Effects of a Novel Push-through Technique Using the Implantable Collamer Lens Injector System for Graft Delivery during Endothelial Keratoplasty

PURPOSE: To investigate effects of a new push-through insertion method for donor lenticules using an injector system on endothelial viability ex vivo and in a clinical case series of endothelial keratoplasty. METHODS: An ex vivo delivery model was used with porcine corneoscleral rims. We compared the endothelial viability in a new push-through insertion method using the Visian Implantable Collamer Lens (ICL) injector versus that of standard forceps-assisted insertion for lenticule delivery. Twenty porcine corneal lenticules were divided into four groups by insertion method and wound size. Vital dye staining was performed and devitalized areas were semi-quantitatively assessed by digital imaging. In the clinical case series, Descemet's stripping endothelial keratoplasty (DSEK) using the push-through method was performed in seven patients and endothelial outcome was determined six months postoperatively. RESULTS: Mean devitalized areas for the push-through method were significantly lower than for forceps-assisted insertion through 3.2 mm incision (23.99 +/- 2.17% vs. 50.48 +/- 5.07%, p = 0.009) in the ex vivo model. Average endothelial cell counts of donor tissues of patients who underwent DSEK were 26.4% lower six months postoperatively. CONCLUSIONS: Push-through delivery of donor lenticules using the Visian ICL injector system appears to be less harmful to endothelial cells than conventional forceps-assisted delivery.

Effects of a Novel Push-through Technique Using the Implantable Collamer Lens Injector System for Graft Delivery during Endothelial Keratoplasty

PURPOSE: To investigate effects of a new push-through insertion method for donor lenticules using an injector system on endothelial viability ex vivo and in a clinical case series of endothelial keratoplasty. METHODS: An ex vivo delivery model was used with porcine corneoscleral rims. We compared the endothelial viability in a new push-through insertion method using the Visian Implantable Collamer Lens (ICL) injector versus that of standard forceps-assisted insertion for lenticule delivery. Twenty porcine corneal lenticules were divided into four groups by insertion method and wound size. Vital dye staining was performed and devitalized areas were semi-quantitatively assessed by digital imaging. In the clinical case series, Descemet's stripping endothelial keratoplasty (DSEK) using the push-through method was performed in seven patients and endothelial outcome was determined six months postoperatively. RESULTS: Mean devitalized areas for the push-through method were significantly lower than for forceps-assisted insertion through 3.2 mm incision (23.99 +/- 2.17% vs. 50.48 +/- 5.07%, p = 0.009) in the ex vivo model. Average endothelial cell counts of donor tissues of patients who underwent DSEK were 26.4% lower six months postoperatively. CONCLUSIONS: Push-through delivery of donor lenticules using the Visian ICL injector system appears to be less harmful to endothelial cells than conventional forceps-assisted delivery.

Accuracy of Ocular Biometry and Postoperative Refraction in Cataract Patients with AL-Scan(R)

PURPOSE: To compare the axial lengths, anterior chamber depths, and keratometric measurements and to predict postoperative refractions of AL-Scan(R), IOL master(R), and ultrasound. METHODS: A total of 40 eyes in 30 patients who received cataract surgery were included in the present study. The axial length, anterior chamber depth, and keratometry were measured by 2 types of partial coherence interferometry (AL-Scan(R) and IOL master(R)) and ultrasound. The SRK/T formula was used to calculate IOL power, and the predictive error which subtracts predictive refraction from postoperative refraction was compared among the ocular biometry devices. RESULTS: Axial lengths were 23.08 +/- 0.62 mm, 23.09 +/- 0.62 mm, and 22.99 +/- 0.62 mm measured by AL scan(R), IOL master(R), and ultrasound, respectively. Axial length measured by ultrasound was statistically significantly shorter than AL scan(R) and IOL master(R) (p < 0.001, p < 0.001, respectively). The anterior chamber depth and keratometry were 3.11 +/- 0.06 mm and 44.82 +/- 1.34 D measured by AL scan(R), and 3.13 +/- 0.06 mm and 44.85 +/- 1.26 D measured by IOL master(R), respectively. The differences of anterior chamber depth and keratometry between the 2 devices were not statistically significant (p = 0.226, p = 0.331, respectively). The mean absolute prediction errors were 0.44 +/- 0.35 D, 0.40 +/- 0.34 D, and 0.39 +/- 0.30 D in AL-Scan(R), IOL master(R) and ultrasound, respectively, and were not statistically significantly different (p = 0.843, p = 0.847, p = 1.000, respectively). CONCLUSIONS: The ocular biometric measurements and prediction of postoperative refraction using AL-Scan(R) were as accurate as IOL master(R) and ultrasound.

The Effects of Laser Refractive Surgery for Correcting Residual Refractive Error after Implantation of ReSTOR(R) Multifocal IOL

PURPOSE: To evaluate the clinical effects of excimer laser refractive surgery on eyes with residual refractive error after implantation of ReSTOR(R) multifocal intraocular lenses. METHODS: We retrospectively reviewed the medical records of 10 eyes of 6 patients who had undergone cataract surgery with implantation of multifocal intraocular lenses. Photorefractive keratectomy (PRK) (5 eyes) and laser-assisted in situ keratomileusis (LASIK) (5 eyes) was performed on 10 eyes with residual refractive error. RESULTS: After cataract surgery and before laser surgery, the mean spherical equivalent (SE) was -0.34 +/- 0.89 D and the mean astigmatism was 2.08 +/- 0.55 D. Six months after laser surgery, the mean SE was -0.33 +/- 0.30 D (p = 0.354) and the mean astigmatism was 0.23 +/- 0.28 D. The changes in astigmatism between paired preoperative and postoperative values were statistically significant (p < 0.0001). At 6 months after surgery, uncorrected distance visual acuity significantly improved to 0.11 +/- 0.10 (log MAR) (p < 0.0001) There were no significant changes in the best corrected distance visual acuity and uncorrected near visual acuity (p = 0.073, p = 0.100). CONCLUSIONS: On the basis of predictability and stability, excimer laser surgery appears to be a clinically useful procedure to correct residual refractive error after implantation of ReSTOR(R) multifocal intraocular lenses.

The Effect of the Remnants after Cataract Extraction on the Lens Epithelial Cell Culture

PURPOSE: To assess the effect of the remnants after lens extraction on posterior capsular opacification with lens epithelial cell culture through in vitro capsular bag model. METHODS: After isolating porcine lens capsules, sterile non-toxic PMMA (polymethyl- mathacrylate) tension ring was inserted into the capsule. These were placed in organ culture medium up to 6 weeks. The grade of cell coverage of the posterior lens capsule was recorded to check the proliferative activity. RESULTS: In the process of cell culture, outgrowth of the epithelial cells was observed across the posterior capsule after a lag period. The rate of cell coverage was dependent upon the added factors. The proliferative activity was the greatest in the group where lens cortical and nuclear materials were added, and other groups showed no difference from a control group. CONCLUSIONS: To reduce posterior capsular opacification, it is important that we should not leave the lens cortical material behind during cataract surgery.

The effect of Hydrogen Peroxide and Ascorbic Acid on Proliferation and Morphology of Lens Epithelial Cells

PURPOSE: The therapeutic effects of amniotic membrane transplantation (AMT) contain anti-fibrosis, anti-inflammation and facilitation of epithelialization. Thus we investigated whether applying of amniotic membrane (AM) ointment could get the same effect as AMT. METHODS: Alkali burn was induced by applying 6 mm round filter paper which was soaked with 1 N NaOH, onto the central cornea for 60 seconds on both eyes of 10 white rabbits. Then we applied AM ointment on one eye and base ointment on the other eye, four times a day for 1 week. The corneas were harvested for histopathologic studies at 1 day and 3 weeks. Corneal opacity and thickness were measured in 3 days and 1, 2, 3 weeks. RESULTS: In the AM ointment applicated group, the number of the infiltrated PMNs (polymorp-honuclear cells) and apoptotic keratocytes were significantly less than that of the control group (P<0.05). The degree of lipid peroxidation and myofibroblast differentiation were less than those of the control group. Corneal opacity and corneal edema were less in AM ointment group than control group. CONCLUSIONS: AM ointment application after alkali burn is beneficial to reduce inflammation, keratocyte apoptosis and lipid peroxidation, and is considered to suppress corneal haze by these effects. Therefore, this report may be a basic study for the AM ointment research to treat recalcitrant keratitis.

Visual Prognosis of Macular Edema Associated with Macular Ischemia in Branch Retinal Vein Occlusion

PURPOSE: We compared the perifoveal capillary ring state and the size of the macular ischemic area in patients with the macular edema, then analyzed the effect of grid photocoagulation on macular edema. The aim of the present study was to evaluate visual prognosis and to determine treatment modality of macular edema with macular ischemia in branch retinal vein occlusion (BRVO). METHODS: We did retrospective clinical analysis on the macular edema and macular circulatory state using clinical records, and performed fluorescein angiography in 89 patients (92 eyes) who were diagnosed with BRVO at Inha University Hospital from June 1996 through October 2000 and were followed for over 6 months. RESULTS: The incidence of macular edema was not statistically correlated with occlusion site of retinal vein, size of macular ischemic area and perifoveal capillary ring state. The initial visual acuity was a statistically significant factor in the prognosis of final visual acuity. The macular ischemic area was statistically correlated with initial visual acuity, and the perifoveal capillary ring state was not correlated with initial and final visual acuities. The improvement of visual acuity after grid photocoagulation for macular edema was noted in patients with intact perifoveal capillary ring state and small macular ischemic area. CONCLUSIONS: The only facator to final visual acuity is initial visual acuity. Prospective study is needed to evaluate effect of early treatment of macular edema with grid photocoagulation at an early stage of BRVO in patients with intact perifoveal capillary ring state and small macular ischemic area.

The Color Vision Test in Acute Central Serous Chorioretinopathy

PURPOSE: To evaluate the usefullness of color vision test for early detection of abnormal choroidal circulation of central serous chorioretinopathy (CSCR) METHODS: We investigated the color vision defect in central serous chorioreinopathy at active and resolved phase on both eyes and to identify the relation between fluorescein angiography (FAG), indocyanine green angiography (ICGA) finding and color vision defect. We examined the color vision with the Neitz anomaloscope OT-II, Farnsworth-Munsell 100-hue test, Ishihara pseudoisochromatic plate in 72 eyes of typical acute CSCR patients. We also performed ICGA in 13 eyes revealed color vision defect in fellow eye and 13 eyes not revealed color vision defect in fellow eye at resolved phase. RESULTS: Dyschromatopsia was detected in CSCR at active and resolved phase on both eyes. Most of them showed blue-yellow color defect. Location of leaking point was associated with red-green color defect in active affected eyes. Dyschromatopsia of fellow eyes at resolved phase was associated with abnormal choroidal circulation on ICGA finding. CONCLUSIONS: We suggest that color vision test, as a non-invasive screening test, might be useful for early detection of abnormal choroidal circulation of CSCR.