Excimer Laser Photorefractive Keratectomy for the Correction of Compound Myopic Astigmatism: One Year Follow-Up

To prospectively examine the predictability of excimer laser photorefractive keratectomy for compound myopic astigmatism, we treated 107 eyes of 70 patients with a VisX Twenty/Twenty excimer laser and followed them up for 12 months. Patients were divided into three groups with preoperative myopia: group 1 with diopters of -6.00 or less, group 2 with diopters between -6.01 and -10.00, and group 3 with diopters greater than -10.00. Also, two groups of patients were evaluated with preoperative astigmatism: group I with -2.00 diopters or less and group II with greater than -2.00 diopters. At 12 months group1, with amean preoperative refractive error of -4.332D, changed to -0.19D, group 2 changed from -7.35D to -0.66D, and group 3 changed from -11.72D to -1.23D. Group I with a mean preoperative refractive error of -1.22D changed to -0.55D, while group II changed from -2.63D to -0.77D. Finally, 85% of eyes with preoperative spherical equivalent diopters of -6.00 or less, 65% of eyes between -6.01 and -10.00D, and 42% of eyes greater than -10.00D were corrected within 1D of intended refraction, respectively.

Measurements of the Diameter and Area of the OpticDisc in Enucleated Human eyes

To measure the optic disc diamete and area in enucleated human eyes, thirty-three enucleated human eyes (20 men, 13 women), with a mean age of 44.2+/-17.7 years (+/-standard deviation; range 8 -74 years), were studied. After enucleation, the globes were immediately fixed in a solution of 10% formalin, were bisected through the optic nerve head and specimens were stained with hematoxylin-eosin. The slides were histomorphometerically evaluated with a light microscope. Each disc was measureed vertically and horizontally on a macrophotograph of the whole specimens with an aligned micromete scale. For correction preparation-induced shrinkage factor, one specimen was measured on the unfixed state. Compared to values obtained in unfixed specimens, preparation-induced shrinkage factor was 6.5% Mean maximal and minimal diameters of the optic disc were 2.16+/-0.15mm (range 1.38 -3.25mm) and 1.79+/-0.44mm (range 1.06 -2.90mm), rrespectively. Mean area of the optic disc was 3.20+/-1.58mm2(range 1.15 - 7.40mm2). These practical values of the optic disc diameter and area may be the important standard units to the further quantiative optic nerve studies.

Result of Excimer Laser Photorefractive Keratectomy Correction of Myopia: One and Two-Years Follow-up

To examine prospectively the efficacy and reliability of excimer laser photorefractive keratectomy for myopia. we treated 147 eyes of 86 patients with a VisX Twenty/Twenty excimer laser and followed them up for 1 year and follow up 48 eyes of 26 patients for 2 years. The patients were divided into two groups with preoperative myopia: group 1 with diopters between -1.50 and -6.00, group 2 with diopters between -6.01 and -10.00. At 1 year, the group 1 with a mean preoperative refractive error of -4.61D changed to -0.40D, the group 2 changed from -7.50D to -0.92D. At 2 years, the group 1 with a mean preoperative refractive error of -4.28D changed to -0.41D, the group 2 changed from -7.75D to -1.04D. At 1 yera, in group 1, 90.91% (70 of 77) of eyes and in group 2, 64.29%(45 of 70) of eyes were corrected within 1D of intended refraction,respectively. At 1 years, in group 1, 94.81% (73 of 77) of eyes and in group 2, 84.29%(59 of 70) of eyes achieved an uncorrected visual acuity of 0.5 or better. And at 2 years, in group 1, 81.82% (18 of 22)of eyes, and in group 2, 50.00% (13 of 26) of eyes were corrected within 1D of intended refraction, respectively. At 2 years, in group 1, 95.50% (21% of 22) of eyes and in group 2, 84.62%(22 of 26) of eyes achieved an uncorrected visual acuity of 0.5 or better.

Measurements of Diameter and Area of Optic Disc with the Scale of the Volk Lens

The measurement of the area of the optic disc is important to classification of congenital anomaly of optic disc and diagnosis and following up of glaucoma. This study was performed to measure easily the diameter and area of the optic disc using the retinal scale of the Volk lens although recently the study was reported to measure the optic disc with computerized optic disc analysis system. We evaluated the measurement of the diameter and area of the optic disc of 31 patients(56 eyes) using the retinal scale of Volk lens and then corrected the magnification of central fundus photographs using Litmann's method. The mean refractive power and the mean axial length was -0.24 diopter(range -4.5 to 4.25 diopter), and 22.91 mm (range 20.5 to 26.1mm), respectively. The mean horizontal diameter, the mean verticaI diameter, and the mean area of optic disc was 1.75 +/- 0.18mm, 1.90 +/- 0.19mm, and 2.62 +/- 0.50mm2, respectively. We think that the measurement of the optic disc area with Volk lens is useful method in following up of cup-disc ratio in outpatient basis.

Increased numbers of Langerhans cell and expression of HLA-Dr antigen in the giant papilla of patients with giant papillary conjunctivitis

A study of histopathologic changes, ultrastructure, and expression of the HLA-Dr antigen within the giant papillae of patients with giant papillary conjunctivitis was performed to determine whether cell-mediated immune response is related to this condition. Conjunctival giant papillae from ten patients with giant papillary conjunctivitis were examined by light and electron microscopy and by the indirect immunofluorescent staining method with HLA-Dr antibody. The infiltration of eosinophilic neutrophils and granules was most prominent, with the occasional infiltration of mast cells, as shown by light microscopy. The infiltration of activated fibroblasts and Langerhans cells was also observed. Cells expressing HLA-Dr antigen were also markedly increased, as shown by the immunofluorescent method. These findings suggest that delayed hypersensitivity may, along with the processes of antigen presentation by HLA-Dr-expressing (including Langerhans) cells, contribute to the pathogenesis of giant papillary conjunctivitis.

Ischemic Changes in Hypertensive Choroidopathy by Fluorescein Angiography

The retinal and choroidal blood vessels respond independently to the abruptly increased arterial pressure due to their differences in the anatomic and physiologic properties, which induce hypertensive retinopathy and hypertensive choroidopathy respectively. The authors reviewed the fluorescein angiogram retrospectively to observe the ischemic changes of the choroid in 15 cases of hypertensive choroidopathy. The ischemic changes of the choroid in hypertensive choroidopathy were characterized by generalized or sectorial filling delay which was followed by staining or leakage of dye. These findings suggest that the choroidal circulation may lead to the sectorial and generalized ischemic conditions following the abruptly increased arterial pressure due to their differences in the anatomic structures. The fluorescein angiographic findings in the hypertensive choroidopathy depend on both the degree of the circulatory disturbance and the levels of the affected choroidal vessels.

Ultrastructural change of the Muller cell in the culture of sensory retina

This study was performed to investigate the sequential changes of the retinal tissue in tissue culture condition. The human sensory retinal tissues were cultured for up to 2 weeks and 4 weeks, respectively. The initial changes showed the separation of the intercellular space and the consequent widening of the intercellular space with prolapse of cytoplasmic processes into the widened intercellular space. The internal limiting membrane was also separated from the inner retina, which led to the prolapse of the cytoplasm of the Muller cell. The growth of the Muller cell was most prominent during the 4-weeks' tissue culture period. These findings suggest that the Muller cell might contribute to the formation of cellular membrane in case of the defect of the internal limiting membrane in several pathologic conditions.

Demonstration of Virus in Retinal Necrosis following Intravitreal Inoculation of Herpes Simplex Virus-1

This study was performed to observe the retinal changes in rabbits by intravitreal inoculation of HSV-1. The solution of HSV-1 virus(Kos strain) was inoculated into the vitreous cavity in 5 eyes. All the eyes were checked with a slit lamp and an indirect ophthalmoscope. Two eyes that showed the retinal lesion were enucleated for the histopathologic examination. The focal infiltration of inflammatory cells was marked around the retinal vessels in one eye and there was the diffuse infiltration of plasma cells and lymphocytes in the choroid and the retina in the other eye. The pattern of proliferation and migration of retinal pigment epithelial cells was observed at the outer retina. The virus-infected nuclei were evident in the photoreceptor cells and ganglion cells. The viral particles and intranuclear inclusion were prominent in the deformed nuclei and free-floating viral particle was shown at the extracellular space of the necrotic retina. These results suggest that the intravitreal inoculation of HSV-1 might induce retinal necrosis. The inflammatory reactions was initiated at the vitreoretinal interface and perivascular area. Virus might be propagated through axons or infected cell from free-flating virus.

Morphological changes of the sensory retina following the occlusion of ciliary arteries in rabbits

The whole retina, except for the medullary fiber zone in a rabbit eye, is supplied by choroidal circulation. Therefore, the histopathological changes of the sensory retina due to choroidal circulatory disturbance in rabbits may be comparable to that of the human sensory retina in the case of ophthalmic artery occlusion. This study was carried out to evaluate the histopathological changes of the ischemic retina secondary to the occlusion of choroidal circulation. The experimental occlusion of all posterior ciliary arteries and anterior ciliary arteries in the horizontal rectus muscle of rabbit eyes was performed and the subsequent histopathological changes of the sensory retina were observed by transmission electron microscopy. The morphological changes of the sensory retina following the occlusion of the ciliary arterial system are as follows: severe loss of the inner and outer segments of the photoreceptor, mild to moderate degeneration of the ganglion cells, and excellent preservation of the Muller's cell fibers and the extension of the cytoplasmic villous processes to the cytoplasmic vacuolar spaces of other degenerated cells. These findings indicate that the Muller's fibers in the ischemic condition of retina might contribute to the formation of gliosis or scarring of a damaged retina.

Suppressed Secretion of The Extracellular Matrix of The Cultured Corneal Epithelial Cell following Inoculation of HSV-1

In order to assess the extracellular matrix(ECM) secretion of corneal epithelial cells inoculated with herpes simplex virus-1 in vitro the indirect immunofluorescent technique was used. In this study, ECM such as fibronectin, type IV collagen and laminin were rich in cultured rabbit corneal epithelial cells under the normal condition, while those became poor after inoculation with herpes simplex virus-1. This result suggested that herpes simplex virus-1 inhibit ECM secretion of the corneal epithelial cells. These findings mean that delayed epithelial wound healing after herpes simplex virus-1 infection is due to suppressed secretion of ECM which is the principal component of corneal epithelial wound healing.

The Morphologic Changes of Epikeratoplasty Lenticule In a Case

The patients initially underwent epikeratoplasty for keratoconus but a penetrating kerato plasty was required due to the opacity in the cornea. By using of this specimen, which was obtained by trephination the healing process of the host-Ienticule cornea could be examined by electron microscopy and immunofluorescence method. Epithelial ingrowth over the lenticule was well formed by the regeneration of the basement membrane over the Bowman's membrane. However, the poor attachment of the lenticule over the host corneal stroma made the interface easily separated during the sectioning processes. Electron microscopic study revealed the keratocytes in the lenticule stroma vacuolized with large number of degenerated microorganelles. These results suggest that it may take a long time to complete the wound healing of the host-Ienticule interface despite the epithelial ingrowth onto the lenticule was well formed.

Co-cultivation of Adenovirus with Cultivated Conjunctival Epithelial Cell: Morphological Changes in Infected Cell

This study was performed to investigate the morphological changes of the human conjunctival epithelium when the cultured conjunctival tissue was co-cultivated with the inoculated adenovirus. Specimens swabbed from the lower conjunctival sac of patients with epidemic Keratoconjunctivitis were inoculated into the cultured conjunctival epithelial cells and co-cultivated. The adenovirus-infected cell revealed viral particles, crystalline arrays of adenovirus, paracrystalline inclusions and three types of inclusions within the nucleus. The cytoplasm did not show the specific pathologic changes. These results suggest that adenovirus can be co-cultured with conjunctival epthelial cell and the infected cell showes the typical morphological changes within the nucleus. This in-vitro co-cultivation of adenovirus with conjunctival epithelial cell may be used for an in-vitro model in the research of adenovirus.

Fibronectin in the trabecular meshwork: immunofluorescent and immunoelectron microscopic findings

We examined the fibronectin (FN) secretion of cultured trabecular meshwork (TM) cells in a normal human eye by indirect immunofluorescent technique using mouse anti-human FN monoclonal antibody and FITC-conjugated goat anti-mouse IgG. To localize FN on frozen sections of normal TM, which were obtained from 7 enucleated eyes owing to traumatic eyeball rupture, the same indirect immunofluorescent method was used. Immunoelectron microscopy was applied to demonstrate the distribution pattern of FN in the normal TM of 2 human eyes using an avidin-biotin-peroxidase complex method. In the tissue culture of TM, the TM cell walls and extracellular matrices showed an intense staining with antibody to FN. Indirect immunofluorescent staining of FN on frozen sections of TM showed strong positive reactions in the subendothelial region. There was no reaction in the central core of the trabecular beam. Immunoelectron microscopy revealed the reaction products to FN in the areas lining the trabecular endothelial cells.

Detection of Chlamydia Trachomatis in Cultured Conjunctival Cell

This study was performed to observe the elementary body and initial body in the cultured conjuntival epithelial cell, which was co-cultures with Chlamydia trachomatis serotype-D. Following 3 weeks of cultivation of the rabbit conjuntival epithelial cell, Chlamydia trachomatis seretype-D was inoculated into the epithelial cells and co-cultured for 24, 48, and 96 hours respectively. The infected conjunctival epithelial cells was stained with fluorescence-conjugated chlamydial antibody and iodine staining. Regardless of the duration of the cocultivation time, the cultured conjunctival cells showed the positive reaction to immunofluorescent staining and iodine staining. These results indicate that Chlamydia trachomatis can be cultured in the cultured conjuntival epothelial cell of rabbit and iodine staining is a good alternative to the immunofluorescent method.

Measurements of the Diameter and Area of the Optic Disc

Using Littmann's method for correcting the magnification of central fundus photographs, we evaluated the color photographs of 195 optic discs to measure the diameter and area of the optic disc. Minimal disc diameter ranged from 1.30mm to 2.53mm(mean 1.81mm) and maximal diameter from 1.53mm to 3.08mm(mean 2.04mm). Mean optic disc area measured 2.93mm2(minimum 1.63mm2, maximum 5.53mm2). The correlation coefficients between the refractive diopter of right eye and the disc diameter of right eye were 0.34 and between the refractive diopter of left eye and the disc diameter were 0.42. The correlation coefficients between the disc area and the refractive diopter were 0.43. There was no statistically significant difference in each optic disc diameter. Regarding the Gaussian distribution curve based on these preliminary data, microdiscs can be defined as being smaller than 1.57mm2(mean minus two standard deviations) and macrodiscs as being larger than 429mm2(mean plus two standard deviations).

Fibronectin in the Trabecular Meshwork: Immunofluorescent and Immunoeledron Microscopic Findings

We examined the fibronectin(FN) secretion by cultured trabecular meshwork(TM) cells from a normal human eye by indirect immunofluorescent technique using mouse anti-human FN monoclonal antibody and FITC-conjugated goat anti-mouse IgG. To localize FN on frozen sections of normal TM which were obtained from 7 enucleated eyes owing to traumatic eyeball rupture, the same indirect immunofluorescent method was used. Immunoelectron microscopy was applied to demonstrate the distribution pattern of FN in the normal TM of 2 human eyes using an avidin-biotin-peroxidase complex method. In tissue culture of TM, TM cell walls and extracellular matrices showed an intense staining with antibody to FN. Indirect immunofluorescent staining of FN on frozen sections of TM showed strong positive reactions in the subendothelial region. There was no reaction in the central core of the trabecular beam. Immunoelectron microscopy revealed the reaction products to FN in the areas lining the trabecular endothelial cells.

Extracellular Matrix in Human Trabecular Meshwork

This study was performed to evaluate the distribution of extracellular matrix in the normal human trabecular meshwork. The trabecular meshworks obtained from 5 enucleated eyes due to traumatic eye-ball rupture were frozen processed, stained with monoclonal antibodies for fibronectin and type IV collagen, and observed by fluorescent microscopy. The indirect immunofluorescent study showed strong positive reactions in the subendothelial basement membrane for fibronectin and type IV collagen and negative reaction in the central core of trabecular beam. These results suggest that fibronectin and type IV collagen distribute predominantly in the basement membrane of the trabecular beam.

Growth and Characterization of the Uveal Melanoma in Vitro

This study was performed to observe the influence of the feeder layer on the culture of the human uveal melanoma cell. Two types of melanoma cells which were obtained from the patients with choroidal melanoma were implanted into the culture flask. The melanoma cell was seeded onto the culture dish covered with conjunctival fibroblast, Vero cell, and culture dish which did not contain the feeder layer respectively. The growth pattern of the melanoma cell was observed with phase contrast microscopy upto 30 days after seeding. There was no definite difference in growth pattern between each group. These results may indicate that the feeder layer is not an essential factor in the culture of uveal melanoma cell.

Ultrastructure and blood-iris barrier in experimental rubeosis iridis in rabbit

Iris neovascularization was produced in rabbits by hypotony following repeated aspiration of the vitreous. The hypotony was produced after 0.3 ml of vitreous fluid was aspirated using a 25-gauge needle through the pars plana of 10 rabbits. For the histochemical study, horseradish peroxidase(HRP) was injected through the ear lobe vein. After fixation of the iris tissue, the tissue was treated with diaminobenzidine and examined with both light microscopy and transmission electron microscopy. The newly-formed vessel was abundant, particularly on the upper stroma of the iris. The new vessel formation was evident due to the proliferation of endothelial cells, which may have been derived from preexisting iris vessels. The endothelial cells of the newly-formed vessels revealed prominent villous processes into the vascular lumen, formation of the marginal flap, numerous fenestrations in the endothelial junction, and reaction product onto extravascular space by the cytochemical electron microscopy. These results suggest that hypotony in the rabbit produces the disruption of the blood-iris barrier and the balance between angiogenesis-antiangiogenesis modulation.

Influence of Soft Contact lens on Tear Excretion Measured with lacrimal Scintillography

In order to evaluate the influence of soft contact lens(SCL) on the tear turnover rate in the conjunctival sac with SCL, this study was performed with lacrimal scintillography. Two determinations were carried out in the same eye: the first determination was carried out in both eyes without SCL(control group) and the second determination was carried out in both eyes after adaptation to the SCL from 4 hours to 8 hours only in the left eye(study group). In the results, there was no statistical difference of the fractional turnover rate of the tear between both eyes without SCL. In left eyes, the fractional tunover rate of the study group was significantly lower than that of the control group, because the accumulation of the Technetium 99m sodium pertechnetate in the SCL. In right eyes, there was no statistical difference of the fractional turnover rate of the tear between the control group and the study group. This result may be derived from 'fatigue block' and/or the decreased sensitivity of the cornea fitted with SCL.