Comparison of Intraocular Lens Power Calculation Methods Following Myopic Laser Refractive Surgery: New Options Using a Rotating Scheimpflug Camera

PURPOSE: To evaluate and compare published methods of calculating intraocular lens (IOL) power following myopic laser refractive surgery. METHODS: We performed a retrospective review of the medical records of 69 patients (69 eyes) who had undergone myopic laser refractive surgery previously and subsequently underwent cataract surgery at Samsung Medical Center in Seoul, South Korea from January 2010 to June 2016. None of the patients had pre-refractive surgery biometric data available. The Haigis-L, Shammas, Barrett True-K (no history), Wang-Koch-Maloney, Scheimpflug total corneal refractive power (TCRP) 3 and 4 mm (SRK-T and Haigis), Scheimpflug true net power, and Scheimpflug true refractive power (TRP) 3 mm, 4 mm, and 5 mm (SRK-T and Haigis) methods were employed. IOL power required for target refraction was back-calculated using stable post-cataract surgery manifest refraction, and implanted IOL power and formula accuracy were subsequently compared among calculation methods. RESULTS: Haigis-L, Shammas, Barrett True-K (no history), Wang-Koch-Maloney, Scheimpflug TCRP 4 mm (Haigis), Scheimpflug true net power 4 mm (Haigis), and Scheimpflug TRP 4 mm (Haigis) formulae showed high predictability, with mean arithmetic prediction errors and standard deviations of −0.25 ± 0.59, −0.05 ± 1.19, 0.00 ± 0.88, −0.26 ± 1.17, 0.00 ± 1.09, −0.71 ± 1.20, and 0.03 ± 1.25 diopters, respectively. CONCLUSIONS: Visual outcomes within 1.0 diopter of target refraction were achieved in 85% of eyes using the calculation methods listed above. Haigis-L, Barrett True-K (no history), and Scheimpflug TCRP 4 mm (Haigis) and TRP 4 mm (Haigis) methods showed comparably low prediction errors, despite the absence of historical patient information.

The Incidence and Risk Factors of Lens-iris Diaphragm Retropulsion Syndrome during Phacoemulsification

PURPOSE: In the present study, the incidence and risk factors of lens-iris diaphragm retropulsion syndrome (LIDRS) were evaluated. METHODS: Patients who underwent cataract surgery using phacoemulsification between June 2014 and December 2014 were included in the study. The preoperative ocular biometric and intraoperative surgical parameters were examined. The incidence of LIDRS and various risk factors were analyzed using an independent t-test, Pearson's chi-square test, and univariable and multivariable logistic regression analyses. RESULTS: Among 124 eyes of 124 patients, 100 (80.6%) had no LIDRS and 24 (19.4%) had LIDRS. LIDRS occurred in 13 of 31 vitrectomized eyes (41.9%) and 11 of 93 non-vitrectomized eyes (11.8%). Based on univariable analysis, age (odds ratio [OR], 0.920; p = 0.001), vitrectomized eye (OR, 5.038; p = 0.001), spherical equivalent (OR, 0.778; p < 0.001), axial length (OR, 1.716; p < 0.001), anterior chamber depth (OR, 3.328; p = 0.037), and 3.0 mm vs. 2.2 mm incision size (OR, 4.964; p = 0.001) were statistically significant risk factors associated with the development of LIDRS. Conditional multivariable logistic regression showed that vitrectomized eye (OR, 3.865; 95% confidence interval [CI], 1.201 to 12.436; p = 0.023), long axial length (OR, 1.709; 95% CI, 1.264 to 2.310; p = 0.001), and 3.0 vs. 2.2 mm incision size (OR, 3.571; 95% CI, 1.120 to 11.393; p = 0.031) were significant independent risk factors associated with LIDRS. CONCLUSIONS: LIDRS is a relatively common occurrence and was found to be associated with vitrectomized eye, long axial length, and larger incision size. Evaluating risk factors prior to cataract surgery can help reduce associated morbidity.

Prevalence and Risk Factors of Dry Eye Disease after Refractive Surgery

PURPOSE: To assess the prevalence and the risk factors of dry eye disease after refractive surgery. METHODS: A retrospective study was performed on 180 eyes of 98 patients based on medical records. Those who had tear break-up time less of than 5 seconds or had an Oxford stain scale equal to or greater than 2 were defined to have dry eye disease. We analyzed the prevalence of dry eye, compared demographic and clinical features of the dry eye group and normal group, and found risk factors of dry eye after refractive surgery. RESULTS: The prevalence of postoperative dry eye was 62.2%. Compared to the normal eye group, the dry eye group had a significantly higher proportion of women (p = 0.016), older age (p = 0.001), and thin cornea (p = 0.002). The most significant risk factor of dry eye after refractive surgery was presence of dry eye before refractive surgery (odds ratio [OR] = 9.02, confidence interval [CI] = 3.8-21.4). Old age was also found to be an independent risk factor of dry eye after refractive surgery (OR = 1.06, CI = 1.01-1.11). CONCLUSIONS: The risk of dry eye after refractive surgery was increased in older age and preoperative dry eye disease. In order to prevent post-refractive surgery dry eye, caution should be exercised in middle aged patients with preoperative dry eye disease.

Effects of Continuous Curvilinear Capsulorhexis, Intraocular Lens Decentration and Tilt on Clinical Outcomes

PURPOSE: To evaluate the effects of continuous curvilinear capsulorhexis, intraocular lens (IOL) decentration and tilt on postoperative clinical outcomes after cataract surgery. METHODS: We reviewed 62 eyes of 52 patients who underwent cataract surgery and measured the uncorrected visual acuity, best corrected visual acuity and manifest refraction preoperatively and 3 months postoperatively. IOL decentration on anterior segment photography and IOL tilt on anterior optical coherent tomography were analyzed and correlations of postoperative uncorrected visual acuity, best corrected visual acuity, and higher order aberrations were evaluated. In addition, we inspected the relationship of size and decentration of continuous curvilinear capsulorhexis (CCC) intraoperatively with the change in IOL position postoperatively. RESULTS: The average size of CCC was 5.40 ± 0.51 mm (4.12-6.24 mm) and the average decentration of CCC was 0.30 ± 0.19 mm (0.09-1.21 mm) intraoperatively. The average decentration of IOL was 0.23 ± 0.15 mm (0.00-0.71 mm) and the average IOL tilt was 1.43 ± 0.73° (0.00-4.22°) postoperatively. Intraoperative CCC size and decentration were associated with postoperative IOL decentration (p = 0.01, p < 0.001), but not with IOL tilt (p = 0.69, p = 0.52). There were no significant correlations between IOL decentration and tilt with postoperative visual outcomes and higher order aberrations. CONCLUSIONS: The CCC size and decentration can affect the IOL decentration, but IOL decentration and tilt do not have a significant impact on clinical outcomes after cataract surgery.

Effects of Continuous Curvilinear Capsulorhexis, Intraocular Lens Decentration and Tilt on Clinical Outcomes

PURPOSE: To evaluate the effects of continuous curvilinear capsulorhexis, intraocular lens (IOL) decentration and tilt on postoperative clinical outcomes after cataract surgery. METHODS: We reviewed 62 eyes of 52 patients who underwent cataract surgery and measured the uncorrected visual acuity, best corrected visual acuity and manifest refraction preoperatively and 3 months postoperatively. IOL decentration on anterior segment photography and IOL tilt on anterior optical coherent tomography were analyzed and correlations of postoperative uncorrected visual acuity, best corrected visual acuity, and higher order aberrations were evaluated. In addition, we inspected the relationship of size and decentration of continuous curvilinear capsulorhexis (CCC) intraoperatively with the change in IOL position postoperatively. RESULTS: The average size of CCC was 5.40 ± 0.51 mm (4.12-6.24 mm) and the average decentration of CCC was 0.30 ± 0.19 mm (0.09-1.21 mm) intraoperatively. The average decentration of IOL was 0.23 ± 0.15 mm (0.00-0.71 mm) and the average IOL tilt was 1.43 ± 0.73° (0.00-4.22°) postoperatively. Intraoperative CCC size and decentration were associated with postoperative IOL decentration (p = 0.01, p < 0.001), but not with IOL tilt (p = 0.69, p = 0.52). There were no significant correlations between IOL decentration and tilt with postoperative visual outcomes and higher order aberrations. CONCLUSIONS: The CCC size and decentration can affect the IOL decentration, but IOL decentration and tilt do not have a significant impact on clinical outcomes after cataract surgery.

Second-Eye Refractive Error Depending on the Reflection Rate of First-Eye Refractive Error in Cataract Surgeries

PURPOSE: To evaluate the reflection rate of the first eye in order to minimize the real refractive error in the second eye in bilateral consecutive cataract surgeries. METHODS: A retrospective analysis was performed with 248 patients who underwent bilateral sequential uncomplicated phacoemulsification and posterior chamber intraocular lens implantation. Predicted spherical equivalent was compared with postoperative spherical equivalent, and the range of real refractive error was analyzed by calculating the reflection rate of the first eye. RESULTS: When the difference between predicted spherical equivalent and postoperative spherical equivalent was greater than 0.5 D as calculated with the formula of Sanders-Retzlaff-Kraff Theoretical (SRK)-T and SRK II, application of 50-60%, 40-50% of the difference of the first eye was high probability to reduce the second-eye real refractive error (75%, 100%). CONCLUSIONS: Application of 40-60% of the real refractive error in the first-eye can minimize the real refractive error in the second-eye in bilateral sequential cataract surgeries.

Predisposing Factors and Surgical Outcomes of Intraocular Lens Dislocation after Phacoemulsification

PURPOSE: To report the predisposing factors and surgical outcomes of intraocular lens dislocation (IOL) after phacoemulsification. METHODS: We performed a retrospective study of 131 eyes in 120 patients who were diagnosed with IOL dislocation after phacoemulsification between January 2008 and December 2013. The main outcomes are possible predisposing factors, characteristics of IOL dislocation, and outcomes of rectification surgery, including visual acuity (VA), and refractive status before and at 3 months after surgery. RESULTS: The main conditions associated with IOL dislocation were as follows: status after vitrectomy (27.5%), long axial length (9.2%), neodymium-doped yttrium aluminium garnet (Nd:YAG) posterior capsulotomy (8.4%), uveitis (6.1%), trauma (5.3%), mature cataract (3.8%), and pseudoexfoliation (2.3%). Mean uncorrected VA improved significantly after rectification surgery (p = 0.00), and best-corrected VA also improved significantly (p = 0.01). Mean value of spherical equivalent tended to decrease, although the decrease was not significant (p = 0.07). Whereas astigmatism showed a significant increase (p = 0.01). 6 eyes (4.6%) were associated with recurrence of IOL dislocation. CONCLUSIONS: Possible major predisposing factors for IOL dislocation are status after vitrectomy, long axial length, Nd:YAG posterior capsulotomy, uveitis, and trauma. The surgical outcome and improvement of postoperative visual acuity were satisfactory.

Mutation Analysis of the TGFBI Gene in Consecutive Korean Patients With Corneal Dystrophies

BACKGROUND: Mutations in the transforming growth factor beta-induced gene (TGFBI) are major causes of genetic corneal dystrophies (CDs), which can be grouped into TGFBI CDs. Although a few studies have reported the clinical and genetic features of Korean patients with TGFBI CD, no data are available regarding the frequency and spectrum of TGFBI mutations in a consecutive series of Korean patients with clinically diagnosed CDs. METHODS: Patients with any type of CD, who underwent both ophthalmologic examination and TGFBI gene analysis by Sanger sequencing at a tertiary care hospital in Seoul, Korea from 2006 to 2013, were enrolled in this study. RESULTS: Among a total of 89 patients, 77 (86.5%) were diagnosed as having clinical TGFBI CD. Seventy-three out of 74 patients (98.6%) with granular CD type 2 (GCD2), had the p.R124H mutation. Of particular note, one patient with rapidly progressive CD had the p.R124H mutation as well as a novel nonsense variant with unknown clinical significance (p.A179*). In three patients with lattice CD type 1 (LCD1), one known mutation (p.R124C) and two novel variants (p.L569Q and p.T621P) in the TGFBI gene were identified. CONCLUSIONS: This study provides epidemiological insight into CDs in a Korean population and reaffirms that GCD2 is the most common TGFBI CD phenotype and that p.R124H is the only mutation identified in patients with GCD2. In addition, we broaden the spectrum of TGFBI mutations by identifying two novel missense variants in patients with LCD1.

Clinical Outcomes of Descemet's Membrane Endothelial Keratoplasty: A 1-Year Retrospective Study

PURPOSE: To evaluate the 1-year results of Descemet's membrane endothelial keratoplasty (DMEK) in Korea. METHODS: The medical records of 9 patients (10 eyes) with endothelial disease who underwent DMEK from January 2012 to December 2013, and were followed up for more than 12 months were reviewed retrospectively. RESULTS: In 8 eyes with successful results after surgery, best corrective visual acuity (BCVA) was significantly improved from 1.64 +/- 0.21 (log MAR, mean) to 0.35 +/- 0.22 at 1 month and was maintained at 12 months (p = 0.012, Wilcoxon signed ranks test). BCVA at postoperative 3, 6 and 12 months were gradually increased (0.25 +/- 0.23, 0.20 +/- 0.17 and 0.16 +/- 0.17 log MAR). Endothelial cell counts were 1,996 +/- 528/mm2, 1,564 +/- 174/mm2 and 1,463 +/- 541/mm2, 1,205 +/- 358/mm2 at 1, 3, 6, and 12 months after surgery, tended to decrease but showed no statistical significance. There was no statistical difference in astigmatism before and 3 months after the operation (3.32 +/- 2.36 diopter and 2.57+/- 1.44 diopter). Primary graft failure occurred in 2 eyes and 1 received reoperation. Total detachment was found in 1 eye. CONCLUSIONS: The 1-year results of DMEK showed fast visual recovery which was maintained for 12 months. DMEK may be a very efficient option for the surgical management of corneal endothelial disease.

Effect of Cysteamine on Human Peripheral Blood Mononuclear Cells-Chemically Injured Keratocytes Reaction

PURPOSE: To investigate the effect of cysteamine on mixed peripheral blood mononuclear cells (PBMCs)-chemically injured keratocytes reaction (mixed lymphocyte-keratocyte reaction; MLKR). METHODS: PBMC stimulation assay was performed after keratocytes were chemically injured with 0.05 N NaOH for 60 seconds. MLKR was treated with various concentrations of cysteamine (0-10 mM). Intracellular reactive oxygen species (ROS) formation was measured using the oxidation-sensitive fluorescent probe, 2'7'-dichlorofluorescein diacetate (DCF-DA). Proliferation rate of PBMCs stimulated by NaOH-treated keratocytes and secretion profiles of matrix metalloprotease-9 (MMP-9), transforming growth factor-beta1 (TGF-beta1), interleukin-6 (IL-6), and macrophage migration inhibitory factor (MIF) were determined using the bromodeoxyuridine proliferation assay and enzyme-linked immunosorbent assay, respectively. RESULTS: Proliferation rate of PMBCs was suppressed by cysteamine in a dose-dependent manner (p = 0.019). Fluorescence of DCF-DA decreased depending on cysteamine concentration (p < 0.001). MMP-9, IL-6 and TGF-beta1 levels were suppressed by cysteamine in a dose-dependent manner (p < 0.05), whereas MIF levels increased with cysteamine concentration of 0.5-10 mM (p = 0.008). CONCLUSIONS: These study results indicate that cysteamine induced the ROS-mediated inhibition of inflammatory cytokine release and proliferation of PBMCs stimulated by chemically injured keratocytes. Thus, cysteamine can be used in the treatment of chemical corneal burns.

Comparison of Intracorneal Inlay for Presbyopia Correction: Hydrogel and Small-Aperture Inlays with a Six- Months Follow-Up

PURPOSE: To study the safety and efficacy of corneal reshaping and small-aperture inlays and compare the clinical results. METHODS: From February 2014 to November 2014, 22 corneal reshaping inlays were inserted at Asan Medical Center and from October 2012 to March 2013, 26 small-aperture inlay surgeries were performed: 6 eyes at Asan Medical Center and 20 eyes at Samsung Medical Center. The preoperative and postoperative parameters were reviewed retrospectively and included monocular uncorrected distance visual acuity (UDVA; log MAR), uncorrected near visual acuity (UNVA; log MAR), refraction and corneal curvature based on automated refractor keratometry, reading distance and patient satisfaction. RESULTS: In the hydrogel inlay group, preoperative mean monocular UNVA was 0.83 +/- 0.05 and monocular UDVA 0.07 +/- 0.03. At 6 months, mean monocular UNVA was 0.23 +/- 0.05 and UDVA 0.05 +/- 0.02. The most preferred mean reading distance in the hydrogel inlay group was 39.38 +/- 3.18 cm. In the small-aperture inlay group, preoperative mean monocular UNVA was 0.4 +/- 0.06 and monocular uncorrected visual acuity 0.27 +/- 0.04. At 6 months, mean monocular UNVA was 0.11 +/- 0.02 and UDVA 0.09 +/- 0.05 and the most preferred mean reading distance was 44.23 +/- 5.17 cm. Although 85% of patients in the corneal reshaping inlay group were satisfied or very satisfied, only 20% of patients in the small-aperture inlay group were satisfied. CONCLUSIONS: Both inlays are considered good options for correcting presbyopia. However, postoperative satisfaction score was higher and less glare symptoms were reported in the hydrogel inlay group.

Clinical Outcome of Retreatment after Refractive Surgery

PURPOSE: To evaluate the clinical outcome of retreatment after refractive surgery. METHODS: Retrospective analysis of 38 eyes of 24 patients who received retreatment surgery after refractive surgery from August 2008 to May 2013 was performed. Pre-initial surgery characteristics and the reason for retreatment were investigated, and preand post-retreatment uncorrected visual acuity, best corrected visual acuity, safety index, efficacy index, predictability, and postoperative complication were also investigated. RESULTS: Age at initial refractive surgery and retreatment were 28.50 +/- 7.29 years (17-49 years) and 31.21 +/- 6.49 years (21-49 years). Reasons for retreatment were myopic regression in 36 eyes (94.7%) and overcorrection in two eyes (5.3%). Methods of retreatment were laser subepithelial keratomileusis (LASEK) in 31 eyes (81.6%) and laser-assisted in situ keratomileusis (LASIK) in seven eyes (18.4%). Safety index values for all were above 1.0 and efficacy index values were 0.92, 0.93, and 0.95 in postoperative examination at 1 month, 3 months, and 6 months, respectively. No eye showed a decrease in best corrected visual acuity. One eye had transient hyperopia after retreatment, and two eyes had postoperative corneal opacity, but no eye experienced significant alteration in visual prognosis. CONCLUSIONS: Retreatment after refractive surgery was an efficient and safe clinical course in our clinic. No long-term complications were observed, and uncorrected visual acuity and refractive errors significantly improved after retreatment. In particular, LASEK can be considered as a safe and efficient retreatment modality without risk of keratectasia.

Korean Guidelines for the Diagnosis and Management of Dry Eye: Development and Validation of Clinical Efficacy

PURPOSE: To evaluate the clinical efficacy of newly developed guidelines for the diagnosis and management of dry eye. METHODS: This retrospective, multi-center, non-randomized, observational study included a total of 1,612 patients with dry eye disease who initially visited the clinics from March 2010 to August 2010. Korean guidelines for the diagnosis and management of dry eye were newly developed from concise, expert-consensus recommendations. Severity levels at initial and final visits were determined using the guidelines in patients with 90 +/- 7 days of follow-up visits (n = 526). Groups with different clinical outcomes were compared with respect to clinical parameters, treatment modalities, and guideline compliance. Main outcome measures were ocular and visual symptoms, ocular surface disease index, global assessment by patient and physician, tear film break-up time, Schirmer-1 test score, ocular surface staining score at initial and final visits, clinical outcome after three months of treatment, and guideline compliance. RESULTS: Severity level was reduced in 47.37% of patients treated as recommended by the guidelines. Younger age (odd ratio [OR], 0.984; p = 0.044), higher severity level at initial visit, compliance to treatment recommendation (OR, 1.832; p = 0.047), and use of topical cyclosporine (OR, 1.838; p = 0.011) were significantly associated with improved clinical outcomes. CONCLUSIONS: Korean guidelines for the diagnosis and management of dry eye can be used as a valid and effective tool for the treatment of dry eye disease.

Formula Comparison for Intraocular Lens Power Calculation Using IOL Master and Ultrasound for the ZCB00 IOL

PURPOSE: To evaluation the accuracy of the IOL power calculation formulae measured by IOL Master(R) and applanation ultrasonography for the Tecnis ZCB00 IOL. METHODS: We performed a retrospective study of 170 eyes in 121 patients who underwent cataract surgery in our hospital with AMO Tecnis ZCB00 IOL.s. The SRK/T formula was used to predict the patient's implanted IOL power. Differences in the predicted refractive errors between IOL Master(R) and ultrasonography were analyzed and factors attributed to the differences were also analyzed. Three months after cataract surgery, mean numeric error and mean absolute error were analyzed. RESULTS: SRK/II and SRK/T formulas calculated using ultrasonography showed differences compared to the same formulas calculated using IOL Master(R), in which hyperopic shift was also demonstrated. No definite factor was attributed to the differences between the 2 methods. Although the 3 formulas of IOL Master(R) showed no significant difference in refractive errors, the SRK/T formula calculated using IOL Master(R) showed the least mean absolute and numeric errors. CONCLUSIONS: IOL Master(R) is considered more suitable when determining proper AMO Tecnis ZCB00 IOL power in cataract surgery. The hyperopic shift should be considered when calculating the IOL power using only ultrasonography.

Clinical Manifestations and Risk Factors of Ocular Graft-versus-Host Disease (GVHD) after Hematopoietic Stem Cell Transplantation

PURPOSE: To investigate the incidence, clinical manifestations, and risk factors of ocular graft-versus-host disease (GVHD) as well as the survival of the patients after allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: The medical records of 99 patients who visited our clinic and were screened for ocular GVHD after allogeneic HSCT were reviewed retrospectively. Subjects were divided into 2 groups depending on the occurrence of ocular GVHD on slit-lamp biomicroscopy. We compared clinical manifestations and survival between the 2 groups and analyzed the risk factors associated with the development of ocular GVHD. RESULTS: Ocular GVHD was diagnosed in 38 patients (38.38%) at a mean of 315 days after HSCT. Out of the 38 patients who developed ocular GVHD, 22 patients (57.89%) were diagnosed with dry eye only and 16 patients (42.11%) were diagnosed with conjunctival disease. The presence of extraocular GVHD (hazard ratio (HR) 35.76, p < 0.001), the number of extraocular GVHD (HR 3.07, p < 0.001), skin GVHD (HR 2.31, p = 0.029), oral GVHD (HR 8.16, p < 0.001), and gastrointestinal tract GVHD (HR 5.00, p = 0.002) were independent risk factors of ocular GVHD. Comparisons of the survival demonstrated decreased survival of patients with conjunctival disease compared to patients without ocular GVHD and patients with dry eye only, but there was no statistically significant differences (log rank test, p = 0.208). CONCLUSIONS: Ocular GVHD is common after allogeneic HSCT. The majority of ocular GVHD occurs in the chronic stage and is associated with decreased survival. Therefore, more intensive and long-term follow-up with ophthalmic and systemic monitoring is necessary, especially in patients who have extraocular GVHD, for early recognition and proper treatment of ocular GVHD.

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.

Refractive Changes after Removal of Anterior IOLs in Temporary Piggyback IOL Implantation for Congenital Cataracts

PURPOSE: To assess the refractive change and prediction error after temporary intraocular lens (IOL) removal in temporary polypseudophakic eyes using IOL power calculation formulas and Gills' formula. METHODS: Four consecutive patients (7 eyes) who underwent temporary IOL explantation were enrolled. Postoperative refractions calculated using IOL power calculation formulas (SRK-II, SRK-T, Hoffer-Q, Holladay, and the modified Gills' formula for residual myopia and residual hyperopia) were compared to the manifest spherical equivalents checked at 1 month postoperatively. RESULTS: The mean ages of temporary piggyback IOL implantation and IOL removal were 6.71 +/- 3.68 months (range, 3 to 12 months) and 51.14 +/- 18.38 months (range, 29 to 74 months), respectively. The average refractive error was -13.11 +/- 3.10 diopters (D) just before IOL removal, and improved to -1.99 +/- 1.04 D after surgery. SRK-T showed the best prediction error of 1.17 +/- 1.00 D. The modified Gills' formula for myopia yielded a relatively good result of 1.47 +/- 1.27 D, with only the variable being axial length. CONCLUSIONS: Formulas to predict refractive change after temporary IOL removal in pediatric polypseudophakia were not as accurate as those used for single IOL implantation in adult eyes. Nonetheless, this study will be helpful in predicting postoperative refraction after temporary IOL removal.

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.

Refractive Changes after Removal of Anterior IOLs in Temporary Piggyback IOL Implantation for Congenital Cataracts

PURPOSE: To assess the refractive change and prediction error after temporary intraocular lens (IOL) removal in temporary polypseudophakic eyes using IOL power calculation formulas and Gills' formula. METHODS: Four consecutive patients (7 eyes) who underwent temporary IOL explantation were enrolled. Postoperative refractions calculated using IOL power calculation formulas (SRK-II, SRK-T, Hoffer-Q, Holladay, and the modified Gills' formula for residual myopia and residual hyperopia) were compared to the manifest spherical equivalents checked at 1 month postoperatively. RESULTS: The mean ages of temporary piggyback IOL implantation and IOL removal were 6.71 +/- 3.68 months (range, 3 to 12 months) and 51.14 +/- 18.38 months (range, 29 to 74 months), respectively. The average refractive error was -13.11 +/- 3.10 diopters (D) just before IOL removal, and improved to -1.99 +/- 1.04 D after surgery. SRK-T showed the best prediction error of 1.17 +/- 1.00 D. The modified Gills' formula for myopia yielded a relatively good result of 1.47 +/- 1.27 D, with only the variable being axial length. CONCLUSIONS: Formulas to predict refractive change after temporary IOL removal in pediatric polypseudophakia were not as accurate as those used for single IOL implantation in adult eyes. Nonetheless, this study will be helpful in predicting postoperative refraction after temporary IOL removal.

The Correlations between Donor Endothelial Lenticule Thickness and Visual Prognosis in DSAEK

PURPOSE: To determine the correlations between donor endothelial lenticule thickness and visual prognosis in Descemet's stripping automated endothelial keratoplasty (DSAEK). METHODS: The present study included 22 patients (22 eyes), who underwent DSAEK surgery in our clinic due to endothelial decompensation. BCVA (log MAR) was compared at 1 month, 3 months and 6 months postoperatively between the thin lenticule group and thick lenticule group (> or =130 micrometer). RESULTS: The BCVA (log MAR) at 1 month postoperatively was 0.46 +/- 0.22 in the thin lenticule group, and 0.71 +/- 0.26 in the thick lenticule group, and significant statistical correlations between donor lenticule thickness and visual acuity were observed (p = 0.025). However, no significant correlations were observed at 3 months (p = 0.129) and 6 months (p = 0.141) postoperatively. CONCLUSIONS: The thin donor lenticule ( or =130 micrometer), however, there is no difference in visual acuity between the 2 groups at 3 and 6 months postoperatively.