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PubMedDate not supplied

Conductive keratoplasty for the correction of residual hyperopia after LASIK.

PURPOSE: To report the 6-month results concerning efficacy, safety, predictability, and stability of conductive keratoplasty for the correction of residual hyperopia after corneal refractive surgery. METHODS: A total of 35 eyes (26 patients) with residual hyperopia after corneal refractive surgery ranging between +1.00 to +4.75 diopters (D) of spherical equivalent refraction were enrolled in the study and underwent conductive keratoplasty following a modified nomogram. RESULTS: Variables and data were available for all eyes at 6 months postoperatively. A total of 24 (69%) eyes had uncorrected visual acuity (UCVA) of > or = 20/40, and 10 (29%) eyes had UCVA of 20/20. Manifest refractive spherical equivalent was within +/- 0.50 D in 17 (49%) eyes and within +/- 1.00 D in 25 (71%) eyes in cases of previous hyperopic LASIK; the optical zone was significantly increased. CONCLUSIONS: Using a modified nomogram, conductive keratoplasty for correction of residual hyperopia was effective, but predictability was not satisfactory and safety needs to be established.

Adult↗

PubMedDate not supplied

Excimer laser photorefractive keratectomy for hyperopia.

BACKGROUND AND OBJECTIVE: Photorefractive keratectomy (PRK) has been extensively evaluated for the correction of myopia. This study was undertaken to assess the safety, efficacy, and reliability of PRK in the correction of hyperopia. PATIENTS AND METHODS: There were 28 eyes with refractions of +1 to +7.75 D treated for hyperopia with the Chiron Technolas 217-C excimer laser. Thorough visual assessments were made before treatment and at regular follow-up to 18 months. Complications and patient satisfaction were noted. RESULTS: At 18 months the mean subjective refraction was +0.46+/-1.00 D with 26 eyes (92.8%) within 1 D of emmetropia. Thirteen eyes (46.4%) achieved uncorrected visual acuity (UCVA) of 20/20 or better and all patients had an UCVA of > or = 20/32 or better. Best corrected visual acuity (BCVA) remained unchanged in 26 eyes (92.8%) and improved in 2 eyes (7.2%). On the seventh day from treatment, 17 eyes (25%) had a loss of 2 or more lines of BCVA. At 15 days this was reduced to 8 eyes (14.3%) and at one month to 3 eyes (3.6%). There were no cases of loss of 2 or more lines of BCVA at 18 months of follow-up. All patients expressed a high degree of satisfaction. CONCLUSIONS: Photorefractive keratectomy safely and effectively reduced hyperopia in the patients studied. The technique was reliable and still offered good results at 18 months of follow-up.

Adult↗

PubMed2001

Conductive keratoplasty for the correction of hyperopia.

BACKGROUND/PURPOSE: Conductive keratoplasty (CK) is a surgical technique that delivers radio frequency (350 kHz) current directly into the corneal stroma through a Keratoplasty tip inserted into the peripheral cornea at 8 to 32 treatment points. A full circle of CK spots produces a cinching effect that increases the curvature of the central cornea, thereby decreasing hyperopia. We report here the 12-month results of a 2-year, prospective, multicenter US clinical trial conducted to evaluate the efficacy, safety, and stability of CK. METHODS: A total of 233 patients (401 eyes) with preoperative hyperopia of +0.75 to +3.00 D and < or = 0.75 D of astigmatism (mean preoperative manifest refractive spherical equivalent = +1.76 D +/- 0.60) were enrolled into the study at 13 centers and underwent CK treatment. RESULTS: Twelve-month postoperative data are available on 203 eyes for safety and stability and 171 eyes for safety, stability, and efficacy. A total of 91% had uncorrected visual acuity (UCVA) of 20/40 or better, and 51% had UCVA of 20/20 or better. Manifest refractive spherical equivalent was within +/- 0.50 D in 58%, within +/- 1.00 D in 91%, and within +/- 2.00 D in 99%. The mean change in residual refraction was 0.26 D +/- 0.49 between 3 and 6 months, 0.09 D +/- 0.37 between 6 and 9 months, and 0.13 D +/- 0.39 between 9 and 12 months. CONCLUSIONS: One-year data show safety and efficacy of CK in the treatment of hyperopia. Changes in residual refractive error after CK appeared to be small, suggesting that a stable refraction could be achieved by 6 months.

Adult↗

PubMedDate not supplied

Circular and interrupted suture technique for correction of hyperopia following radial keratotomy.

BACKGROUND: Hyperopia is a possible complication following radial keratotomy. In this article, we describe a circular and interrupted corneal compression suture technique for the correction of hyperopia induced by radial keratotomy. METHODS: A retrospective study was performed to evaluate the effectiveness of this procedure in nine consecutive patients. RESULTS: The procedure achieved an average of -1.70 diopters change in spherical equivalent refraction. This accounted for an overall correction of 68% of the hyperopia caused by radial keratotomy after a minimum 3-month follow up. Seven of nine eyes (78%) were within 1.00 D of emmetropia after surgery. Uncorrected visual acuity of 20/40 or better was present in only two eyes (22%) preoperatively, and nine eyes (100%), after the corneal suturing procedure. The mean improvement of uncorrected visual acuity was 4.0 Snellen lines (P = .0004). All patients were pleased with their visual outcomes. CONCLUSIONS: We found that this technique is an easy, safe, and reasonably successful treatment for radial keratotomy overcorrection.

Adult↗

PubMed2005

Conductive keratoplasty: a radiofrequency-based technique for the correction of hyperopia.

PURPOSE: To evaluate the data on the safety, effectiveness, and stability of conductive keratoplasty (CK), a thermal, radiofrequency-based technique for treating 0.75 to 3.00 diopters (D) of spherical hyperopia. METHODS: A prospective, consecutive series, multicenter clinical trial involving 400 hyperopic eyes was conducted by 19 surgeons at 12 centers. The treatment goal was emmetropia. Cohort follow-up was up to 2 years. RESULTS: At 12 months postoperatively, data were available for 97.5% (354/363) of eyes for efficacy variables and 98% (391/400) of eyes for safety variables. A total of 54% of the CK eyes showed 20/20 or better uncorrected visual acuity, and 92% showed 20/40 or better at 12 months. The mean postoperative manifest refractive spherical equivalent was within 0.50 D in 61% and within 1.00 D in 88%. After CK, eyes were approximately 0.50 D myopic at month 1 and effectively emmetropic at 6 months. At 24 months, there was a 20% loss of initial effect. Safety results showed a 2-line loss of best-corrected visual acuity in 2% of the CK-treated eyes. The incidence of induced cylinder of 2.00 D or greater was below 1%. CONCLUSION: The CK technique corrects low to moderate hyperopia effectively and safely and with acceptable stability. It spares the visual axis, does not require the creation of a large flap, and is not associated with postoperative dry eye. CK has value as an alternative to hyperopic LASIK for patients with hyperopia.

Adult↗

PubMed1981

Consecutive exotropia after correction of hyperopia.

A study was done of 22 children in whom exotropia developed following correction of hyperopia because of accommodative esotropia that had not been corrected surgically. The early onset of esotropia and high degree of hyperopia seemed to predispose to the spontaneous development of exotropia. Reduction of the hyperopia by 50% to 60% resulted in satisfactory realignment of the eyes and some form of binocularity.

Accommodation, Ocular↗

PubMed1996

Hyperopia correction by noncontact holmium:YAG laser thermal keratoplasty. United States phase IIA clinical study with a 1-year follow-up.

PURPOSE: This study was performed to evaluate the safety and effectiveness of noncontact holmium: YAG (Ho:YAG) laser thermal keratoplasty (LTK) for correcting low to moderate hyperopia. METHODS: Twenty-eight patients were treated unilaterally to correct low to moderate hyperopia (up to +3.88 diopters [D] refractive error) using simultaneous noncontact delivery of Ho:YAG laser energy. Treatment parameters included one or two symmetric octagonal rings of eight spots per ring with centerline diameters of 6 mm (1 ring) or 6 and 7 mm (2 rings), ten pulses of laser light at 5-Hz pulse repetition frequency, and variable pulse energy, ranging from 208 to 242 mJ. Follow-up was 1 year in 26 (93%) of the 28 patients. RESULTS: At 1 year postoperatively, uncorrected distance visual acuity was improved in all patients. The mean change in subjective manifest refraction (+/- spherical equivalent [SE]) was -0.55 +/- 0.33 D and -1.64 +/- 0.61 D for one and two-ring treatment groups, respectively, with good stability in the refractive change after approximately 6 months. In the one-ring treatment group (17 eyes), refractive corrections of -0.50 to -1.13 D were achieved in ten eyes (59%), and seven eyes (41%) were unchanged (within +/- 0.25 D) relative to their preoperative measurements. In the two-ring treatment group, all eight eyes (100%) had substantial refractive corrections (range, -0.75 to -2.50 D). Mean induced refractive astigmatism was 0.25 +/- 0.29 D and 0.47 +/- 0.53 D for one- and two-ring treatments, respectively. None of the eyes lost two or more lines of spectacle-corrected distance visual acuity. These was no clinically significant change in endothelial cell density with respect to preoperative values. Glare and contrast sensitivity testing indicate that peripheral corneal opacities produced by LTK do not degrade vision. The amount of refractive change in each group was correlated with the amount of laser pulse energy. CONCLUSIONS: This initial United States clinical study with 1-year follow-up indicates that noncontact LTK treatment of low hyperopia is safe and effective, providing persistent, though modest, refractive corrections in 59% of the one-ring group and larger, persistent, refractive corrections in 100% of the two-ring group.

Adult↗

PubMed1997

Chalazion-induced hyperopia as a cause of decreased vision.

This article presents three cases of decreased vision due to acquired hyperopia, which were caused by a chalazion of the upper eyelid. Through manifest refraction and computerized corneal topographic analysis, acquired hyperopia associated with central corneal flattening was revealed. These findings were responsible for the blurred vision that was reversed by chalazion resolution or removal. Although not usually considered a risk factor for refractive disorders other than astigmatism, chalazia of the upper eyelid can present as a decrease in vision associated with reversible central corneal flattening and acquired hyperopia.

Aged↗

PubMed2002

LASIK correction of spherical hyperopia, hyperopic astigmatism, and mixed astigmatism with the LADARVision excimer laser system.

OBJECTIVE: To assess the safety and effectiveness of the LADARVision active tracking narrow beam excimer laser system (Alcon Surgical, Orlando, FL) using laser in situ keratomileusis (LASIK) for correction of spherical hyperopia, hyperopic astigmatism, and mixed astigmatism. DESIGN: A multicenter, prospective non-randomized (self-controlled) comparative trial. PARTICIPANTS: A total of 360 eyes, including 152 spherical hyperopic, 143 hyperopic astigmatic, and 65 mixed astigmatic, were treated for up to +6.00-diopter (D) sphere with up to -6.00-D cylinder. INTERVENTION: Treatments were performed at six sites in the United States using a 6-mm optic zone with a 1.5-mm peripheral blend zone for a maximum ablation zone diameter of 9 mm. MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA), manifest refraction, vector analysis, best spectacle-corrected visual acuity (BSCVA), complications and adverse reactions, subjective symptoms, and patient satisfaction. RESULTS: Six and 12 months of follow-up, respectively, were available on 143 and 117 spherical hyperopic eyes, 124 and 74 hyperopic astigmatic eyes, and 57 and 38 mixed astigmatic eyes, respectively. For spherical hyperopes at 6 and 12 months, UCVA was 20/40 or better in 93.4% and 93.9% of eyes, respectively. The manifest refraction spherical equivalent (MRSE) was within 0.50 D of intended in 65.0% and 74.1% of eyes, respectively, and within 1.00 D in 87.4% and 91.4%, respectively. Refractive stability was demonstrated in 94.2% or more of eyes between the intervals of 1 to 3 months and 3 to 6 months and in 95.3% or more of eyes to 12 months. A loss of two lines of BSCVA occurred in 3.5% and 3.4%, respectively, and no eyes lost more than two lines. For hyperopic astigmats at 6 and 12 months, UCVA was 20/40 or better in 90.9% and 93.8% of eyes, respectively. The MRSE was within 0.50 D of intended in 60.5% and 73.0% of eyes, respectively, and within 1.00 D in 88.7% and 89.2% of eyes, respectively. Refractive stability was demonstrated in 96.5% or more of eyes, respectively, between the intervals of 1 to 3 months and 3 to 6 months and 95.5% or more to 12 months. A loss of two lines of BSCVA occurred in 5.8% and 1.4% of eyes, respectively, and no eyes lost more than two lines. For mixed astigmats at 6 and 12 months, UCVA was 20/40 or better in 92.6% and 94.4% of eyes, respectively. The MRSE was within 0.50 D of intended in 64.9% and 73.7% of eyes, respectively, and within 1.00 D in 87.7% and 94.7% of eyes, respectively. Refractive stability was demonstrated in 100% of eyes between the intervals of 1 to 3 months and 3 to 6 months and in 97.0% or more to 12 months. A loss of two lines of BSCVA occurred in 1.9% and 0.0% of eyes, respectively, and no eyes lost more than two lines. CONCLUSIONS: The data support safety and effectiveness of the LASIK correction of spherical hyperopia, hyperopic astigmatism, and mixed astigmatism with the LADARVision system.

Adult↗

PubMed1988

X-linked congenital stationary night blindness. Review and report of a family with hyperopia.

X-linked congenital stationary night blindness is almost always associated with myopia. We have reviewed all previously reported pedigrees and have found only two with patients without myopia. A recently proposed classification of night blindness includes a complete type associated with myopia and an incomplete type in which both hyperopia and myopia were found. Complete and incomplete types did not occur within the same pedigree. We report on a family in which three of the five affected members had hyperopia and could be classified as the incomplete type and in which a fourth member with myopia was more consistent with the complete type. The lack of myopia in three members of our pedigree can be explained by two hypotheses: crossing over of the night blindness and myopic genes on the X-chromosome, or an autosomal dominant hyperopic gene that masks the myopic gene. The data from our family support the first of these two hypotheses.

Adult↗

PubMed1990

Excessive loss of hyperopia. A presenting sign of juvenile aphakic glaucoma.

We present the cases of four patients in whom juvenile aphakic glaucoma developed. An excessive loss of hyperopia was the initial clinical sign that alerted us to the diagnosis of glaucoma. At the time of diagnosis, the mean refractive error of the six glaucomatous eyes in the four patients was +4.75 diopters (D) (range, -0.25 to +6.75 D). The mean change in refraction from time of cataract extraction to diagnosis of juvenile aphakic glaucoma was 17.00 D (range, 9.25 to 21.00 D). All aphakic patients in the private practice of one of us (B.J.K.) with a spherical equivalent of less than +8.00 D in either eye have glaucoma. The only exception are those patients with a coexisting condition predisposing them to myopia. We have found an excessive loss of hyperopia to be a useful sign in alerting the ophthalmologist to the diagnosis of juvenile aphakic glaucoma.

Aphakia, Postcataract↗

PubMed1997

Hyperopia correction by noncontact holmium: YAG laser thermal keratoplasty: five-pulse treatments with 1-year follow-up.

BACKGROUND: Previous noncontact holmium (Ho): YAG laser thermal keratoplasty (LTK) studies on correction of low to moderate hyperopia have used treatment algorithms based on ten-pulse, variable-pulse-energy treatment parameters. The purpose of this study was to evaluate the safety, effectiveness, and stability of new five-pulse, constant-pulse-energy treatment parameters for noncontact Ho:YAG LTK. METHODS: Thirty-nine hyperopic patient eyes [up to +4.75 diopters (D) refractive error] were treated using simultaneous noncontact delivery of Ho:YAG laser energy (Sunrise) with two symmetrical octagonal rings of eight spots per ring and radial spot patterns on centerline diameters of 5 and 6 mm (group A), 6 and 7 mm (group B), or 6.5 and 7.5 mm (group C). Each ring of spots received five pulses of laser light at 5 Hz pulse repetition frequency and a fixed pulse energy of 240 mJ. Thirty of the 39 patient eyes (77%) had 1-year follow-up exams. RESULTS: At 1 year, the mean Snellen uncorrected distance visual acuity lines gained was 3.7 +/- 0.5/6.8 +/- 2.7/5.3 +/- 3.3 for groups A, B, and C. The mean changes in subjective manifest refraction (spherical equivalent) were -2.08 +/- 1.13 D, -1.83 +/- 0.88 D, -1.22 +/- 0.88 D for groups A, B, and C respectively. None of the eyes lost two or more lines of spectacle-corrected distance visual acuity. There were no clinically significant complications in any patient. CONCLUSION: This clinical study indicates that five-pulse noncontact LTK treatments of low hyperopia are safe and effective. The stability has to be confirmed with longer follow-up.

Adult↗

PubMed2003

Refractive lensectomy and accommodating lens implantation in a case of hyperopia.

We present a 39-year-old woman with high hyperopia who developed an intolerance to contact lenses due to dry-eye syndrome and Grave's disease. Refractive lensectomy with implantation of a custom-made +31.00 diopter (D) accommodating intraocular lens (IOL) (1CU, HumanOptics) was performed in both eyes. This foldable IOL has modified haptics with transmission elements that allow axial movement of the IOL optic and capsular bag secondary to contraction of the ciliary muscle. The calculated pseudophakic accommodation induced by the anterior shift of a +31.00 D IOL is 2.20 D per millimeter of axial displacement. After 6 months, the accommodative range determined by defocusing was 3.00 D. The subjective near point with best distance correction was 32.00 cm. Refractive lensectomy and implantation of an accommodating IOL based on focus shift may be a refractive solution in eyes with high hyperopia and a short axial length.

Accommodation, Ocular↗

PubMed2004

Laser in situ keratomileusis for hyperopia with the LADARVision 4000 with centration on the coaxially sighted corneal light reflex.

PURPOSE: To analyze the visual acuity, contrast sensitivity, and target deviations in patients who had laser in situ keratomileusis (LASIK) for primary hyperopia with the ablation centered on the coaxially sighted corneal light reflex. SETTING: University-based refractive surgery practice. METHODS: Retrospective review comprised 37 consecutive patients (61 eyes) who had LASIK for hyperopia with the LADARVision 4000 excimer laser (Alcon Laboratories). Preoperative and 3-month postoperative visual acuity and contrast sensitivity, as well as the target deviation, were assessed for each eye. The change in best spectacle-corrected visual acuity (BSCVA), best spectacle-corrected contrast sensitivity (BSCCS), and target deviation from the intended correction were analyzed. RESULTS: Postoperatively, the uncorrected visual acuity (UCVA) was 20/20 or better in 44.4% of eyes. The mean deviation from target was +0.25 diopter (D) +/- 0.82 (SD), with 65.6% of eyes within +/-0.50 D of target. None eye lost 2 or more lines of BSCVA. A loss of 3 or more patches of BSCCS were seen in 6.6% of the eyes and a loss of 4 or more patches, in 1.6%. CONCLUSION: Hyperopic LASIK with LADARVision 4000 with the ablation zone centered on the coaxially sighted corneal light reflex did not adversely affect BSCVA and BSCCS.

Adult↗

PubMed2005

Laser in situ keratomileusis for primary hyperopia.

PURPOSE: To evaluate the efficacy, predictability, stability, and safety of hyperopic laser in situ keratomileusis (H-LASIK) over a 24-month period and analyze topographic changes after H-LASIK to assess topographic pseudokeratectasia (TPKE) following H-LASIK. SETTING: Eye Institute of Utah, Salt Lake City, Utah, USA. METHODS: This prospective study included 139 eyes of 77 patients having H-LASIK for primary hyperopia. The mean follow-up was 15.6 months +/- 7.6 (SD) (range 6 to 48 months). One hundred twenty-two eyes (88%) were followed at 1 year and 36 eyes (26%) at 24 months. Topographic pseudokeratectasia was defined as 1 or more positive keratoconus screening findings in an eye with topographic central or inferior steepening detected by the Topography Modeling System but without corneal thinning or progressive change. RESULTS: The mean spherical equivalent manifest refraction was +2.39 +/- 0.99 diopter (D) preoperatively and -0.05 +/- 0.61 D at the last visit. Ninety-one percent of eyes were within +/-1.00 D of emmetropia and 71% of the eyes were within +/-0.50 D. Uncorrected visual acuity of 20/20 or better was present in 42%, 20/25 in 63%, and 20/40 or better in 93% of eyes. Loss of 2 lines of BSCVA occurred in 2 eyes (1.4%). In 1 eye, ischemic optic neuropathy occurred, and in another, choroidal neovascularization developed postoperatively. Topographic pseudokeratectasia was detected in 28% to 56% of eyes postoperatively. No significant difference between postoperative visual and refractive outcome, regression, or irregularity was found between the eyes with or without TPKE. CONCLUSION: Hyperopic LASIK appears to be an effective, predictable, and safe procedure to correct low to moderate primary hyperopia. Topographic pseudokeratectasia, which was observed after H-LASIK with a keratoconus-like topographic pattern in otherwise normal eyes, may represent a relatively static condition.

Adult↗

PubMed2005

Angle-supported phakic intraocular lenses in hyperopia.

PURPOSE: To evaluate the efficacy and safety of angle-supported phakic intraocular lenses (PIOLs) in hyperopia. SETTING: Private practice, Siena, Italy. METHODS: A prospective noncomparative single-surgeon interventional case series comprised 42 consecutive hyperopic eyes of 22 patients having implantation of a type PIOL (Morcher) through a sclero-corneal 5.5 mm x 3.0 mm tunnel along the steepest meridian, with surgical iridectomy. The mean preoperative defocus equivalent (DEQ) was 7.30 diopters (D) +/- 1.89 (SD). The mean spherical equivalent (SE) was 6.61 +/- 1.47 D (range 4.0 to 10.5 D), and the mean refractive astigmatism was 1.51 +/- 1.33 D (range 0 to 5 D). The mean age was 29.9 +/- 6.0 years (range 22 to 42 years). Thirteen patients (59%) were men. RESULTS: Postoperative mean SE was 0.38 +/- 0.52 D (range 0 to 2 D); mean DEQ 0.93 +/- 0.98 D; mean astigmatism 0.95 +/- 1.17 D; mean surgically induced astigmatism (vector analysis) 0.67 +/- 0.58 D (95% confidence interval, 0.49-0.85); 38 eyes (90%) were within +/-2 D of DEQ, 34 eyes (81%) within +/-1 D, and 24 eyes (57%) within +/-0.5 D. Safety index was 1.05; efficacy index 0.85. Complications were night halos 10%; pupil ovalization 7%; pupillary block reversed by neodymium:YAG laser 7%; monocular anterior subcapsular opacity 5%; monocular iridocyclitis 5%; and intraocular pressure rise due to topical steroids 2%. Endothelial cell loss at 12 month was 6% (range +2.5% to -11%). CONCLUSION: High hyperopia was corrected safely and predictably by an angle-supported PIOL with limited complications.

Adult↗

PubMed1991

Early-onset autosomal dominant retinitis pigmentosa with severe hyperopia.

We studied a four-generation family with early-onset autosomal dominant retinitis pigmentosa, severe hyperopia, and axial eye lengths of less than 20 mm. The affected members had decreased vision, night blindness, typical peripheral retinal pigmentary changes, and electroretinographic abnormalities characteristic of retinitis pigmentosa. This pedigree suggests there is another variant of retinitis pigmentosa associated with hyperopia besides Leber's congenital amaurosis and preserved para-arteriole retinal pigment epithelium.

Adolescent↗

PubMed1997

Flicker parameters are different for suppression of myopia and hyperopia.

Axial eye growth rates in the chicken are controlled by local retinal image-processing circuits. These circuits quantify the loss of contrast for different spatial frequencies and promote axial eye growth rates in correlation with the amount of retinal image degradation ("deprivation myopia"). They also distinguish whether the plane of focus lies in front of or behind the retina. How the sign of defocus is detected still remains unclear. Cues from chromatic aberration are not important. In an attempt to isolate retinal circuits controlling the development of myopia or hyperopia, young chickens were raised in flickering light of different frequencies (12 and 6 Hz) and duty cycles (4-75%) produced by rotating chopper disks. The effects of flickering light on refractive errors and change in axial growth rates induced by translucent occluders or defocusing lenses were measured by infrared retinoscopy and A-scan ultrasound, respectively. Retinal electrical activity was evaluated by flicker ERG after matching flicker parameters and stimulation brightness at retinal surface. Changes in retinal and vitreal dopamine content caused by flicker in occluded and normal eyes were determined by HPLC-ECD. Strikingly, suppression of myopia occurred for similar flicker parameters, whether induced by translucent occluders ("deprivation") or negative lenses ("defocus"). The degree to which myopia was suppressed was correlated with the duration of flicker dark phase and with the ERG amplitude. In contrast, suppression of hyperopia did not correlate with these parameters. We conclude that two different retinal circuits with different temporal characteristics are involved in the processing of hyperopic defocus/deprivation and of myopic defocus, the first one dependent on flicker ERG amplitude. However, we did not find any correlation between the rate of dopamine release and the degree of inhibition of deprivation myopia in flickering light.

Animals↗