20 research outputs found
The Effect of Mitomycin-C on Corneal Endothelial Cells after Photorefractive Keratectomy
Purpose: To evaluate short-term changes in central corneal endothelial cell density and morphology after photorefractive keratectomy (PRK) with mitomycin-C (MMC) 0.02% in patients with moderate myopia.
Methods: In this prospective interventional case series, patients with moderate myopia (spherical equivalent refractive error from ‑4.0 to ‑8.0 D) underwent PRK with a single intraoperative application of MMC 0.02% for 40 seconds. Specular microscopy was performed preoperatively and repeated 6 months after surgery to determine changes in central corneal endothelial cell density (ECD), mean cell area (MCA) and coefficient of variation in cell size (CV).
Results: Overall, 42 eyes of 21 participants with mean age of 26.2±6.3 years underwent surgery. Mean preoperative spherical equivalent refractive error was ‑5.2}1.2 D which was reduced to ‑0.4}0.5 D postoperatively (P < 0.001). Mean ECD was reduced insignificantly from 2,920±363 cells/mm2 preoperatively to 2,802±339 cells/mm2 postoperatively (P = 0.59). Similarly, there was no significant change in MCA or CV at six months (P = 0.76 and 0.52, respectively).
Conclusion: Application of MMC 0.02% for 40 seconds during PRK in patients with moderate myopia did not significantly affect central corneal endothelial cell density and morphology after a 6 month follow up period
Femtosecond Laser-assisted Allogenic Additive Stromal Keratoplasty with or without Excimer Laser Donor Keratomileusis for Management of Keratoconus
We describe a modified allogenic intrastromal lenticule implantation technique for management of keratoconus (KCN). Patients with advanced KCN already scheduled for corneal transplantation were enrolled. An allogenic corneal lenticule was implanted inside a stromal pocket created by femtosecond laser. In three cases, the estimated refractive error of the recipient eyes was corrected on the donor lenticules using an Excimer laser. All operated eyes underwent corneal crosslinking at the time of surgery. This method was named “Femtosecond Laser-assisted Allogenic Stromal Keratoplasty Without and With Excimer Laser-assisted Donor Keratomileusis”; briefly called FASK and FASK Plus EDK, respectively. Two out of five patients were satisfied with the results. There was a decrease in the average simulated keratometric values as well as myopia when FASK Plus EDK was performed. Increased corneal thickness was achieved in all cases. Graft edema gradually decreased over weeks but interface wrinkling and lenticule folds in the visual axis remained as a problem during follow-up period. No other complications were encountered
Immunologic Corneal Graft Rejection after Administration of Topical Latanoprost: a Report of Two Patients
Purpose: To report endothelial corneal graft rejection after administration of topical latanoprost eye drops.
Case Report: Two eyes of two patients with a history of multiple intraocular procedures prior to penetrating keratoplasty developed endothelial graft rejection one month after administration of topical latanoprost. Cystoid macular edema developed simultaneously in one patient.
Conclusion: Latanoprost may trigger endothelial graft rejection in susceptible eyes
Secondary Piggyback Intraocular Lens for Management of Residual Ametropia after Cataract Surgery
Purpose: To investigate the indications, clinical outcomes, and complications of secondary piggyback intraocular lens (IOL) implantation for correcting residual refractive error after cataract surgery.
Methods: In this prospective interventional case series, patients who had residual refractive error after cataract surgery and were candidates for secondary piggyback IOL implantation between June 2015 and September 2018 were included. All eyes underwent secondary IOL implantation with the piggyback technique in the ciliary sulcus. The types of IOLs included Sulcoflex and three-piece foldable acrylic lenses. Patients were followed-up for at least one year.
Results: Eleven patients were included. Seven patients had hyperopic ametropia, and four patients had residual myopia after cataract surgery. The preoperative mean of absolute residual refractive error was 7.20 ± 7.92, which reached 0.42 ± 1.26 postoperatively (P < 0.001). The postoperative spherical equivalent was within ±1 diopter of target refraction in all patients. The average preoperative uncorrected distance visual acuity was 1.13 ± 0.35 LogMAR, which significantly improved to 0.41 ± 0.24 LogMAR postoperatively (P = 0.008). There were no intraor postoperative complications during the 22.4 ± 9.5 months of follow-up.
Conclusion: Secondary piggyback IOL implantation is an effective and safe technique for the correction of residual ametropia following cataract surgery. Three-piece IOLs can be safely placed as secondary piggyback IOLs in situations where specifically designed IOLs are not available
Aspheric versus Spherical Posterior Chamber Intraocular Lenses
Purpose: To compare spherical aberration and contrast sensitivity function following implantation of four different foldable posterior chamber intraocular lenses (IOLs), namely Sensar, Akreos AO, Tecnis, and AcrySof IQ.
Methods: In this randomized clinical trial, 68 eyes of 68 patients with senile cataracts underwent phacoemulsification and IOL implantation with Sensar (n=17), Akreos AO (n=17), Tecnis (n=17), or AcrySof IQ (n=17). Uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA), spherical aberration and contrast sensitivity function (CSF) were compared among the study groups, 3 months after surgery.
Results: There was no significant difference between the study groups in terms of age (P = 0.21). Mean postoperative BSCVA with Sensar, Akreos AO, Tecnis, and AcrySof IQ was 0.15±0.10, 0.12±0.9, 0.08±0.08, and 0.08±0.07 logMAR, respectively (P=0.08). Spherical aberration measured over a 4 mm pupil was significantly higher with Sensar and Akreos AO than the two other IOLs. The difference between Tecnis and AcrySof IQ was significantly in favor of the former IOL. Over a 6 mm pupil, spherical aberrations were comparable with Sensar and Akreos AO, furthermore spherical aberration was also comparable among eyes implanted with Akreos AO, AcrySof IQ, and Tecnis. Sensar yielded significantly inferior results as compared to Acrysof IQ and Tecnis. CSF with Sensar was inferior to the three aspheric IOLs at the majority of spatial frequencies. Tecnis yielded significantly better mesopic CSF at 1.5 and 3 cycles per degree spatial frequencies.
Conclusion: Tecnis and AcrySof IQ provided significantly better visual function as compared to Sensar and Akreos AO, especially with smaller pupil size. However, this difference diminished with increasing pupil size
A Modified Formula for Intraocular Lens Power Calculation Based on Aphakic Refraction in a Pediatric Population
Purpose: To investigate and optimize the accuracy of aphakic refraction (AR) techniques for secondary intraocular lens (IOL) power calculation in aphakic children.Methods: Thirty-three aphakic eyes of 18 patients who were candidates for secondary IOL implantation were enrolled in the present study. Axial length (AL) measured by optical biometry was used in the biometric formula (SRK-T, Holladay II, and Hoffer-Q). AR and spherical equivalent (SE) were used in two AR-based formulas (Ianchulev, Leccissotti). True power was calculated based on postoperative SE at three months’ follow-up. Results: Regarding the postoperative SE, 13 (40%) eyes were within ±1.00 diopters (D) and 22 (66%) were within ±2.00 D. Median absolute error (MedAE) was predicted to be 4.4 and 7.3 D with the use of Ianchulev and Leccissotti formulas, respectively. The corresponding value was 0.8 D with the biometric formula. All eyes were deemed to have myopic refraction when using the AR-based formulas except one eye with the Ianchulev formula. The coefficient of our modified formula was 1.7 instead of 2.01 in the Ianchulev formula. MedAE with the use of new formulae was 0.5 D and was comparable with the true IOL power (P = 0.22). Conclusion: Both Ianchulev and Leccissotti formulas resulted in a significant myopic surprise in aphakic children aged between 4.5 and 14 years. The modified formula proved to determine a more accurate SE that is comparable with biometric formulas
Aloe Vera Gel-derived Eye Drops for Alkaline Corneal Injury in a Rabbit Model
Purpose: To investigate the efficacy of topical Aloe Vera (AV) gel-derived eye drops on the healing of alkali-burned corneas in rabbits.
Methods: Thirty alkali-burned corneas of 30 New Zealand albino rabbits were categorized into three groups: AV treatment group that received AV gel-derived eye drops four times a day; medical therapy (MT) group that received conventional treatment; and the control group. Clinical examinations together with digital imaging of the corneas were performed on days 0, 1, 2, 4, and 7. The area of the corneal epithelial defect (CED) was measured using ImageJ software. After euthanizing the rabbits, the affected corneas were evaluated by histopathological examination. Finally, the clinical and histopathological results were compared among the groups.
Results: The CED area on days 2 and 7 was significantly less in the AV group than that in the MT group (P = 0.007 and P = 0.024, respectively) and the control group (P = 0.003 and P = 0.037, respectively). None of the cases developed hypersensitivity reactions, limbal ischemia, descemetocele, or corneal perforation during the study period. Based on histopathology, the AV group had notably less keratocyte loss than the MT group (P = 0.001) and the control group (P = 0.022). The inflammatory response after the alkali burn was higher in the AV group than that in the controls (P = 0.028).
Conclusion: Short-term topical AV treatment was effective in healing alkali-burned corneas and hastened corneal re-epithelialization as compared to MT; however, AV gel-derived eye drops did not reduce the inflammatory response
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Immunologic corneal graft rejection after administration of topical latanoprost: a report of two patients.
PurposeTo report endothelial corneal graft rejection after administration of topical latanoprost eye drops.Case reportTwo eyes of two patients with a history of multiple intraocular procedures prior to penetrating keratoplasty developed endothelial graft rejection one month after administration of topical latanoprost. Cystoid macular edema developed simultaneously in one patient.ConclusionLatanoprost may trigger endothelial graft rejection in susceptible eyes
Visual Outcomes of Two Aspheric PCIOLs: Tecnis Z9000 versus Akreos AO
<!--[if gte mso 9]><xml> Normal 0 false false false MicrosoftInternetExplorer4 </xml><![endif]--><!--[if gte mso 9]><xml> </xml><![endif]--> <!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> <p>PURPOSE: To compare spherical aberration and contrast sensitivity with two different types of aspheric posterior chamber intraocular lenses (PCIOLs): Tecnis Z9000 versus Akreos AO. METHODS: Thirty-four eyes of 34 patients undergoing phacoemulsification for senile cataracts were randomly assigned to implantation of Tecnis Z9000 or Akreos AO PCIOLs. Outcome measures included best-corrected visual acuity (BCVA), spherical aberration (SA) with 4 and 6 mm pupil diameters and contrast sensitivity under photopic and mesopic conditions at spatial frequencies of 1, 2, 5, 10 and 20 cycles per degree (cpd) three months postoperatively. RESULTS: Mean BCVA was 0.08±0.08 logMAR in the Tecnis Z9000 group and 0.11±0.09 logMAR in the Akreos AO group (P=0.33). SA was less with Tecnis than Akreos AO with 4 and 6 mm pupil diameter (0.14±0.10 µm vs 0.28±0.09 µm, P < 0.001 and 0.30±0.18 µm vs 0.33±0.08 µm, P=0.4, respectively). Contrast sensitivity was significantly higher in the Tecnis Z9000 group at 1, 2, 5 and 10 cpd under photopic and at 1, 2 and 10 cpd under mesopic conditions. CONCLUSION: Tecnis Z9000 IOL seems to entail better visual outcomes in terms of spherical aberration and contrast sensitivity as compared to Akreos AO.</p> <!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning /> <w:ValidateAgainstSchemas /> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables /> <w:SnapToGridInCell /> <w:WrapTextWithPunct /> <w:UseAsianBreakRules /> <w:DontGrowAutofit /> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--> <!-- /* Font Definitions */ @font-face {font-family:Palatino; mso-font-alt:"Book Antiqua"; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:7 0 0 0 147 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> <!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]-->