Evaluation of the impact of binocular versus monocular cataract surgery using Catquest-9SF: a randomized controlled trial.

PURPOSE: This prospective, randomized, unmasked, clinical trial aimed to report the visual outcomes of cataract surgery on both eyes versus cataract surgery on one eye in Brazilian patients. METHODS: This study included patients with bilateral cataracts and binocular visual acuity worse than or equal to 0.3 logarithm of the minimum angle of resolution. The patients were randomly assigned to undergo surgery on one (Control Group) or both eyes (one eye at a time; Intervention Group). Postoperatively, self-reported visual function using Catquest-9SF (primary outcome measure), binocular visual acuity, stereopsis, and ocular dominance (secondary outcome measures) were compared. RESULTS: A total of 151 patients (77 and 148 eyes in the Control and Intervention Groups, respectively) completed the follow-up. Patients who underwent surgery on both eyes exhibited significantly better self-reported visual function (p=0.036) and stereopsis (p=0.026) than those who underwent surgery on one eye. Binocular visual acuity and ocular dominance did not affect the group comparisons. CONCLUSIONS: Surgery on both eyes resulted in significantly better self-reported visual function and stereopsis than surgery on one eye.

Clinical performance after implantation of an EDOF intraocular lens in the dominant eye and a presbyopia-correcting intraocular lens in the nondominant eye.

PURPOSE: To evaluate subjective and objective outcomes after combined implantation of an extended depth-of-focus (EDOF) intraocular lens (IOL) and a combined technology multifocal lens (CT-IOL). SETTING: 2 clinical practices (Carolina Eyecare Physicians, Center For Sight) in the United States. DESIGN: Prospective, unmasked, multicenter, nonrandomized bilateral eye study. METHODS: Patients interested in reducing their dependence on spectacles were implanted with an EDOF IOL in the dominant eye and a CT-IOL in the nondominant eye. Refractive and visual acuity (VA) data at various distances (4 m, 66 cm, 40 cm, and 33 cm) were collected 3 months postsurgery, along with the distance-corrected binocular defocus curve and responses to questionnaires related to spectacle independence, visual disturbances, and overall visual function. RESULTS: Data from 37 participants were analyzed. The distance-corrected binocular defocus curve showed a mean VA better than 0.1 logMAR (20/25) at all vergences from +1.00 to -2.50 diopters (D). 36 participants (97%) had an uncorrected binocular VA of 0.3 logMAR or better, at all test distances. 70% of participants (26/37) reported never wearing spectacles at any distance, and 84% (31/37) were "completely" or "mostly" satisfied with their overall vision after surgery. Halos were the disturbance reported most frequently and reported as most bothersome, with difficulty driving at night the most common visual function issue. Difficulty reading was the next most reported issue. Overall eyesight was rated as "excellent" or "good" by 92% (34/37) of participants. CONCLUSIONS: This combined EDOF/CT-IOL approach was well-tolerated by participants and provided some potential benefits relative to bilateral implantation of either lens.

Ocular dominance in cataract surgery: research status and progress.

Ocular dominance (OD), a commonly used concept in clinical practice, plays an important role in optometry and refractive surgery. With the development of refractive cataract surgery, the refractive function of the intraocular lens determines the achievement of the postoperative full range of vision based on the retinal defocus blur suppression and binocular monovision principle. Therefore, OD plays an important role in cataract surgery. OD is related to the visual formation of the cerebral cortex, and its plasticity suggests that visual experience can influence the visual system. Cataract surgery changes the visual experience and transforms the dominant eye, which confirms the plasticity of the visual system. Based on the concept and mechanism of OD, this review summarizes the application of OD in cataract surgery.

Sensory eye dominance following surgically correction for acute acquired concomitant esotropia of adulthood.

BACKGROUND: Acute acquired concomitant esotropia (AACE) is an unusual presentation characterized by acute onset of esotropia after infancy. For patients with AACE of adulthood, the outcome of surgery, which is a common treatment, often shows successful recovery of stereopsis. However, whether surgically corrected patients with AACE of adulthood achieved balanced eyes is yet unclear. METHODS: Here, we used a binocular phase combination paradigm to quantitatively assess the ocular dominance of 22 surgically aligned patients with AACE of adulthood, which all had regained normal stereopsis after the surgery and 14 adult controls with normal vision. The sensory eye dominance was quantified as the interocular contrast ratio, termed balance point, at which each eye contributed equally to the perception of cyclopean grating. RESULTS: We found that, normal controls had a mean balance point value close to unity (0.96 ± 0.01), whereas adult AACE patients exhibited apparent interocular imbalance (0.76 ± 0.04), which was significantly different from control group (Mann-Whitney U = 135, P < 0.001, two tailed). In addition, the balance point of adults with AACE didn't correlate with the interval between onset of esotropia and the surgery (r = - 0.262, p = 0.239), or the length of postoperative follow-up period (r = 0.127, p = 0.575). CONCLUSION: Our results suggest that, for patients with AACE of adulthood whose eyes had been straightened, there is still residual sensory imbalance which may be a potential risk factor for AACE of adulthood.

Host interneurons mediate plasticity reactivated by embryonic inhibitory cell transplantation in mouse visual cortex.

The adult brain lacks sensitivity to changes in the sensory environment found in the juvenile brain. The transplantation of embryonic interneurons has been shown to restore juvenile plasticity to the adult host visual cortex. It is unclear whether transplanted interneurons directly mediate the renewed cortical plasticity or whether these cells act indirectly by modifying the host interneuron circuitry. Here we find that the transplant-induced reorganization of mouse host circuits is specifically mediated by Neuregulin (NRG1)/ErbB4 signaling in host parvalbumin (PV) interneurons. Brief visual deprivation reduces the visual activity of host PV interneurons but has negligible effects on the responses of transplanted PV interneurons. Exogenous NRG1 both prevents the deprivation-induced reduction in the visual responses of host PV interneurons and blocks the transplant-induced reorganization of the host circuit. While deletion of ErbB4 receptors from host PV interneurons blocks cortical plasticity in the transplant recipients, deletion of the receptors from the donor PV interneurons does not. Altogether, our results indicate that transplanted embryonic interneurons reactivate cortical plasticity by rejuvenating the function of host PV interneurons.

Phosphoinositide-3-Kinase γ Is Not a Predominant Regulator of ATP-Dependent Directed Microglial Process Motility or Experience-Dependent Ocular Dominance Plasticity.

Microglia are dynamic cells whose extensive interactions with neurons and glia during development allow them to regulate neuronal development and function. The microglial P2Y12 receptor is crucial for microglial responsiveness to extracellular ATP and mediates numerous microglial functions, including ATP-dependent directional motility, microglia-neuron interactions, and experience-dependent synaptic plasticity. However, little is known about the downstream signaling effectors that mediate these diverse actions of P2Y12. Phosphoinositide-3-kinase γ (PI3Kγ), a lipid kinase activated downstream of Gi-protein-coupled receptors such as P2Y12, could translate localized extracellular ATP signals into directed microglial action and serve as a broad effector of P2Y12-dependent signaling. Here, we used pharmacological and genetic methods to manipulate P2Y12 and PI3Kγ signaling to determine whether inhibiting PI3Kγ phenocopied the loss of P2Y12 signaling in mouse microglia. While pan-inhibition of all PI3K activity substantially affected P2Y12-dependent microglial responses, our results suggest that PI3Kγ specifically is only a minor part of the P2Y12 signaling pathway. PI3Kγ was not required to maintain homeostatic microglial morphology or their dynamic surveillance in vivo Further, PI3Kγ was not strictly required for P2Y12-dependent microglial responses ex vivo or in vivo, although we did observe subtle deficits in the recruitment of microglial process toward sources of ATP. Finally, PI3Kγ was not required for ocular dominance plasticity, a P2Y12-dependent form of experience-dependent synaptic plasticity that occurs in the developing visual cortex. Overall, our results demonstrate that PI3Kγ is not the major mediator of P2Y12 function in microglia, but may have a role in amplifying or fine-tuning the chemotactic response.

Ocular dominance plasticity: Molecular mechanisms revisited.

Ocular dominance plasticity (ODP) is a type of cortical plasticity operating in visual cortex of mammals that are endowed with binocular vision based on the competition-driven disparity. Earlier, a molecular mechanism was proposed that catecholamines play an important role in the maintenance of ODP in kittens. Having survived the initial test, the hypothesis was further advanced to identify noradrenaline (NA) as a key factor that regulates ODP in the immature cortex. Later, the ODP-promoting effect of NA is extended to the adult with age-related limitations. Following the enhanced NA availability, the chain events downstream lead to the ß-adrenoreceptor-induced cAMP accumulation, which in turn activates the protein kinase A. Eventually, the protein kinase translocates to the cell nucleus to activate cAMP responsive element binding protein (CREB). CREB is a cellular transcription factor that controls the transcription of various genes, underpinning neuronal plasticity and long-term memory. In the advent of molecular genetics in that various types of new tools have become available with relative ease, ODP research has lightly adopted in the rodent model the original concepts and methodologies. Here, after briefly tracing the strategic maturation of our quest, the review moves to the later development of the field, with the emphasis placed around the following issues: (a) Are we testing ODP per se? (b) What does monocular deprivation deprive of the immature cortex? (c) The critical importance of binocular competition, (d) What is the adult plasticity? (e) Excitation-Inhibition balance in local circuits, and (f) Species differences in the animal models.

Difference in myopia progression between dominant and non-dominant eye in patients with intermittent exotropia.

OBJECTIVE: To investigate the difference in the rate of myopia progression between the dominant and non-dominant eye in patients with intermittent exotropia (IXT). METHODS: We retrospectively reviewed the medical records of 33 patients who underwent surgery and later reoperation for IXT. We included only patients whose spherical equivalent refractive errors (SER) were ≤ - 0.50 diopter (D) in at least one eye at the time of reoperation. The main outcome measurement was the rate of myopia progression, which was defined as the mean annual change in SER between the first and second surgery. We classified patients into two groups: group A, which comprised 25 patients whose non-dominant eyes showed a faster myopia progression than their dominant eyes, and group B, which comprised the remaining 8 patients showing the opposite. RESULTS: Mean age of the patients at the time of the initial surgery was 5.64 years. Mean interval between the initial and second surgery was 4.45 years. Mean rate of myopia progression over the interval was - 0.37 D/year in the dominant eyes and - 0.50 D/year in the non-dominant eyes (P < 0.001). Group A had a significantly greater amount of distance deviation (31.0 vs. 25.6 PD, P = 0.020) and near deviation (30.8 vs 26.0 PD, P = 0.039) before the initial surgery and a significantly worse score of distance control (3.05 vs. 2.00, P = 0.023) before the second surgery than group B. CONCLUSIONS: The non-dominant eyes experienced a faster myopia progression than the dominant eyes in patients with IXT. This faster myopia progression demonstrated in the non-dominant eyes was associated with clinically severe exotropia in terms of the amount of deviation and the degree of control.

Treatment of refractory amblyopia with levodopa associated with full-time occlusion in the dominant eye / Tratamento da ambliopia refratária com o uso de levodopa associada à oclusão total do olho dominante

Abstract Purpose: To evaluate visual outcomes of levodopa treatment associated with full occlusion of the dominant eye in patients with refractory amblyopia. Methods: A prospective study of 19 attended patients who were subject to treatment with Levodopa and Carbidopa on doses of 0.7mg/kg/day, a ratio of 4:1 divided into three daily doses for 5 weeks, combined with full occlusion (24 hours/day) of the dominant eye. The ophthalmologic exam from previous consultations up to treatment and after 8 weeks of therapy were collected from medical record data. Patients who had completed treatment for more than 12 months were included for complete eye examination. Results: The mean age before treatment with levodopa was 11.0 ± 4.2 years old (varying from 7 to 23 years). The best-corrected visual acuity (Snellen chart) of the amblyopic eye before treatment was 0.24 (0.6 in logMAR) ± 0.16, after 8 weeks of treatment it was 0.47(0.3 in logMAR) ± 0.33, while during the final evaluation it was 0.46 (0.3 in logMAR) ± 0.34. There was a statistically significant improvement in vision after 8 weeks of therapy which was maintained until the final evaluation (p = 0.007). Conclusion: Levodopa/Carbidopa therapyat doses of 0.7 mg/kg/day at a ratio of 4:1 divided in three daily doses, associated with full occlusion of the dominant eye during 5 weeks had a significant improvement on the visual acuity of the amblyopic eye, and persisted up to 1 year after the treatment.

Resumo Objetivo: Avaliar os resultados visuais do tratamento com levodopa associada à oclusão total do olho dominante em pacientes amblíopes. Métodos: Estudo prospectivo de 19 pacientes atendidos e submetidos ao tratamento com levodopa e carbidopa na dose de 0,7 mg/kg/dia e proporção de 4:1, divididos em três doses diárias, durante cinco semanas, combinada a oclusão total (24 horas/dia) do olho dominante. Foram coletados dados do prontuário referentes ao exame oftalmológico da consulta anterior ao tratamento e após 8 semanas de terapia. Os pacientes com término do tratamento com mais de 12 meses foram reconvocados para exame oftalmológico completo. Resultados: A média de idade dos pacientes previamente ao tratamento com levodopa foi de 11,0 ± 4,2 anos (variando de 7 a 23 anos). A acuidade visual melhor corrigida (Snellen) do olho amblíope antes do tratamento foi de 0,24 (0,6 em logMAR) ± 0,16, após 8 semanas de tratamento foi de 0,47 (0,3 em logMAR) ± 0,33 e na avaliação final foi de 0,46 (0,3 em logMAR) ± 0,34. Houve melhora estatisticamente significante da visão após 8 semanas de tratamento que se manteve até a avaliação final (p = 0,007) Conclusão: A terapia com levodopa/carbidopa em doses de 0,7mg/kg/dia na proporção de 4:1 dividida em três doses diárias, associada à oclusão total do olho dominante durante 5 semanas, apresentou uma melhora significativa na acuidade visual do olho ambliópico e persistiu até 1 ano após o tratamento.

Inhibition of Semaphorin3A Promotes Ocular Dominance Plasticity in the Adult Rat Visual Cortex.

Perineuronal nets (PNNs) are condensed structures in the extracellular matrix that mainly surround GABA-ergic parvalbumin-positive interneurons in the adult brain. Previous studies revealed a parallel between PNN formation and the closure of the critical period. Moreover, ocular dominance plasticity is enhanced in response to PNN manipulations in adult animals. However, the mechanisms through which perineuronal nets modulate plasticity are still poorly understood. Recent work indicated that perineuronal nets may convey molecular signals by binding and storing proteins with important roles in cellular communication. Here we report that semaphorin3A (Sema3A), a chemorepulsive axon guidance cue known to bind to important perineuronal net components, is necessary to dampen ocular dominance plasticity in adult rats. First, we showed that the accumulation of Sema3A in PNNs in the visual cortex correlates with critical period closure, following the same time course of perineuronal nets maturation. Second, the accumulation of Sema3A in perineuronal nets was significantly reduced by rearing animals in the dark in the absence of any visual experience. Finally, we developed and characterized a tool to interfere with Sema3A signaling by means of AAV-mediated expression of receptor bodies, soluble proteins formed by the extracellular domain of the endogenous Sema3A receptor (neuropilin1) fused to a human IgG Fc fragment. By using this tool to antagonize Sema3A signaling in the adult rat visual cortex, we found that the specific inhibition of Sema3A promoted ocular dominance plasticity. Thus, Sema3A accumulates in perineuronal nets in an experience-dependent manner and its presence in the mature visual cortex inhibits plasticity.

Non-cell Autonomous OTX2 Homeoprotein Regulates Visual Cortex Plasticity Through Gadd45b/g.

The non-cell autonomous transfer of OTX2 homeoprotein transcription factor into juvenile mouse cerebral cortex regulates parvalbumin interneuron maturation and critical period timing. By analyzing gene expression in primary visual cortex of wild-type and Otx2+/GFP mice at plastic and nonplastic ages, we identified several putative genes implicated in Otx2-dependent visual cortex plasticity for ocular dominance. Cortical OTX2 infusion in juvenile mice induced Gadd45b/g expression through direct regulation of transcription. Intriguingly, a reverse effect was found in the adult, where reducing cortical OTX2 resulted in Gadd45b/g upregulation. Viral expression of Gadd45b in adult visual cortex directly induced ocular dominance plasticity with concomitant changes in MeCP2 foci within parvalbumin interneurons and in methylation states of several plasticity gene promoters, suggesting epigenetic regulation. This interaction provides a molecular mechanism for OTX2 to trigger critical period plasticity yet suppress adult plasticity.

Macular thickness and retinal nerve fiber thickness analysis in ocular dominance / Espessura macular e fibra nervosa da retina análise de espessura no domínio ocular

Abstract Objective: To compare macular and peripapillary retinal nerve fiber layer thicknesses of dominant eye and non-dominant eye using optical coherence tomography (OCT). Methods: 104 eyes of 52 healthy young adults were included. Ophthalmological examinations; including measuring refraction, best corrected visual acuity, intraocular pressure (IOP) measurement, slit-lamb biomicroscopy, dilated fundus examination, measuring of central macular thickness (CMT), and peripapillary retinal nerve fiber layer (PRNFL) thickness were performed on each subject. Hole-in-the-card test was used to detect the ocular dominance. Results: There were 25 females (48%) and 27 males (52%) in the study. Eight participants had left eye dominance (15%), forty-four participants had right eye dominance (85%). Mean CMT was 192.5µm in dominant group and 191.9 µm in non-dominant group. There was no statistically significant difference between dominant eye group and non-dominant eye group in either macular thickness or peripapillary retinal nerve fiber layer thickness. Conclusions: No difference between macular and peripapillary retinal nerve fiber layer thicknesses were detected in dominant and non-dominant groups. Further evaluation is needed.

Resumo Objetivo: Comparar as espessuras da camada de fibras nervosas da retina macular e peripapilar do olho dominante e não dominante usando a tomografia de coerência óptica (OCT). Métodos: 104 olhos de 52 adultos jovens saudáveis foram incluídos. Exames oftalmológicos; incluindo medidas de refração, melhor acuidade visual corrigida, medição da pressão intraocular (PIO), biomicroscopia de fenda-cordeiro, exame do fundo dilatado, medição da espessura macular central (CMT) e espessura da camada de fibras nervosas da retina peripapilar (PRNFL) foram realizadas em cada sujeito. O teste Hole-in-the-card foi usado para detectar a dominância ocular. Resultados: houve 25 mulheres (48%) e 27 homens (52%) no estudo. Oito participantes tinham deixado a dominância do olho (15%), quarenta e quatro participantes tinham dominância do olho direito (85%). A CMT média foi de 192,5 µm no grupo dominante e 191,9 µm no grupo não dominante. Não houve diferença estatisticamente significativa entre o grupo dominante de olho e o grupo de olho não dominante tanto na espessura macular quanto na espessura da camada de fibras nervosas da retina peripapilar. Conclusões: Não houve diferença entre as espessuras das camadas de fibras nervosas da retina macular e peripapilar nos grupos dominante e não dominante. Mais avaliações são necessárias.

Sighting ocular dominance magnitude varies with test distance.

BACKGROUND: Ocular dominance can be defined as the preference of an individual for viewing with one eye over the other for particular visual tasks. It is relevant to monovision contact lens wear, cataract surgery and sports vision. Clinically, the measurement of ocular dominance is typically done at an arbitrary distance using a sighting test, such as the hole-in-card method that has a binary outcome. We investigated the effect of test distance on ocular dominance measured using a binocular sighting test that provided a continuous measurement of dominance. METHODS: Ten participants with normal binocular vision took part in this study. Their binocular sighting ocular dominance and phorias were measured at one, two, four, eight and 10 metres. During the dominance tests participants made a binocular alignment judgment and then were asked to indicate the relative alignment of each eye using a visual analogue scale as a reference. RESULTS: Eight participants had strong ocular dominance (five right, three left). For these participants, there was a significant increase in the magnitude of dominance with increasing test distance (p < 0.001). This could not be fully explained by changes in convergence demand. Two participants showed very weak ocular dominance across all test distances (p > 0.05), despite changes in convergence demand. CONCLUSION: When ocular dominance is present, its magnitude varies significantly with test distance. This has significant implications for the accurate measurement of ocular dominance in the clinic and may reflect the neural processes that influence eye preference.

The effect of Lasik surgery on myopic anisometropes' sensory eye dominance.

Lasik is a common surgery for treating anisometropia. In this study, we asked a specific question: what's the effect of Lasik surgery on anisometropes' sensory eye dominance ? Fifteen myopic anisometropes (mean age: 23 ± 6.9 years old; 6 females) participated in our experiment. We quantitatively measured participants' sensory eye dominance before and after the Lasik surgery using a binocular phase combination paradigm. We found no significant change of sensory eye dominance within 16 weeks (measured between 8 to 96 days, for one or two repetitions) after the surgery (t(14) = -1.44, p = 0.17). A further following on eight patients showed that patients' two eyes were much more balanced at 16 weeks or more (measured one or two times between 112 to 408 days) after the surgery (t(7) = -3.79, p = 0.007). Our results suggest that the benefit of Lasik surgery on anisometropes' sensory eye dominance is not immediate, a long-term 'adaptation' period (16 weeks or more) is necessary to enable the surgery to be truly effective.

Association of Visual Acuity with Ocular Dominance in 2045 Myopic Patients.

PURPOSE: Previous studies of the relationship between visual acuity (VA) and ocular dominance have produced conflicting results. We hypothesized that (1) the discrepancies were related mostly to sample size and interocular visual acuity difference (IOVAD); (2) in large samples of individuals with marked IOVADs, the eye with the better uncorrected distance visual acuity (UDVA) would be dominant. These hypotheses were tested in a large group of myopic patients. METHODS: This prospective study of cycloplegic refraction involved 2045 myopic refractive surgery candidates. Patients with amblyopia or strabismus were excluded. Ocular dominance was assessed using the hole-in-the-card test. RESULTS: In 2045 patients, the dominant eye had significantly better UDVA (p = 0.028) and was less astigmatic (p = 0.000) than the nondominant eye. In 426 patients with marked interocular difference in the UDVA (≥0.2 logMAR), the dominant eye not only had significant UDVA (p = 0.022) but also significantly less myopic (p = 0.028) and had a shorter axial length (AL; p = 0.001). In patients with smaller differences in UDVA (0.1 logMAR, n = 411) or no difference (n = 1208), the dominant and nondominant eyes did not differ significantly with respect to UDVA, myopic power, and AL (p > 0.05). CONCLUSIONS: The present study showed that the dominant eyes had significantly better UDVA than the nondominant eyes, especially in individuals with marked differences in UDVA. These results supported our hypothesis regarding the relationship between better VA and ocular dominance.

Dynamic features of animate motion activate septal and preoptic areas in visually naïve chicks (Gallus gallus).

The septum is an evolutionarily well-conserved part of the limbic system. It is known to be involved in many aspects of social behavior and is considered a key node of the social behavior network, together with the preoptic area. Involvement of these two brain regions has been recently observed in newly hatched chicks exposed to the natural motion of a living conspecific. However, it is unknown whether these areas respond also to simple motion cues that elicit animacy perception in humans and social predispositions in chicks. For example, naïve chicks are attracted by visual objects that appear to spontaneously change their speed (an index of self-propulsion, typical of animate creatures). Here we show that the right septum and the preoptic area of newly hatched visually naïve chicks exposed to speed changes have higher neuronal activity (revealed by c-Fos expression), compared with that of chicks exposed to constant motion. We thus found an involvement of these two areas in the perception of motion cues associated with animacy in newly hatched chicks without any previous visual experience. This demonstrates their early involvement in processing simple motion cues that allow the detection of animate creatures and elicit social predispositions in this animal model, as well as preferential attention in human infants and the perception of animacy in human adults.

Quality of vision after wavefront-guided laser in situ keratomileusis or photorefractive keratectomy: Contralateral eye evaluation.

PURPOSE: To compare quality of vision between laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). SETTING: Byers Eye Institute, Stanford University School of Medicine, Palo Alto, California, USA. DESIGN: Prospective randomized case series. METHODS: Patients had refractive surgery, with 1 eye treated with LASIK and the other with PRK. Eyes were randomized for dominance. The patients completed a questionnaire assessing quality of vision in each eye at the initial visit and 1, 3, 6, and 12 months postoperatively. RESULTS: The study comprised 34 patients (68 eyes). There were no initial differences in quality of vision. The PRK eyes had worse clarity during the day (P = .001) and at night (P = .001), worse overall vision (P = .024), more vision fluctuation (P = .006), and more double vision (P = .022) at 1 month. Eyes with higher preoperative higher-order aberrations (HOAs) having PRK had worse clarity during the day and at night (P = .006 and P = .012, respectively) and more vision fluctuation (P = .041); PRK eyes with lower preoperative HOAs had worse daytime clarity (P = .036) at 1 month. After 1 month, there were no differences. CONCLUSIONS: The quality of vision was better in LASIK eyes after 1 month. At subsequent visits, there was no significant difference in quality of vision.