Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Hyperopia”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1997

Excimer laser photorefractive keratectomy for the correction of hyperopia using an erodible mask and axicon system.

PURPOSE: The purpose of the study is to evaluate photorefractive keratectomy for the correction of hyperopia using the erodible mask and Axicon system. METHODS: Forty-three patients (43 eyes) with a mean refraction (spherical equivalent) of +4.54 diopter (D) (range, +1.75 to +7.50 D) were treated using a Summit Technology "Apex Plus" excimer laser. This system uses an erodible mask to create a 6.50-mm diameter hyperopic correction over the axial cornea. An Axicon then is used to fashion a 1.50-mm "blend zone" around the correction. On the basis of preoperative refractions, patients were assigned to 3 groups: 2 groups of 14 patients underwent either "+2.00 D" or "+3.00 D" corrections and 15 patients had "+4.00 D" corrections. RESULTS: All patients had a reduction in their hyperopia with an overcorrection, especially in the first month after surgery and some stability in the refractive change at 3 to 6 months. The mean manifest refraction (n = 43) at 6 months was -0.17 D (range, +4.50 D to -3.125 D). Patient satisfaction was high. At 6 months, all eyes had an improvement in unaided near visual acuity. Unaided distance acuity was improved in 37 eyes (86%). A ring of haze 6.5 mm in diameter appeared in all eyes 1 month after surgery. Night halo measurements at 6 months showed no differences from preoperative levels. Flicker contrast sensitivity and forward light scatter (glare) measurements showed no differences after surgery. CONCLUSIONS: In this short-term study, photorefractive keratectomy for hyperopia using the erodible mask and Axicon system appeared to be a promising procedure. Visual performance, in terms of flicker contrast sensitivity, forward light scatter, and night halos, was not compromised. There was an overcorrection based on the manufacturer's algorithms. Manipulation of the treatment algorithms should improve future predictability.

Adult↗
PubMed1997

Photorefractive keratectomy for hyperopia: six months results in 45 eyes.

OBJECTIVE: To evaluate the safety and efficacy of photorefractive and photoastigmatic keratectomy for hyperopia. METHODS: The Chiron Keracor 116 excimer laser (Chiron Technolas, Munich, Germany) was used to create a peripheral annular ablation profile for the correction of hyperopia and a prior cylindrical ablation in the negative axis for correction of the astigmatic component in 45 consecutive eyes with up to +6.50 diopters (D). All patients were followed for a minimum of 6 months. RESULTS: At 6 months, mean subjective refraction was +0.12 D (standard deviation, 0.70), with 87% within 1 D of emmetropia. Ninety-three percent achieved uncorrected visual acuity of 20/40 or better. Three eyes (6.7%) lost 2 lines of best spectacle-corrected visual acuity and six eyes (13.3%) gained 2 lines or more. CONCLUSIONS: Photorefractive and photoastigmatic keratectomy effectively and predictably reduced hyperopia, improving uncorrected visual acuity in all patients at 6 months. Longer follow-up is required to be certain that refractive changes are stable.

Astigmatism↗
PubMed1998

Laser vision correction for low hyperopia. An 18-month assessment of safety and efficacy.

OBJECTIVE: This study aimed to assess the efficacy and safety of hyperopic photorefractive keratectomy (PRK) and to evaluate the effect of degree of hyperopia, two epithelial removal methods, and various postoperative patient management techniques on clinical outcomes. DESIGN: Prospective, nonrandomized, open-label clinical trial. PARTICIPANTS: A total of 38 patients with mean follow-up of 13.9 months (n = 65 eyes with hyperopia from +1.00 diopter [D] to +4.00 D) participated. INTERVENTION: Hyperopic PRK with the VISX STAR Excimer Laser System was performed. MAIN OUTCOME MEASURES: Spherical equivalent (SE) including vector analysis of SE; uncorrected visual acuity (UCVA); best-spectacle corrected visual acuity (BSCVA); low-, medium- and high-contrast visual acuities; topography; keratometry; pachymetry; and intraocular pressure, haze, and all other potential complications were measured. RESULTS: A total of 80% of eyes were within +/- 0.5 D and all but 1 eye (98%) were within +/- 1.0 D of intended manifest SE at 1 year. There was no induced astigmatism at 1 year. At 12 months, 72% of eyes had UCVA of 20/25 or better and 70% had achieved preoperative BSCVA, with no eye seeing worse than 20/25. These results remained constant at 18 months. There was a tendency toward regression between months 1 and 6 with stabilization of SEs between months 6 and 12. Thereafter, up to 18 months, there was some regression with a mean of +0.31 D, but the number of patients was small. There was one mild decentration and very slight decreases in mean intraocular pressure and central corneal thickness. One patient had grade 1.0 haze develop in both eyes at 12 and 18 months; all other patients experienced trace or no haze. There were no significant complications. CONCLUSIONS: The results of this study support the hypothesis that laser vision correction is safe and effective for treating low hyperopia. The predictability of the hyperopic laser vision correction procedure used in this study was very good. Other than the slower recovery of BSCVA and UCVA seen with this procedure, as compared with myopic PRK, there were no significant complications. The trend toward some later regression needs to be further evaluated in a larger number of patients. Overall, patients were very pleased with the treatment, even in the first 6 months.

Adult↗
PubMed1988

Hexagonal keratotomy for correction of low hyperopia: preliminary results of a prospective study.

Fifteen sighted eyes of 11 patients had hexagonal keratotomy for the correction of low hyperopia. Mean preoperative hyperopia of +3.21 diopters (range +1.75 to +5.50) was reduced a mean of 2.16 diopters (range 0 to -3.25) and keratometry was increased a mean of +2.22 diopters (range +0.75 to +3.71). Follow-up averaged 9.5 months (range 2.0 to 17.5). Ten of the 15 eyes (67%) had at least six months follow-up. No eye had better than 20/80 uncorrected visual acuity preoperatively. Fourteen eyes (93%) had 20/80 or better uncorrected acuity at the most recent postoperative visit. Nine of the 15 eyes (60%) had uncorrected acuity of 20/40 or better. Refractive spherical equivalent appeared to stabilize by three months for most patients. Astigmatism was increased a mean of only +0.02 diopter and no serious complications occurred. Further follow-up is required to assess the safety and efficacy of hexagonal keratotomy for reducing low levels of hyperopia.

Astigmatism↗
PubMed1997

Excimer laser photorefractive keratectomy for low hyperopia: safety and efficacy.

PURPOSE: To assess the safety and efficacy of photorefractive keratectomy (PRK) to correct low hyperopia. SETTING: University of Ottawa Eye Institute, Ottawa General Hospital, Ontario, Canada. METHODS: Twenty-five eyes with refractions of +1.00 to +4.00 diopters (D) and cylinder of 1.00 D or less were treated for hyperopia with the VISX Star excimer laser system using a refined ablation architecture. Thorough visual assessments were performed preoperatively (baseline) and 1, 3, and 6 months postoperatively. Complications were recorded and the level of patient satisfaction was noted. RESULTS: Mean spherical equivalent at 6 months was +0.27 D +/- 0.55 (SD), which was an 89% reduction over baseline. Eighty-four percent of patients gained two to seven lines of near uncorrected visual acuity (UCVA) and 1 patient (4%) lost more than one line. Eight percent achieved 20/25 or better UCVA. Approximately half realized their preoperative distance best corrected visual acuity (BCVA) by 1 month. By the end of the study, all patients had improved, achieved, or were within one line of their baseline distance BCVA. There were some slight reductions in lower contrast acuity at 6 months, although dim lighting conditions did not further reduce these acuities. Most patients had no clinically meaningful change in cylinder. The most common complications included early, transient corneal surface irregularities and visual symptoms and trace haze (grade < or = 0.5) in 14 of 23 patients at 6 months. All but 1 patient expressed a high degree of satisfaction. CONCLUSIONS: These results support the hypothesis that PRK shows great promise as a safe and effective treatment for low hyperopia. There were no significant complications and no decentered ablations. The slight regression occurred with or without the presence of trace haze. Overall, refractive stability was encouraging, although longer follow-up is needed.

Adult↗
PubMed1998

Noncontact thermokeratoplasty to correct hyperopia induced by laser in situ keratomileusis.

PURPOSE: To evaluate the efficacy and safety of noncontact holmium:YAG (Ho:YAG) laser thermokeratoplasty (LTK) for treating hyperopia induced by laser in situ keratomileusis (LASIK). SETTING: Department of Ophthalmology, University of Alicante, Instituto Oftalmológico de Alicante, Alicante, Spain, and the University of Al-Azhar, Cairo, Egypt. METHODS: Noncontact LTK was applied to 13 eyes (11 patients) with significant hyperopia after LASIK using a Ho:YAG laser (model gLase 210, Sunrise Technologies). Mean spherical equivalent before LTK was +4.60 diopters (D) +/- 1.40 (SD) (range +2.50 to +7.25 D). The results were evaluated 18 months after the LTK surgery. RESULTS: A significant myopic shift developed in all eyes that gradually receded to emmetropia 6 to 8 weeks after LTK. After 12 months, refraction was relatively stable. At 18 months, there was a statistically significant difference between the mean uncorrected visual acuity (UCVA) before LTK (0.19 +/- 0.09) and mean postoperative UCVA (0.61 +/- 0.22) (P < .005). At the end of the study, there was a mean increase of 4.10 +/- 1.12 D in central keratometric power. Total regression did not occur in any eye. CONCLUSION: Noncontact Ho:YAG LTK was safe and effective in correcting LASIK-induced hyperopia. The cutting of Bowman's layer and a thinner corneal center may contribute to the stability of LTK in such cases.

Adult↗
PubMed1998

Laser in situ keratomileusis for hyperopia.

PURPOSE: To examine the initial results of laser in situ keratomileusis (LASIK) for hyperopia. SETTING: Arzt für Augenheilkunde, Mannheim, and Photoingenieur, Wendelstein, Germany. METHODS: This retrospective study evaluated 43 eyes having hyperopic LASIK using the Automatic Corneal Shaper (Chiron Vision) and the MEL 60 excimer laser (model 94, Aesculap-Meditec). Patients were divided into two groups. Group 1 consisted of 20 eyes with a refraction from +1.00 to +4.00 diopters (D) and Group 2, 23 eyes from +4.25 to +8.00 D. Objective refraction and visual acuity were measured over 12 months. RESULTS: One year after LASIK, Group 1 had a mean spherical equivalent of +0.33 D (range -0.79 to +1.45 D) and Group 2, +1.91 D (range -0.08 to +3.71 D). Best corrected visual acuity remained unchanged in 35.0% in Group 1 and 56.5% in Group 2. Five percent in Group 1 and 7.3% in Group 2 lost more than 2 lines of best corrected visual acuity. CONCLUSIONS: Laser in situ keratomileusis for hyperopia resulted in less regression, minimal haze, and better predictability and stability than surface photorefractive keratectomy. Preoperative corneal radius appeared to be an important factor in eyes with high hyperopia.

Adolescent↗
PubMed1998

Abnormal head posture associated with high hyperopia.

BACKGROUND: An abnormal head posture may be adopted for ocular or nonocular reasons. The most common ocular reasons are to maintain binocularity and to obtain the best possible visual acuity. Patients with undercorrected or overcorrected refractive errors have been reported to adopt a variety of head positions, thought to be an attempt to obtain the best possible visual acuity. METHODS: Five patients with symmetric high hyperopia (at least + 5.00 D) and an abnormal head posture are presented. RESULTS: All five patients demonstrated an abnormal head posture of chin down for fixation without the spectacle correction in place. This abnormal head posture was eliminated by occlusion of either eye and also by wearing of the refractive correction. No patient demonstrated significant strabismus. CONCLUSION: An abnormal head posture when not wearing spectacle correction can occur in children who have high hyperopia and insignificant strabismus. This may be a mechanism by which the best visual acuity is obtained (indicated by the disappearance of the abnormal head posture on wearing of the glasses) and also to maintain binocularity (indicated by the disappearance of the abnormal head posture under monocular testing conditions). The presence of a chin-down abnormal head posture should alert the examiner to the possible presence of high hyperopia and therefore the necessity for a cycloplegic refraction.

Child↗
PubMedDate not supplied

Axial length and hyperopia in eyes with retinal vein occlusions.

We performed a prospective study in order to elucidate the predisposing role of axial length and hyperopia in retinal vein occlusions. The study group comprised 39 patients with unilateral central retinal vein occlusion (CRVO), 50 patients with unilateral branch retinal vein occlusion (BRVO), 13 patients with unilateral hemispheric retinal vein occlusion (HRVO) and 45 control eyes. The axial length of affected eyes was compared to fellow eyes and control eyes in each subgroup of patients with retinal vein occlusion. No statistical difference was noted for any of the subgroups (p > 0.05). Hyperopia was detected in 12 of 39 eyes (31%) with CRVO, 14 of 50 eyes (28%) with BRVO, 4 of 13 eyes (31%) with HRVO and 15 of 45 eyes (33%) in the control group. No statistically significant difference was discovered (p > 0.05). In the light of our study, we believe that axial length and hyperopia may not be risk factors in retinal vein occlusions, in contrast to common belief.

Adult↗
PubMed1998

Autosomal dominant nanophthalmos (NNO1) with high hyperopia and angle-closure glaucoma maps to chromosome 11.

Nanophthalmos is an uncommon developmental ocular disorder characterized by a small eye, as indicated by short axial length, high hyperopia (severe farsightedness), high lens/eye volume ratio, and a high incidence of angle-closure glaucoma. We performed clinical and genetic evaluations of members of a large family in which nanophthalmos is transmitted in an autosomal dominant manner. Ocular examinations of 22 affected family members revealed high hyperopia (range +7.25-+13.00 diopters; mean +9.88 diopters) and short axial length (range 17.55-19.28 mm; mean 18.13 mm). Twelve affected family members had angle-closure glaucoma or occludable anterior-chamber angles. Linkage analysis of a genome scan demonstrated highly significant evidence that nanophthalmos in this family is the result of a defect in a previously unidentified locus (NNO1) on chromosome 11. The gene was localized to a 14.7-cM interval between D11S905 and D11S987, with a maximum LOD score of 5. 92 at a recombination fraction of .00 for marker D11S903 and a multipoint maximum LOD score of 6.31 for marker D11S1313. NNO1 is the first human locus associated with nanophthalmos or with an angle-closure glaucoma phenotype, and the identification of the NNO1 locus is the first step toward the cloning of the gene. A cloned copy of the gene will enable examination of the relationship, if any, between nanophthalmos and less severe forms of hyperopia and between nanophthalmos and other conditions in which angle-closure glaucoma is a feature.

Chromosome Mapping↗
PubMed1978

Effects of induced hyperopia.

Hyperopia of 1.00, 1.50, and 2.00 D was induced in 42 subjects by means of concave lenses. A significant decrease in performance on a standard intelligence test occurred with the highest-power lenses. Symptoms induced indicate that the results are applicable to hyperopia. Prescriptions and vision screening criteria for hyperopia are indicated.

Adolescent↗
PubMed1991

Inducing myopia, hyperopia, and astigmatism in chicks.

Myopia and hyperopia have been produced in chicks by applying specially designed convex and concave soft contact lenses to the eyes of newly hatched birds. After 2 weeks of wear, the eyes develop refractive states equivalent in sign and amount (+8 and -10 D) to the lens used. However, the lenses produce an artificial hyperopic shift during the first week of wear due to corneal flattening. We have developed a new approach involving the use of goggles with hard convex and concave contact lens inserts placed between the frontal and lateral visual fields. Myopia and hyperopia (+10 and -10 D) can be produced within days (4 days for hyperopia and 7 days for myopia) if the defocus is applied from the day of hatching. We can also produce significant amounts of astigmatism (1 to 5 D) axis at 90 degrees and 180 degrees by using cylindrical contact lens inserts. Although these last results are preliminary, they suggest that accommodation is not likely involved at this stage of refractive development because we do not believe that the accommodative mechanism can cope with cylindrical defocus. All spherical refractive errors produced using the goggle system appear to result from alterations in vitreous chamber depth.

Animals↗
PubMed1997

Holmium laser thermokeratoplasty for the reversal of hyperopia after myopic photorefractive keratectomy.

BACKGROUND: Overcorrection following myopic photorefractive keratectomy, with a target of emmetropia, leaving a spherical equivalent of more than 1.0 D of hyperopia is of the order of 1%. This study analyses the efficacy, safety, and 1 year stability of outcome of laser thermokeratoplasty (LTK) carried out on eyes with persistent symptomatic hyperopia following photorefractive keratectomy (PRK) for myopia. METHOD: 11 consecutive eyes in 11 patients underwent LTK using the Technomed Holmium 25, contact holmium:YAG laser system. The mean spherical equivalent before LTK was +2.06 D (SD 1.02 D, range +1.00 D to +4.75 D) based on a non-cycloplegic refraction. Between four and 16 burns were used per eye, depending on the error to be corrected. RESULTS: The mean spherical equivalent was +0.511 D (SD 0.551) at 1 year. Ten of the 11 eyes were seeing 6/12 or greater, unaided (91%) and nine were within 1.0 D of the target sphere equivalent (82%). Recovery of unaided acuity occurred during the first week in four cases and the first month in the rest. One eye lost greater than one line of best corrected vision (9%), going from 6/5 to 6/7.5 and one gained a line (9%), 6/12 to 6/7.5. No complications occurred during the follow up period. CONCLUSIONS: In this study of a small number of eyes with hyperopia induced by PRK, LTK appears safe, predictable, and stable for low errors followed for 1 year.

Adult↗
PubMed1997

Noncontact holmium:YAG laser thermal keratoplasty to correct hyperopia: 18-month follow-up.

PURPOSE: To assess the safety and efficacy of noncontact holmium:yttrium aluminium garnet laser thermal keratoplasty (Ho:YAG LTK) for correction of low to moderate hyperopia. METHODS: We performed noncontact Ho:YAG LTK on 1 eye each of 28 patients for correction of hyperopia up to +3.88 dpt. Treatments were conducted with 1 or 2 symmetrical octagonal rings of 8 spots/ring with centerline diameters of 6 mm (1 ring) or 6 and 7 mm (2 rings), 10 pulses of laser light at 5 Hz pulse repetition frequency, variable pulse energy in the range of 208-242 mJ and a nominal spot diameter between 615 and 623 microns. RESULTS: At 18 months after surgery, 20 of 22 (91%) treated patient eyes had improved uncorrected distance visual acuity. The mean change in subjective manifest refraction (spherical equivalent) was -0.52 +/- 0.35 dpt and -1.41 +/- 0.53 dpt for 1- and 2-ring treatment groups, respectively, with good stability in the refractive change after 6 months. The mean induced refractive astigmatism was small (0.30 +/- 0.37 dpt/0.25 +/- 0.29 dpt for 1-/2-ring treatments). None of the eyes lost 2 or more lines of spectacle-corrected distance visual acuity. There were no clinically significant changes in glare and contrast sensitivity. CONCLUSIONS: Noncontact LTK treatment of low hyperopia is safe and effective, and it is more stable and less prone to induce astigmatism than previously reported contact mode LTK treatments.

Adult↗
PubMedDate not supplied

Correction of hyperopia induced by photorefractive keratectomy using non-contact Ho:YAG laser thermal keratoplasty.

PURPOSE: To evaluate the safety and effectiveness of non-contact holmium:YAG laser thermal keratoplasty in correcting hyperopia induced by photorefractive keratectomy (PRK). METHODS: Non-contact holmium:YAG laser thermal keratoplasty was applied to 14 eyes with significant hyperopia induced by PRK. The mean spherical equivalent refraction before holmium:YAG laser thermal keratoplasty was +4.20 +/- 1.80 diopters (D) (range, +1.75 to +6.25 D). The results were evaluated 12 months after holmium:YAG laser thermal keratoplasty. RESULTS: No sight-threatening complications occurred. Recovery of spectacle-corrected visual acuity took from 2 to 6 weeks. The immediate significant myopic shift that developed in all eyes gradually receded over 6 to 8 weeks. All eyes were relatively stable after 9 months. At 12 months, there was no statistically significant difference (p < .005) between the mean preoperative spectacle-corrected visual acuity (0.71 +/- 0.12) and the mean postoperative uncorrected visual acuity (0.65 +/- 0.28). At 12 months there was a mean increase of 4.60 +/- 1.20 D in central keratometric power. Total regression did not occur in any eye. CONCLUSIONS: Non-contact holmium:YAG laser thermal keratoplasty offers a safe and effective alternative to correct PRK-induced hyperopia.

Adult↗
PubMedDate not supplied

Excimer laser photorefractive keratectomy for hyperopia.

OBJECTIVE: To prospectively study excimer laser correction of hyperopia, with a 1-year followup. METHODS: Eleven consecutive hyperopic eyes (10 phakic and 1 aphakic) underwent correction of hyperopia using the Summit Technology SVS Apex Plus excimer laser. Data collection included cycloplegic refraction, spectacle-corrected visual acuity, contrast sensitivity, corneal haze, manual keratometry, and videokeratography. Prior to treatment the mean hyperopic spherical equivalent refraction (corneal plane) was +5.80 diopters (D) (SD2.10). The mean attempted correction was +3.09 D at the corneal plane. RESULTS: Refractive data for the group showed a mean overcorrection at 1 month of +3.18 D. This regressed slightly before stabilizing at 3 months, with a mean overcorrection of +1.88 D. Thereafter there was no statistically significant fluctuation in refraction (p = 0.67). The amount of overcorrection and regression was greater in eyes that received higher corrections. Changes in manual keratometry and videokeratography mirrored the attempted correction more closely than refraction, although stabilization did not occur until 6 months. CONCLUSIONS: Because the hyperopic correction achieved when measured by refraction was greater than expected, algorithms should be adjusted. The hyperopic erodible disc and Axicon lens system is capable of treating low to moderate amounts of hyperopia.

Adult↗
PubMedDate not supplied

Posterior chamber phakic intraocular lens for hyperopia of +4 to +11 diopters.

PURPOSE: To examine the efficacy, predictability, stability, and safety of posterior chamber phakic intraocular lens (IOL) implantation in eyes with high hyperopia. METHODS: We analyzed the results of 24 eyes that received a posterior chamber hydrogel-collagen plate phakic IOL (Staar Collamer Implantable Contact Lens, ICL) for the correction of hyperopia with the goal of emmetropia. Mean follow-up was 8.4 months (range, 1 to 18 mo). RESULTS: The mean preoperative spherical equivalent refraction was +6.51 +/- 2.08 D (range, +3.75 to +10.50 D). Mean postoperative spherical equivalent refraction at last examination was -0.39 +/- 1.29 D (range, +1.25 to -3.88 D), with 79% (19 eyes) within +/-1.00 D and 58% (14 eyes) within +/-0.50 D of emmetropia. Postoperative uncorrected visual acuity at last examination was 20/20 or better in 8% (two eyes) and 20/40 or better in 63% (15 eyes). A gain of two or more lines of spectacle-corrected visual acuity was seen in two eyes (8%) at last examination. One eye (4%) lost two or more lines of spectacle-corrected visual acuity due to progressive neovascular glaucoma initiated by early postoperative pupillary block. CONCLUSION: Posterior chamber phakic IOL implantation with the Staar Collamer plate lens is an effective method for correcting high hyperopia. Large, patent iridotomies are important in hyperopic eyes to lower the risk of postoperative pupillary block. Improved phakic IOL power calculation formulas will refine predictability of refractive outcome.

Adult↗
PubMedDate not supplied

Centered vs. inferior off-center ablation to correct hyperopia and presbyopia.

BACKGROUND: We describe a new technique of inferior off-center ablation with laser in situ keratomileusis (LASIK) to correct both hyperopia and presbyopia. METHODS: This prospective clinical study was based on the empirical results obtained with LASIK in 16 hyperopic eyes of 8 patients. All patients had a centered ablation in one eye and an inferior decentered ablation in the other eye. A Schwind excimer laser was used and a planned inferior off-center ablation of 1 mm was performed. Maximum follow-up was 22 months (8 eyes). RESULTS: Patients with hyperopia that underwent inferior decentered ablation were able to read for a prolonged period of time, compared with eyes that had conventional centered excimer laser ablation. Patients with steepened corneas in the inferior and eccentric zone ended up not only with better distance but also better near vision. No loss of spectacle-corrected visual acuity in any eye has been observed to date. CONCLUSION: Planned inferior off-center ablation to correct hyperopia and presbyopia achieved better distance and near visual acuity than centered ablation. As with centered ablation, no significant regression of effect occurred with off-center ablation; reading near vision was better and more stable with inferior off-center ablation.

Cornea↗