Improvements in Optical Characteristics after Excision of an Overhanging Bleb Developed following Trabeculectomy

Introduction. To examine the corneal total higher-order aberrations before and after the excision of an overhanging bleb that developed following trabeculectomy. Case Presentation. Two patients who developed overhanging blebs following trabeculectomy with a fornix-based conjunctival flap using mitomycin C (MMC) were assessed. We measured the corneal total higher-order aberrations for a 4 mm pupil diameter using the TOPCON KR-1W wavefront analyzer and the visual acuity before and after bleb excision. The corneal total higher-order aberration (HOA) improved from 0.50 μm to 0.38 μm in case 1 and from 0.59 μm to 0.49 μm in case 2 after bleb excision. The intraocular pressure was identical before and after bleb excision in both cases. No significant changes in the best-corrected visual acuity (BCVA) were noted in case 1; however, BCVA was improved from 20/25 to 20/20 in case 2. Both cases showed improvements in the symptoms of dysesthesia. Conclusion. Excision of the overhanging bleb developed following trabeculectomy may have beneficial possibility in some cases where corneal total HOA is affected and reduces the symptoms of dysesthesia.

Usefulness of Itrace in Diagnosing Unclear Cases of the Deterioration in Visual Acuity. Congenital Lens Dysfunction as a New Disease Entity. Preliminary Reports.

The article analyses 22 cases of severe impairment of vision to far distances for no apparent reason. Visual impairment was observed regardless of patients’ age and type of eye defect diagnosed, with the majority of people suffering from myopia and accompanying astigmatism. The exclusion of causes related to the cornea and retina, optic nerve damage and the lack of visible pathologies of the lens in the physical examination did not allow for the determination of the cause of deterioration in visual acuity to far distances despite good vision to near distances. The results of examinations using iTrace indicated the lens as the cause of visual impairment despite the apparent lack of opacity and other pathologies within it. The results of examinations in the field of Higher Order Aberration, Opacity Map, Modulation Transfer Function™ and their graphical presentation using the Dysfunctional Lens Index™ module were analysed. Low values of visual contrast sensitivity and high values of higher order aberrations for the internal optics were observed, with the correct values for the cornea. The more pathological the results of the visual contrast sensitivity and higher order aberration, the lower the values of visual acuity to far distances. In most cases removing the dysfunctional lens and replacing it with an artificial lens allowed for a significant improvement in vision to far distances while maintaining proper vision to near distances. The procedure was performed on patients over 18 years of age. The medical history in the study group may indicate a congenital nature of the abnormal structure of the lens. Thus, it is necessary to consider verification of the diagnosis made in some patients, pointing to a new disease entity, i.e. congenital lens dysfunction.

Wavefront Guided LASIK with a High-Resolution Aberrometer Induces Less Higher-Order Aberration than Early Custom LASIK

Background: The use of 'high-resolution' aberrometer wavefront-guided LASIK system offers the theretical advantages. To date there have been a few papers that proved the clinical superiority of the 'high-resolution' wavefront-guided LASIK. The purpose of this present study was to To evaluate the surgical outcomes of wavefront-guided laser in-situ keratomileusis (LASIK) via a high-resolution aberrometer to treat myopic refractive error. Methods: This study involved 51 eyes of 26 consecutive patients (high-resolution group) who underwent wavefront-guided LASIK from 2012 to 2015 via high-resolution aberrometer and excimer laser surgical unit at the Baptist Eye Institute, Kyoto, Japan and who were followed for 6-months postoperative. Postoperative outcomes were compared with our historical control data (early custom group) from 2002 to 2007 (51 eyes of 26 patients) treated with the same correction amount. Measured parameters included Visual acuity (VA), spherical equivalent refractive error (SER), higher-order aberration (HOA), and contrast sensitivity (CS).Results: In the high-resolution group and the early custom group, the mean SER was -5.86±2.57 diopters (D) and -5.99±2.52D, respectively, and the mean patient age was 33.8±9.2 and 34.3±6.9 years, respectively. LogCS of 18 cycles-per-degree (cpd) change was more satisfactory in the high-resolution group than in the early custom group. Postoperative spherical aberration change in the high-resolution group was significantly lower than that in the control group (P<0.05). Decrease of induced spherical aberration produced a positive effect on the post LogCS of 18 cpd.Discussion: The latest wavefront-guided LASIK induced less HOAs than early custom LASIK, and although similar VA and refractive precision findings were observed, the high-resolution group tended to acquire better visual function post surgery.