Effect of Intravitreal Bevacizumab on Vascular Endothelial Growth Factor Expression in Patients with Proliferative Diabetic Retinopathy

PURPOSE: To investigate the effect of bevacizumab (Avastin; Genentech, San Francisco, CA, USA) on vascular endothelial growth factor (VEGF) expression and inflammation in fibrovascular membranes in patients with proliferative diabetic retinopathy (PDR). MATERIALS AND METHODS: Fibrovascular membranes from 19 eyes of 18 patients with PDR were studied using immunohistochemistry and analyzed in the following 3 groups; group 1: 4 inactive PDR eyes, group 2: 10 active PDR eyes treated preoperatively with adjunctive intravitreal bevacizumab, group 3: five active PDR eyes not treated preoperatively with bevacizumab. Immunohistochemical staining for VEGF, CD31 and CD68 were done. RESULTS: The immunoreactivity to VEGF and CD 31-positive blood vessels was significantly higher in membranes from group 3 than group 1 (p = 0.007 for VEGF, 0.013 for CD 31-positive vessels). Intravitreal bevacizumab caused a reduction in VEGF expression and vascular densities in 4 out of 10 (40%) excised membranes from eyes with PDR. However, six membranes (60%) in group 2 still demonstrated relatively strong VEGF expression and high vascular density. Infiltration of macrophages was observed in 16 out of the 19 membranes, and the density of macrophages was increased in group 2 compared with group 1 (p = 0.043). CONCLUSION: Intravitreal bevacizumab injections caused some reduction in VEGF expression and vascular densities in a limited number of active PDR patients. A single intravitreal bevacizumab injection may not be enough to induce complete blockage of VEGF and pathologic neovascularization in active PDR patients. Repeated injections, panretinal photocoagulation and/or PPV may be necessary following intravitreal bevacizumab to reinforce the anti-VEGF effect of the drug.

Motility restriction after resection of an extraocular muscle

Restriction of eye movement after surgery is an unusual but troublesome complication. A patient presented with a limitation of abduction after a 5 mm resection of medial rectus muscle and an 8 mm recession of lateral rectus muscle. Since the forced duction test was positive, restrictive factors were suggested to be implicated. A reparative operation was performed at the postoperative 9 month, and the forced duction test was negative after releasing the resected medial rectus muscle. The patient showed an improved abduction after recessing the resected muscle. Even after an uneventful surgery, resection of an extraocular muscle may cause restriction of ocular rotation caused by muscle scarring to the sclera or by an increased tightness of the muscle.

The mucinous layer of corneal endothelial cells

PURPOSE: The goal of this study was to characterize the morphology of the mucinous layer on rabbit, bovine, owl, and human corneal endothelial cells. METHODS: Corneoscleral buttons were fixed using cetylpyridinium chloride to stabilize "mucus" and the tissue was prepared for transmission electron microscopy. Photomicrographs were measured to determine the thickness of the endothelial and epithelial mucinous layer in the central cornea. RESULTS: The endothelial mucinous layer was seen as a nearly uniform electrodense region on the apical aspect of the endothelium. It was found to be 0.9 microm, 0.9 microm, 0.9 microm, and 0.5 microm thick in rabbit, bovine, owl, and human, respectively. The owl endothelium had an additional less electrodense layer with a granular appearance and a thickness of about 200 microm. The mucinous layer on the epithelium was similar in appearance to that on the endothelium and across species. CONCLUSIONS: The morphologic similarity of the endothelial and epithelial mucinous layers is a serendipitous finding that should prove valuable in experimental design. Ultimately, it is hoped that studies of the posterior corneal surface will deepen our knowledge of endothelial protection.

Effects of Air Bubble on the Corneal Endothelium

During intraocular surgery including cataract, air bubbles occasionally enter the anterior chamber during irrigation. The influences of these air bubbles on the cornea endothelium, however, have yet to be known. The purpose of this study is to investigate the effects of bubbles on the rabbit corneal endothelium during irrigation and aspiration mode in experimental phacoemulsification. After anesthesia, the anterior chamber was irrigated and aspirated for 1 minute with balanced salt solution. The rabbits were then randomly divided into 4 groups. In group 1, corneal endothelial irrigation and aspiration were performed without air bubbles for 1 minute. In group 2, corneal endothelial irrigation was performed in the presence of air bubbles in the anterior chamber for 1 minute. In group 3, corneal endothelial irrigation and aspiration were performed in the presence of air bubbles in the anterior chamber for 1minute. In group 4, corneal endothelial irrigation was performed with silicone oil at 50 mmHg pressure in the presence of air bubbles in the anterior chamber for 1 minute. In group 1, the cornea endothelial cells showed normal F-actin without cell damage. In group 2, a ring shaped endothelial cell destruction area adjacent to the border was found along the margin of the air bubble. In group 3, similar ring-shaped lesion found in group 2 were observed but with more extensive cell destruction. In group 4, a partial number of cell to cell separation was found without endothelial cell destruction. In conclusion, air bubbles in the anterior chamber during irrigation with balanced salt solution showed destructive changes in rabbit corneal endothelial cell.

The Effect of High dose Corticosteroid Therapy on the Optic Nerve Head Blood Flow in Experimental Traumatic Optic Neuropathy

The objective of this study was to establish the effect of high dose steroid therapy in traumatic optic neuropathy with Heidelberg Retina Flowmeter(HRF) to detect the changes of optic nerve head bleed flow. HRF permits the noninvasive assessment of the blood velocity, volume and flow(flux) in a sample volume of the nerve head. Such measurements were performed in two groups of experimental traumatic optic neuropathy rabbits. We experimentally damaged the optic nerves of ten white rabbits with a Hartman mosquito. The first group(n=5) was intravenously infected with 0.25mg/kg dexamethasone every six hours for a 48 hour period. The second group(n-5) was used as controls. Both groups were tested before operation, 1 week, 1 month, and 2 months later Experimental optic nerve damage created a significant decrease in optic nerve head blood flow 50.51%(p=0.001), with blood volume decreased by 46.02%(p=0.001) and blood velocity reduced by 43.12%(p=0.002) compared to the baseline value. After 2 months of high dose corticosteroid therapy, optic nerve head blood flow was increased by 76.90% (p=0.012), blood volume 77.53%(p=0.012)and blood velocity 47.21%(p=0.012) as compared to control group. The high dose corticosteroid therapy improved the optic nerve head blood flow as demonstrated in traumatic optic neuropathy. HRF may be used to assess the therapeutic responses in traumatic optic neuropathy under variable conditions.

The Therapeutic Effect of Levocabastine Eye Drops on Allergic Conjunctivitis: A Multicenter Study

The efficacy nd tolerance of topical administration of levocabastine(0.5mg/ml)were evaluated in patients with allergic conjunctivitis. A total of 166 patients who had a typical history of atopy and a positive skin test were recruited in this study. Five clinicl symptoms(itch, tearing, chemosis, lid edema and conjunctival injection) were assessed according to a four point scale before the treatment and at 1 and 2 weeks post-therapy. Total symptom severity score before the therapy, 6.68, was remarkably decreased to 2.86 at 1 week and 2.08 at 2 weeks after the treatment. The investigators rated the treatment as globally good or excellent in 68.1% of patients checked at 1 week and 72.5% at 2 weejs after treatment. And the patients evaluated that the therapy ws good to excellent in 66.9% at 1 week and 73.1% at 2 weeks after treatment. Levocabastine eye drops has a fast onet of action with 55.4% of the patients feeling symptom relief within 15 minutes after the first administration. The adverse effect was experienced in 44 patients. Ocular irritation sign, such as foreign body sensation or soreness, was the most frequently reported complaint. These results suggest that levocabastine eye drops is an effective and safe topical alternative for treatment of allergic conjunctivitis.

Hematic cyst formation after repair of blow-out fracture

Alloplastic implants are known to be inert for many years, though complications are infrequently reported many years after their insertion. We report the case of a patient who had undergone a blow-out fracture repair five years before the discovery of a hematic cyst. He had been free of symptoms for the first five years after his orbital floor repair but then developed pain on eyeball movement and persistent vertical diplopia, which finally led to surgical intervention. At surgery, a hematic cyst was found to have formed around the implanted silastic plate. When alloplastic material is used in orbital fracture repair, we should be alert for late complications which may occur many years after surgery.

IgG-lambda extramedullary Plasmacytoma of the Anterior Uveal Tract: Case Report

A solitary anterior uveal tumor was identified as a extramedullary plasmacytoma. A 72 year old woman presented incidentally with a solitary iris tumor. The mass was round to invade into the ciliary body. Total excision was successfully done by an en bloc resection with a good visual result. There were no positive findings in the systemic work-up for multiple myeloma. The light microscopic and imrnunoperoxidase staining findings suggest that the mass was of anterior uveal tract origin and showed an monoc1onality of IgG and lambda. It is the first case of extramedullary Plasmacytoma of iris-ciliary body origin presented as an iris mass.

Corneal Endothelial F-actin Changes after Deep Photorefractive Keratectomy(PRK) in Rabbit

Laser-assisted in situ keratomileusis(LASIK) theoretically provide less corneal haze and more accurate correction. In the LASIK. however, photo refractive keratectomy(PRK) will be done on the stromal surface exposed after removal of the 130 micrometer thick lenticule. Deep stromal ablation after removal of 130 micrometer thick lenticule may result in endothelial damage. We observed endothelial cytoskeletal changes after deep PRK to evaluate the endothelial safety in rabbit. PRK was performed on the rabbit cornea without removing the epithelium with VISX 20/20 (160mj/cm2/pulse, 5Hz) to correct 6, 9, 12, and 15 diopters of myopia by single or multiple zone. Seven days after ablation, the rabbit was euthanized, corneas excised and endothelial F-actin was stained with NBD-phallacidin to demonstrate any cytoskeletal changes. No F-actin changes were observed in corneas after either single zone, 6 or 9 diopter correction, and multiple zone ablation. However, 12 diopters or higher correction in a single zone resulted in pleomorphism and polymegethism on focal areas. In the LASIK procedure, the endothelium might be damaged and further investigation for the endothelial preservation during the procedure is needed in human.

Behcet's Disease in Korean

Behcet's disease is a chronic, multi systemic disorder which is more frequently seen in the Mediterranean basin, Middle East, and Far East. One thousand four hundred fifty four patients, who had visited the Behcet's Disease Specialty Clinic of Yonsei Universtiy, College of Medicine from November, 1983 to December, 1990, were grouped into 4 groups by Shimizu's classification, and their clinical and epidemiological characteristics were evaluated. 1. The disease occurred more often in women than men, and the mean age of onset was 29.0 years old. 2. About 85% of the patients were from Seoul, Kyunggi, and lnchon. 3. The number of new patients has increased yearly. 4. By the Shimizu classification, incomplete type was most common. 5. The most frequent major symptom was oral ulcer (97.5%), and the most frequent minor symptom was arthritis (29.5%). The most frequent initial symptom was oral ulcer (78.1%). 6. The mean interval between the initial symptom and ocular symtom was 44 months. 7. Ocular lesions appeared in 239 patients, and occurred more often in men than women. Their mean age was 28.2 years old, and the most common ocular symptom was iritis (64.0%). 8. About 30% of the patients had corrected visual acuity of 0.01 or worse at their first visit. Visual acuity was worsened in 50.9% of the eyes followed for over 24 months. 9. Twenty nine Behcet's disease patients with refractory ocular involvement were treated with Cyclosporin A (CYA), and visual acuity was improved in 52.7% of the patients treated over 6 months with CYA.

A Case of Mobius Syndrome

Mobius syndrome is a rare congenital condition of uncertain etiology, characterized by facial diplegia, bilateral external rectus paralysis, and various abnormalities of other tissues such as extremities and branchial musculature. We have experienced a case of Mobius syndrome, reporting it with a review of literature.

A Standard Method of Measuring Tear Film Break-Up Time in Normal Subjects

The tear film break-up time test is a useful diagnostic test for dry eye syndrome,but it shows a wide range of results in normal subjects according to many factors, especially the methods of measuring it. We studied the factors having some influences on B.U.T. and tried to find out a standard method of measuring B.U.T. in normal subjects. The results were as follows: 1. The subjects were healthy without any ocular disease or symptoms. Total subjects were 200 persons, 400 eyes. 2. The standard method of measuring B.U.T. was as follows: a drop of 0.125% sodium fluorescein was applied into the conjunctival sac and the patient was allowed to blink for at least 1-2 minutes. The tear film was then scanned without holding the lids, using the slit lamp beam, 4-5mm in width. 3. The mean B.U.T. measured by the standard method was 20.35 +/- 6.45 sec in normal subjects. 4. The mean B.U.T. was 18.17 +/- 8.02'sec in the group using fluorescein paper, 9.68 +/- 6.19 sec in the group blinking just 4-5 times,16.54 +/- 8.32 sec in the group measured holding the lids with the fingers, and 18.36 +/- 7.95 sec in the group using a broad beam. 5. There were statistically significant decreases of B.U.T. in the group blinking just 4-5 times and in the group measured holding the lids with the fingers.