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At least 775 records · Page 43Linked to original sources
PubMed2001

Laser in situ keratomileusis to correct myopia, hypermetropia and astigmatism after penetrating keratoplasty for keratoconus: a series of 27 cases.

BACKGROUND: Excimer laser treatment has been shown to be effective and safe in correcting anisometropia following penetrating keratoplasty (PKP). In this report we review our experience with excimer laser in situ keratomileusis (LASIK) to correct refractive myopia, hypermetropia and astigmatism in patients who had undergone PKP for keratoconus. METHODS: We reviewed the records of 22 patients (27 eyes) who had undergone LASIK to correct myopia, hypermetropia or astigmatism, in simple or combined forms, following corneal transplantation for keratoconus. LASIK was performed at a hospital in Curitiba, Brazil, between September 1998 and February 2000. The eyes were classified into two groups: those with a negative spherical equivalent and those with a positive spherical equivalent. LASIK was performed using the Moria LSK microkeratome and the Nidek EC-5000 excimer laser. RESULTS: The mean length of follow-up was 9.52 months for the 23 eyes with myopia and 5.75 months for the 4 eyes with hypermetropia. The mean refractive spherical equivalent in the myopic eyes was -5.27 (standard deviation [SD] 1.91) dioptres before LASIK and -0.45 D (SD 1.68 D) at the last follow-up visit. The corresponding values in the eyes with hypermetropia were +5.18 D (SD 1.46 D) and + 1.18 D (SD 0.94 D). The rate of regression of astigmatism in the myopic eyes was 76%. After surgery 18 (78%) of the myopic eyes and all the hypermetropic eyes had an uncorrected visual acuity of 20/40 or better. The best spectacle-corrected visual acuity was better than 20/25 in 22 (95.7%) of the myopic eyes and all the hypermetropic eyes. One eye lost 1 line of best spectacle-corrected Snellen visual acuity, and one eye lost 6 lines secondary to epithelial ingrowth. Wound dehiscence, intraoperative flap complications, graft rejection or other complications did not develop in this series. INTERPRETATION: In this series, LASIK proved to be relatively safe and effective in correcting refractive errors after PKP for keratoconus.

Adult↗
PubMedDate not supplied

Comparison of two procedures: photorefractive keratectomy versus laser in situ keratomileusis for low to moderate myopia.

PURPOSE: A prospective study was conducted to compare the effectiveness, safety, and stability of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for correction of low to moderate myopia. METHODS: Forty-five patients with a manifest refraction (PRK, -4.54 +/- 0.80; LASIK, -4.82 +/- 1.10) from -1.50 to -6.00 diopters (D) were treated and followed-up for 6 months. In each case, 1 eye received PRK and the other LASIK. The first eye treated, and the surgical method used in the first eye, were randomized. Uncorrected and corrected visual acuity, manifest refraction, corneal haze, and topographic analysis of ablation decentration were examined. RESULTS: The uncorrected visual acuity was 20/20 or better in 35 PRK eyes (77.8%) and 28 LASIK eyes (62.2%) at 6 months (P =.107). At 6 months, 28 eyes (62.2%) that received PRK showed a spherical equivalent of within +/-0.5 D as compared with 24 eyes (53.4%) that received LASIK (P =.393). The amount of ablation decentration was 0.37 +/- 0.25 mm in PRK eyes and 0.49 +/- 0.38 mm in LASIK eyes at 3 months (P =.36). CONCLUSIONS: In our study, PRK and LASIK were found to be similarly effective and predictive of correction in low to moderate myopia. PRK has the advantage of less ablation decentration and is safer than LASIK, so we recommend PRK for eyes with low to moderate myopia.

Cornea↗
PubMed2000

Optical correction of form deprivation myopia inhibits refractive recovery in chick eyes with intact or sectioned optic nerves.

The finding that the eyes of young chicks recover quickly from form deprivation myopia (FDM) has been interpreted as indirect evidence for active emmetropization. More direct evidence would be the demonstration that correction of FDM with spectacle lenses, thereby removing the defocus signal, prevents recovery. We investigated this issue in eyes with intact and sectioned (ONS) optic nerves. Previous studies suggest that an intact optic nerve is necessary for accurate emmetropization. Seventy day-old male chicks were monocularly deprived using velcro-mounted diffusers, which were removed after 5-6 days and in some (n=51), but not all cases, replaced by spectacle lenses (-5, -10 or -15 D). Approximately half (n=34) of the chicks also underwent ONS on day 1. Refractive errors and axial ocular dimensions were measured when the diffusers were first removed and thereafter at 2-4 day intervals over the following 1-2 weeks. In one case, measurements were continued at less regular intervals to 33 days. Lens powers were selected to either approximately correct or under-correct the refractive errors present when the diffusers were removed. Form deprivation in normal chicks produced large myopic shifts in refraction (means for groups range from -9.20 to -16.07 D). When the deprivation treatment was terminated, the myopia quickly decreased to negligible levels unless optically corrected. Correcting lenses stabilized the myopia to a level consistent with the lens power used. Interocular differences in axial length were consistent with an axial origin to the refractive changes. Results for the ONS groups exhibited similar trends although there was increased variability in the data. The findings support the interpretation that recovery from FDM is a product of active emmetropization. That ONS increased the variability of such responses implies that an intact optic nerve is required for accurate emmetropization.

Animals↗
PubMed1998

The role of neural and optical factors in limiting visual resolution in myopia.

The myopic growth process has the potential to modify both the optical and neural performance of the eye. We provide three simple models, based on different types of retinal stretching, to predict changes in neural resolution resulting from axial length increases in myopia. These predictions are compared to visual acuity (VA) measures in 34 subjects with refractive errors ranging from plano to -14 D. Our results show a reduction in VA with increasing myopia but not in a manner predicted by our models. We discuss the relative contribution of optical and neural factors to the reduction in visual resolution in myopia.

Anthropometry↗
PubMed2000

Astigmatism and the development of myopia in children.

While it is now established that astigmatism is more prevalent in infants and young children than in the adult population, little is known about the functional significance of this astigmatism, especially its role, if any, in emmetropization and the development of myopia. Manifest refractions (mean of 16 per subject) were obtained from 245 subjects starting in the first year, with 6-23 years of regular follow-up. Results showed that infantile astigmatism is associated with increased astigmatism and myopia during the school years. Two possible mechanisms underlying this association are discussed: (1) infantile astigmatism disrupts focusing mechanisms; and (2) ocular growth induces astigmatism and myopia.

Adolescent↗
PubMed2001

Safety of posterior chamber phakic intraocular lenses for the correction of high myopia: anterior segment changes after posterior chamber phakic intraocular lens implantation.

OBJECTIVE: To assess the safety of posterior chamber phakic intraocular lens (PCPIOL) implantation in patients with high myopia. DESIGN: Prospective, noncomparative, interventional case series. PARTICIPANTS: Twenty eyes of 10 patients were included. INTERVENTION: Staar Collamer Implantable Contact Lens PCPIOLs were implanted for the correction of high myopia. MAIN OUTCOME MEASURES: Intra- and postoperative complications were recorded. Specular microscopy, lens fluorophotometry, laser flare-meter, and ultrasound biomicroscopy were performed before surgery and at different stages of the follow-up period to evaluate endothelial cell density, crystalline lens transmittance, aqueous flare, and anatomic relations of the implanted lenses with the other structures of the anterior segment. RESULTS: There were no intraoperative complications. One patient experienced pupillary entrapment by the lens in the immediate postoperative period, which was resolved without incident. Pigmentary dispersion or cataracts did not appear during the postoperative period. All the lenses remained correctly centered, and no patient reported night halos or glare. Anterior chamber depth showed a statistically significant reduction, between 9% and 12%. Central endothelial density was significantly decreased after surgery. The percentages of cell loss after 3, 6, 12, 18, and 24 months were 4.41%, 4.83%, 5.17%, 5.46%, and 6.57%, respectively. Aqueous flare increased by 49.19% in the first postoperative month in relation to preoperative values. Afterward, it decreased and then remained above preoperative values for the entire follow-up period (33.76% at month 3, 27.81% at month 6, 27.65% at month 12, 23.39% at month 18, and 27.27% at month 24). Crystalline lens transmittance decreased by 0.72% at month 3, by 1.44% at month 6, by 1.95% at month 12, by 2.25% at month 18, and by 2.24% at month 24. Finally, by ultrasound biomicroscopy it was observed that the PCPIOL and the crystalline lens were in contact on the peripheral level in 12 patients (60%) and in the center in another three patients (15%) during at least one checkup. In all the patients, contact between the PCPIOL and the posterior iris surface could be observed. CONCLUSIONS: Posterior chamber phakic IOL implantation for the surgical correction of high myopia is a safe procedure with regard to immediate visual and refractive results. The short-term clinical benefit and lack of immediate surgical complications are impressive. However, the increase in flare, the endothelial cell loss, the decrease in crystalline lens transmittance, and the iris-PCPIOL and crystalline lens-PCPIOL contact are findings that suggest caution regarding the long-term safety of this lens implant.

Adult↗
PubMed2001

Photodynamic therapy of subfoveal choroidal neovascularization in pathologic myopia with verteporfin. 1-year results of a randomized clinical trial--VIP report no. 1.

OBJECTIVE: To determine if photodynamic therapy with verteporfin (Visudyne; CIBA Vision Corp, Duluth, GA) can improve the chance of stabilizing or improving vision (<8 letter loss) safely in patients with subfoveal choroidal neovascularization (CNV) caused by pathologic myopia. DESIGN: Multicenter, double-masked, placebo-controlled, randomized clinical trial at 28 ophthalmology practices in Europe and North AMERICA: PARTICIPANTS: One hundred twenty patients with subfoveal CNV caused by pathologic myopia with a greatest linear dimension no more than 5400 microM and best-corrected visual acuity (Snellen equivalent) of approximately 20/100 or better. INTERVENTION: Patients were randomly assigned (2:1) to verteporfin (6 mg per square meter of body surface area; n = 81) or placebo (5% dextrose in water; n = 39) administered via intravenous infusion of 30 ml over 10 minutes. Fifteen minutes after the start of the infusion, a laser light at 689 nm was delivered at an intensity of 600 mW/cm(2) over 83 seconds to give a light dose of 50 J/cm(2) to a round spot size on the retina with a diameter of 1000, microM larger than the greatest linear dimension of the choroidal neovascular lesion. At follow-up examinations every 3 months, retreatment with either verteporfin or placebo (as assigned at baseline) was applied to areas of fluorescein leakage if present. MAIN OUTCOME MEASURES: The primary outcome was the proportion of eyes at the follow-up examination 12 months after study entry with fewer than eight letters (approximately 1.5 lines) of visual acuity lost, adhering to an intent-to-treat analysis. RESULTS: At baseline, more than 90% of each group had evidence of classic CNV (regardless of whether occult CNV was present) and only 12 (15%) and 5 (13%) cases in the verteporfin and placebo groups, respectively, had occult CNV (regardless of whether classic CNV was present). Seventy-nine of the 81 verteporfin-treated patients (98%) compared with 36 of the 39 placebo-treated patients (92%) completed the month 12 examination. Visual acuity, contrast sensitivity, and fluorescein angiographic outcomes were better in the verteporfin-treated eyes than in the placebo-treated eyes at every follow-up examination through the month 12 examination. At the month 12 examination, 58 (72%) of the verteporfin-treated patients compared with 17 (44%) of the placebo-treated patients lost fewer than eight letters (P < 0.01), including 26 (32%) versus 6 (15%) improving at least five letters (>/=1 line). Seventy (86%) of the verteporfin-treated patients compared with 26 (67%) of the placebo-treated patients lost fewer than 15 letters (P = 0.01). Few ocular or other systemic adverse events were associated with verteporfin therapy compared with placebo treatment. CONCLUSIONS: Because photodynamic therapy with verteporfin can safely increase the chance of stabilizing or improving vision in patients with subfoveal CNV from pathologic myopia compared with a placebo, we recommend ophthalmologists consider verteporfin therapy for treatment of such patients.

Adult↗
PubMed2001

Intrastromal corneal ring segments for low myopia: a report by the American Academy of Ophthalmology.

OBJECTIVE: This document describes intrastromal corneal ring segments (Intacs) inserts technology and examines the evidence to answer the key question about whether the treatment is safe and effective in correcting low myopia. METHODS: A literature search that was conducted in September 2000 retrieved 13 relevant citations, and the reference lists of these articles were consulted for additional citations. Panel members reviewed this information and articles were rated according to the strength of evidence. RESULTS: Prospective multicenter phase II and III clinical trials (Level II evidence rating) of Intacs inserts for myopia of -1.00 to -3.00 diopters (D), with a maximum of +1.00 D of astigmatism, enrolled a total of 452 subjects, with a total of 454 surgical attempts. The results from phase II and phase III were pooled for much of the analysis. At 1 year, 97% of patients who completed follow-up had 20/40 or better uncorrected visual acuity (UCVA). Seventy-four percent of patients had 20/20 or better UCVA. Ninety-two percent of eyes were within +/-1 D of intended refractive correction, and 69% were within 0.5 D of intended refractive correction. At 3 months, 90% of patients had less than 1.0 D of change from the previous examination performed at 1 month. The ocular complication rate, which was defined as clinically significant events but not resulting in permanent sequelae, was 11% at 12 months. The adverse event rate was 1.1%, defined as a serious event if untreated. Nearly 9% of patients requested to have their inserts removed and a total of 3.8% of patients required a secondary surgical intervention. CONCLUSIONS: To date, evidence suggests that low myopia (-1 to -3 D) in a well-defined group of patients who have a stable manifest refraction and less than +1.0 D of astigmatism can be treated with Intacs inserts with a reasonable assurance of safety and effectiveness. Additional clinical research is needed to determine the long-term effectiveness of treatment and the comparative safety, effectiveness, and costs with other treatment modalities, including laser-assisted in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK).

Academies and Institutes↗
PubMed2002

Tracker-assisted laser in situ keratomileusis for myopia using the autonomous scanning and tracking laser: 12-month results.

OBJECTIVE: To determine the safety, efficacy, and predictability of the Autonomous scanning and tracking laser for the correction of myopia and myopic astigmatism with laser in situ keratomileusis (LASIK) procedure. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: The first 129 consecutive eyes with up to -13.00 diopters (D) of myopia and -5.00 D of astigmatism. INTERVENTION: Myopic tracker-assisted LASIK (T-LASIK) using the Autonomous Laser (Alcon Summit Autonomous, Waltham, MA) and Hansatome microkeratome (Bausch & Lomb Surgical, Bracknell, England). MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA), manifest spherical equivalent (MSE), best spectacle-corrected visual acuity (BSCVA), and complications were studied. RESULTS: At 12 months, the mean MSE was -0.02 +/- 1.01 D, with 79.1% of eyes within 0.5 D and 89.9% of eyes within 1 D of the intended correction. UCVA was 20/20 or better in 71.4%, 20/25 or better in 78.5%, and 20/40 or better in 92.8% of eyes. Two eyes (1.6%) lost 2 lines and five eyes (3.8%) gained 2 lines of BSCVA. Sixteen eyes (12.4%) required retreatment to correct residual myopia or astigmatism. After retreatment, 14 of 16 eyes were within 0.5 D of emmetropia. Nine eyes (6.9%) had minor flap complications; two eyes (1.6%) had grade 2 diffuse lamellar keratitis, of which one eye had associated peripheral flap melt. One eye showed slight decentration; this eye was rolling throughout the procedure. All eyes had some dryness, with 10% severe enough to require temporary punctual occlusion with plugs. CONCLUSIONS: T-LASIK for myopic astigmatism with the Autonomous Laser is relatively safe, effective, and predictable. The tracker seems to be effective, and the complications are relatively few. Retreatment rates are acceptable and can be performed safely and effectively to improve visual outcome. The outcomes are comparable with other published data.

Adult↗
PubMed2002

A randomized paired eye comparison of two techniques for treating moderately high myopia: LASIK and artisan phakic lens.

OBJECTIVE: To compare refractive performance and safety of laser in situ keratomileusis (LASIK) and Artisan phakic intraocular lens (PIOL) for moderately high myopia. DESIGN: A prospective, randomized trial with paired eye control. PARTICIPANTS: Twenty-five patients with myopia ranging from -8.00 to -12.00 diopters (D). INTERVENTION: For each patient, one eye received LASIK and the other one was implanted with an Artisan phakic intraocular lens. The treated eye and the surgical technique were randomized. MAIN OUTCOME MEASURES: Primary outcome measure was spherical equivalent refraction. Main secondary outcome measures were the change of two or more lines and safety index (ratio postoperative to preoperative best-corrected visual acuity). RESULTS: One year after surgery, the mean spherical equivalent refraction was -0.74 +/- 0.67 D for LASIK-treated eyes and -0.95 +/- 0.45 D for Artisan-treated eyes, and the majority of LASIK-treated eyes (64%) and Artisan-treated eyes (60%) were within +/-1.00 D of the intended result. At 1 month, the mean spherical equivalent refraction was -0.28 +/- 0.71 D for LASIK and -1.07 +/- 0.59 D for Artisan (P < 0.01). The changes of two or more lines were in favor of Artisan (P < 0.05). The safety index was significantly better for Artisan (1.12 +/- 0.21) than for LASIK (0.99 +/- 0.17) at 1 year (P < 0.02). CONCLUSIONS: In cases of moderately high myopia, LASIK and Artisan phakic intraocular lenses seemed to produce a similar predictability. The best-corrected visual acuity and subjective evaluation of quality of vision were better for Artisan.

Adult↗
PubMed2002

Artisan phakic intraocular lens for myopia:short-term results of a prospective, multicenter study.

PURPOSE: To evaluate the safety and efficiency of the Artisan iris-supported phakic intraocular lens (Ophtec BV, Groningen, Netherlands) for the correction of high myopia. STUDY DESIGN: Nonrandomized, prospective, multicenter trial conducted under a United States Food and Drug Administration (FDA) Investigational Device Exemption. PARTICIPANTS: One hundred fifty-five eyes of 155 patients with myopia from -5.5 to -22.5 diopters (D) underwent implantation of an Artisan lens, as part of a phase I, II, or III FDA trial. METHODS: Eyes were examined at 1 day (154 eyes), 2 weeks (142 eyes), 2 months (130 eyes), and 6 months (84 eyes). Intraocular pressure and presence of flare and cell on slit-lamp biomicroscopy were recorded at each visit. MAIN OUTCOME MEASURES: Achieved correction, stability of spherical equivalent refraction, change in astigmatism, postoperative uncorrected vision, change in best spectacle-corrected acuity, and change in endothelial cell count. RESULTS: Mean spherical equivalent manifest refraction stabilized on postoperative day 1. Mean difference between attempted and achieved correction at 2 months was -0.32 +/- 0.95 D (mean +/- standard deviation; range, -4.42 to +2.2 D). At 6 months, 85% of eyes saw 20/40 or better uncorrected, and 90% of eyes were within 1 D of the attempted correction. Refractive astigmatism increased in 4.8% of eyes and decreased in 17% of eyes at 6 months. At 2 months, six eyes (4.8%) lost two or more lines of best spectacle-corrected visual acuity; by 6 months, no eyes lost two or more lines of best-corrected visual acuity. Endothelial cell count was unchanged at 6 months compared with the preoperative count. Nonprogressive lens opacities developed in four eyes as a result of surgical trauma. Chronic inflammation was not detected in any eye by slit-lamp biomicroscopy, nor did any eye develop angle closure or glaucoma. CONCLUSIONS: Short-term results suggest that the Artisan lens is an accurate and safe method for the correction of high myopia. Surgical skill is important in avoiding lens opacities. Longer-term data are needed to assess the impact of the lens on the endothelium, the crystalline lens, and the iris.

Adult↗
PubMed2003

Ten-year follow-up of epikeratophakia for the correction of high myopia.

OBJECTIVE: To determine the long-term functional results of epikeratophakia for myopic patients. DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Twenty-two patients (32 eyes; average age, 43+/-6 years) who underwent epikeratophakia surgery for high myopia. Mean preoperative myopia was -18.74+/-9.16 diopters (D; range, -7 D to -49 D). Follow-up was 12+/-2 years. MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), change in mean keratometry, visual acuity under glare conditions, BCVA versus potential acuity meter reading, and patient satisfaction with the visual outcome. RESULTS: Mean preoperative UCVA increased from 20/800+/-20/400 (range, counting fingers-20/400) to 20/80+/-20/200 (range, 20/250-20/32) in 24 eyes. Mean preoperative BCVA of 20/32+/-20/64 increased only in five eyes, whereas six eyes had no change and 18 eyes had a more than one line loss of Snellen BCVA. Mean preoperative keratometry reading decreased from 43.67+/-0.90 D (range, 41.0-46.25 D) to 37.40+/-2.92 D (range, 29.43-47.68 D). In the presence of glare, mean BCVA decreased to 20/100+/-20/100 (range, counting fingers-20/32). Potential acuity meter (PAM) readings were significantly (P<0.05) higher than BCVA. Mean PAM reading was 20/25+/-20/100 (range, 20/100-20/16). Seven patients (11 eyes) were extremely satisfied with the operative result more than 10 years after the operation, whereas four patients (four eyes) were not satisfied at all. CONCLUSIONS: Epikeratophakia for the correction of myopia improved UCVA significantly, but BCVA decreased. The removal of the lenticules in patients who were not satisfied with their visual acuity was uncomplicated, and acceptable vision could be achieved with either contact lenses or intraocular lens implantation.

Adult↗
PubMed1979

Five years' follow-up in the surgical management of cataracts in high myopia treated with the Kelman phacoemulsification technique.

With the advent of phacoemulsification, much interest has again been rekindled in extracapsular cataract surgery and its effects on the vitreoretinopathies associated in high myopia. Since 1972, 278 patients with high myopia greater than --7.50 D, as as determined by axial length echography, have been operated on by the author. The five-year follow-up with statistical analysis of these cases is presented. Comments as to the merits of extracapsular versus intracapsular surgery in high myopia will be set forth.

Adult↗
PubMed1979

Role of cyclopegics in progressive myopia.

Atropine sulfate 1% was instilled in both eyes of 86 children (172 eyes) on a daily basis for a period of two to eight years. No untoward changes in intraocular pressure, pupillary response, accommodation, or appearance of the ocular fundi were noted. A comparison with a similar group of children having only glasses prescribed during a similar time span revealed that atropine is effective in reducing theprogression of myopia in children; a permanent reduction in the degree of myopia may be achieved. Relaxation of accommodation by means of cycloplegic drugs may be a safe and effective treatment of myopia.

Adolescent↗
PubMed1979

Physiologic vs pathologic myopia: genetics vs environment.

Physiologic myopia occurs as the result of a correlation failure of refraction components in the normal eye. Pathologic myopia is caused by excessive axial elongation that primarily involves the ora-equatorial area and the posterior pole. Peripheral fundus changes and posterior staphyloma formation are ophthalmoscopic evidences of this process. Heredity is the basic determinant of ocular refraction, but numerous agents produce both temporary and permanent myopias.

Animals↗
PubMed1993

Excimer laser photorefractive keratectomy for myopia. Clinical results in sighted eyes.

PURPOSE: To evaluate the refractive results of excimer laser photorefractive keratectomy (PRK) performed on normal, sighted myopic eyes; to assess the role of postoperative topical steroid treatment in patients with PRK; and to study the regression of effect. METHODS: An argon fluoride 193-nm excimer laser was used. Photorefractive keratectomy was performed on 420 eyes with preoperative refraction ranging from -1.25 to -7.50 diopters (D). Minimum follow-up time was 12 months, and 194 of the eyes were followed for 15 months. Postoperative treatment generally consisted of topical dexamethasone for 3 months, but in a sub-study, some eyes were treated for only 5 weeks. RESULTS: Mean refraction (spherical equivalent +/- standard deviation) at 12 months was -0.04 +/- 0.84 D and at 15 months -0.22 +/- 0.78 D. At 12 months postoperatively, 86% of the eyes were within 1.00 D of emmetropia, at 15 months 87%. At 12 months, 91% of the eyes had an uncorrected visual acuity of at least 20/40, at 15 months 87%. Eyes treated with dexamethasone for 3 months regressed significantly less than those treated for only 5 weeks (P < 0.01). Dexamethasone also was effective in reversing regression later in the postoperative course. Eyes with preoperative myopia up to 4.90 D had significantly better refractive results at 12 months than eyes with myopia ranging from 5.00 to 7.50 D (P < 0.01). CONCLUSION: These data show that excimer laser PRK can correct myopia with good predictability. Results at 12 and 15 months tend to suggest stability of postoperative refraction. Regression of effect was more common in higher myopes. Topical steroids postoperatively seem to play a crucial role for the refractive result.

Adult↗
PubMed1995

A multicenter trial of photorefractive keratectomy for residual myopia after previous ocular surgery. Summit Therapeutic Refractive Study Group.

PURPOSE: The Summit Therapeutic Refractive Clinical Trial is a nine-center prospective, nonrandomized, self-controlled trial to assess the efficacy, stability, and safety of using a standardized technique of excimer laser photorefractive keratectomy (PRK) to correct residual myopia in eyes with previous refractive surgery or cataract surgery. PATIENTS AND METHODS: Eligible eyes with a mean residual myopia of -3.7 +/- 1.8 diopters (D) (range, -0.63 to -11.00 D) underwent PRK with a 193-nm excimer laser for myopic corrections between -1.50 and -7.50 D. Standardized settings were used for the ablation zone, ablation rate, repetition rate, and fluence. One hundred seven of the first 114 treated eyes were examined 1 year after PRK, with 98% of eyes having had refractive keratotomy and 2% having had cataract surgery. RESULTS: One year postoperatively, the mean manifest spherical equivalent refraction was -0.6 +/- 1.4 D (range, -6.50 to 2.50 D); 63% of eyes were within +/-1.00 D of the attempted correction; and uncorrected visual acuity was 20/40 or better in 74% of eyes. Twenty-nine percent of eyes lost two or more Snellen lines of best-corrected visual acuity, and central corneal haze was moderate or severe in 8% of eyes. CONCLUSIONS: Excimer laser PRK is effective in reducing residual myopia after previous refractive and cataract surgery. However, it is less accurate than PRK in eyes that did not undergo surgery and is more likely to cause a loss of best-corrected visual acuity 1 year after treatment.

Adult↗
PubMed1995

Association of congenital microcoria with myopia and glaucoma. A study of 23 patients with congenital microcoria.

BACKGROUND: Congenital microcoria, a bilateral condition of the iris dilatator, is defined as a pupil with a diameter of less than 2 mm when looking at a distant object. Although it is usually a hereditary condition resulting from autosomal dominant transmission with no marked difference between the sexes, it is sometimes sporadic. The ocular abnormalities associated with this condition (myopia, astigmatism, and glaucoma) have never been linked to the malformation. METHOD: Forty-two members of a family were examined: 23 had microcoria and 19 did not. The two groups were studied to identify symptoms of the condition and its associated abnormalities. RESULTS: There was a very strong correlation between microcoria and myopia (Fisher's exact test, P < 0.00001), between microcoria and astigmatism (Fisher's exact test, P < 0.0001), and between microcoria and glaucoma (Fisher's exact test, P = 0.011). CONCLUSIONS: There is a statistical correlation among myopia, glaucoma, and microcoria, and the disorders are associated with the condition in a nonfortuitous way. The functional prognosis for microcoria appears to be extremely poor because of refractive disorders and, particularly, a link between microcoria and glaucoma that is difficult to explain.

Adolescent↗