Clinical Outcomes of a Refractive, Aspheric, Bifocal Intraocular Lens Imparting 1.5 Diopters Adding Power

Purpose@#We evaluated the 3-month, postoperative clinical outcomes of patients implanted with refractive, aspheric, bifocal, Lentis Comfort (LS313-MF15, Oculentis) intraocular lenses (IOLs). @*Methods@#Eighty-two eyes of 51 cataract patients underwent phacoemulsification and were implanted with LentisComfort IOLs. The uncorrected distant visual acuity (UCDVA), the 80-cm uncorrected intermediate visual acuity (UCIVA), the 40-cm uncorrected near visual acuity (UCNVA), and refractive values were evaluated 1 and 3 months postoperatively. At the latter time, defocus curves were drawn, contrast sensitivity tested, and satisfaction surveyed. @*Results@#At the 3-month postoperative follow-up, the mean spherical equivalent was -0.12 ± 0.21 D; and the mean LogMAR UCDVA, 80-cm UCIVA, and 40-cm UCNVA were 0.02 ± 0.03, 0.13 ± 0.07, and 0.42 ± 0.10 respectively. The defocus curves revealed visual acuities in excess of 0.2 LogMAR at points between the distant and intermediate targets. The mean contrast sensitivity fell in the range of 90% of a normal population under both photopic and mesopic conditions. In terms of satisfaction, 71.8% of patients were satisfied or very satisfied, but about 20% reported dysphotopsia. @*Conclusions@#Implantation of the refractive, aspheric, bifocal, intraocular, LentisComfort in patients with cataracts improved both the distant and intermediate visual acuities by 3 months after surgery and the visual quality was comparable to that afforded by other IOLs both objectively and subjectively.

Clinical Outcomes of Intraocular Lenses Produced in the Republic of Korea

PURPOSE@#To evaluate the clinical outcomes of aspheric hydrophilic acrylic EYELIKE® (Koryo Eyetech Co., Seoul, Korea) intraocular lenses (IOLs).@*METHODS@#We conducted a retrospective study of 176 consecutive eyes of 160 patients who underwent cataract surgery with implantation of aspheric EYELIKE® IOLs. The following preoperative measurements were collected: slit-lamp examination, uncorrected distance visual acuity (UCDVA), corrected distance visual acuity (CDVA), intraocular pressure (IOP), automatic and manual keratometry, fundus examination, corneal topography, and specular microscopy. The UCDVA, CDVA, IOP, refraction, and slit-lamp examination were evaluated postoperatively at 1 week and at 1, 3, and 6 months. Specular microscopy was also postoperatively conducted at 1 month.@*RESULTS@#At the 6-month postoperative visit, the mean UCDVA was 0.15 ± 0.23, and the mean CDVA was 0.03 ± 0.07 logarithm of minimal angle of resolution (logMAR). No statistically significant differences were observed among the four groups (postoperative 1 week, postoperative 1 month, postoperative 3 months, and postoperative 6 months) in the manifest spherical equivalent. In total, 74% of IOL Master700 and 54% of A-scan measurements were within ± 0.5 diopters (D) difference from the target refraction, and 95% and 77%, respectively, were within ± 1.0 D from the target refraction. With regard to complications, one case of CME and posterior capsule opacification with decreased visual acuity was detected at month 3 postoperatively; in this case, the CDVA recovered to 0 logMAR with conventional treatment and yttrium aluminium garnetlaser posterior capsulotomy after postoperative 6 months.@*CONCLUSIONS@#Domestically produced EYELIKE® IOLs had high refraction predictability and stability.

Clinical Outcomes of Diffractive Aspheric Trifocal Intraocular Lens Implantation

PURPOSE: To evaluate the clinical outcomes of patients with diffractive aspheric trifocal intraocular lens FineVision Pod F IOL (PhysIOL, Liège, Belgium) implantation. METHODS: Thirty eight eyes received phacoemulsification and implantation of FineVision Pod F IOL. Uncorrected distant visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), refractive values, and defocus curve were evaluated at postoperative 1 month and 3 months. Optical quality was evaluated with the contrast sensitivity test, OQAS® (Optical Quality Analysis System, Visiometrics, Cerdanyola del Vallès, Spain) and questionnaire. RESULTS: At the 3-month postoperative follow-up, the mean spherical equivalent was 0.01 ± 0.31 D and the mean UDVA, UIVA and UNVA were 0.04 ± 0.07, 0.19 ± 0.12, and 0.04 ± 0.07, respectively. Mean contrast sensitivities at 0.75, 1.5, 3, 6, 12, and 18 cycles per degrees were 2.00 ± 1.54, 2.16 ± 1.60, 2.25 ± 1.76, 2.16 ± 1.83, 1.52 ± 1.47 and 1.03 ± 0.95 respectively and mean objective scatter index by OQAS® (Optical Quality Analysis System, Visiometrics) was 1.54 ± 0.74. In satisfaction analysis, general satisfaction with surgery was 89% and spectacle independence were 89% at far, 78% at intermediate and 83% at near distance. Postoperative dissatisfaction factors were dryness (36%), glare at night (32%), halo (18%). CONCLUSIONS: The FineVision Pod F IOL showed excellent distant and near visual acuities with an effective intermediate visual acuity. The eyes with FineVision Pod F IOL expected to achieve the favorable visual outcome and patient satisfaction.

Comparison of Ocular Biometry Using New Swept-source Optical Coherence Tomography-based Optical Biometer with Other Devices

PURPOSE: To evaluate the agreement between optical biometry with swept-source optical coherence tomography-based optical biometry (IOLMaster 700) and other devices. METHODS: A total of 137 eyes (78 patients) with cataracts were included in this retrospective study. Axial length (AL), anterior chamber depth (ACD), keratometry, and white-to-white (WTW) distance measured using IOLMaster 700 were compared with results for the following five different biometers: IOLMaster 500, A-scan, automated refractor, manual keratometry, and Galilei G4. Differences and correlations among the devices were assessed using the Bland-Altman plot and intraclass correlation coefficient (ICC). RESULTS: For AL values, the IOLMaster 700, IOLMaster 500, and A-scan measurements showed excellent agreement (all ICC >0.99). For ACD values, ICC of IOLMaster 700 and Galilei G4 was 0.965 but A-scan was poorly correlated with either IOLMaster 700 or Galilei G4. The ICCs of IOLMaster 700 and other devices were all greater than 0.9 for average keratometry, but those of the mean cylinder keratometry were all between 0.7 and 0.8. The mean difference in the WTW distance between the IOLMaster 700 and Galilei G4 was 0.029 mm, but the ICC was 0.525. AL measurements were not possible for 10 eyes with the IOLMaster 500 but were obtained in all eyes with the IOLMaster 700. CONCLUSIONS: In clinical practice, AL, ACD, and average keratometry values of IOLMaster 700 can be used interchangeably with those of the other devices tested. However, the ACD value between IOLMaster 700 and A-scan or the WTW distance between IOLMaster 700 and Galilei G4 are not interchangeable because of clinical and statistical differences in measurements between the devices.

Comparison of Reading Speed after Bilateral Bifocal and Trifocal Intraocular Lens Implantation

PURPOSE: To evaluate and compare visual acuity and reading speed for Korean language between a diffractive bifocal and trifocal intraocular lens (IOL) of the same material and haptic design. METHODS: We reviewed the medical records of the patients who had undergone bilateral cataract surgery with bifocal IOLs (AT LISA 801) on the both eyes (bifocal group) and trifocal IOLs (AT LISA tri 839 MP, trifocal group). The main outcome measures were the uncorrected distance, intermediate, and near visual acuity (uncorrected distance visual acuity [UCDVA], uncorrected intermediate visual acuity [UCIVA], and uncorrected near visual acuity [UCNVA]) and corrected distance, near, and distance-corrected intermediate visual acuity (corrected distance visual acuity [CDVA], corrected near visual acuity [CNVA], and distance-corrected intermediate visual acuity [DCIVA]) at last postoperative follow-up month. Reading speeds for Korean language were measured to check near visual function. RESULTS: Fourteen eyes (7 patients) were included in the bifocal group and 32 eyes of 16 patients in the trifocal group. There were no statistical differences between the two groups with respect to UCDVA, UCNVA, CDVA, and CNVA. However, UCIVA (0.35 vs. 0.22 logarithm of the minimum angle of resolution [logMAR], p < 0.01) and DCIVA (0.34 vs. 0.20 logMAR, p < 0.01) were significantly better in the trifocal group than in the bifocal group. The mean reading speed for logMAR 0.5 optotype (point 10) was 86.50 words per minute (wpm) in the bifocal group and 81.48 wpm in the trifocal group without a significant difference (p = 0.70). CONCLUSIONS: Trifocal IOLs provided the same level of distance and near visual acuity and reading speed as that of bifocal IOLs with better intermediate visual acuity.

Comparison between Active and Gravity-based Phacoemulsification Fluidics Systems in Immediate Sequential Bilateral Cataract Surgery

PURPOSE: To compare the clinical outcomes during phacoemulsification when using active fluidics (Centurion®) and gravity-based fluidics (Infiniti®) in immediate sequential bilateral cataract surgery. METHODS: From January 2015 to September 2015, 68 eyes of 34 patients with bilateral cataract were assigned to receive immediate sequential bilateral cataract surgery by Centurion® in one eye and Infiniti® in the other eye. We measured and compared intraoperative factors, including cumulative dissipated energy (CDE), ultrasound time, mean amount of balanced salt solution (BSS) used, and pain using a scale. Best corrected visual acuity (BCVA), central corneal thickness (CCT), and endothelial cell density (ECD) were also evaluated preoperatively and 1 month postoperatively. RESULTS: Intraoperative measurements showed significantly less CDE (5.05 ± 2.18 vs. 7.05 ± 3.82), ultrasound time (24.65 ± 9.68 vs. 34.95 ± 17.95 seconds), and mean amount of BSS used (37.06 ± 10.25 vs. 44.88 ± 16.38 mL) in the Centurion® group than in the Infiniti® group (p = 0.011, p = 0.005, p = 0.021, respectively). The intraoperative pain scale was 0.26 ± 0.51 in the Centurion® group and 0.50 ± 0.71 in the Infiniti® group, and was not significantly different (p = 0.121). BCVA, increase of CCT and decrease of ECD were not significantly different between the two groups at 1 month postoperatively. CONCLUSIONS: The efficacy of phacoemulsification in the Centurion® group was superior to that in the Infiniti® group. The level of intraoperative pain and clinical outcomes 1 month after surgery were not significantly different between the two groups.

Comparison of Clinical Outcomes between Laser Blended Vision and Monovision Laser Refractive Surgery for Presbyopia

PURPOSE: To compare the efficacy and safety of Laser Blended Vision (LBV) and monovision laser refractive surgery (monovision) for presbyopia correction in patients with myopia. METHODS: This retrospective comparative study included 42 eyes of 21 patients with LBV and 50 eyes of 25 patients with monovision. Monocular and binocular distance, intermediate and near visual acuity, and refractive changes were evaluated preoperatively and 3 months after the surgery and compared. The patients in the LBV group underwent further evaluation of spherical aberration 3 months after the surgery and treatment satisfaction 3-6 months after the surgery. RESULTS: The mean age of the patients was 47.9 years in the LBV group and 41.7 years in the monovision group. Three months after surgery, the spherical equivalents were +0.11 ± 0.17 D in the dominant eye and -1.52 ± 0.36 D in the non-dominant eye in the LBV group. In contrast, the spherical equivalents were +0.23 ± 0.26 D in the dominant eye and -0.82 ± 0.28 D in the non-dominant eye in the monovision group. All patients achieved a binocular uncorrected distance visual acuity of 0.10 (log MAR) or better, and 86% of the LBV group and 100% of the monovision group achieved a binocular uncorrected intermediate visual acuity of better than 0.10. Moreover, 95% of the LBV group and 100% of the monovision group achieved a binocular uncorrected near visual acuity of better than 0.18. In the LBV group, mean spherical aberration increased after surgery than before, but it was not statistically significant. Complications such as corneal opacity that could decrease visual acuity were absent in both groups. Overall patient satisfaction after surgery was 80% in the LBV group. CONCLUSIONS: Despite the relatively higher mean age of the LBV group, both groups showed similar results regarding presbyopia correction in patients with myopia.

Efficacy and Safety of Immediate Sequential Bilateral Cataract Surgery

PURPOSE: To evaluate the efficacy and safety of immediate sequential bilateral cataract surgery with respect to patient outcomes and complication rates. METHODS: From January 2010 to December 2014, we conducted a retrospective study of patients who had immediate sequential bilateral cataract surgery (ISBCS) and delayed sequential bilateral cataract surgery (DSBCS) with an interval of one to two months between the first and the fellow eye operations. The changes in visual acuity, manifest spherical equivalent, and refractive error of 140 eyes of 70 patients of both groups were compared postoperatively at one month. The incidence of endophthalmitis was investigated during the same period. RESULTS: At one month postoperatively, log MAR best corrected visual acuity were measured to be 0.06 +/- 0.72 in the ISBCS group and 0.09 +/- 0.66 in the DSBCS group, and that of the fellow eyes were 0.07 +/- 0.64 and 0.07 +/- 0.18, respectively (p = 0.331, p = 0.781, respectively). The postoperative spherical equivalents were -0.18 +/- 0.23 D in the ISBCS group and -0.19 +/- 0.25 D in the DSCBS group, and that of the fellow eyes were -0.15 +/- 0.18 D and -0.16 +/- 0.21 D, respectively. There were no significant statistical differences between the two groups (p = 0.835, p = 0.676, respectively). The postoperative refractive error was -0.20 +/- 0.21 D in the ISCBS group and -0.18 +/- 0.13 D in the DSBCS group, and that of the fellow eyes were -0.14 +/- 0.22 D and -0.19 +/- 0.22 D, respectively (p = 0.482, p = 0.237, respectively). A total of 21,140 eyes had cataract surgery performed, and only 10 eyes (0.05%) developed endophthalmitis. Endophthalmitis did not occur in the ISBCS group. CONCLUSIONS: In experienced hands, with stringent patient selection criteria and with a strict aseptic protocol, ISBCS can safely provide comparable visual outcome and better satisfaction of the patient with good efficacy.

Comparison of Clinical Outcomes in Implantable Collamer Lens Implantation between AQUA ICL(R) and Conventional ICL

PURPOSE: To compare the clinical outcomes between AQUA ICL(R) (V4C) and conventional implantable collamer lens (ICL, V4B) in patients with high myopia. METHODS: We compared preoperative and postoperative visual acuities, spherical equivalent, intraocular pressure, postoperative vault and visual quality assessed using optical quality analyzing system (OQAS(R)) between 20 eyes implanted with ICL (V4B) and 22 eyes implanted with AQUA ICL(R) (V4C). RESULTS: Visual acuity (log MAR) and spherical equivalent at postoperative 3 months were 0.06 +/- 0.09 and -0.26 +/- 0.17 D in the V4B group and 0.03 +/- 0.03 and -0.23 +/- 0.19 D in the V4C group, respectively. There was no statistical difference in visual acuity and spherical equivalent between the 2 groups (p > 0.05). Postoperative intraocular pressure (IOP) elevated significantly in both groups until 6 hours after the operation (p 0.05). V4C resulted in lower IOP than V4B 6 hours postoperatively. In ICL (V4B) and AQUA ICL(R) (V4C) groups, the objective scattering index (OSI) was 1.29 +/- 0.90 and 1.36 +/- 0.68, modulation transfer function (MTF) cut off value was 29.62 +/- 11.31 c/deg and 29.61 +/- 9.56 c/deg and Sterhl ratio was 0.18 +/- 0.07 and 0.17 +/- 0.04, respectively, 3 months postoperatively. None of these values were significantly different between the 2 groups. CONCLUSIONS: AQUA ICL(R) (V4C) implantation is an effective, convenient and safe surgery for myopia correction and yields better outcome than ICL (V4B) in terms of early postoperative IOP.

Clinical Outcomes of Diffractive Aspheric Trifocal Intraocular Lens Implantation

PURPOSE: To evaluate the clinical outcomes of patients with diffractive aspheric trifocal intraocular lens (AT.LISA tri839 MP(R) IOL, Carl Zeiss Meditec, Jena, Germany) implantation. METHODS: Forty eyes of 53 patients received phacoemulsification and implantation of AT.LISA tri839 MP(R) IOL (Carl Zeiss Meditec). Uncorrected distant visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), refractive values, and defocus curve were evaluated at postoperative 1 month and 3 months. Optical quality was evaluated with the Optical Quality Analysis System (OQAS(R), Visiometrics, Castelldefels, Spain). RESULTS: At the 3-month postoperative follow-up, the mean spherical equivalent was 0.01 +/- 0.31 D and the mean UDVA, UIVA and UNVA were 0.023 +/- 0.020, 0.155 +/- 0.091, and 0.139 +/- 0.069, respectively. The means of the objective scatter index, modulation transfer function cut-off value, Strehl ratio measured by OQAS(R) (Visiometrics) were 1.83 +/- 0.52, 33.58 +/- 14.27 cycle per degree and 0.18 +/- 0.11, respectively. Intermediate visual acuity did not fall sharply at defocus curve. CONCLUSIONS: Implantation of the diffractive aspheric trifocal intraocular lens in patients with cataracts provided excellent distant, intermediate and near visual acuities with high visual quality.

Anterior and Posterior Corneal Spherical Aberration Measured With Pentacam in the Korean

PURPOSE: To evaluate the spherical aberrations of the anterior and posterior surfaces of normal corneas using Pentacam in a Korean sample population and determine their ranges and changes with age. METHODS: We used Pentacam (Oculus Inc.,Germany) to measure the anterior and posterior corneal spherical aberrations of 240 eyes in 240 patients with normal corneas who visited our clinic. The means and ranges of spherical aberrations and their changes with age were determined. We examined both eyes of 90 patients to confirm the inter-ocular symmetry in spherical aberration. RESULTS: The mean age of the 240 patients (M:F=103:137) was 49.8 years (range: 20-79), and the mean spherical aberrations of the anterior and posterior surfaces of the cornea were 0.230+/-0.078 micrometer, and -0.04+/-0.021 micrometer, respectively. The mean total corneal spherical aberration was 0.19+/-0.087 micrometer. There were no differences between males and females, and inter-ocular symmetry was observed in all tested patients. There was a tendency for the values of anterior, posterior and total corneal spherical aberration to increase with age. Ranges of spherical aberrations were from -0.177 micrometer to 0.423 micrometer in the anterior cornea, from -0.083 micrometer to 0.034 micrometer in the posterior cornea, and from -0.238 micrometer to 0.410 micrometer in the total cornea. CONCLUSIONS: In a Korean population, the mean total corneal spherical aberration was 0.19 micrometer, which was shown to increase with age. Some patients were shown to have an extreme value. Based on these results, a preoperative analysis for corneal spherical aberration may be helpful when selecting aspheric intraocular lenses.

Corneal Melting and Descemetocele Resulting From Noninfectious Keratitis Related to the Cosmetic Contact Lenses

PURPOSE:To report 2 cases of corneal melting and corneal melting with descemetocele that occurred in users of cosmetic contact lenses. CASE SUMMARY: A-12-year-old and a 13-year-old female who used cosmetic contact lenses were referred to our clinic under the preliminary diagnosis of keratitis and corneal melting. The patients had purchased the lenses from an optician and had worn the lenses for approximately 1 month without being educated on their proper use. The signs and symptoms improved after 2 weeks of treatment with oral steroid and 1% topical prednisolone acetate. However, descemetocele occurred in the 12-year-old patient. Reepithelization of the cornea had been completed within the treatment period. However, corneal thinning with mild opacity remained in the lesions, and the best corrected visual acuities on the Snellen chart were 20/30 in both patients.

The Comparison of Central and Mean True-Net Power (Pentacam) in Calculating IOL-Power After Refractive Surgery

PURPOSE: To compare the accuracy of central true net corneal power (cTNP) and mean true net corneal power (mTNP) of the Pentacam system to give a keratometry (K) reading for calculating IOL (intraocular lens) power in eyes following refractive surgery. METHODS: Refraction, an automated K-reading (Km), cTNP and mTNP were measured for 15 eyes that required cataract surgery and had previously undergone refractive surgery. The difference between postoperative manifest refraction values and target refraction values calculated with the SRK/T formula using cTNP were compared with the one using mTNP. RESULTS: The mean deviation from the desired post-cataract refractive outcome was 0.60 diopter (D) +/-0.47 (standard deviation) using cTNP; 0.75+/-0.54 using mTNP (p=0.386). The actual refraction was within +/-0.50D of the intended refraction for 60% (cTNP) and 33.3% (mTNP) of eyes, and within +/-1.00D for 93% (cTNP) and 66.7% (mTNP) of eyes. CONCLUSIONS: Although not statistically significant, the cTNP showed better accuracy than mTNP to give a keratometry (K) reading for post-refractive surgery eyes requiring cataract surgery.

Relationship between Scanning Laser Polarimetry with Enhanced Corneal Compensation and with Variable Corneal Compensation

PURPOSE: To evaluate the structure-function relationships between retinal sensitivity measured by Humphrey visual field analyzer (HVFA) and the retinal nerve fiber layer (RNFL) thickness measured by scanning laser polarimetry (SLP) with variable corneal compensation (VCC) and enhanced corneal compensation (ECC) in glaucomatous and healthy eyes. METHODS: Fifty-three eyes with an atypical birefringence pattern (ABP) based on SLP-VCC (28 glaucomatous eyes and 25 normal healthy eyes) were enrolled in this cross-sectional study. RNFL thickness was measured by both VCC and ECC techniques, and the visual field was examined by HVFA with 24-2 full-threshold program. The relationships between RNFL measurements in superior and inferior sectors and corresponding retinal mean sensitivity were sought globally and regionally with linear regression analysis in each group. Coefficients of the determination were calculated and compared between VCC and ECC techniques. RESULTS: In eyes with ABP, R2 values for the association between SLP parameters and retinal sensitivity were 0.06-0.16 with VCC, whereas they were 0.21-0.48 with ECC. The association of RNFL thickness with retinal sensitivity was significantly better with ECC than with VCC in 5 out of 8 regression models between SLP parameters and HVF parameters (P<0.05). CONCLUSIONS: The strength of the structure-function association was higher with ECC than with VCC in eyes with ABP, which suggests that the ECC algorithm is a better approach for evaluating the structure-function relationship in eyes with ABP.

Comparison of Contrast Sensitivity with ACV (Visual Capacity Analyzer) in Different Types of Posterior Capsular Opacification

PURPOSE: To compare contrast sensitivity (CS) in type and degree of posterior capsule opacification (PCO) in pseudophakic eyes before and after neodymium: YAG capsulotomy. METHODS: Nine eyes with fibrosis-type PCO and 26 with Elschnig-pearl type PCO were examined for best corrected visual acuity (BCVA) and CS before and 1 week after capsulotomy. CS was tested with visual capacity analyzer (ACV) which uses a Landolt ring of 5 different spatial frequencies (SF) under two different conditions of day (100cd/m2) and night (30cd/m2). The patients were divided into two groups based on the BCVA before capsulotomy: Group A, 4 eyes and 18 eyes with below 0.63 in fibrosis-type and pearls-type PCO, respectively; Group B, 5 eyes and 8 eyes with above 0.63 in fibrosis-type and pearls-type PCO, respectively. RESULTS: The patients with PCO had worse BCVA and CS, but these were improved by Nd: YAG capsulotomy. This was not affected by the types and degrees of PCO. In the daytime condition, CS of B group was worse at all SF in patients with pearl-type PCO than in those with fibrosis-type PCO before capsulotomy, except 19 cpd (p0.05). CONCLUSIONS: In the daytime condition, the patients with pearls-type PCO of relatively poor BCVA had lower CS than those with fibrosis-type PCO.

A Case of Netherton's Syndrome in a Newborn

Netherton's syndrome is an unusual disorder which consists of triad of ichtyosiform dermatosis, multiple defects of hair shaft and an atopic diathesis. The finding of bamboo hair is pathognomic in Netherton's syndrome and the ichthyosiform dermatosis may consist of either ichtyosis linearis circumflexa or congenital ichthyosiform erythroderma. Often, variability in the clinical features leads to a delay in diagnosis in many cases. We report a case of Netherton's syndrome diagnosed in the neonatal period. The patient presented with severe ichthyosis and confirmed microscopically distinctive bamboo hair.

Corneal Epithelial Cell Survival and Electron Microscopic Changes after Ethanol Treatment

PURPOSE: In LASEK models, the viability of corneal epithelial cells after ethanol treatment was investigated in addition to morphological analysis. METHODS: Cell viability was assayed using a confocal laser scanning microscopy(CLSM) and MTT assay for in vivo and cultured rabbit corneal epithelial cells after treatment with various concentrations of ethanol. Ethanol treated human corneas were compared with control in terms of structural changes. RESULTS: CLSM assay showed that cells were viable at the ratio of 78.5, 75.0, 57.3, 43.3, 23.9, 4.3% for 0, 10, 20, 30 40, 60 % ethanol groups, respectively. The relative survival rates in comparison to 0% ethanol-treated (control) corneas were 95.5(10%), 72.9(20%), 55.2(30%), 30.4(40%), 5.5(60%). On MTT assay after 10, 20, 25, 30, 40, 60% ethanol treatment, cultured epithelial cells were still alive at the percentage of 92.7, 92.2, 36.6, 30.7, 5.4, 5.1% (20 sec), 90.8, 57.1, 29.0. 28.6, 5.0, 4.7% (40 sec) at 0 hr with decreasing cell survival over time in 20% ethanol group. TEM showed multiple vacuole-like loosenings along the intercellular junction of superficial squamous and wing cells. The loss and break-up of hemidesmosome and basement membrane were also demonstrated in conjunction with the loosening of sub-basal interface. CONCLUSIONS: After 20% ethanol exposure for 40 seconds, 72.9% and 57.1% of in vivo and cultured rabbit corneal epithelial cells were in viable state with decreasing cell survival over increasing ethanol concentration and time. The loss and break-up of hemidesmosome and basement membrane, resulting in loosening of sub-basal interface, might be the mechanism for the detachment of LASEK flap en bloc.

Gene Transfer into Corneal Keratocytes using a Hybrid EBV/retroviral Vector

PURPOSE: We tried to determine the feasibility and efficiency of foreign gene transfer into corneal keratocytes using a hybrid EBV/retroviral vector as an investigative trial for gene therapy in corneal diseases. METHODS: LZRSpBMN-Z, alac Z-transducing hybrid EBV/retroviral vector, was transfected into Phoenix(T M) amphotropic packaging cells based on a 293T cell line and then collected without/with puromycin selection (puro (-)/puro (+) vector respectively). Cultured human and rabbit keratocytes were transduced with lac-Z gene using the puro (-) or puro (+) vector solutions, then stained with 5-bromo-4-chloro-3-indolyl galactopyranoside (X-gal). FACS-Gal analysis of transduced corneal keratocytes was also performed for calculating gene transfer efficiency. In addition, as an in vivo trial, we tried to transduce rabbit keratocytes by topical application of the vector supernatants following PRK or lamellar dissection of rabbit corneas. RESULTS: In vitro, both cultred human and rabbit keratocytes were transduced successfully with lac - Z gene. Transduction efficiency was 22% and 16% for human and rabbit keratocytes respectively with puro (-) vector, and slightly increased to 24% and 22% with puro (+) vector. In vivo corneas, however, no keratocytes were stained with X-gal. CONCLUSIONS: A hybrid EBV/retroviral vector, LZRSpBMN-Z, successfully transduced corneal keratocytes in in vitro conditions but not in vivo corneas.

Factors Associated with the Posterior Corneal Surface Elevation in Mmyopic Eye

PURPOSE: To know the factors associated with the posterior corneal surface elevation in myopic eye. METHODS: The posterior corneal surface elevation (PCSE), keratometry, central corneal thickness (CCT), peripheral corneal thickness (PCT), thinnest corneal thickness (TCT) were measured in 64 right myopic eyes with the Orbscan topography system. The correlation between PCSE and age, refractive error, intraocular pressure (IOP), keratometry, CCT, TCT, PCT, PCT-CCT, PCT/CCT, PCT-TCT, and PCT/TCT was evaluated. RESULTS: The posterior corneal surface elevation has correlation with CCT (r:.0.3306, p:0.0071), TCT ( r :.0.4094, p:0.0007), PCT-CCT(r:0.3326, p:0.0068), PCT/CCT (r:0.3759, p:0.0020), PCT-TCT (r: 0.4750, p:0.0001), and PCT/TCT (r:0.5145, p:0.0001) but does not have correlation with age, keratometry, refractive error, IOP (r:.0.0627, p:0.6225), and PCT. CONCLUSIONS: In myopic eyes, the posterior corneal surface elevation correlates with central corneal thickness and specifically the ratio PCT to TCT.

The Effect of Preoperative Keratometric Value on Corneal Flap Dimensions in LASIK

PURPOSE: To evaluate the effect of preoperative keratometric value on corneal flap dimensions, records of 81 eyes of 45 patients who had LASIK were analyzed retrospectively. METHOD: Corneal thickness and diameter , and keratometric value were measured preoperatively. RESULTS: In this study, SCMD Turbokeratome was set for making a corneal flap with 150 micron thickness and 8.25 mm diameter. In reality, however, the mean corneal flap thickness was 110.7+/-15.7 micron and the mean corneal flap diameter was 7.89+/-0.33 mm. The lower mean preoperative keratometric value, the thicker(r=-0.325, p=0.003) and the smaller(r=0.460, p=0.009) diameter flap was made. When we divided eyes into three groups according to their keratometric values, eyes with keratometric values lower than 42.5 D resulted in corneal flap with 116.70+/-12.6 micron thickness and 7.65(0.28mm diameter as opposed to 102.16+/-13.41 micron thickness and 8.05+/-0.37 mm diameter flap in corneas having keratometric values above 44.5 D(p<0.05). CONCLUSION: When a LASIK flap was made using SCMD manual keratome, steeper corneas tend to have larger and thinner corneal flaps. In conclusion, for making the corneal flap according to the intended thickness and diameter in LASIK, preoperative keratometric value should be considered carefully.