The effective concentration and exposure time of mitomycin-C for the inhibition of lens epithelial cell proliferation in rabbit eyes

The proliferation of residual lens epithelial cells following cataract surgery is assumed to be a major cause of posterior capsular opacification. To assess the efficacy of mitomycin-C in preventing posterior capsular opacification, we determined the effective concentration and exposure time of mitomycin-C in inhibiting rabbit lens epithelial cell proliferation. The fourth-passaged rabbit lens epithelial cells were maintained for one day and then exposed to mitomycin-C for 1, 2, 3, and 5 minutes, respectively. There were 9 different plating concentrations of mitomycin-C with two-fold serial dilution. The maintenance of the phenotypic properties of lens epithelial cells was confirmed by continuous transcription of lambda-crystalline mRNA determined by reverse transcription-polymerase chain reaction and the polymorphism of the restriction fragment. Cell proliferation was assayed with 3H-thymidine incorporation into DNA. The fourth-passaged cells maintained the expression of lambda-crystalline mRNA, suggesting that they are phenotypically authentic lens epithelial cells. The effective concentrations and exposure time of mitomycin-C were 0.1 mg/ml for 1 minute and 2 minutes, and 0.025 mg/ml for 2 minutes. By these results, we postulated that mitomycin-C at relatively short incubation times could be clinically used for prevention of posterior capsular opacification after cataract surgery.

Trabeculectomy with Mitomycin C in Congenital Glaucoma

We assessed the efficacy of trabeculectomy with mitomycin C in the management of congenital glaucoma of which prognosis is known to be poor. Twelve consecutive eyes of 7 primary congenital glaucoma patients who underwent trabeculectomy with mitomycin C were retrospectively reviewed. The mean age was 3.2 years(ranging from 1 to 10 years) and the mean follow-up period was 31.6 months (ranging from 15 to 42 months). The mean postoperatie intraocular pressure (IOP) at the end of follow-up period was 11.0 +/-3.0mmHg, significantly lower than the mean preoperative IOP which was 25.4 +/-6.3mmHg (P<0.01). The overall success rate was 50% after a single procedure. All the 6 failed eyes underwent the same operation again and the overall success rate was 83%. The complications included hypotony in 4 eyes (33.3%) and shallow anterior chamber in 2 eyes (16.6%), and they were all resolved spontaneously. There was no evidence of hypotonic maculopathy and endophthalmitis. Trabeculectomy with mitomycin C successfully lowered the IOP in congenital glaucoma patients without serious complication and further investigation will be required to determine ling-term effects in terms of successful filtration and possible late complications.

Observation of Damage to the Blood-Aqueous Barrier after Trabeculectomy with Mitomycin C

We observed the breakdown of the blood-aqueous barrier after trabeculectomy with mitomycin C by using laser flaremeter. There were 20 patients (25 eyes) of which 9 patients(11 eyes) were applied 0.02% MMC for 3minutes during the trabeculectomy and 11 patients (14 eyes) were not applied MMC. All patients were diagnosed as primary open angle glaucoma and underwent trabeculectomy. The preoperative, postoperative 1 day and 3 months aqueous flare intensity were 10.8+/- 5.05, 15.6+/- 5.32, 10.1+/- 4.55(photon count/msec)in group with MMC and 10.6+/-4.04,15.9+/-3.30, 9.2+/-3.94(photon count/msec) in group without MMC Anterior chamber flares were highest on the first postoperative day, declining rapidly in the first week with more gradual recovery to preoperative level by 1 month postoperatively, which shows the breakdown of blood-aqueous barrier by surgery. There was no statistically significant difference between the two groups in postsurgical aqueous flare intensity. 0.02% MMC does not appear.

Reproducibility of Optic Nerve Head Topographic Measurements with the Heidelberg Retina Tomograph

Laser scanning tomography is an accurate method for the three-dimentional assessment of the optic nerve head. But its topographic measurement should be highly reproducible for early diagnosis and follow-up of patients with glaucoma. The authors evaluated the reproducibility of optic nerve head topographic measurements by the Heidelberg retina tomograph(HRT). The mean standard deviation of height measurements and the mean coefficient of variation of each parameters were calculated on the 10 independent measurements in five normal eyes. The results showed that the mean standard deviation of height measurements was 29.19 microgram. The mean coefficient of variation of the cup area, rim area, rim volume, mean cup depth and the mean retinal nerve fiber layer thickness was under 10%. Optic nerve head topographic measurement by the HRT is highly reprooucible, which may help follow-up of glaucoma patients.

Topographic Measurements of the Optic Nerve Head with Confocal Scanning Laser Tomography in Normal Subjects and Patients with Glaucoma

We analyzed the optic nerve head of 100 normal eyes with a confocal scanning laser tomograph(Heidelberg Retina Tomograph: HRT), and got the mean value of each parameter in HRT. We also examined 84 eyes of glaucoma patients. Glaucoma patients were divided into 3 groups according to decibel(dB) loss of mean defect on Humphrey visual field test(Central 30-2 program; Group 1:less than 5dB, group 2:between 5dB and 10dB. group 3:greater than 10dB). The mean value of the parameter in HRT are as follows: disk area, 2.35mm2; cup area, 0.48mm2; C/D ratio, 0.20; rim area, 1.86mm2; cup volume, 0.10mm2; rim volume, 0.55mm2; mean cup depth, 0.19mm; maximal cup depth, 0.59mm; cup shape measure, -0.23; height variation contour, 0.42; mean retinal nerve fiber layer thickness, 0.28mm; retinal nerve fiber layer cross sectional area, 1.52mm2. Comparing with normal subjects, group 1 patients had significant difference in cup area, C/D ratio, rim area, cup volume, rim volume, mean cup depth, maximal cup depth, cup shape measure, height variation contour, and mean retinal nerve fiber layer thickness. All glaucoma patients had significantly different value in all parameters. The comparison among each group of glaucoma patients showed significant difference in cup area, C/D ratio, rim area, cup volume, rim volume, cup shape measure, and mean retinal nerve fiber layer thickness.

Regional Comparison of Heidelberg Retinal Tomographic Measurements of Normal and Early Glaucomatous Optic Nerve Head

To estimate normal values for optic nerve head parameters in Korean adults and establish pattern of early glaucomatous neuroretinal rim loss, we measured the mean value of each parameter according to 6 predefined sectors with Heidelberg Retina Tomograph. 500 eyes of normal 500 individuals and 30 eyes of early primary open angle glaucoma patients whose mean defect was less than -5dB in automated threshold perimetry(Humphrey programs C30-2) were enrolled in this study. Comparing with normal subjects, the early glaucoma group had significant difference in 8 parameters(p<0.05). The neuroretinal rim area in normal eyes were significantly largest in the nasal inferior and nasal sectors, decreased in the order of nasal superior, temporal inferior, temporal, nasal inferior, and nasal sectors(p<0.05). We established normal values of optic nerve head parameters in Korean adults and these results suggest the regional preference of optic nerve head damage in early glaucoma.

Topographic Measurements of the Optic Nerve Head with Confocal Scanning Laser Tomography in Normal Subjects and Patients with Glaucoma

We analyzed the optic nerve head of 100 normal eyes with a confocal scanning laser tomograph(Heidelberg Retina Tomograph: HRT), and got the mean value of each parameter in HRT. We also examined 84 eyes of glaucoma patients. Glaucoma patients were divided into 3 groups according to decibel(dB) loss of mean defect on Humphrey visual field test(Central 30-2 program; Group 1:less than 5dB, group 2:between 5dB and 10dB. group 3:greater than 10dB). The mean value of the parameter in HRT are as follows: disk area, 2.35mm2; cup area, 0.48mm2; C/D ratio, 0.20; rim area, 1.86mm2; cup volume, 0.10mm2; rim volume, 0.55mm2; mean cup depth, 0.19mm; maximal cup depth, 0.59mm; cup shape measure, -0.23; height variation contour, 0.42; mean retinal nerve fiber layer thickness, 0.28mm; retinal nerve fiber layer cross sectional area, 1.52mm2. Comparing with normal subjects, group 1 patients had significant difference in cup area, C/D ratio, rim area, cup volume, rim volume, mean cup depth, maximal cup depth, cup shape measure, height variation contour, and mean retinal nerve fiber layer thickness. All glaucoma patients had significantly different value in all parameters. The comparison among each group of glaucoma patients showed significant difference in cup area, C/D ratio, rim area, cup volume, rim volume, cup shape measure, and mean retinal nerve fiber layer thickness.

Regional Comparison of Heidelberg Retinal Tomographic Measurements of Normal and Early Glaucomatous Optic Nerve Head

To estimate normal values for optic nerve head parameters in Korean adults and establish pattern of early glaucomatous neuroretinal rim loss, we measured the mean value of each parameter according to 6 predefined sectors with Heidelberg Retina Tomograph. 500 eyes of normal 500 individuals and 30 eyes of early primary open angle glaucoma patients whose mean defect was less than -5dB in automated threshold perimetry(Humphrey programs C30-2) were enrolled in this study. Comparing with normal subjects, the early glaucoma group had significant difference in 8 parameters(p<0.05). The neuroretinal rim area in normal eyes were significantly largest in the nasal inferior and nasal sectors, decreased in the order of nasal superior, temporal inferior, temporal, nasal inferior, and nasal sectors(p<0.05). We established normal values of optic nerve head parameters in Korean adults and these results suggest the regional preference of optic nerve head damage in early glaucoma.

The Effect of Mitomycin-C on Postoperative Corneal Astigmatism in Trabeculectomy and Triple Procedure

Mitomycin-C is known to delay wound healing and it may have influence upon the post operative astigmatism changes. We calculated the postoperative induced astigmatism of patients who underwent trabeculectomy or triple procedures with or without the use of mitomycin-C. And the vector analysis method was used. To compare the induced astigmatism between the groups we calculated the induced astigmatism corresponding to the 180degree axis. The patients who underwent triple procedure without and with mitomycin-C showed a mean induced astigmatism of -4.50D, -1.81D, respectively, after 7 days(p<0.05) and -0.13D, 1.73D, respectively, after 12 months (p<0.05). Those who underwent trabeculectomy without mitomycin-C and with mitomycin-C showed a mean induced astigmatism of -2.63D, -1.01D, respectively, after 1 month(p<0.05) and -1.42D, 0.34D, respectively, after 12 months(p<0.05). The use of mitomycin-C reduces the total amount of astigmatism in trabeculectomy patients. However, in the triple procedure patients it increases the total amount of astigmatism. The entire amount of against the rule astigmatic change was similar between the mitomycin-C applied group and non-applied group. The astigmatic shift of the group without mitomycin-C, reached a plateau after 3 months. However, the other group showed continuous against the rule shift until 12 months.

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.

Implantation of Posterior Chamber Lens in the Absenee of Posterior Capsular Support

In the implantation of intraocular lens, anterior chamber lenses are usually avoided in glaucoma patients. And because of its close anatomic proximity to the cornea, iris and outflow structures, anterior chamber lense may give rise to more complications as compared with posterior chamber lenses. Thus, the dramatic trend toward clear decrease in the number of anterior chamber lens implantations continues. But despite these complications, the anterior chamber lenses are most often implanted secondarily in the aphakic patients, who, after having had intracapsular cataract extraction or a complicated extracapsular cataract extraction, have lost posterior capsular support. To avoid the many potential complications associated with anterior chamber lenses, attention has shifted toward posterior chamber lens insertion in these cases and particularly in glaucoma patients. From January 1989 to June 1989, we performed newly developed surgical techniques for the implantation of posterior chamber lenses in 7 eyes, including 5 eyes with glaucoma, without posterior capsular support, This was done by securing both haptics of the posterior chamber lens to the sclera at the ciliary sulcus with 10-0 nylon suture. The patients have been followed from 3 to 8 months, all have achieved visual acuity of 20/30 or better without any serious complications, and the postoperative intraocular pressure was well controlled in all 5 eyes with glaucoma.

The Incidence of Congenital Nasolacrimal Duct Obstruction in Korean Neonates

Congenital obstruction of the nasolacrimal drainage system is a condition frequ endy encountered by the ophthalmologist. In the development of the lacrimal pathway, the lower end of the duct is frequently separated from the cavity of the inferior meatus at birth by a membrane. In most instances, the nasolacrimal duct becomes patent during the first several weeks of life. But there are no exact data in Korean literature regarding the incidence of congenital nasolacrimal duct obstruction. The aim of our work is to get information about the incidence of congenital nasolacrimal duct obstruction in Korean neonates. Between May 1987 and September 1988, we examined 248(496 eyes) 1-to 3-day-old newborns for evaluation of the nasolacrimal duct patency by syringing. The results were as follows: 1. The incidence of congenital nasolacrimal duct obstruction was 6.25%(31 eyes) among 496 eyes of 1-to 3-day-old-new borns. 2. The rate having discharge was significantly higher in the obstructed group than in the patent group. 3. There were no significant differences between the impatency rates of the first 3 days of life, and between the impatency rates in newborns, born either via birth canal or via Cesarean section.

The Incidence of Congenital Nasolacrimal Duct Obstruction in Korean Neonates

Congenital obstruction of the nasolacrimal drainage system is a condition frequ endy encountered by the ophthalmologist. In the development of the lacrimal pathway, the lower end of the duct is frequently separated from the cavity of the inferior meatus at birth by a membrane. In most instances, the nasolacrimal duct becomes patent during the first several weeks of life. But there are no exact data in Korean literature regarding the incidence of congenital nasolacrimal duct obstruction. The aim of our work is to get information about the incidence of congenital nasolacrimal duct obstruction in Korean neonates. Between May 1987 and September 1988, we examined 248(496 eyes) 1-to 3-day-old newborns for evaluation of the nasolacrimal duct patency by syringing. The results were as follows: 1. The incidence of congenital nasolacrimal duct obstruction was 6.25%(31 eyes) among 496 eyes of 1-to 3-day-old-new borns. 2. The rate having discharge was significantly higher in the obstructed group than in the patent group. 3. There were no significant differences between the impatency rates of the first 3 days of life, and between the impatency rates in newborns, born either via birth canal or via Cesarean section.