Ocular Dominance Research Articles

Comparison of ganglion cell-inner plexiform layer thickness among patients with intermittent exotropia according to fixation preference: a retrospective observational study.

This study was performed to compare the thickness of the ganglion cell-inner plexiform layer (GCIPL) depending on the presence or absence of fixation preference in patients with intermittent exotropia (IXT) with refractive values close to emmetropia and with no amblyopia. The study recruited pediatric patients diagnosed with IXT with a spherical equivalent within ±1.25 diopter and no amblyopia. The patients were categorized into two groups: a monocular exotropia group with fixation preference and an alternating exotropia group without fixation preference. GCIPL thickness was measured using spectral domain optical coherence tomography, and the macula was divided into nine sectors according to the Early Treatment Diabetic Retinopathy Study (ETDRS). GCIPL thickness in each sector was compared between the monocular and alternating exotropia groups. In the monocular exotropia group, GCIPL thickness was significantly thinner in the dominant eye than in the nondominant eye in the S1 sector (91.2±7.4 μm vs. 93.3±5.2 μm, p=0.019). However, in the alternating exotropia group, there were no significant differences between the eyes across all ETDRS sectors. When comparing the interocular differences in GCIPL thickness between the two groups, the monocular exotropia group (absolute value of the dominant eye minus the nondominant eye) exhibited significantly greater differences in several ETDRS sectors than the alternating exotropia group (absolute value of the right eye minus the left eye). The significant interocular difference in GCIPL thickness in the monocular exotropia group suggests that fixation preference may influence the anatomical structure of the macula in patients with IXT.

The effect of ocular dominance on choroidal structures

ABSTRACT This study aimed to compare the dominant and non-dominant eyes of healthy individuals in terms of CT and CVI values to assess the effect of ocular dominance on choroidal morphology. Three hundred eyes of 150 individuals were included in this study. All patients underwent routine ophthalmological examinations and hole-in-the-card tests to determine the dominant eye. EDI-OCT was used to obtain choroidal images. Choroidal thickness (CT) was measured at three points on the choroid including the subfoveal region (subfoveal choroidal thickness (SFCT)), 1500 μm nasal (NCT) and temporal (TCT) to the fovea. Choroidal vascularity index (CVI), total choroidal area (TCA), luminal area (LA), and stromal area (SA) were measured at fovea-centered choroidal area by image binarization via Image J software. While 93(%62) participants were right-eyed, 57(%38) participants were left-eyed. We could not detect any difference in SFCT, NCT, TCT, TCA, LA, SA, and CVI measurements between the dominant and the non-dominant eyes. (p > 0.05 for all). We could not detect any effect of ocular dominance on choroidal structures. These results also support the use of randomized ocular data regardless of which eye is dominant when investigating CVI and CT in scientific research.

Use of a Microelectromechanical Systems Sensor for Objective Measurements of Abnormal Head Posture in Congenital Superior Oblique Palsy Patients.

The purpose of this study was to design an objective method for measurement of head positions as achieved with use of a microelectromechanical systems (MEMS) sensor. In addition, to use this system to observe the abnormal head position (AHP) in patients with congenital superior oblique palsy (SOP) before and after their surgery. An MEMS sensor was designed for recording of the pitch, roll, and yaw values of the head position in real time. The MEMS sensor was then fixed on the synoptophore from -30 degrees to +30 degrees positions horizontally and vertically to test the accuracy of these measurements. Then, we tested 13 participants with AHP using the MEMS method and the photographic method and compared their correlations. Finally, the pitch, roll, and yaw values of head positions were measured using this MEMS sensor in 31 patients with congenital SOP as performed before and after their surgery. The MEMS sensor (LPMS-B2; Alubi, Guangzhou, China; 400 hertz [Hz]), as based on the theory of a gyroscope, was designed and connected to a smartphone via Bluetooth. It was able to conveniently record the patient's pitch, roll, and yaw head positions in real time, recordings which were consistent with the scales of the synoptophore (P > 0.05) and good correlations with the photographic method (P < 0.001). The main preoperative AHP in patients with SOP was roll (22/31, 71%). Pre- and postoperative vertical deviations were 16.4 ± 7.3 prism diopters (PD) and 4.1 ± 4.2 PD, respectively (P = 0.001). The AHP in patients with SOP was positively correlated with the angle of extorsion in the dominant eye (P = 0.01), rather than that of the vertical deviation. The MEMS sensor described in this report is a simple, practical, and accurate objective device for use in head position measurements. In patients with SOP, the AHP is related to the angle of extorsion in the dominant eye. The MEMS sensor was designed as a micro-wireless dynamic high-precision device for AHP measurement, which has the potential for use in a clinic.

Effect of Fresnel prism in small-angle esotropia (≤ 20 prism diopters) with fixation preference.

We aimed to investigate the effects of Fresnel prism treatment for small-angle esotropia (≤ 20 prism diopters [PD]) with fixation preference. We included 32 patients with remaining esotropia ≤ 20 PD measured using the simultaneous prism and cover test (SPCT) after full refractive error correction. Fresnel prism was applied to make patients orthotropic with glasses. Treatment was discontinued if remaining esotropia ≤ 4 PD was sustained during two consecutive follow-ups (2-month intervals) or if the angle continued to increase with prism adaptation. Patients were divided into treatment success and failure groups. Treatment success was defined by motor and visual acuity (VA) aspects. Criteria for motor success was residual esotropia ≤ 8 PD in patients with initial esotropia > 8 PD and a 30% decrease of esotropia in those with initial esotropia ≤ 8 PD. VA success was improvement of > 0.2 logMAR in the non-dominant eye. The initial esodeviation angle was 6.92 ± 4.66 PD at distance and 10.53 ± 5.58 at near. The logMAR VA was 0.10 ± 0.13 and 0.26 ± 0.20 in the dominant and non-dominant eye, respectively. Among the 32 patients, 14 showed motor success. Among 26 patients whose VA could be measured, 15 showed VA success. Factors influencing motor success were a small amount of maximum prescribed Fresnel prism, less frequent need for Fresnel prism adaptation, and high percentage of achieving orthotropia with Fresnel prism treatment. VA success was influenced by low frequency of anisometropia and the small amount of maximum prescribed Fresnel prism. Fresnel prism could be a non-invasive treatment option for some patients with small-angle esotropia with fixation preference. What is known The optimal approach for addressing small-angle esotropia is a topic of debate. Not much research has been conducted on Fresnel prism treatment in patients with small-angle esotropia. What is new Motor success and visual acuity improvement were observed in some patients undergoing Fresnel prism treatment. Factors contributing to motor success were the small maximum angle of esodeviation, the less frequent necessity for Fresnel prism adaptation, and the achievement of orthotropia during Fresnel prism treatment. Visual acuity improvement was hindered by the presence of anisometropia and thelarge maximum prescribed amount of Fresnel prism. Fresnel prism treatment can be used as a treatment option for some patients with small-angle esotropia with fixation preference.

Attention enhances short-term monocular deprivation effect.

Patching one eye of an adult human for a few hours has been found to promote the dominance of the patched eye, which is called short-term monocular deprivation effect. Interestingly, recent work has reported that prolonged eye-specific attention can also cause a shift of ocular dominance toward the unattended eye though visual inputs during adaptation are balanced across the eyes. Considering that patching blocks all input information from one eye, attention is presumably deployed to the opposite eye. Therefore, the short-term monocular deprivation effect might be, in part, mediated by eye-specific attentional modulation. Yet this question remains largely unanswered. To address this issue, here we asked participants to perform an attentive tracking task with one eye patched. During the tracking, participants were presented with both target gratings (attended stimuli) and distractor gratings (unattended stimuli) that were distinct from each other in fundamental visual features. Before and after one hour of tracking, they completed a binocular rivalry task to measure perceptual ocular dominance. A larger shift of ocular dominance toward the deprived eye was observed when the binocular rivalry testing gratings shared features with the target gratings during the tracking compared to when they shared features with the distractor gratings. This result, for the first time, suggests that attention can boost the strength of the short-term monocular deprivation effect. Therefore, the present study sheds new light on the role of attention in ocular dominance plasticity.

Postural control strategies with alterations in visual input conditions in a standing position.

Mediated by balance systems, postural control relies heavily on visual input. However, the precise relationship between various visual conditions and postural strategies for balance remains unclear. This study investigated alterations in the center of pressure (COP) and ankle muscle activity during standing positions in healthy individuals under different visual conditions. Fifty-three healthy university students participated in the study. Stabilometry was conducted to evaluate the total path length and outer circumferential area for the COP. Further, surface electromyography was utilized to assess the activity of the bilateral tibialis anterior (TA) and lateral head of gastrocnemius muscles. Participants were instructed to maintain an upright posture under three visual conditions: binocular (eyes open) and monocular (either closing the dominant or nondominant eye). The three conditions were compared using a one-way analysis of variance. No significant differences were observed in the COP across visual conditions. However, in the TA of the nondominant leg, the mean values for the binocular, dominant eye, and nondominant eye conditions were 0.91, 1.08, and 1.14 times that of the resting standing position. Notably, the TA of the nondominant leg was significantly lower in the binocular condition than the dominant and nondominant eye conditions. The study findings indicate that the COP remain consistent despite variations in external visual input. This stability is likely maintained through compensatory adjustments, such as increased TA muscle activity in the nondominant leg under the nondominant eye condition. These observations highlight the complex interplay between the visual perception and postural stability.

Prospective Evaluation of Clinical and Patient-Reported Outcomes Following Contralateral Implantation of an Extended Depth of Focus (EDOF) and Hybrid EDOF-Multifocal IOL.

To evaluate clinical outcomes following contralateral implantation of a diffractive extended depth of focus (EDOF) and a hybrid EDOF-multifocal intraocular lens (IOL) with a violet filter in a U.S.-based population. In this prospective, non-comparative study, 60 eyes of 30 patients aged 40 years and older underwent bilateral cataract surgery and implantation of a DXR00V IOL (Tecnis Symfony OptiBlue) in the dominant eye and a DFR00V (Tecnis Synergy) IOL in the non-dominant eye. Outcome measures included uncorrected (UDVA) and corrected (CDVA) distance visual acuity, distance-corrected intermediate (DCIVA, 66 cm), near and very near visual acuity (DCNVA, 40 and 33 cm), and patient-reported outcomes. At 6 months postoperatively, binocular mean UDVA and CDVA were -0.10 ± 0.07 and -0.11 ± 0.05 logarithm of the minimum angle of resolution (logMAR), respectively. The mean DCIVA was 0.26 ± 0.08 logMAR in the DXR00V eyes and 0.23 ± 0.06 logMAR in the DFR00V eyes. The mean DCNVA at 40 and 33 cm were 0.28 ± 0.12 and 0.30 ± 0.15 logMAR, respectively, in the DXR00V eyes and 0.07 ± 0.08 and 0.07 ± 0.10 logMAR, respectively, in the DFR00V eyes. The mean binocular DCIVA and DCNVA at 33 and 40 cm were 0.18 ± 0.05, 0.06 ± 0.08, and 0.06 ± 0.07 logMAR, respectively. The percentages of patients achieving spectacle independence at far, intermediate, and near distances were 100%, 100%, and 81%, respectively. Contralateral implantation of the diffractive EDOF and a hybrid EDOF-multifocal IOL yielded excellent binocular visual acuity at all distances, as well as high patient satisfaction and functional performance on visual tasks. [J Refract Surg. 2024;40(10):e699-e705.].

Evaluation of Intermediate Visual Outcomes in Eyes Implanted with Bilateral Advanced Monofocal Intraocular Lens Targeting for Mini-Monovision and Its Association with Age and Corneal Asphericity.

To assess the visualoutcomes in patients bilaterally implanted with novel Clareon® intraocular lens when targeting mini monovision post-operatively. The study was conducted at Laxmi Eye Institute; itis a tertiary care eye institution in Panvel, India. This is an investigator initiated, prospective, single-centre longitudinal study of 45 patients to assess the visual outcomes in patients who were implanted with Clareon ® IOL bilaterally. Patients with corneal astigmatism of ≤0.75 D who underwent bilateral cataract surgery with pseudophakic mini-monovision and implanted with novel Clareon® intraocular lens were included. Patients having post op manifest refraction >±0.25 D in the dominant eye and <-0.5 D or >-0.75 D in the non-dominant eye were excluded. The main study outcomes were assessed at 1 and 3 months; itincluded uncorrected visual acuities assessment, defocus curve, and patient reported spectacle use. The mean (SD) binocular distance corrected intermediate visual acuity at 3 months was 0.22 (0.09) LogMAR. At 3 months, 54% of patients enjoyed 0.4 LogMAR or better BUCNVA. The defocus curve showed good distance and intermediate visual acuity with >0.2 LogMAR vision from +0.50 D to -1.50 D. We found a positive correlation between the Q value of the dominant eye and the BCIVA at 3 months postoperatively, however it was not statistically significant. The Q value was more negative when the intermediate vision was closer to 0 LogMAR. Post operatively, at3 months,95% patients did not need glasses for distance and intermediate vision and 73% of patients were comfortable for intermediate vision without glasses all the time. Mini-monovision with Clareon® monofocal IOL implantation can offer overall satisfactory vision for far and intermediate distances with minimal need for use of spectacles for near vision.

Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile.

The study aims to evaluate visual acuity and objective visual quality before and after the monocular bi-aspheric ablation profile for correction of presbyopia surgery. This prospective self-control study included 20 cases and 38 eyes of patients who underwent monocular bi-aspheric ablation profile correction of myopia with presbyopia at the Eye Hospital of Shandong University of Traditional Chinese Medicine from January 2023 to January 2024. These patients were selected for observation, and each patient's preoperative and postoperative uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), corrected distance visual acuity (CDVA), spherical aberration (SA) (within 6 mm), horizontal and vertical coma (within 6 mm), and corneal aspheric index (Q-value) (within 6 mm) were evaluated. Statistical data analysis was performed at different time points before and after the operation. There were statistically significant differences in UDVA between dominant and non-dominant eyes before and after surgery (Z = -3.784, p < 0.001; Z = -3.817, p < 0.001). Post-operatively, 90% of the non-dominant eyes achieved UNVA of J1 and above, and 95% of the bilateral eyes achieved UNVA of J1 and above. Significant differences were found in the SA of the dominant eyes, which showed a positive increase (Z= -3.784, p < 0.001); however, compared with the dominant eye, the SA of the non-dominant eye was negatively increased, but the difference was not statistically significant (p = 0.08). There was a significant difference in the vertical coma of the dominant eye before and after the operation, but there was no significant difference in non-dominant eyes. There was no significant difference in the change of binocular horizontal coma before and after the operation. There were significant changes in the Q value of both eyes before and after the operation (Z = -3.923, p < 0.001; Z = -3.51, p < 0.001). After the monocular bi-aspheric ablation profile, the cornea of the non-dominant eye showed a prolate shape, negative SA increased, and the UDVA and UNVA improved after the operation.

Visual and Demographic Risk Factors for Falls and the Impact of Cataract Surgery in Elderly Patients.

To evaluate the effect of cataract surgery and visual impairment and the associated risk factors on the frequency of falls among older adults in northeast Iran. This cross-sectional study, conducted between 2019 and 2020, analyzed the potential risk factors of falling in older adults over 50 years of age. To this end, 380 patients were randomly selected by convenience sampling and classified into two groups: those who had undergone cataract surgery in the last 12 months (surgery group) and those who had not (cataract group). The data were collected from the medical records and face-to-face interviews, and logistic regression was used to identify potential risk factors for falling. The frequency of falls in the cataract and surgery groups was 18.9% and 11.6%, respectively. The mean decimal visual acuity of the dominant eye was significantly lower in the cataract group than in the surgery group (P 0.001). There were no significant differences in the mean number of medications used, Charlson Comorbidity Index score, Instrumental Activities of Daily Living score, and 10-Meter Walk Test speed between the two groups. According to the results of backward logistic regression, taking more than four medications per day and slow gait speed were the most important factors influencing the frequency of falls in older adults. Logistic regression analysis indicated that undergoing cataract surgery is not a significant protective factor against falls. However, older adults in the surgery group experienced fewer falls than in the other group. Besides, the results suggest that taking more than four medications daily and having a slow gait speed are significant fall risk factors.

Assessing variations in eye dominance across the visual field

Assessing variations in eye dominance across the visual field

Variances in sensory eye dominance across the visual field

Variances in sensory eye dominance across the visual field

Intermittent theta burst stimulation (iTBS) of primary visual cortex reduces sensory eye dominance.

Intermittent theta burst stimulation (iTBS) of primary visual cortex reduces sensory eye dominance.

Interim safety and efficacy of gene therapy for RLBP1-associated retinal dystrophy: a phase 1/2 trial

Gene therapy holds promise for treatment of inherited retinal dystrophies, a group of rare genetic disorders characterized by severe loss of vision. Here, we report up to 3-year pre-specified interim safety and efficacy results of an open-label first-in-human dose-escalation phase 1/2 gene therapy clinical trial in 12 patients with retinal dystrophy caused by biallelic mutations in the retinaldehyde-binding protein 1 (RLBP1) gene of the visual cycle. The primary endpoints were systemic and ocular safety and recovery of dark adaptation. Secondary endpoints included microperimetry, visual field sensitivity, dominant eye test and patient-reported outcomes. Subretinal delivery of an adeno-associated viral vector (AAV8-RLBP1) was well tolerated with dose-dependent intraocular inflammation which responded to corticosteroid treatment, and focal atrophy of the retinal pigment epithelium as the dose limiting toxicity. Dark adaptation kinetics, the primary efficacy endpoint, improved significantly in all dose-cohorts. Treatment with AAV8-RLBP1 resulted in the resolution of disease-related retinal deposits, suggestive of successful restoration of the visual cycle. In conclusion, to date, AAV8-RLBP1 has shown preliminary safety and efficacy in patients with RLBP1-associated retinal dystrophy. Trial number: NCT03374657.

From Cats to the Cortex: Unravelling the Hierarchical Processing System of Vision and Brain Plasticity.

The groundbreaking research conducted by neurophysiologists David Hubel and Torsten Wiesel during the late 1950s and 1960s revolutionized the field of visual neuroscience. Through single-unit recordings in the visual cortex of cats, they made several key discoveries that fundamentally changed our understanding of visual processing. Their work introduced the concept of orientation selectivity, revealing that neurons in the visual cortex are specifically tuned to line orientations, thereby illustrating how the brain constructs visual representations through edge detection. Additionally, they discovered ocular dominance columns, the specialized cortical regions that respond preferentially to input from one eye, providing crucial insights into the organization of visual processing and the importance of binocular vision. Hubel and Wiesel's research also established the concept of a critical period in visual development, demonstrating that early visual experiences are essential for the proper maturation of the visual system. This discovery has had significant implications for understanding neural plasticity and the role of sensory input in neural development. The impact of their work goes beyond theoretical knowledge, contributing to the development of therapeutic strategies for some visual disorders and guiding current research into brain plasticity and visual processing. This review synthesizes the monumental contributions of Hubel and Wiesel, evaluating how their key discoveries have shaped subsequent research in visual neuroscience. It traces the evolution of knowledge related to visual pathways, feature detection, and brain plasticity, highlighting the enduring influence of their foundational work on contemporary studies. By exploring the progression from their pioneering findings to modern advancements, this review emphasizes the legacy of Hubel and Wiesel's contributions to our understanding of vision and neural function.

Transient eye closure and ocular preference in patients with intermittent exotropia

PurposeTo assess the relationship of sensory and motor ocular dominance to transient eye closure (TEC) under bright light conditions in patients with intermittent exotropia. MethodsForty patients (age range, 7-40 years) with intermittent exotropia were included in this prospective study. Motor and sensory ocular dominance were evaluated using the hole-in-the-card and Worth 4-Dot tests. Presence of any outward eye deviation or TEC was assessed and recorded in all participants under bright light conditions. Based on the fusion control grade of exodeviation, patients were assigned to good, fair, and poor control groups, and the results were compared. ResultsA total of 23 patients (58%) showed TEC under bright light: 18 (45%) in the good control group, 14 (35%) in the fair control group, and 8 (20%) in the poor control group. Eighteen patients (56%) with good and fair control showed TEC in the dominant eye. Five (63%) with poor control closed their nondominant eyes, and in all of them, outward eye deviation was observed before TEC. The angle of deviation at far and near and the degree of near stereopsis were not related to presence of TEC (P = 0.70, P = 0.06, and P = 0.34, resp.). ConclusionsIn patients with intermittent exotropia who exhibit TEC under bright light, those with good control tend to close the dominant eye, whereas in the majority of patients with poor control, spontaneous deviation occurs and is then followed by TEC of the nondominant eye.

Clinical Outcomes of Enhanced Monofocal (Mono-EDOF) Intraocular Lenses with the Mini-Monovision Technique versus Trifocal Intraocular Lenses: A Comparative Study.

It was aimed to compare the clinical results of the mini-monovision technique (MMV) with enhanced monofocal intraocular lens (IOL) and trifocal IOL applications and to evaluate the intereye differences in the MMV group. This retrospective observational study evaluated the results of cataract surgeries performed on 48 eyes of 24 patients. Surgeries in Group I were performed for MMV using the RayOne EMV IOL targeting emmetropia in dominant eyes (Group IA) and -0.70 diopter (D) myopia in non-dominant eyes (Group IB), while those in Group II were performed with the AcrySof® IQ PanOptixTM TNFT00 IOL targeting emmetropia. After the surgeries, uncorrected and corrected distance, intermediate, and near distance visual acuities, contrast sensitivity measurements, and defocus curves were determined. Subjective evaluation was made with the National Eye Institute Visual Function Questionnaire (NEI VFQ-25). The groups were compared statistically. Postoperative refraction mean spherical equivalent was -0.25±0.22 D, -0.67±0.33 D, and -0.16±0.31 D in the three groups, respectively. A statistical difference was identified in favor of Group IA for uncorrected distance vision and in favor of Group IB for near vision (p<0.05). There was no difference in bilateral uncorrected visions in Groups I and II (p>0.05). While contrast sensitivity was better in Group I at all spatial frequencies (p<0.05), better vision was achieved in the defocus curve at distance in Group IA and at near in Group IB. In the binocular evaluation, it was seen that Groups I and II had similar results. In the subjective evaluation, NEI-VFQ-25 scores were 94.1±4.2/100 in Group I and 91.5±3.0/100 in Group II at 6 months (p>0.05). Photic complaints were significantly more common in Group II. With the MMV technique, it was observed that enhanced monofocal lenses provided better visual acuity at all distances and less dysphotopsia than trifocal lenses, whereas trifocal lenses were better at providing independence from glasses.

Evaluation of the effect of ocular dominance on macular microcirculation via swept-source optical coherence tomography angiography

PurposeTo determine the existence of differences in the retinal microcirculation of dominant and non-dominant eyes, as well as of interocular differences in macular microcirculation, using swept-source optical coherence tomography angiography (OCTA). MethodsIn total, 122 eyes of 61 individuals were enrolled in this cross-sectional study. Measurements were taken using the swept-source optical coherence tomography Triton device (Topcon Corp, Tokyo, Japan) coupled with non-invasive OCTA technology. Macular perfusion parameters were assessed, including superficial vascular complex, vascular density of the deep vascular complex, vascular density of the choriocapillaris vascular complex, superficial foveal avascular zone and deep foveal avascular zone. Ocular dominance was determined among individuals with healthy eyes using the hole-in-the-card test. ResultsOcular dominance was found in 68.9 % of right eyes and 31.1 % of left eyes. The mean age of the subjects was 34.45 ± 16.48 years (range: 18–73 years). We found that 16 (30.76 %) males and 22 (31.42 %) females had left-eye dominance (p > 0.05). None of the OCTA parameters differed between the eyes based on dominance (p > 0.05). Central macular thickness and sub-foveal choroidal thickness did not show significant differences (p > 0.05). When comparing interocular parameters, a significant difference was observed only in the inferior sector of the superficial vascular complex (p = 0.04). ConclusionThere was no significant difference in OCTA parameters between dominant and non-dominant eyes. There was no predominant interocular difference in the measurements.

Efficacy of small incision lenticule extraction combined with femtosecond laser-assisted in situ keratomileusis for optimized monovision correction in myopia patients with presbyopia

Objective: To evaluate the efficacy of optimized monovision correction using small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) in myopic patients with presbyopia and to assess the corneal epithelial remodeling following these procedures. Methods: A prospective study was conducted. Thirty-two patients (64 eyes) with myopia and presbyopia who underwent surgical correction at Chongqing Bai Ji Eye Clinic from August 2021 to April 2023 were continuously included. There were 9 males and 23 females, with an average age of (44.25±2.96) years. The dominant eyes (32 eyes) underwent SMILE, while the non-dominant eyes (32 eyes) underwent FS-LASIK with mild myopia and partial negative spherical aberration induction. Data on visual acuity and refraction were collected preoperatively and at 1 week, 1 month, 3 months, and 6 months postoperatively. Total ocular aberrations were measured using the iProfiler Plus, and the corneal epithelial thickness in different regions was assessed using anterior segment optical coherence tomography. Safety and efficacy indices were calculated based on visual acuity, the defocus and contrast sensitivity were measured using the Binoptometer 4P binocular vision tester, and a patient satisfaction survey was performed. Results: At 1 week postoperatively, the uncorrected distance visual acuity (UDVA) of dominant eyes significantly improved compared to preoperative values. At 3 months postoperatively, the uncorrected near visual acuity (UNVA) of non-dominant eyes showed significant improvement (P<0.05), 96.9% (31 eyes) of the dominant eyes achieved UDVA of 1.0 or better, and 93.8% (30 eyes) of the non-dominant eyes achieved UNVA of 0.8 or better. The safety index for distance vision was 1.15±0.09, and the efficacy index was 1.15±0.11. At 1 week, 1 month, 3 months, and 6 months postoperatively, the proportion of dominant eyes with a spherical equivalent (SE) deviation within ±0.50 D of the target was 90.6% (29 eyes), 90.6% (29 eyes), 93.8% (30 eyes), and 96.2% (31 eyes), respectively; for non-dominant eyes, the corresponding proportions were 81.3% (26 eyes), 87.5% (28 eyes), 93.8% (30 eyes), and 96.2% (31 eyes). The postoperative spherical aberration was (0.11±0.03) μm for dominant eyes and (-0.01±0.04) μm for non-dominant eyes, showing a statistically significant difference (P<0.05). At 1 week and 1 month postoperatively, the central corneal epithelial thickness of non-dominant eyes was significantly higher than that of dominant eyes [(71.34±21.69) μm vs. (51.97±6.33) μm at 1 week, and (61.34±15.85) μm vs. (52.72±6.32) μm at 1 month; P<0.05]. Patient satisfaction was high, with 96.9% (31 patients) rating their satisfaction as "satisfactory" or higher. Conclusions: The combined use of SMILE and FS-LASIK for optimized monovision correction in myopic patients with presbyopia is both safe and effective, achieving high postoperative satisfaction. The SMILE procedure reduces the extent of corneal epithelial remodeling compared to FS-LASIK.

Evaluation of visual quality and refractive outcomes of myopia with presbyopia after laser blended vision surgery

Objective: To investigate the postoperative outcomes and visual quality following laser blended vision (LBV) surgery for the correction of myopia with presbyopia. Methods: This is a prospective study. A total of 50 patients (100 eyes) who underwent LBV surgery for myopia with presbyopia at Beijing Tongren Hospital, Capital Medical University, between August 2021 and March 2022 were included. Uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), best-corrected distance visual acuity (BCDVA), manifest refraction spherical equivalent (MRSE) were measured preoperatively and at 1, 3, 6, 12, and 24 months postoperatively for the dominant eye, non-dominant eye, and both eyes. Effectiveness Index (EI) and Safety Index (SI) were calculated to evaluate refractive outcomes. Accommodation function and contrast sensitivity were assessed to evaluate functional vision. Objective visual quality was assessed using higher-order aberrations (HOAs) and a dual-channel visual quality analysis system. Subjective visual quality was evaluated using a questionnaire. Results: At 24 months postoperatively, the EI and SI for the dominant eye were 1.04±0.23 and 1.14±0.14, respectively, while for the non-dominant eye, they were 0.85±0.21 and 1.06±0.08, respectively. Although there were statistically significant differences in UNVA between the eyes at 1 and 3 months postoperatively (all P<0.05), no significant differences were observed from 6 months onward (all P>0.05). At 6 months postoperatively, the UNVA for the dominant and non-dominant eyes were 0.07±0.13 and 0.03±0.13, respectively, with no significant difference (P>0.05). MRSE showed no significant differences at any follow-up time points up to 24 months. Accommodation function did not decrease compared to preoperative levels at any postoperative follow-up. Increases in HOAs were primarily due to spherical aberrations, and there were no significant differences in objective visual quality before and after surgery. Contrast sensitivity improved significantly at 24 months postoperatively compared to preoperative levels. At 24 months postoperatively, 11 out of 12 patients reported good visual quality in the questionnaire. Conclusions: LBV surgery gradually achieves good binocular blended vision within 6 months postoperatively and demonstrates good safety, efficacy, and stability at 24 months. It maintains good functional vision and visual quality with high postoperative patient satisfaction.