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At least 955 records · Page 53Linked to original sources
PubMed2000

Excimer laser photorefractive keratectomy and laser in situ keratomileusis for myopia and astigmatism.

The efficacy, predictability, safety, and short-term stability of excimer laser photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for treatment of myopia and astigmatism were determined. The preoperative myopia ranged from -1.50 to -15.75 D and the astigmatism was less than 4.0 D. Of the 147 eyes, 73 and 74 underwent PRK and LASIK, respectively. Mean preoperative spherical equivalent refraction (SE) was -3.72 +/- 1.69 D in the PRK group and -7.66 +/- 2.30 D in the LASIK group. Mean postoperative SE at the last examination (3 to 6 months) was -0.13 +/- 0.82 D and -0.38 +/- 1.19 D in the PRK and LASIK groups, respectively. Eighty six percent in the PRK group and 77 per cent in the LASIK group achieved a SE within +/- 1.0 D and the refractions were stable between 1 month and 3-6 months. Uncorrected visual acuity of 20/40 or better was noted in 91 per cent in the PRK group and 97 per cent in the LASIK group. No eyes lost one or more lines of best spectacle-corrected visual acuity in both groups. PRK and LASIK appear to be effective, safe, predictable, and short-term stable in treating myopia and astigmatism. Longer follow-up studies will help evaluate the long-term stability of the procedure and possibility of later complications.

Adult↗
PubMed2000

Contact lens fitting difficulties following refractive surgery for high myopia.

PURPOSE: To describe the clinical and optical problems encountered in contact lens fitting following refractive surgery for high myopia. METHODS: Following refractive surgery for high myopia (greater than -10.00 D) we corrected residual refractive errors with contact lenses in the four eyes of two patients. The first patient had undergone bilateral laser in situ keratomileusis (LASIK),with two subsequent LASIK retreatments in the left eye. Ten months later she was fit with rigid gas permeable (RGP) lenses in both eyes. The second patient had undergone a clear lens extraction in the right eye and radial keratotomy followed by photorefractive keratectomy(PRK) in the left eye. She was fit with toric soft lenses six years postoperatively. RESULTS: Final visual acuity obtained with contact lenses was 20/25-20/20 in all eyes. The first patient required significant minus lens power compensation. Furthermore, the RGP lens in the left eye was slightly decentered due to corneal irregularity induced by LASIK. The second patient had regular corneal surfaces and was successfully fit with daily wear toric soft lenses despite the 2.75 D of residual astigmatism in the left eye. CONCLUSIONS: Following refractive surgery for high myopia a proportion of patients will remain undercorrected. In these patients the alterations in corneal architecture that ensue make contact lens fitting more challenging. Patients with regular astigmatism may be fitted successfully with toric soft lenses. Patients with corneal irregularities should be fit with RGP lenses.

Adult↗
PubMed2000

[Simulation of night myopia in pseudophakic eyes].

PURPOSE: Eyes with an intraocular lens (IOL) implanted that have no accommodative ability are likely to have night myopia caused by Purkinje's shift and chromatic aberration. We evaluated the changes in retinal images caused by night myopia in various IOL-implanted eyes by simulation using model eyes. METHODS: A polymethylmethacrylate (PMMA) IOL, soft acrylic IOLs, and high-refractive-index silicone IOLs were prepared, and inserted into the model eye. The image plane of the model eye was determined as the line image at which a slit light of 560 nm was best focused, which was regarded as emmetropic condition under photopic vision. A slit light of 505 nm was then directed into the model eye. Its line image on the image plane was blurred, which was regarded as myopic condition under scotopic vision. Under each condition, the modulation transfer functions (MTF) were calculated and the line images were photographed. RESULTS: The degree of reduction of MTF and blurring of the line image under the night myopic condition was in the order of PMMA < soft acrylic < high refractive index silicone IOL. CONCLUSION: Eyes with a soft acrylic or high-refractive-index silicone IOL may have more intense night myopia caused by chromatic aberration.

Cataract↗
PubMed2000

Evaluation of optic disc changes in severe myopia.

PURPOSE: To evaluate the changes in the optic nerve head in highly myopic subjects by means of confocal laser scanning opthalmoscope. METHODS: Using laser scanning and a three-dimensional image analysis system, we studied 114 young (21.4 +/- 1.4 years), highly myopic subjects with refractive errors greater than -8.0 D and a control group of 29 subjects (18.9 +/- 1.2 years) with myopia of -3.0 D or less. Measurements included cycloplegic refraction, corneal curvature, biometric axial length, and morphometric values of the optic disc obtained with a laser scanning disc analyzer. RESULTS: The optic disc area in highly myopic eyes was similar to that in mildly myopic eyes. However, regression analysis revealed that the optic disc area increased with axial length in subjects with severe myopia. The cup/disc ratio, the disc depth, the neuroretinal rim area, and the tilting of the disc were not significantly different between the severe and mild myopia groups. CONCLUSIONS: These findings may be useful in further investigations of myopic progression and of the mechanisms responsible for the development of myopic complications.

Adolescent↗
PubMed2000

[Iris-claw phakic (Artisan) lens to correct high myopia].

PURPOSE: To assess the safety and efficacy of the iris claw phakic (6mm Artisan lens) in patients with high myopia. METHODS: Twenty-five eyes with myopia of -7.50 to 16D were implanted with a 6mm artisan lens and followed for 24 months. RESULTS: The mean preoperative spherical equivalent refraction was 13.08+/-3.44D at one year. Mean operative spherical equivalent refraction was 0. 77+/-0.57D and 81.8% of eyes had a spherical equivalent refraction within +/-1.00D. Best spectacle-corrected visual acuity was maintained or improved in 62.5% of cases. No iritis or cataract or glaucoma was observed. CONCLUSION: Implantation with the 6mm Artisan lens is an effective method for reducing or correcting myopia up to -16D. Gains in spectacle corrected visual acuity were common, and results suggested good predictability. Because of the incomplete follow up, we cannot draw conclusions about the long term safety of the 6mm Artisan lens.

Adult↗
PubMed2000

[Myopia: prevalence of retinal tears and throphic holes].

PURPOSE: We study the prevalence of retinal tears and holes in myopia. We consider age distribution, also retinal localization, and its relationship with the different types of posterior vitreous detachment. MATERIAL AND METHODS: 200 eyes from 124 myopic patients were selected. Average age was 34,76 years. Five groups of myopia were considered, and three groups of age. Indirect ophthalmoscopy under cycloplegia, scleral indentation and biomicroscopy with three mirror Goldmann contact lens were performed in all the patients. RESULTS: 7 tears were found in 6 eyes out of the 200 myopic eyes studied (3%), and 16 holes in 14 eyes (7%). No statistical relationship was found for tears or holes between the different groups of myopia or age, neither considering the different types of posterior vitreous detachment. Superotemporal retinal quadrant was more frequently involved by these lesions. CONCLUSIONS: The tears and round trophic holes found (3% and 7% respectively) did not show relationship with posterior vitreous detachment type, age nor myopic grade.

Adult↗
PubMed2000

[Contrast sensitivity after laser in situ keratomileusis for myopia (LASIK-M)].

PURPOSE: To evaluate the effect of laser in situ keratomileusis for the correction of moderate myopia (LASIK) on contrast sensitivity values. METHODS: Seventeen eyes of 10 patients underwent LASIK to correct myopia ranging from 7.75 to -4.75 D (mean +/- SD, -6.53 +/- 0.99 D). Contrast sensitivity was tested preoperatively and 1, 3, 6 and 12 months postoperatively using the CVS -1000 contrast sensitivity test (Vector Vision). RESULTS: Contrast sensitivity decreased in the first postoperative month, the decrease was significant for 6 dg and 12 c/g (P -0.006 and P=0.005, respectively). At 3 months it returned to preoperative values although it was not statistically significant (P>0.05). There was an improvement at 6 months at spatial frequencies of 3 c/g and 6 c/g and at 12 months the improvement was for 3, 6 and 18 c/g, although the changes were not significant. CONCLUSION: Although LASIK decreased contrast sensitivity values at one month after surgery, these values returned to the preoperative levels at 3 months. The improvement at certain frequencies at 6 and 12 months suggests that LASIK can improve the quality of vision in eyes with low to moderate myopia.

Adult↗
PubMed1997

[The incidence of retinal detachment after extracapsular cataract extraction in high myopia].

PURPOSE: A retrospective study was performed to determine the incidence of retinal detachment after extracapsular cataract extraction in high myopia and the risk factors associated with the occurrence of retinal detachment. METHODS: Of the 463 patients (463 eyes) who had undergone extracapsular cataract extraction with or without intraocular lenses implant between July 1993 and January 1994, 90 patients companied with high myopia and the others were senior cataract. All patients had been followed up for 27 to 33 months. RESULTS: One (1.11%) developed retinal detachment in the patients with high myopia, and no retinal detachment occurred in the patients with senior cataract. The difference of the incidence of retinal detachment between two groups were no significant (P > 0.05), More myopic patients underwent Nd:YAG laser capsulotomy (P < 0.05). CONCLUSION: Comparing with intracapsular method, extracapsular cataract extraction decreased the risk of retinal detachment even in the high myopic patients. The risk factors for retinal detachment were young patients, long eye axis and posterior capsulotomy.

Aged↗
PubMedDate not supplied

[Significance of lacrimal fluid peroxidation and anti-radical defense parameters for prediction and treatment of complicated myopia].

Study of lipid peroxidation and antiradical defense parameters in the lacrimal fluid from 270 eyes of children and adolescents with progressive myopia demonstrated a relationship between the development of peripheral vitreochorioretinal dystrophies and imbalance between antioxidant activity (AOA) of lacrimal fluid and intensity of radical formation evaluated by chemiluminescence (CL) intensity. The AOA/CL ratio is proposed as a reliable indicator for predicting the course of progressive myopia. A value < 30 indicates poor level of antioxidant defense of ocular media and tissues and is a prognostically unfavorable sign as regards development of peripheral vitreochorioretinal dystrophy. A local antioxidant remedy has been developed and clinically tried for preventing and treating complicated myopia: ocular medicinal films with emoxipin and pyridoxine hydrochloride.

Adolescent↗
PubMed2001

[Excimer surface photoablation versus Lasik for correction of mild myopia].

INTRODUCTION: Above -6 diopters, Lasik procedure has shown its superiority in term of predictibility, efficacy and stability. In the adverse, in the field of low myopia, Lasik and surface excimer photoablation (PRK) are very controversial. We compare quantitative and qualitative outcome achieved in series of 25 PRK operated patients and 25 Lasik. MATERIAL AND METHOD: 2 homogeneous groups were constituted: group A for Excimer patients and group B for Lasik. Initial ametropia had to be ranged between -2 and -6 diopters (D), eventually associated to a myopic astigmatism that needed to be under -1,75 D. Excimer laser model was a Visx (Visx 20/20 or Star S2). In case of Lasik, flap was performed with an Automated corneal shaper microkératom (Baush & Lomb) or with a Flap Maker (Ioltech). Evaluation of refraction and visual results was associated to measurements of contrast and glare sensitivities and collection of functional complaints. RESULTS: A retrospective analysis is performed with a 2 years follow-up. At that term, rate of eyes, that achieved 20/20 or better is comparable in the two groups (62% in group A and 64% in group B). However, profile of visual recovery goes faster after Lasik. Best corrected visual acuity is favorably preserved in two groups, but is altered with glare in Lasik group. Cycloplegic refraction shows a tendency to regression more important in case of surface ablation (10% versus 4%), especially above -4 D (28%). No significant difference is noted concerning contrast sensitivity, correctly unchanged in the two groups. No case of severe complication is mentioned after both surgical methods. DISCUSSION-CONCLUSION: In the field of low myopia, PRK and Lasik appear to guarantee same predictibility and safety, in conditions of preliminary learning curve. Stability and visual recovery are earlier achieved after Lasik, in addition to postoperative indolence. However, application of this technique to all degrees of myopia requires its perfect control and an adjustment of ablation nomograms.

Adult↗
PubMed2001

[Surgery for choroidal subfoveal neovascularization in patients with severe myopia. Retrospective analysis of 17 patients].

UNLABELLED: Treatment of choroidal neovascularization in pathological myopia is still controversial. METHODS: A retrospective analysis of 17 patients with severe myopia (>-6) and subfoveal choroidal neovascularization who underwent surgical removal of choroidal neovascularization, was performed. The patient population consisted of 2 groups: 9 patients younger than 50 years and 8 patients older than 50 years. All the patients underwent vitrectomy with surgical removal of subfoveal choroidal neovascularization. RESULTS: We reviewed the postoperative clinical and angiographic findings. In group I, visual acuity improved in 4 eyes (44%), remained unchanged in 4 eyes (44%) and decreased in one eye. In group II, none of the patients had visual improvement, visual acuity remained unchanged in 6 eyes (71%), and decreased in 2 eyes. CONCLUSION: The visual outcomes in most patients in this series were better than their natural history. Surgical removal of subfoveal choroidal neovascularization associated with severe myopia may provide visual benefit in young patients. A prospective, randomized clinical trial is necessary to determine the place of this surgical procedure.

Adult↗
PubMedDate not supplied

[Structure of complications of specialized excimer laser keratomileusis in correction of myopia].

Complications of LASIK carried out at Medinvest Center of Laser Correction of Vision (Chelyabinsk) on an EC-500 eximer laser (NIDEK, Japan) with LSK microkeratome Evolution-2 (Moria, France) in 498 patients (984 eyes) for correction of myopia and myopic astigmatism are analyzed. Myopia varied from 2.5 to 17 diopters (mean 7.38 +/- 1.31), astigmatism 0.5-4.5 (mean 1.57 +/- 0.87). No complications occurred during the operation in 84.9% cases. Intraoperative and postoperative complications were observed in 15.1% patients. The intraoperative (10.1%) were hemorrhage from the marginal perilimbic corneal vessels, desquamation of epithelium, flap deficiency, complete dissection of the flap; postoperative (5%) were irregular astigmatism, hyper- and hypocorrection. Hence, our data indicate that LASIK is an effective method for surgical correction of myopia.

Adolescent↗
PubMed2001

[PRK and LASIK in patients with myopia ranging from -6 to -9 D] ].

OBJECTIVE: Observing of effectiveness, safety and short-term stability of patients with myopia ranging from -6.0 to -9.0 diopters (D) after surgery and their comparison. PARTICIPANTS AND METHOD: We were retrospectively analyzing pre- and postoperative outcomes of patients with myopia ranging from -6.0 to -9.0 D. 90 eyes were examined before laser in situ keratomileusis (LASIK) with mean spherical equivalent refraction -7.64 +/- 0.84 D and mean cylinder -1.23 +/- 1.1 D. 56 eyes were examined before photorefractive keratectomy (PRK) with mean spherical equivalent refraction -6.92 +/- 0.72 D and mean cylinder -0.60 +/- 0.55 D. Patients were examined before operation, one week, one month, three months, six months, nine months and one year after operation. Data were collected and analyzed by the computer programme. RESULTS: We observed the patients who underwent the operation and six months after surgery we received following results: After PRK mean spherical equivalent refraction was -0.23 +/- 1.24 D, mean cylinder -0.83 +/- 0.42 D, uncorrected visual acuity (UCVA) 0.86 +/- 0.35, best spectacle-corrected visual acuity (BCVA) 1.13 +/- 0.33. After LASIK mean spherical equivalent refraction was -0.29 +/- 1.19 D, mean cylinder -1.14 +/- 0.77 D, UCVA 0.65 +/- 0.25, BCVA 0.83 +/- 0.25. One year after PRK mean spherical equivalent refraction was -0.44 +/- 1.26 D, mean cylinder -0.80 +/- 0.57 D, UCVA 0.81 +/- 0.31, BCVA 0.97 +/- 0.21. After LASIK mean spherical equivalent refraction was -0.14 +/- 0.86 D, mean cylinder -1.26 +/- 0.89 D, UCVA 0.75 +/- 0.25, BCVA 0.89 +/- 0.20. CONCLUSIONS: Both methods are effective and their results after 3 to 6 months after laser treatment in patients with myopia ranging from -6.0 to -9.0 D were comparable. Based on the complex evaluation, we prefer LASIK nowadays.

Adult↗
PubMedDate not supplied

[Long-term results of surgical prevention and correction of progressive myopia].

In this summing-up paper the authors discuss the results of surgical prevention and correction of progressive myopia carried out at Department of Ophthalmic Diseases of Russian University of Peoples' Friendship during two recent decades. Remote results of bandaging scleroplastic and reduced chondroplastic operations recommend scleroplastic interventions for prevention of myopia progress. Combined scleroplasty and cataract extraction stabilized the elongation of the antero-posterior axis of the eye and essentially improved visual acuity of 18-20 diopters. New variants of interlamellar operations are presented: tunnel-circular and fragmented circular, which are protected by patents of the Russian Federation. These operations are recommended for patients with stable myopia of 8-15 diopters after scleroplasty. Their advantage is low traumatism, absence of deep incisions on the cornea, wide optic center, possibility of regulating the refraction effect by replacing the implants or their complete removal without serious consequences for the cornea.

Female↗
PubMed1998

[A study on the mechanism of apomorphine for treatment of myopia].

OBJECTIVES: To investigate the functions of dopamine D(1) and D(2) receptor in form deprivation myopia (FDM) and the influence of apomorphine (Apo) on inhibition of FDM in chick with radioligand binding assay (RBA). METHODS: All chicks after hatching were divided into three groups: unilateral lid suture, lid-suture and treated with Apo subconjunctival injections and normal control. After two weeks, they were refracted, then were killed, their equator dimensions of the eyeballs were measured quickly, the retinas were dissected out and pooled into three above separate groups. [(3)H]SCH 23390 and [(3)H] Spiperone were used for the saturation tests for D(1) and D(2) receptor protein respectively in the three groups. RESULTS: The numbers of both dopamine receptors in FDM increased (up-regulation). With the treatment of Apo, the numbers of both dopamine receptors decreased (down-regulation). The affinities of both receptors were of no difference. CONCLUSIONS: The dopamine receptors in chick retina are under hypersensitive state in FDM, that is related to the biological level lowering of dopamine. Apo can inhibit the development of myopia, and the D(1) and D(2) receptor numbers are decreased, showing that Apo can affect dopamine receptors in various degrees. The method of this study can provide a route to screen drugs for treatment of myopia.

Animals↗
PubMed1998

[Phacoemulsification in myopia and negative or low powered posterior chamber intraocular lens implantation].

OBJECTIVE: The study was designed to investigate the technique and clinical experience of phacoemulsification in myopia and negative or low powered posterior chamber intraocular lens implantation (PC-IOL). METHODS: 120 eyes of 102 cases with myopia and cataract were included (axial length >or=28 mm) and hardness of nucleus was of grade 2 in 5 eyes, grade 3 in 84 eyes, grade 4 in 16 eyes and grade 5 in 15 eyes. Tunnel incision was made and in situ nuclear fracture technique by phacoemulsification was used. Energy and time of emulsification: 50% - 60% of energy was set up and emulsification spent 40s to 2 min. 10 s (mean, 1 min. 11.3s) for nuclear sclerosis of grade 2 or 3.65% - 70% of energy was set up and emulsification spent 48s to 1 min. 22s (mean, 68.7s) for cutting the central nucleus and removing the divided nucleus (grade 4 or 5). RESULTS: There were 120 eyes in this group. Eleven to 22 months after operation (mean 14.5 months) the visual acuities of 0.5 or better with and without correction were obtained in 62.6% and 43.4% respectively. The major complications were corneal edema and rupture of posterior capsule. No retinal detachment and cystoid macular edema were found. CONCLUSION: This operation is suitable for myopia with cataract. It is worth to spread due to good visual result, proper correction of ametropia, prevention of retinal detachment, and decrease of operative complications.

Adult↗
PubMed2002

Relationship between corneal thickness and level of myopia.

A retrospective study of 533 eyes, which underwent complete pre-operative evaluation for refractive surgery, was done. Regression Analysis was performed to find the correlation between corneal thickness and level of myopia and between corneal thickness and corneal curvature. There was statistically significant correlation between corneal thickness and level of myopia (p = 0.039) and also in corneal thickness and corneal curvature (p = 0.04). No clinical correlation was demonstrated (R2 = 0.014 and R2 = 0.0153, respectively). There was no clinical correlation between corneal thickness and level of myopia and also between corneal thickness and corneal curvature.

Adult↗
PubMed2002

[An analysis of regression after laser in situ keratomileusis for treatment of myopia].

OBJECTIVE: To evaluate the regression relevant reasons of laser in situ kertomileusis (LASIK) for treatment of myopia. METHODS: Four hundred and eight eyes of 250 patients with myopia who received LASIK were studied. They were divided into 2 groups according to preoperative diopters (-6.25- -10.00 D in 194 eyes; -10.25 -15.00 D in 214 eyes). The mean follow-up was 12 months, and the results of the postoperative visual acuity, refractive diopter, corneal thickness and the diameter of the ablation zone were statistically analyzed. RESULTS: (1) A group: There were 173 normal operative eyes (89.2%, post-operative diopter < -1.00 D), the mean pre-operative corneal thickness was (549.5 +/- 31.5) microm, the mean intra-operative laser ablation diameter was (4.96 +/- 0.35) mm, and the post-operative refractive diopter was +0.50- -0.75 D. The regressive operative eyes: There were 21 eyes (10.8%, post- operative diopter >/= -1.00D), the mean preoperative corneal thickness was (547.7 +/- 37.0) microm (P > 0.05 in comparison with that of the normal operative eyes), the mean intra-operative laser ablation diameter was (4.64 +/- 0.41 ) mm (P < 0.01 in comparison with that of the normal operative eyes), and the mean post-operative diopter was (-1.33 +/- 0.58)D. (2) B group: There were 136 normal operative eyes (63.5%), the mean pre-operative corneal thickness was (560.9 +/- 30.9) microm, the mean intra-operative laser ablation diameter was (4.51 +/- 0.28) mm, and the post-operative diopter was +0.50- -0.75 D. The regressive operative eyes: There were 78 eyes (36.5%), the mean pre-operative corneal thickness was (538.0 +/- 31.0) microm (P < 0.01 in comparison with that of the normal operative eyes), the mean intra-operative laser ablation diameter was (4.22 +/- 0.34) mm (P < 0.01 in comparison with that of the normal operative eyes), and the mean post-operative diopter was (-1.99 +/- 1.01) D. CONCLUSIONS: In cases with small laser ablation diameter and the thin pre-operative corneal thickness of high myopia, after the surgery refractive regression is easy to occur. Some modification of the surgical algorithms and laser nomogram will help to improve predictability and reduce regression.

Adolescent↗