7 research outputs found
Keratoconus in a patient with Alport syndrome: A case report
BACKGROUND Known ocular manifestations of Alport syndrome include features such as anterior lenticonus and fleck retinopathy. Reports of keratoconus in such patients are limited. We report tomographic findings consistent with keratoconus in a patient with Alport syndrome.
CASE SUMMARY A 52-year-old female was referred to our ophthalmology clinic with decreased vision and increased tearing. She was diagnosed with stage III Alport syndrome two years prior. Upon examination she was found to have average keratometries of 48 D bilaterally with tomographic evidence of keratoconus.
CONCLUSION Although a rare presentation, concurrent Alport syndrome and keratoconus should be considered when reviewing the ocular health of Alport syndrome patients and appropriate management steps should be taken upon the diagnosis
Pentacam® Corneal Tomography for Screening of Refractive Surgery Candidates: A Review of the Literature, Part I
Corneal tomography and Scheimpflug imaging are frequently used to analyze the corneal surface, especially in the field of cataract and refractive surgery. The Pentacam system is one of the most commonly used commercially available systems for this purpose. Through a rotating Scheimpflug camera, the system is capable of creating a three-dimensional map of the cornea. These advances in tomography have simultaneously enhanced the ability of clinicians to screen surgical candidates and detect subtle corneal changes in diseases such as keratoconus. However, there remains a need to enhance diagnosis in order to recognize mild and early forms of corneal ectasia. As iatrogenic ectasia and keratoconus are dreaded complications of refractive surgery, it is imperative to screen patients appropriately prior to surgery. The Pentacam is one of many systems utilized in the screening process, but the literature has not identified specific protocol nor parameters that are capable of carrying out this process appropriately. Post-operative keratoconus continues to occur despite the advances in technology seen in corneal imaging. Therefore, clear indices for screening are required in order to diagnose early forms of keratoconus and other corneal diseases that may exclude the seemingly asymptomatic patient from undergoing refractive surgery. This article aims to summarize the indices available on the Pentacam system and to identify the most accurate parameters for screening of the refractive surgery candidate
Visual Prognosis after Explantation of Small-Aperture Corneal Inlays in Presbyopic Eyes: A Case Series
The purpose of this study was to report visual prognosis after explantation of a small-aperture corneal inlay used for the treatment of presbyopia. This is a retrospective case series conducted at a single site in Draper, Utah, USA (Hoopes Vision). Medical records of 176 patients who had received a small-aperture corneal inlay (KAMRA™, AcuFocus Inc., Irvine, CA, USA) were reviewed. Patients who had undergone explantation of the device were identified. Uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), corrected distance visual acuity (CDVA), and manifest refraction spherical equivalent (MRSE) were measured pre-implantation, post-implantation, pre-explantation, and post-explantation of the inlay. Ten eyes from ten patients were included in this study. The explantation rate was 5.7% over 31 months, with blurry vision as the most common complaint. After explantation, six patients achieved pre-implantation UDVA, and six achieved pre-implantation UNVA. Eight of nine patients who underwent final manifest refraction achieved pre-operative CDVA. All patients had residual donut-shaped corneal haze in the stroma at the previous position of the inlay. All patients experienced improvement in haze with 20% experiencing complete resolution. The degree of stromal haze was not related to the duration of implantation. Of the subset of patients who underwent explantation of their small-aperture corneal inlay, there was persistent loss of CDVA in 10%. The majority of patients experienced some level of residual stromal haze, which may contribute to deficits in UNVA and CDVA in few patients. A hyperopic shift induced by the corneal inlay may contribute to the blurry vision these patients experienced; there was a reduction of this shift post-explantation. While this device is removable, patients should expect some post-explantation changes such as residual haze with a small subset experiencing persistent deficits in CDVA
Astigmatic correction with implantation of a light adjustable vs monofocal lens: a single site analysis of a randomized controlled trial
AIM To evaluate the light adjustable lens (LAL) vs a standard monofocal lens in achieving target astigmatic refraction and improving postoperative uncorrected distance visual acuity (UDVA). METHODS This randomized controlled clinical trial included 40 patients with pre-existing astigmatism and visually significant cataract. Twenty-eight patients received the LAL and 12 control patients received a monofocal intraocular lens (IOL) after cataract extraction at a single institution. The patients with the LAL underwent adjustment by ultraviolet (UV) light postoperatively plus subsequent lock-in procedures and all patients returned to clinic for follow up of study parameters at 6, 9, and 12mo. Manifest refraction, distance visual acuity, and adverse events were recorded at each visit. RESULTS The mean cylinder before adjustment in eyes with the LAL was -0.89±0.58 D (-2.00 to 0.00 D) and -0.34±0.34 D (-1.25 to 0.00 D) after lock-in (P=1.68x10−8). The mean cylinder in patients with the monofocal lens was -1.00±0.32 D (-1.50 to -0.50 D) at 17-21d postoperatively, which was statistically different from the LAL cylinder post lock-in (P=1.43x10−6). UDVA in the LAL group was 20/20 or better in 79% of patients post lock-in with good stability over 12mo compared with 33% of the control patients with UDVA of 20/20 or better. CONCLUSION These results demonstrate that the LAL is more effective in achieving target refractions and improving postoperative UDVA in patients with pre-existing corneal astigmatism than a standard monofocal lens
Effects of a changing environment on the aboveground and belowground systems of yellow birch (Betula alleghaniensis Britton) and sugar maple (Acer saccharum Marsh)
The environment is constantly changing. A change in one environmental factor will cause changes in many other environmental factors either simultaneously or sequentially. For example, an increase in available light, due to canopy opening by natural disturbances, may increase soil temperature and moisture on the forest floor. Therefore, a changing environment has interactive effects on the trees. In forest ecological studies, the effects of some single environmental factors on tree growth are known, but there is a lack of knowledge of the interactions between multiple factors. An understanding of the interactive effects of abiotic and biotic factors on trees is critical for an understanding of the growth and survival of understory saplings in a complex changing environment. The aboveground and belowground systems of a tree respond differently to the same abiotic factors, such as light, since these systems grow in differing environments. This thesis will focus on the interactive effects among available light (including canopy gap size), tree size, artificial shading, liming and plant competition on the aboveground and belowground systems of yellow birch and sugar maple growing in the understory in two field experiments and the interactive effects of light, elevated CO 2 and mycorrhizae on seedlings of both species in a phytotron experiment. The three investigations will address several key questions concerning the growth of these two species and the development of their mycorrhizae in a complex changing environment in the present and future
Cataract Surgery in Patients with a Previous History of KAMRA Inlay Implantation: A Case Series
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