Astigmatism Research Today is a free monthly online journal that collates and summarizes the latest research about Astigmatism, including details on cornea, retina, treatment, types, signs, tests.

Ocular features of CHARGE syndrome.

McMain K, Robitaille J, Smith I, Johnson J, Wood E, Tremblay F, Blake K

Clinical Vision Science, Dalhousie University, Halifax, Nova Scotia, Canada.

PURPOSE: We sought to detail the presence and severity of ocular and cranial nerve abnormalities found in individuals with CHARGE syndrome in a distinct geographic area. METHODS: Nine individuals with CHARGE syndrome from Maritime Canada identified from a Canadian database were prospectively examined. Structural and sensorial defects associated with functional visual deficits were defined with ophthalmic and neurological evaluation. RESULTS: Consistent with current diagnostic criteria and the literature, colobomas were the major ophthalmic manifestation. These were typically bilateral chorioretinal colobomas involving the optic nerve. All subjects had bilateral severe sensorineural deafness (cranial nerve VIII), and 8 of 9 (89%) had facial nerve (cranial nerve VII) involvement (7 of 9 had unilateral involvement; 1 of 9 had bilateral involvement). Unique to this group of participants were the findings of anisometropia in 8 of the 9 (89%) patients, severe myopic astigmatism in 13 of the 18 eyes (72%), and limited elevation in adduction in 3 of 9 (33%) participants. Associated findings were strabismus, cataracts, microcornea, keratopathy, staphyloma, reduced stereopsis, superior visual field defects, and reduced visual acuity. CONCLUSIONS: The presence of coloboma plus another CHARGE feature warrants further investigation, including genetic screening for the CHD7 gene. Early recognition and management of sensory problems (visual, auditory, and vestibular) are crucial to ensure best psychomotor and cognitive development.

Published 5 May 2008 in J AAPOS.
Full-text of this article is available online (may require subscription).

Articles on Astigmatism published 2 May 2008:

Five-year outcome of LASIK for myopia.   Ophthalmology, 115(5): 839-844.e2.

PURPOSE: To investigate the efficacy and safety of LASIK over a 5-year postoperative period. DESIGN: Observational case series. PARTICIPANTS: We examined 779 eyes in 402 patients with myopia or myopic astigmatism who underwent LASIK to correct their refractive errors and received regular postoperative assessments for 5 years. METHODS: Postoperative examinations were performed 1 day; 1 week; 1, 3, and 6 months; and 1, 2, 3, 4, and 5 years after LASIK surgery. MAIN OUTCOME MEASURES: We evaluated ... [Abstract] [Full-text]

Articles on Astigmatism published 30 April 2008:

Evaluation of different types of lamellar keratoplasty for treatment of peripheral corneal perforation.   Graefes Arch Clin Exp Ophthalmol.

BACKGROUND: To discuss the efficacy and visual outcomes of different types of lamellar keratoplasty (LK) for the treatment of peripheral corneal perforation. METHODS: Sixty patients (67 eyes) with peripheral corneal perforation underwent semilunar LK (16 eyes), crescentic LK (12 eyes), biconvex LK (13 eyes), annular LK (11 eyes) and total LK (15 eyes) respectively. The applied type of LK for each involved eye was decided by different sizes and shapes of corneal ulceration and perforation. ... [Abstract] [Full-text]

Articles on Astigmatism published 28 April 2008:

Comparison of Posterior Lamellar Keratoplasty Techniques to Penetrating Keratoplasty.   Ophthalmology.

PURPOSE: To describe the visual outcomes and intraoperative and postoperative complications after penetrating keratoplasty (PK), deep lamellar endothelial keratoplasty (DLEK), Descemet stripping endothelial keratoplasty (DSEK), and Descemet stripping automated endothelial keratoplasty (DSAEK) and to compare the results with those of previously reported series. DESIGN: Prospective, comparative, nonrandomized study. PARTICIPANTS: One hundred seventy-seven eyes of 161 consecutive patients who had ... [Abstract] [Full-text]

Short-term Results of Penetrating Keratoplasty Performed with the Femtec Femtosecond Laser.   Am J Ophthalmol.

PURPOSE: To evaluate the use of the Femtec femtosecond (fs) laser for penetrating keratoplasty (PK) in the treatment of corneal diseases. DESIGN: Prospective, nonrandomized clinical study. METHODS: Nine eyes of nine patients underwent surgery for PK. Five had pseudophakic bullous keratopathy, three had Fuchs dystrophy, and one presented in a keratoconus patient. A Femtec (20/10 PerfectVision; GmbH, Heidelberg, Germany) fs laser was used to create penetrating cuts on donor and recipient corneas. ... [Abstract] [Full-text]

Articles on Astigmatism published 25 April 2008:

Outcomes of femtosecond laser-assisted penetrating keratoplasty.   Am J Ophthalmol, 145(5): 772-774.e2.

PURPOSE: To evaluate outcomes from the use of a femtosecond laser to trephine both donor and recipient corneas during penetrating keratoplasty (PK). DESIGN: Prospective interventional case series. METHODS: Patients were recruited from the cornea clinic of the Singapore National Eye Centre. We used a 10-kHz Femtec (20/10 Perfect Vision, Heidelberg, Germany) femtosecond laser to perform trephination of the donor cornea on an artificial anterior chamber, followed by trephination of the recipient ... [Abstract] [Full-text]

Articles on Astigmatism published 24 April 2008:

Analysis of Pterygium Size and Induced Corneal Astigmatism.   Cornea, 27(4): 434-438.

PURPOSE:: To study the relationship between pterygium size (extension, width, total area) and corneal astigmatism in eyes with unilateral primary pterygium. Also to determine the critical size for surgery before the occurrence of a significant corneal astigmatism. METHODS:: This study was conducted on 77 eyes of 77 patients with unilateral primary pterygium. The extension and width were measured and the total area was calculated. Automated keratometry was used to determine corneal astigmatism. ... [Abstract] [Full-text]

Photorefractive keratectomy with mitomycin C after deep anterior lamellar keratoplasty for keratoconus.   Cornea, 27(4): 417-20.

PURPOSE:: To evaluate the safety and efficacy of photorefractive keratectomy (PRK) with intraoperative mitomycin C (MMC) after deep anterior lamellar keratoplasty (DALK) for keratoconus. METHODS:: This was a prospective, noncomparative single-surgeon study. Eyes with compound myopic astigmatism after DALK with a spherical equivalent (SE) between -3 and -10 D were treated by PRK. After ablation, MMC 0.2 mg/mL was placed on the stromal bed for 45 seconds. A 6% undercorrection was planned. ... [Abstract] [Full-text]

Articles on Astigmatism published 22 April 2008:

Optimal spherical focus in the peripheral retina.   Ophthalmic Physiol Opt, 28(3): 269-76.

It is well known that, in most eyes, astigmatism increases with the field angle. A simple reduced-eye model is used to demonstrate that, for point imagery in the peripheral retina, the combination of oblique astigmatism with elliptical entrance and exit pupils means that the retinal image with the optimal rotational symmetry is not necessarily at a focus corresponding to a 'best-sphere' correction. Equations are derived for the position of focus at which a circularly symmetric blur patch is ... [Abstract] [Full-text]

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