according to corneal eccentricity difference. The amount of lens rotation for symmetric and asymmetric bowtie-typed corneas increased more than it for oval-typed cornea, and it was same even with time elapsing. The speed of lens rotation in lying posture was the slowest in asymmetric bowtie-typed cornea compared with other corneal types. Conclusions: From the present study, it was revealed that the rotational pattern of toric soft lens was affected by corneal eccentricity and corneal shape when the wearer's posture changed. Thus, it should be considered for the development of the fitting guideline and the design of toric soft lens.

• Applied Microscopy
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• v.24 no.3
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• pp.1-9
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• 1994

Pardosa astrigera possessed eight eyes arranged in three rows on the frontal carapace. A pair of small anterior lateral eyes (ALE) flanked each side by an anterior median eyes (AME) lay along the anterior margin that was situated on the anterior row of clypeus. The anterior lateral eye was composed of cornea, vitreous body, and retina. Cornea was made up mainly of exocuticle lining the cuticle. Lens in anterior lateral eye was biconvex type which bulged into the cavity of the eyecup. Outer and inner central region of lens were approximately spherical with radius of curvature $5.6{\mu}m$ and $12.5{\mu}m$, respectly. Vitreous body formed a layer between the cuticular lens and retina. They formed biconcave shape. Retina of the anterior lateral eyes was composed of three types of cells: visual cells, glia cells, and pigment cells. The visual cells were unipolar neuron, as were the receptor of the posterior lateral eye. But cell body was unique to the anterior lateral eyes. They were giant cell, relatively a few in number, and under the layer of vitreous bodies. Each visual cell healed rhabdomeres for a short stretch beneath the cell body. Rhabdomes were irregulary pattern in retina and electron dense pigment granules scattered between the rhabdomes. Glia cell situated at the cell body of visual cell and glia cell process reached to rhabdomere portion. Below the rhabdome, tapetum were about $30{\mu}m$ distance from lens, which composed of 4-5 layers. It was about $25{\mu}m$ length that intermediate segment of distal portion of visual cell. Electron dense pigment granules between the intermediate segment were observed.

• BMB Reports
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• v.48 no.3
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• pp.153-158
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• 2015

As FK506 binding proteins (FK506BPs) are known to play an important role in the regulation of a variety of biological processes related to cell survival, this study was designed to examined the protective effects of FK506 binding protein 12 (FK506BP) on low humidity air flow induced dry eye in a rat model using transduced PEP-1-FK506BP. After the topical application of PEP-1-FK506BP, tear volumes were markedly increased and significant prevention of cornea damage was observed compared with dry eye rats. Further, immunohistochemical analysis demonstrated that PEP-1-FK506BP markedly prevented damage to the cornea, the bulbar conjunctiva, and the palpebral conjunctiva epithelial lining compared with dry eye rats. In addition, caspase-3 and PARP expression levels were found to be decreased. These results demonstrated that topical application of PEP-1-FK506BP significantly ameliorates dry eye injury in an animal model. Thus, we suggest that PEP-1-FK506BP can be developed as a new ophthalmic drop to treat dry eye diseases.

• Applied Microscopy
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• v.28 no.3
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• pp.363-377
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• 1998

After the investigation on the eye of Incilaria fruhstorieri with light and electron microscopes, the following results were obtained. The eye of Incilaria fruhstorferi comprises cornea, lens, vitreous body, retina, and optic nerve inward from the outside. Cornea is composed of squamous, cuboid, columnar and irregular cells, which appear to be light due to their low electron density. In their cytoplasms, glycogen granules, multivesicular body, and nucleus were observed. Vitreous body, located behind non-cellular transparent lens, is filled with long and short microvilli protruding from the retinal epithelia. Retinal epithelium, the organ to perceive objects, is divided into four parts; microvillar layer pigment layer, nuclear layer, and neutrophils layer, from the apical portion. Microvillar layer consists of the type-I photoreceptor cells and pigmented granule cells. In the apical portion of their cytoplasms, long microvilli (length, $19{\mu}m$) , short microvilli (length, $8{\mu}m$), and rolled microvilli grow thick in the irregular and mixed forms. Photoreceptor cells are classified into type-I and type-II, according to their structures. The type-I cell has the apical portion rising roundly like a fan and the lower part which looks like the helve of a fan. In the cytoplasm of the apical portion, there are clear vesicles, cored vesicles, ovoid mitochondria, and microfilaments, and in the cytoplasm of the lower part, photic vesicles with their diameters about 60nm aggregate densely. The type-II photoreceptor cell, located at the lower end of the type-I cells, has a very large ovoid nucleus 3nd no microvilli. In the cytoplasm of the type-II cell, the photic vesicles with sizes 60nm aggregate more densely than in the cytoplasm of the type-I cell. Pigmented cells are classified into type-A and type-B, according to their structures. The type-A is identified to be a large cell containing round granules (diameter, $0.5{\mu}m$) of very high electron density, while the type-B is identified as a small cell where the irregular granules (diameter, $0.6{\mu}m$) of a little lower electron density amalgamate. Nuclear layer ranges from the bottom of pigment layer to the top of the capsule, and contains three kinds of nuclei (nuclei of the type-II photoreceptor cell, pigmented granule cell, and accessory neuron). The capsules covering the outmost part of the eyeball are composed of collagenous fiber and three longitudinal muscle layers (the thickness of each longitudinal muscle layer, $0.4{\mu}m$) and thick circular muscle layer (thickness, $0.3{\mu}m$). Around the capsules, there is a neurophile layer consisting of neurons and nerve fibers. Each neuron has a relatively large ovoid nucleus for its cytoplasm, and in the karyosome, large lumps of keterochromatin form a wheel nucleus.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.19-25
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• 2007

It was studied how using soft contact lens multi-purpose solution (MPS), often used for medical treatment, effects the inhibition on cell growth, and how using the MPS demages eye cells, on rabbit eye's corneal epithelium and endothelium tissue. $ReNu^{(R)}$ (Baush & Lomb, USA), Opti-free $express^{(R)}$ (Alcon, USA), Free-sol $plus^{(R)}$ (Hanamedicon, Korea) were used as MPS. After culturing Clone 1-5C-4 cell lines (Human conjunctival cell lines), cell growth inhibition rate was measured by MIT assay. By making Hematoxylin and Eosin stain specimen, the morphology was observed by optical microscope. In the In vivo experiment, 9 white rabbit eyes (18 eyes) were classified into 3 groups. The experiment group is left eyes (9 eyes) of rabbit, and MPS were dropped; however the control group, the right eyes (9 eyes), were only used a saline solution without a preservatives. After the dropping within the period, the cornea surface of rabbit endothelium tissue was observed using scanning electron microscopy (SEM).