Astigmatism

Unequal curvature of the refractive surfaces of the eye. Thus a point source of light cannot be brought to a point focus on the retina but is spread over a more or less diffuse area. This results from the radius of curvature in one plane being longer or shorter than the radius at right angles to it. (Dorland, 27th ed)

Networked: 3054 relevant articles (241 outcomes, 296 trials/studies)

Relationship Network

Disease Context: Research Results

Related Diseases

1.	Myopia
2.	Cataract (Cataracts)
3.	Hyperopia (Hypermetropia)
4.	Keratoconus
5.	Wounds and Injuries (Trauma)

Experts

1.	Alió, Jorge L: 22 articles (04/2015 - 10/2002)
2.	Shimizu, Kimiya: 21 articles (11/2015 - 02/2008)
3.	Kamiya, Kazutaka: 21 articles (11/2015 - 02/2008)
4.	Langenbucher, Achim: 21 articles (03/2015 - 01/2002)
5.	Langenbucher, A: 20 articles (09/2013 - 08/2000)
6.	Seitz, Berthold: 20 articles (11/2007 - 01/2002)
7.	Seitz, B: 19 articles (09/2013 - 08/2000)
8.	Montés-Micó, Robert: 16 articles (04/2015 - 07/2004)
9.	Nuijts, Rudy M M A: 14 articles (12/2014 - 01/2004)
10.	Dick, H Burkhard: 14 articles (10/2012 - 03/2002)

Drugs and Biologics

Drugs and Important Biological Agents (IBA) related to Astigmatism:

1.	Retinaldehyde (Retinal)IBA 07/01/2015 - "The study demonstrates that OCT parameters such as retinal nerve fibre layer, central sub-field thickness and mean signal strength are affected by irregular astigmatism. " 08/01/2015 - "The shifts are consistent with a bias towards vertical and horizontal retinal blur in WTR and ATR astigmats, respectively, indicating adaptation to native astigmatism. " 04/01/2014 - "However, an analysis of the effects of astigmatism on the retinal image suggests that this "logical" refutation of the El Greco fallacy promulgates another fallacy--that of astigmatism as a source of a constant perceptual error." 02/01/2012 - "To evaluate the effect of astigmatism change on measurement of retinal nerve fiber layer (RNFL) and macular thickness by Cirrus HD spectral-domain optical coherence tomography (Cirrus HD OCT; Carl Zeiss Meditec, Dublin, CA, USA). " 01/01/2012 - "The influence of corneal astigmatism on retinal nerve fiber layer thickness and optic nerve head parameter measurements by spectral-domain optical coherence tomography."
2.	Propranolol (Inderal)FDA LinkGeneric 04/01/2014 - "Astigmatism was reduced in both propranolol and steroid studies (P < 0.0001, P < 0.0001), but a significant reduction in spherical power was only demonstrated in propranolol studies (P = 0.005). " 12/01/2011 - "Early diagnosis of infantile periocular capillary haemangioma and prompt treatment with propranolol lead to a significant reduction in the involved ocular area, in astigmatism, and prevent ocular/facial disfiguration/deformation, without rebound. " 08/01/2010 - "Our main outcome measures were colour and size of infantile haemangioma before and after treatment, the change in astigmatism of our patients and the incidence of complications from propranolol. " 07/01/2011 - "Oral propranolol for treatment of infantile hemangiomas was effective in all patients, with 33% reduction in astigmatism and 39% reduction in surface area. " 01/01/2011 - "Infants can benefit from a rapid, meaningful reduction in periocular capillary hemangioma-induced astigmatism following oral propranolol treatment. "
3.	chironIBA 11/01/1999 - "LASIK with the Chiron-Technolas Keracor 116 excimer laser was effective for correction of myopic astigmatism, with good stability after 3 months. " 07/01/2004 - "This prospective study included 28 eyes of 21 patients with mixed astigmatism who had bitoric LASIK using the Hansatome microkeratome (Bausch & Lomb Surgical) and the Chiron Technolas 217 excimer laser (Bausch & Lomb Surgical). " 11/01/1999 - "Two hundred sixty-six eyes of 150 patients were subjected to PRK with the Chiron Technolas Keracor 117C for the correction of myopia and astigmatism. " 03/01/2001 - "Patients with myopia and myopic astigmatism (N=2,972; refraction from -1.25 to -15.50 D) were treated with the Nidek EC-5000 excimer laser, using the Chiron Vision HT-230 Hansatome microkeratome. " 11/01/2000 - "LASIK was performed on 19 patients (19 eyes) with high astigmatism after penetrating keratoplasty, using the Chiron Automated Corneal Shaper and the Chiron-Technolas Keracor 116 excimer laser. "
4.	Nylons (Nylon)IBA 12/01/1979 - "With interrupted suturing techniques, the axis of the correcting cylinder was more often against the rule while continuous closures with monofilament nylon more frequently produced with the rule astigmatism." 05/01/1977 - "It ranged from 1 to 10-5 dioptres, the mean value 4-09 dioptres with a standard deviation of +/-2-5. Removing the nylon suture eliminated this astigmatism and within a few weeks the corneal astigmatism correction in 48% of eyes returned to the preoperative level. " 12/15/1992 - "The use of a less biodegradable suture enables the maintenance of low levels of astigmatism for longer periods when compared with a previous study that used 11-0 nylon suture." 04/01/2009 - "Interrupted 10-0 nylon compression sutures were added in the opposite meridian to overcorrect astigmatism. " 10/01/1997 - "Patients with preoperative with-the-rule astigmatism might benefit from 10-0 nylon sutures and those with preoperative against-the-rule astigmatism, from 9-0 nylon sutures."
5.	Polymethyl Methacrylate (Sol)IBA 02/01/2011 - "The changes in ATR astigmatism according to the IOL type were more effective in single-piece acrylic IOLs than in the three-piece polymethylmethacrylate haptic IOL group. " 12/01/2010 - "Evolution of postoperative astigmatism after large incision PMMA lens implantation in children." 07/01/2007 - "Increased astigmatism is more frequently seen in the PMMA group. " 07/01/2007 - "Postoperative final induced astigmatism was 0.5+/-0.5 D (SD) in the acrylic group and 1.11+/-0.65 D (SD) in the PMMA group (p=0.0001) (independent samples t-test). " 09/01/2000 - "The 4. 1-mm corneal incision using PMMA lens implants can be used on the steep meridian to reduce preoperative astigmatism."
6.	Mitomycin (Mitomycin-C)FDA LinkGeneric 02/01/2008 - "The mitomycin C group produced the most induced astigmatism and the limbal-conjunctival autograft group produced the least induced astigmatism. " 04/01/2014 - "To examine the refractive and visual outcome of laser-assisted subepithelial keratomileusis (LASEK) with mitomycin C(MMC) in eyes with myopic astigmatism ≥2.00 diopters (D). " 04/01/2014 - "Laser-assisted subepithelial keratomileusis with mitomycin C for myopic astigmatism ≥2.00 diopters using a Zeiss MEL 80 Excimer." 04/01/2001 - "To evaluate the short-term effect of trabeculectomy with adjunctive mitomycin-C (MMC) on corneal astigmatism and axial length. " 04/01/2001 - "Short-term effect of mitomycin-C augmented trabeculectomy on axial length and corneal astigmatism."
7.	A-factor (Streptomyces)IBA 01/01/2016 - "To evaluate the corneal horizontal diameter [white-to-white (WTW) distance] as a factor influencing surgically induced astigmatism (SIA) and postoperative astigmatism. " 08/01/2007 - "Astigmatism increased on average by a factor of 2.6 and 3rd and higher order aberrations by a factor of 4.3 after PRK. " 01/01/2001 - "A systematic error of undercorrection of astigmatism is prevalent in the treatment of these 100 patients by a factor of between 15% and 30%, depending on whether refractive or corneal values are examined. " 09/15/2010 - "For example, for a 6mm pupil, in the presence of 0.5D of astigmatism, a value of coma of 0.23mum produced (for best focus) a peak improvement in Strehl Ratio by a factor of 1.7, over having 0.5D of astigmatism alone. " 09/15/2010 - "We found that the combination of coma with astigmatism improved decimal VA by a factor of 1.28 (28%) and 1.47 (47%) in both subjects, over VA with astigmatism alone when all the rest of aberrations were corrected. "
8.	Ophthalmic Solutions (Eye Drops)IBA 03/01/2000 - "The SRI, SAI and astigmatism were significantly reduced, the PVA was improved and the irregular topographic pattern was markedly decreased in the dry eyes after the usage of artificial tears. " 05/01/1999 - "After the instillation of artificial tears, the SRI, SAI, and mean astigmatism all decreased significantly (P<0.001 for SRI, P<0.002 for SAI, P = 0.04 for astigmatism) and the PVA improved (P<0.001) in dry eyes. " 03/01/2002 - "In corneal topography performed after the instillation of artificial tears SAI, SRI, PVA and mean astigmatism values were 0.71 +/- 0.82, 0.43 +/- 0.36, 20/25.92 +/- 20/5.55 and 1.08 +/- 1.18, respectively. " 03/01/2002 - "The surface regularity index (SRI), surface asymmetry index (SAI), potential visual acuity (PVA) and mean astigmatism were compared in dry eyes before and after the instillation of artificial tears. " 06/01/1989 - "No perforation was done, several patients have had an anterior chamber reaction treated with corticoids and antibiotics eye drops and we didn't notice any noteworthy complication except an hypercorrected astigmatism secondary to a transitory hypertonia and a case of +1.5 of hypermetropia. "
9.	CollagenIBA 06/01/2014 - "Patterned corneal collagen crosslinking for astigmatism: computational modeling study." 06/01/2014 - "In silico simulations based on patient-specific geometries suggest that clinically significant reductions in astigmatism are possible with patterned collagen crosslinking. " 05/01/2014 - "To investigate preoperative and postoperative anterior and posterior keratometry and simulated corneal astigmatism in keratoconic eyes treated with collagen cross-linking combined with anterior surface normalization by partial topography-guided excimer ablation (the Athens Protocol). " 02/01/2012 - "Implantation of the collagen copolymer toric pIOL was a safe, effective surgical procedure for the correction of myopic astigmatism in eyes with mild PMD." 10/01/1999 - "The amount of astigmatism was lower in patients who received AK incisions with collagen implants (P < .28). "
10.	ROPIBA 01/01/2015 - "The incidence of astigmatism was significantly different between ROP (37.29%, 22/59) and controls (17.86%, 15/84). " 09/01/2013 - "In the severe ROP group, with-the-rule astigmatism increased significantly with age. " 12/01/2011 - "More eyes with type 2 than type 1 ROP had astigmatism by 6 years. " 12/01/2011 - "However, there was a trend toward higher prevalence of astigmatism and high astigmatism in eyes with ROP residua. " 12/01/2011 - "Presence of astigmatism was not influenced by timing of treatment, zone of acute-phase ROP, or presence of plus disease. "

Therapies and Procedures

1.	Laser In Situ Keratomileusis (LASIK) 01/01/2013 - "This study provides further evidence of the safety, efficacy, and predictability of laser in situ keratomileusis outcomes using an optical ray tracing algorithm to treat moderate to high myopic astigmatism and shows that good results are sustained through 1 year." 12/01/2011 - "The higher indices of success in the high ORA and high LA groups suggest a lower efficacy of LASIK in treating astigmatism primarily located intraocularly. " 12/01/2011 - "In eyes with high myopic astigmatism and suboptimal preoperative BSCVA, laser in situ keratomileusis may result in a significant improvement in BSCVA." 10/01/2010 - "The efficacy of astigmatic correction by LASIK was significantly higher in eyes in which the preoperative refractive astigmatism was located mainly on the anterior corneal surface than in eyes in which it was mainly located posterior to the anterior corneal surface." 02/01/2007 - "To evaluate the efficacy of transverse keratotomy followed by LASIK for patients with high amounts of naturally occurring astigmatism. "
2.	Excimer Lasers 01/01/2012 - "Both methods of PRK, using the NIDEK EC-5000 and VISX excimer laser systems, are effective for correcting moderate-to-high astigmatism. " 11/01/2004 - "The number of reoperations and residual refractive defects were significantly better in Group 2. The 2-step technique improved the accuracy of excimer laser correction of post-PKP astigmatism." 04/01/2000 - "Paracentral ablations with the excimer laser appear to be a safe and effective method to correct higher grades of corneal astigmatism." 04/01/2002 - "Excimer laser PARK was an effective treatment for compound myopic astigmatism, but predictability decreased and complications increased as the attempted astigmatic correction increased." 01/01/1997 - "The mask in-the-rail excimer laser delivery system appears to be effective and predictable in the correction of compound myopic astigmatism. "
3.	Sutures (Suture) 09/01/1994 - "RIs and compression sutures are very useful in reducing postkeratoplasty astigmatism if correction of extremely high cylinder (> 10 D) is not intended. " 06/01/1994 - "Intraoperative suture adjustment significantly decreased postkeratoplasty topographic (P = 0.0001) and refractive (P = 0.0001) astigmatism and improved best spectacle-corrected visual acuity (P = 0.0019) during the first postoperative month. " 05/01/2005 - "All measures of astigmatism and SRI and SAI values showed postoperative improvement with sutures in place; however, astigmatism increased significantly after second suture removal. " 12/01/1997 - "The mean topographic astigmatism, surface regularity index, and corrected visual acuity were improved significantly by suture removal in eyes that had localized flattening but not in eyes without this finding. " 03/15/1987 - "Overall, there was a significantly greater decrease in astigmatism (67% vs 47%, P = .009) when augmentation sutures were placed 90 degrees away from the relaxing incisions. "
4.	Lasers (Laser) 07/01/2014 - "Laser corneal ablation continues to be highly effective for correcting low-to-moderate levels of astigmatism and may be the best option for the younger patient population. " 07/01/2001 - "PRK with the Meditec MEL 60 laser produced the best results in eyes with compound myopic astigmatism (Group 1). " 12/01/2013 - "Femtosecond laser-enabled intrastromal astigmatic keratotomy was performed, resulting in a significant reduction in corneal astigmatism. " 06/01/2013 - "Significant improvement in CDVA and refractive and topographic cylinders indicated a good effect of femtosecond laser-assisted intrastromal relaxing incisions in reducing astigmatism. " 10/01/2004 - "The laser's combination of a small spot, a fast pulse rate, and ultrafast tracking/scanning resulted in good results in 3 patients with difficult irregular astigmatism."
5.	Penetrating Keratoplasty 06/01/2010 - "IntraLase-enabled astigmatic keratotomy is an effective treatment for high astigmatism after penetrating keratoplasty with an encouraging refractive predictability. " 11/01/2009 - "To evaluate the safety and efficacy of intracorneal ring segments (ICRS) for high astigmatism after penetrating keratoplasty (PKP). " 06/01/2009 - "The problems of the current gold standard treatment, conventional penetrating keratoplasty (PKP), have yet to be fully solved, namely accelerated postoperative endothelial cell loss, endothelial immune reactions and the induction of astigmatism, which depends among other things on the trephination technique used. " 07/01/1999 - "Following penetrating keratoplasty in the left eye, uncorrected visual acuity deteriorated from 20/80 to 20/120 due to irregular astigmatism; the eye was not amenable to improvement with spectacle correction, and the patient declined contact lens therapy. " 05/01/2013 - "The purpose of this study was to assess the differences in postoperative visual acuity, astigmatism, and selected postoperative complications between a guided trephine system (GTS) and motor trephine after penetrating keratoplasty. "