A Case of Neovascular Glaucoma in Radiation Retinopathy

PURPOSE: To report a case in which radiotherapy damaged the microvasculatures of the retinal vessels and developed cotton-wool patches and retinal hemorrage as well as rubeosis iridis and intractable neovascular glaucoma. METHODS: A 64-year-old female presented with visual loss in her left eye two years after radiotherapy for malignant melanoma of the nasal cavity. The visual acuity of her left eye was counting fingers. Although any specific signs were not shown in the cornea or lens, multiple cotton-wool patches and retinal hemorrhages were noted around the optic disc. RESULTS: Multiple cotton-wool patches and retinal hemorrhages disappeared gradually. Finally, rubeosis iridis and intractable neovascular glaucoma developed which could not be controlled by panretinal photocoagulation. CONCLUSIONS: Radiotherapy for malignancy of the nasal cavity was associated with intractable neovascular glaucoma.

A New Technique to Reposition the Posteriorly Dislocated Intraocular Lens

The previously reported repositioning methods have been known to be very difficult to be performed. A new external knotting technique was performed to reposition the dislocated intraocular lenses (IOLs). After 3-port vitrectomy, a 30 gauge injecting needle tip into which the thread end of a 10-0 polypropylene was put, was introduced into the vitreous cavity through the ciliary sulcus to make a loop having an external knot. After one haptic of the IOL was engaged into the loop, the thread was pulled back and tied to make a knot. After holding and pulling the haptic of the IOL with the intraocular forceps for proper position of the knot. Then it was sutured and fixed in sclera. The IOLs were kept in central position without complications. The final visual outcome was 0.8 and 0.3 respectively. This method might be safe and easy to correct the dislocated IOL.

Toxic Effect of Mitomycin C in the Rabbit Ciliary Epithelium

Mitomycin C(MMC) is one of the alkylating agents, which is commonly used adjunctively to inhibit the over-growth of the fibroblasts in high-risk filtering surgery. However, it increases the incidence of the complications including persistent postoperative hypotony. The hypotony may be caused by the toxic effect of MMC on the ciliary epithelium. The morphological changes of the ciliary epithelium were evaluated using transmission electron microscope four and twelve weeks after the application of balanced salt solution(BSS) and MMC on the exposed sclera against the ciliary body in the rabbit eyes. There was no specific change in the ciliary epithelium four and twelve weeks after the application of BSS. Four weeks after the application of 0.2mg/ml of MMC, the mitochondria in the nonpigmented epithelium of the applied region were swollen mildly. The mitochondria of both pigmented and nonpigmented epithelia were swollen moderately in the region applied with 0.5mg/ml of MMC. Twelve weeks after the application of either 0.2 or 0.5mg/ml of MMC, the mitochondria were swollen markedly, the nuclear membranes in the pigmented and nonpigmented epithelia were wrinkled, and the heterochromatins of the nuclei faded in both applied and contralateral ciliary epithelia. These findings indicate that mitomycin C causes degenerative changes in the ciliary epithelium decrease aqueous production.

Treatment of Morning Glory Syndrome with Retinal Detachment

Morning glory syndrome is a rare congenital anomaly in optic disc, which is characterized by defect in optic disc due to optic nerve dysgenesis, abnormal retinal vessels, and chorioretinal pigment disturbance around optic disc. Retinal detachment in morning glory syndrome occurs in 26% to 38% of the cases, which is thought to be non-rhegmatogenous in nature and usually develops in posterior pole of the retina. Surgical treatment is indicated in cases with bullous and total retinal detachment in morning glory syndrome. The authors successfully reattached the detached retina in a 3 year old boy with morning glory syndrome using trans pars plana vitrectomy, scleral buckling, retinotomy, silicone oid injection, and endolaser photocoagulation. The authors followed up for 15 weeks after operation, and the vision of left eye was counting finger and the retina remained to be reattached.

Treatment of Morning Glory Syndrome with Retinal Detachment

Morning glory syndrome is a rare congenital anomaly in optic disc, which is characterized by defect in optic disc due to optic nerve dysgenesis, abnormal retinal vessels, and chorioretinal pigment disturbance around optic disc. Retinal detachment in morning glory syndrome occurs in 26% to 38% of the cases, which is thought to be non-rhegmatogenous in nature and usually develops in posterior pole of the retina. Surgical treatment is indicated in cases with bullous and total retinal detachment in morning glory syndrome. The authors successfully reattached the detached retina in a 3 year old boy with morning glory syndrome using trans pars plana vitrectomy, scleral buckling, retinotomy, silicone oid injection, and endolaser photocoagulation. The authors followed up for 15 weeks after operation, and the vision of left eye was counting finger and the retina remained to be reattached.

Purtscher's-lke Retinopathy in Patients with Systemic Hypertension

Since Purtscher's original discriptions similar clinical signs have been described following acute compressive neck or chest injuries, chest compression, val salva maneuvers, long bone fractures, acute pancreatitis and after childbirth. The appearance of Purtscher's retinopathy are believed to be due to ischemic episodes particularly in the end arterioles around the macula and disc. We experienced two cases of Purtscher's-like retinopathy in patients with systemic hypertension who had not any recent trauma history and reviewed the available literatures regarding this disease.

Effect of Encircling Silicone Sponge for Retinal Detachment

120 eyes of 119 patients with retinal detachment were treated with an encircling silicone sponge scleral buckling in the department of Ophthalmolgy, Severance Hospital, Yonsei University Medical Center from September 1, 1988, to January 31, 1991. Results were as follow 107 eyes among 120 eyes (89.2%) showed anatomical success, and 54 eyes of them (45%) showed functional success. As the preoperative factors, the case of over 20/70 vision (100%, p>0.05, 100%, p0.05, 57%, p0.05,61%, p0.05, 54%, p<0.05) showed favorable anatomical and functional success rate. The presence and degree of the proliferative vitreoretinaopathy affected the anatomical and functional success rate, but the age of patients did not affect the success of surgery.

The Temporary Inerement of the Intraoeular Pressure: The Effect on the Retina

After the intraocular bleeding was inuced by amputation of the rabbit retinal artery, the level and duration of the level of the intraocular pressure to control the bleeding was studied. Then, the eyes were enucleated and evaluated for the effect of the increased intraocular pressure. In 3 of 4 eyes studied, the bleeding is controlled at the height of 140-145 cm of the infusion bottle for 10 seconds. And the maintenance of the height of 125 cm for 15 seconds was effective in one eye. Although the expanded intercellular space in the outer nuclear layer, destruction of the photoreceptors and formation of the vacuoles appeared in the first week, they were only the temporary findings for they disappeared after second week. In the rebbit, the retinal arterial bleeding is able to be controlled at the level of about 100 mmHg of the IOP for about 10 seconds effectively and safely.

Radial Retinotomy in the Macula

Retinotomy, cutting of the retina, can be helpful in hte management of giant retinal tears, subretinal strands, and retinal incarceration. Relaxing retinotomies are used in the presence of retinal shortening or fibrous proliferation and contraction, and usually performed in the peripheral or equatorial retina. To fascilitate retinal attachment, the authors used intraocular scissors to perform radial retinotomy in the macula of two patients during vitrectomy surgery. We obtained a successful result using retinotomy in the macula as an adjunct to repair of retinal detachment with macular hole formation.

Histopathologic Findings of Chorioretinal Adhesion After Photocoagulation of the Thretinal Break

Adult albino rabbits were used in this study. The retina was treated with laser photocoagulation around the retinal break. The histopathologic findings were evaluated with light and electron microscopes to determine how quickly chorioretinal adhesion was produced after photocoagulation. Adhesion between the rod and cone layer and the pigment epithelium appeared within 1 hour after photocoagulation, probably due to direct burn effect of the laser. A scar tissue appeared in the chorioretinal lesion 5 days after photocoagulation, derived from the proteinaceous coagulum and accompanying fibrosis.

The Use of Retinal Tacks for the Treatment of Complicated Retinal Detachment

An improved retinal tack and applicator have been increasingly used as an adjunct in the repair of complicated retinal detachments. We used this technique in 7 consecutive cases of complicated retinal detachment. After a mean follow-up of 3 months, anatomical reattachment including partial reattachment was achieved in 5 eyes among 7 eyes, and 6 eyes had improved vision or no change(one improved to 20/70). Retinal tacks appear to be a useful tool either temporarily or permanently in preventing retraction and detachment of the retina until adjunctive diathermy, cryopexy, or photocoagulation becomes effective.

Comparative Bioavailability and Efficasy of Tobra(R) or Tobrex(R)

Two topical 0.3% tobramycin ophthalmic solutions, Tobra(R) and Tobrex(R) were tested for their effects on external eyes in rabbits. The authors studied irritation, epithelial toxicity, pH of solutions and antibiotic pharmacokinetics of two kinds of topical tobramycin solutions. No irritation sings were noted after instillation of the two agents with one hour interval. A rabbit epithelial wound healing model demonstrated slight toxicity, but no substantial difference was noted between Tobra(R) and Tobrex(R). In the case of normal corneal epithelia, more than 1 microgram of tobramycin was detectable per gram of cornea 5 minutes after cessation of topical application with both eye drops. In the case of ulcers, the concentrations of tobramycin in the corneae were significantly high with topical route with both eye drops.