Ocular Dominance Research Articles

Evaluation of retinal microvasculature in exotropia with abnormal binocular vision by optical coherence tomography angiography

BackgroundTo explore the retinal microvasculature in large-angle concomitant exotropia patients with abnormal binocular vision using optical coherence tomography angiography (OCTA) analysis.MethodsOCTA images of 52 healthy and 100 strabismic eyes were analyzed to quantify the retinal thickness (RT), superficial capillary plexus (SCP), deep capillary plexus (DCP), and foveal avascular zone (FAZ). Paired t-tests were performed to compare differences between the two groups, the dominant eye and the deviated eye in the exotropia group, respectively. A p-value < 0.01 was considered significant.ResultsThe mean angle of deviation was 79.38 [± 25.64] (prism diopters, PD). There were significant differences in the DCP in deviated eyes between the exotropia group and the control group (fovea: p = 0.007; temporal: p = 0.014; nasal: p = 0.028; inferior: p = 0.013). The temporal SCP in the exotropia group was significantly higher than in the control group in deviated eyes (p = 0.020). No significant difference was found between dominant eyes and strabismic eyes (p > 0.01).ConclusionsThe study showed that OCTA revealed subnormal DCP in patients with large-angle exotropia and abnormal binocularity which may be related to retinal suppression. Changes in the macular microvasculature may provide valuable insights into the development of strabismus. Further studies are needed to determine the clinical relevance of this finding.Trial registrationThis trial is registered as ChiCTR2100052577 at www.Chictr.org.cn.

Measurement of Aniseikonia Tolerance in Binocular Fusion.

The determination of aniseikonia tolerance may aid in developing optimal treatment plans for cataract surgery, refractive surgery, and refractive correction with glasses and contact lenses. This study aimed to measure aniseikonia tolerance. We included 33 patients (mean age ± standard deviation, 28.9 ± 6.4 years; male/female, 12:21) with anisometropia ≤1.0 D and best spectacle-corrected visual acuity of 20/20 or more in both eyes, with no ophthalmologic disease other than refractive errors and no history of ocular surgery. The exclusion criteria were anisometropia >1.0 D, axial length difference >0.5 mm, corneal refractive power difference >0.5 D, astigmatism >3.0 D, stereoacuity threshold >100 arcsec according to the Titmus Stereo Test, and >0% aniseikonia according to the New Aniseikonia Test. Aniseikonia tolerance was assessed using Eyemark Hello, a haploscope using gaze detection technology. Although the optotype of one eye was enlarged or reduced at a speed of 2%/s, the patients were instructed to press a button on the controller to indicate blurring, flickering, and diplopia. The value at which the patient responded was considered the aniseikonia tolerance value and assessed thrice per eye, five times if the values were highly variable, and then averaged. The mean aniseikonia tolerance was approximately 3%; the median value was approximately 2% (range, 1.0 to 11.5%; dominant eye, 3.3 ± 2.6%; nondominant eye, 2.9 ± 1.8%). No significant difference in aniseikonia tolerance between the dominant and nondominant eyes was observed for the enlarged optotypes. No case showed changes in the ocular alignment before discomfort occurred. No significant correlation was observed between aniseikonia tolerance and anisometropia, axial length difference, corneal power difference, and ocular deviation. Aniseikonia should be maintained at <2% for a comfortable visual environment. Aniseikonia tolerance may be an important indicator for cataract surgery, refractive surgery, and spectacle correction.

Supracor Multifocal Corneal Laser-Assisted In Situ Keratomileusis Procedure for the Correction of Presbyopia in Hyperopic Eyes.

To investigate the outcomes of unilateral Supracor treatment to enhance near vision while maintaining good distance vision in hyperopic eyes. This prospective interventional study includes consecutive hyperopic patients with presbyopia. All eyes underwent femtosecond laser-assisted in situ keratomileusis treatment for hyperopia with an additional Supracor multifocal treatment algorithm in nondominant eyes. Monocular and binocular uncorrected and spectacle-corrected distance visual acuity (UCDVA and SCDVA), monocular and binocular uncorrected near visual acuity (UNVA), and distance-corrected near visual acuity at 40 cm and high-order aberration changes and complications were evaluated for 6 months. Sixty-four patients with a mean age of 51.91 ± 3.64 were enrolled. After 6-month follow-up, the mean binocular UCDVA and UNVA were 0.03 ± 0.05 and 0.04 ± 0.06 logMAR, respectively. UCDVA (logMAR) of nondominant and dominant eyes was 0.30 ± 0.18 and 0.03 ± 0.05, respectively. Preoperative and postoperative mean ± standard deviation manifest refraction spherical equivalent was +1.84 ± 0.75 and -0.48 ± 0.57, respectively, in nondominant eyes and +1.77 ± 0.69 and +0.12 ± 0.33, respectively, in dominant eyes. No complications were observed. Supracor procedure in nondominant eyes may improve functional near, intermediate, and distance vision without significant photic phenomena in presbyopic patients with low and moderate hyperopia.

Men Who Brew: Masculinity and the Production of Drink in Medieval Icelandic Literature

Men Who Brew: Masculinity and the Production of Drink in Medieval Icelandic Literature

Ten-year outcomes of pseudophakic mini-monovision correction of hyperopic presbyopia.

To evaluate long-term efficacy, safety, and spectacle independence after the treatment of hyperopic presbyopia with pseudophakic mini-monovision using standard monofocal intraocular lenses (IOLs) after bilateral cataract surgery. Private practice in Barcelona, Spain. Retrospective, noncomparative case series. Patients with hyperopic presbyopia underwent bilateral cataract surgery with pseudophakic mini-monovision using standard monofocal IOLs between 2008 and 2018. Main outcomes analyzed were uncorrected distance visual acuity (UDVA), uncorrected near distance visual acuity (UNVA), and rates of spectacle independence at postoperative day 1 (POD1), months 1, 6 and 12, and at 5 and 10 years (Y10) postoperatively. The study enrolled 463 patients. Both UDVA and UNVA significantly improved postoperatively ( P < .05). The mean binocular UDVA improved from 0.47 ± 0.3 logMAR preoperatively to 0.096 ± 0.14 at POD1 to 0.16 ± 0.2 at Y10 ( P = .0033). The binocular UNVA was 0.05 logMAR at Y10, whereas in preoperative visits, all patients needed spectacles. The mean UDVA for the dominant eye ≤0.20 logMAR was achieved in 84.29% at the Y10. Self-reported and measured complete spectacle independence for near vision was achieved in 79.61% of patients at POD1 and 71.92% at Y10 postoperatively. For distance, respectively, in 86.29% of patients at POD1 and 78.43% at Y10. The achieved results were stable. No serious events were reported, as well as no photic phenomena. Pseudophakic mini-monovision in hyperopic presbyopes is a safe, effective, and low-cost approach for the long-term correction of presbyopia. It significantly reduces spectacle dependence and fulfils patients' expectations after bilateral cataract surgery.

AN ASSESSMENT OF OCULAR DOMINANCE: A TERTIARY LEVEL HEALTH CARE CENTRE OBSERVATIONAL STUDY

Background: Ocular Dominance was first described by Rosenbach. Ocular Dominance is the tendency to physiological preference of one eye over another eye. However, the role of Ocular Dominance in processing of visual memory and analytic tasks is unknown. Research has showed significant effects of Ocular Dominance on visual perception, motor control, color vision and sports performance. The aim of present study was to determine Ocular Dominance by the Gundogan Method which is Near Far Alignment Test. Method:This study attempts to assess Ocular Dominance and the relationship between Ocular Dominance, Gender and cerebral laterality. It is a cross sectional, comparative and analytic type of study which is carried out on 170 healthy young adults with normal visual acuity. Among them 101 subjects were male and 69 subjects were female. Detection of Ocular Dominance was done by Gundogan Test. Result: Ocular Dominance was present in human beings. Ocular Dominance was most commonly present in Right Eye. Right Eye was dominant in (118) 69.4 % subjects and Left Eye was dominant in (52)30.6 % subjects. Gender based distribution of Right eye dominancy was 70.3%(n=71) for males and 68.1%(n=47) for females. Gender distribution For Left eye dominancy, was 29.7%(n=30) for males and 31.8%(n=22) for females (p value = 0.89). Conclusion: Ocular Dominance markedly observed in human beings, and Right eye dominancy is more preponderant than Left eye. It was also concluded that gender is not a major factor to affect eye dominancy. We insinuate that Gundogen Performance Test was appear to be a more practical and fluently applicable performance Test.

Premenstrual sendromu olan adolesan kızlarda serebral lateralizasyon

Purpose: In this study, it was aimed to compare differences and similarities the cerebral lateralization of adolescent girls with Premenstrual Syndrome (PMS) with the control group. We also aimed to investigate whether there was a relationship between PMS severity and cerebral lateralization.&#x0D; Materials and Methods: A total of 79 female adolescents aged 14-18 years who met the study inclusion criteria completed the study. A second interview was held with all participants who filled out the Premenstrual Assessment Form (PAF) during the luteal periods of menstrual cycles (1-7 days before menstruation). All participants completed the Harris lateralization test.&#x0D; Results: The mean age was 192.85 ± 14.54 (range 167 - 216) months. The median PMS score was found to be 2.26 (1.00 - 5.10). While PMS was not detected in 35 (44.30%) participants, mild PMS was detected in 20 (25.32%) participants, moderate in 14 (17.72%), and severe in 10 (12.66%) participants. Sixty-seven (84.81%) participants had right hand dominance and three (3.80%) left hand dominance, nine (11.39%) participants had hand uncertainty. While the hand and eye dominance were on the same side in 41 (51.90%) participants, cross-lateralization (all right hand, left eye) was detected in 11 (13.92%) participants. Indeterminate lateralization (Harris lateralization score of 1 or 2) for the hand and eye was significantly higher in the PMS group.&#x0D; Conclusion: The findings raise the question of whether lateralization (hand-eye) is less common in individuals with PMS and whether there will be a common etiology for lateralization problem and PMS. Further studies are needed considering the factors that may contribute to this etiology and some of the limitations we have presented in our study.

Development of myelin in fetal and postnatal neocortex of the pig, the European wild boar Sus scrofa

Myelination of the neocortex of altricial species is mostly a postnatal event, and the appearance of myelin has been associated with the end of the critical period for ocular dominance plasticity in rodent visual cortex. Due to their precocality, ungulates may tell a different story. Here, we analyzed the development of PDGFRα positive oligodendrocyte precursor cells and expression of myelin proteins in the laminar compartments of fetal and postnatal porcine cortex from E45 onwards. Precursor cell density initially increased and then decreased but remained present at P90. MAG and MBP staining were detectable at E70 in subventricular zone and deep white matter, ascending into gyral white matter at E85, and into the gray matter and marginal zone at E100 (birth in pig at E114). Protein blots confirmed the declining expression of PDGFRα from E65 onwards, and the increase of MBP and MAG expression from E80 onwards. Somatosensory input elicited by spontaneous activity is considered important for the formation of the body representation. Indeed, PDGFRα, MBP and MAG expression started earlier in somatosensory than in visual cortex. Taken together, myelination proceeded in white and gray matter and marginal zone of pig cortex before birth with an areal-specific time course, and an almost mature pattern was present at P5 in visual cortex.

Visual Outcomes, Contrast Sensitivity, and Satisfaction with Multifocal Intraocular Lens Blended Technique: Late Mid-term Results

To describe clinical visual outcomes, spectacle independence, and patient satisfaction after cataract surgery with blending implantation of ReSTOR (Alcon laboratories) multifocal intraocular lenses. A single-arm, non-randomized prospective study assessed patients undergoing cataract surgery with ReSTOR® +2.50 intraocular lens in the dominant eye and +3.00 add in the fellow eye between January 2015 to January 2020. In total, 47 patients (94 eyes) were enrolled, 28 women and 19 men. The average age at surgery time was 64 ±8 years, average postoperative follow-up was 45.4 ±7.0 months, with a minimum of 18.9 months. Postoperative binocular uncorrected distance visual acuity (UDVA) was on average 0.07 logMar (Snellen 20/24), uncorrected binocular intermediate visual acuity at 65 cm was 0.07 logMar (20/24), uncorrected binocular near visual acuity at 40 cm was 0.06 logMar (20/23). Contrast sensitivity under photopic and scotopic conditions, with and without glare, remained at the upper limit of normality. 98% of patients were quite satisfied or very satisfied. 87% did not require glasses for any activities, either at distant vision, nor at near vision. Cataract surgery with ReSTOR® IOL blended vision showed medium-term satisfactory visual results, achieving spectacle independence and a high level of satisfaction.

Is ocular dominance plasticity a special case of contrast adaptation?

The visual system can regulate its sensitivity depending on the prevailing contrast conditions. This is known as contrast adaptation and reflects contrast gain changes at different stages along the visual pathway. Recently, it has been shown that depriving an eye of visual stimulation for a short period of time can lead to neuroplastic changes in ocular dominance as the result of homeostatic changes in contrast gain. Here we examine, on the basis of previously published results, whether the neuroplastic ocular dominance changes are just manifestation of the mechanism responsible for contrast adaptation. The evidence suggests that these two visual processes are separate and do not have a common neural substrate.

Case Report: Asymmetric Changes of Ophthalmic Findings in Bilateral Solar Eclipse Maculopathy.

A more profound understanding of the relationship between ophthalmic findings and eye dominance is needed to guide the timely and proper treatment of binocular photic maculopathy or other macular degeneration. A patient with binocular solar maculopathy presented with asymmetric ophthalmic manifestations and changes over 14 months of observation. Early recognition of solar maculopathy can be vital for early diagnosis and better prognosis. A 21-year-old male was reported to have blurred vision after staring directly at an annular solar eclipse several times for a few seconds on June 21, 2020. His Snellen best-corrected visual acuity (BCVA) declined to 20/50 in both eyes. He was right-eye dominant according to the hole-in-the-card test. The fundoscopy found a yellow spot in the center of both maculae. Spectral domain optical coherence tomography (SD-OCT) images revealed a full thickness hyperreflectivity extending from the inner retinal layers to the retinal pigment epithelium (RPE) along with a localized disruption of the ellipsoid portion of the inner segments and RPE in both eyes. The medical history and clinical manifestations described above supported the diagnosis of solar maculopathy. SD-OCT images during follow-up indicated a diminishing disruption of the ellipsoid portion of the inner segments and RPE without treatment. Interestingly, the non-dominant left eye made a better anatomical recovery. Finally, the Snellen BCVA remained 20/20 in both eyes after 14 months. Binocular solar maculopathy can present asymmetrically and recover asymmetrically as well. The dominant eye suffered more obvious damage and poorer anatomical recovery than the non-dominant eye.

Thalamic regulation of a visual critical period and motor behavior

During the visual critical period (CP), sensory experience refines the structure and function of visual circuits. The basis of this plasticity was long thought to be limited to cortical circuits, but recently described thalamic plasticity challenges this dogma and demonstrates greater complexity underlying visual plasticity. Yet how visual experience modulates thalamic neurons or how the thalamus modulates CP timing is incompletely understood. Using a larval zebrafish, thalamus-centric ocular dominance model, we show functional changes in the thalamus and a role of inhibitory signaling to establish CP timing using a combination of functional imaging, optogenetics, and pharmacology. Hemisphere-specific changes in genetically defined thalamic neurons correlate with changes in visuomotor behavior, establishing a role of thalamic plasticity in modulating motor performance. Our work demonstrates that visual plasticity is broadly conserved and that visual experience leads to neuron-level functional changes in the thalamus that require inhibitory signaling to establish critical period timing.

Modulation of Visual Responses and Ocular Dominance by Contralateral Inhibitory Activation in the Mouse Visual Cortex.

Both hemispheres connect with each other by excitatory callosal projections, and whether inhibitory interneurons, usually believed to have local innervation, engage in transcallosal activity modulation is unknown. Here, we used optogenetics in combination with cell-type-specific channelrhodopsin-2 expression to activate different inhibitory neuron subpopulations in the visual cortex and recorded the response of the entire visual cortex using intrinsic signal optical imaging. We found that optogenetic stimulation of inhibitory neurons reduced spontaneous activity (increase in the reflection of illumination) in the binocular area of the contralateral hemisphere, although these stimulations had different local effects ipsilaterally. The activation of contralateral interneurons differentially affected both eye responses to visual stimuli and, thus, changed ocular dominance. Optogenetic silencing of excitatory neurons affects the ipsilateral eye response and ocular dominance in the contralateral cortex to a lesser extent. Our results revealed a transcallosal effect of interneuron activation in the mouse visual cortex.

Mesoscale functional connectivity in macaque visual areas

Studies of resting-state functional connectivity (rsFC) have provided rich insights into the structures and functions of the human brain. However, most rsFC studies have focused on large-scale brain connectivity. To explore rsFC at a finer scale, we used intrinsic signal optical imaging to image the ongoing activity of the anesthetized macaque visual cortex. Differential signals from functional domains were used to quantify network-specific fluctuations. In 30–60 min resting-state imaging, a series of coherent activation patterns were observed in all three visual areas we examined (V1, V2, and V4). These patterns matched the known functional maps (ocular dominance, orientation, color) obtained in visual stimulation conditions. These functional connectivity (FC) networks fluctuated independently over time and exhibited similar temporal characteristics. Coherent fluctuations, however, were observed from orientation FC networks in different areas and even across two hemispheres. Thus, FC in the macaque visual cortex was fully mapped both on a fine scale and over a long range. Hemodynamic signals can be used to explore mesoscale rsFC in a submillimeter resolution.

Morphological study of extraocular muscles in dissociated vertical deviation by magnetic resonance imaging

Objective: To observe the changes of pulley locations and muscle volumes of extraocular rectus muscles in dissociated vertical deviation. Methods: This was a cross-sectional study. Data was collected from January 2020 to December 2020 in Tianjin Eye Hospital. The pulley locations and muscle volumes of extraocular rectus muscles in DVD patients and healthy volunteers were observed and calculated by continuous coronal MRI scan. One-way ANOVA and independent sample T test were used for statistical analysis. According to the examination results, Groups were divided into A (symmetric DVD), B (asymmetric DVD) and C (healthy volunteers). Data of symmetric DVD patients were divided into dominant eye (A-D) and non-dominant eye (A-nD), while that of asymmetric DVD patients were divided into severe DVD (B-s) and mild DVD (B-m). Volume of 4 rectus muscles and superior oblique muscle were calculated and compared to Group C, respectively. Results: Group A included 5 patients (10 eyes), 2 males and 3 females, aged (22±4) years; Group B included 4 patients (8 eyes), 2 males and 2 females, aged (28±8) years; Group C included 10 patients (20 eyes), including 4 males and 6 females, aged (25±6) years. There was no significant differences in age(F=0.45,P=0.648)or gender(χ2=0.78;P=0.833)among the three groups. There was no significant difference in pulley locations of extraocular rectus muscles between the three groups (FMR=0.52,FLR=0.62,FSR=0.72,FIR=1.16;all P>0.05). Among the four exterocular rectus muscles, the muscle volume of MR [A-D: (562.8±64.4) mm3,A-nD: (560.6±53.2) mm3,B-s: (557.0±48.7) mm3,B-m: (551.5±45.8) mm3], LR [A-D: (519.8±44.5) mm3,A-nD: (511.0±49.4) mm3,B-s: (501.0±35.6) mm3,B-m: (498.3±45.3) mm3] and SR [A-D: (472.8±66.9) mm3,A-nD: (449.4±41.7) mm3,B-s: (433.0±60.8) mm3,B-m: (412.5±54.5) mm3] in group A and group B was higher than that in group C [MR: (423.3±51.9)mm3,LR: (439.7±35.3)mm3,SR: (328.1±36.5)mm3], and the difference was statistically significant (All P<0.05). The inferior rectus muscle volume of dominant eye in group A and mild DVD eye in group B was significantly different from that of healthy volunteers in group C [(453.8±46.8) and (463.0±16.6) vs. (380.4±59.7) mm3, respectively], and the difference was statistically significant (all P<0.05). Conclusions: There are no significant changes in pulley locations of extraocular rectus muscles in patients with symmetric and asymmetric DVD, and the muscle volumes of medial, lateral and superior rectus muscle are greater than those of healthy people. However, the muscle volumes of inferior rectus muscle of dominant eye in symmetric DVD and mild DVD eye are significantly greater.

Combined Foot and Eye Dominance Scale as a useful tool for the assessment of lateralization

IntroductionLateralization is the functional dominance of one of the dual organs of the body: eyes, arms, legs and even ears, during their spontaneous or purposeful actions. The handedness is influenced by many factors like geographic region, genetic and cultural factors as well as sex. The most used assessment for functional lateralization is hand dominance. When assessing foot and eye dominance, however, we find significantly higher left foot dominance as well as very strong left eye dominance in schizophrenic patients versus controls. We consider the explanation of this results is because in Bulgaria, during the communist regime (before 1990) left hand writing was under cultural pressure. Also handedness itself is influenced by other cultural factors as mentioned already. All of the above made us conclude that foot and eye dominance may assess much better the lateralization than hand dominance.ObjectivesThe aim of the study was to investigate the relaibility (internal consistency) of a combined Foot and Eye Dominance Scale in women- patients with schizophrenia and healthy subjects.MethodsA sample of 94 women- scizophrenia patients and healthy controls were assessed with a Combined afaoot and Eye Dominance Scale. It consisted of two subscales Foot Dominance Subscale and Eye Dominance Subscale. The Foot Dominance Subscale included a modified Chapman &amp; Chapman Foot Dominance Scale and a new Complex Task Scales with four foot tests, reflecting on complex tasks. The Eye Dominance Subscale included three eye tests. Scale reliability statistics (item-scale statistics, summary statistics for the items, Cronbach’s alpha), non-parametric Mann-Whitney test and Spearman’s rank correlation coefficient were used.ResultsConsiderable differences were found in the contribution of the single items to the Combined Foot and Eye Dominance Scale. Some items show greater means than other items (from 0,14 to 0,80), which suggested greater phenogenetic component and consequently greater contribution of these items to the total scale mean. The mean correlation between the items of the Combined Foot and Eye Dominance Scale was positive (0,32), indicating good internal consistency of the scale.ConclusionsThe Combined Foot and Eye Dominance Scale more strongly and objectively reflect leftedness and could be a more useful tool for the assessment of lateralization irrespectively of culture and nation. The Combined Scale allows cross-cultural worldwide equivalence to the different studies in different neuroontogenetic diagnoses with presumed abnormal cerebral asymmetry.Disclosure of InterestNone Declared

NNOS-induced tyrosine nitration of TRKB impairs BDNF signaling and restrains neuronal plasticity.

Nitric oxide (NO) has been long recognized as an important modulator of neural plasticity, but characterization of the molecular mechanisms involved - specially the guanylyl cyclase-independent ones - has been challenging. There is evidence that NO could modify BDNF-TRKB signaling, a key mediator of neuronal plasticity. However, the mechanism underlying the interplay of NO and TRKB remains unclear. Here we show that NO induces nitration of the tyrosine 816 in the TRKB receptor in vivo and in vitro, and that post-translational modification inhibits TRKB phosphorylation and binding of phospholipase Cγ1 (PLCγ1) to this same tyrosine residue. Additionally, nitration triggers clathrin-dependent endocytosis of TRKB through the adaptor protein AP-2 and ubiquitination, thereby increasing translocation of TRKB away from the neuronal surface and directing it towards lysosomal degradation. Accordingly, inhibition of nitric oxide increases TRKB phosphorylation and TRKB-dependent neurite branching in neuronal cultures. In vivo, chronic inhibition of neuronal nitric oxide synthase (nNOS) dramatically reduced TRKB nitration and facilitated TRKB signaling in the visual cortex, and promoted a shift in ocular dominance upon monocular deprivation - an indicator of increased plasticity. Altogether, our data describe and characterize a new molecular brake on plasticity, namely nitration of TRKB receptors.

Clinical Outcomes of a New Non-Diffractive Extended Depth-of-Focus Intraocular Lens Targeted for Mini-Monovision.

To assess visual acuity, binocular defocus curve, spectacle independence, and photic phenomena after bilateral same-day cataract surgery with implantation of an extended depth-of-focus intraocular lens (IOL) with mini-monovision. Single-center retrospective study including 124 eyes from 62 patients who underwent bilateral implantation of an isofocal EDOF lens [Isopure® (BVI)] with mini-monovision (-0.50 D). Refraction, visual acuity at different distances, binocular defocus curves, spectacle independence, and subjective ratings of picture-referenced photic phenomena were assessed one to two months postoperatively. The mean postoperative refractive spherical equivalent was -0.15±0.41D in the dominant eyes and -0.46±0.35D in the mini-monovision eyes (p<0.01). Overall, 98.4% and 87.7% of the eyes were within ±1.00D and ±0.50D of the target refraction, respectively. Postoperative monocular corrected distance visual acuity was -0.04±0.07 logMAR. Binocular uncorrected visual acuity was -0.02±0.07, 0.13±0.11and 0.40±0.20 logMAR for far, intermediate and near, respectively. At the visual acuity threshold of 0.20 logMAR (or better) the defocus curve ranged from -1.6D to +0.9D. Reported spectacle-independence was 96% for far distance, 95% for intermediate, and 34% for near. Five percent of patients reported halos, 16% starburst, and 16% glare. Only 7% of all patients considered them bothersome. In patients undergoing same-day bilateral cataract surgery, an isofocal EDOF lens provided an extended range of functional vision, up to 63 cm, resulting in useful uncorrected near vision, good uncorrected intermediate vision, and excellent uncorrected distance vision. Subjective patient satisfaction in terms of spectacle independence and photic phenomena was high.

Decision taking in corneal refractive surgery.

A 27-year-old woman who wants to get rid of contact lenses and spectacles was seen at our clinic. She had strabismus surgery as a child and was patched for the right eye but now shows mild nondisturbing exophoria. Infrequently, she likes to box in the sports school. Her corrected distance visual acuity at presentation in the right eye was 20/16 with -3.75 -0.75 × 50 and in the left eye 20/16 with -3.75 -1.25 × 142. Her cycloplegic refraction in the right eye was -3.75 -0.75 × 44 and in the left eye was -3.25 -1.25 × 147. The left eye is the dominant eye. The tear break-up time was 8 seconds in both eyes, and the Schirmer tear test was 7 to 10 mm in right and left eyes, respectively. Pupil sizes under mesopic conditions were 6.62 mm and 6.68 mm. The anterior chamber depth (ACD) (measured from the epithelium) in the right eye was 3.89 mm and in the left eye was 3.87 mm. The corneal thickness was 503 μm and 493 μm of the right and left eye, respectively. Corneal endothelial cell density was on average 2700 cells/mm2 for both eyes. Slitlamp biomicroscopy showed clear corneas and a normal flat iris configuration. Supplemental Figures 1 to 4 (available at http://links.lww.com/JRS/A818, http://links.lww.com/JRS/A819, http://links.lww.com/JRS/A820, and http://links.lww.com/JRS/A821) show the corneal topography and Belin-Ambrósio deviation (BAD) maps at presentation of the right eye and left eye, respectively. Would you consider this patient a candidate for corneal refractive surgery (eg, laser-assisted subepithelial keratectomy, laser in situ keratomileusis [LASIK], or small-incision lenticule extraction [SMILE] procedure)? Has your opinion changed given the recent opinion of the U.S. Food and Drug Administration (FDA) regarding LASIK?1 The patient herself is slightly favoring an implantation of a phakic intraocular lens (pIOL), as she prefers something reversible. Would you implant a pIOL, and which type of IOL, for this level of myopia? What is your diagnosis or are additional diagnostic methodologies needed to establish a diagnosis? What is your treatment advice for this patient? REFERENCES 1. U.S. Food and Drug Administration, HHS. Laser-assisted in situ keratomileusis (LASIK) lasers-patient labeling recommendations; draft guidance for industry and food and drug administration staff; availability. July 28, 2022, Federal Register; 87 FR 45334. Available at: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/laser-assisted-situ-keratomileusis-lasik-lasers-patient-labeling-recommendations Accessed January 25, 2023.

Interocular Contrast Balancing Partially Improves Stereoacuity in Keratoconus.

Partial improvement in stereoacuity may be achieved by balancing the contrast input to the two eyes of patients with bilaterally asymmetric keratoconus. Interocular differences in image quality, characterized by dissimilar contrast loss and phase shifts, are implicated in stereoacuity loss in keratoconus. This study determined whether contrast balancing improves stereoacuity in this disease condition and, if so, whether it is dependent on the baseline interocular contrast imbalance. Interocular contrast imbalance and stereoacuity of 43 subjects (16 to 33 years) with bilaterally asymmetric keratoconus were tested with spectacle correction as baseline using a binocular rivalry paradigm and random-dot stereograms, respectively. Stereoacuity measurements were repeated in a subset of 33 subjects at their contrast balance point (i.e., contrast level in stronger eye allowing balanced rivalry with 100% contrast in weaker eye) and with contrast levels biased in favor of stronger or weaker eye, all conditions in randomized order. Contrast imbalance level was significantly correlated with the subject's stereoacuity at baseline ( r = -0.47, P = .002). The median (25th to 75th interquartile range) stereoacuity improved by 34.6% (19.0 to 65.1%) from baseline (748.8 arc sec [261.3 to 1257.3 arc sec]) to the contrast balanced condition (419.0 arc sec [86.6 to 868.9 arc sec]) ( P < .001), independent of their baseline stereoacuity or contrast imbalance levels ( r < 0.2, P > .26 for both). Contrast bias in favor of the weaker eye (881.3 arc sec [239.6 to 1707.6 arc sec]) worsened stereoacuity more than a bias toward the stronger eye (502.6 arc sec [181.9 to 1161.4 arc sec]), both relative to the contrast balanced condition ( P < .002). Interocular contrast balancing partially improves stereoacuity in bilaterally asymmetric keratoconus, independent of their baseline contrast imbalance level. Cyclopean viewing may be inherently biased toward the input from the stronger eye in keratoconus.