Photopic Conditions Research Articles

Spatiotemporal summation of perimetric stimuli in healthy observers.

Spatial summation of perimetric stimuli has been used to derive conclusions about the spatial extent of retinal-cortical convergence, mostly from the size of the critical area of summation (Ricco's area, RA) and critical number of retinal ganglion cells (RGCs). However, spatial summation is known to change dynamically with stimulus duration. Conversely, temporal summation and critical duration also vary with stimulus size. Such an important and often neglected spatiotemporal interaction has important implications for modeling perimetric sensitivity in healthy observers and for formulating hypotheses for changes measured in disease. In this work, we performed experiments on visually heathy observers confirming the interaction of stimulus size and duration in determining summation responses in photopic conditions. We then propose a simplified computational model that captures these aspects of perimetric sensitivity by modelling the total retinal input, the combined effect of stimulus size, duration, and retinal cones-to-RGC ratio. We additionally show that, in the macula, the enlargement of RA with eccentricity might not correspond to a constant critical number of RGCs, as often reported, but to a constant critical total retinal input. We finally compare our results with previous literature and show possible implications for modeling disease, especially glaucoma.

Higher order aberrations and visual function in a young Asian population of high myopes

PurposeTo examine the associations between higher order aberrations (HOAs), visual performance, demographics, and ocular characteristics in a young Asian population with high myopia. MethodsThis was a retrospective review of military pre-enlistees conducted between March 2014 to September 2018. Visual acuity and contrast sensitivity were tested under photopic, mesopic and simulated night conditions. Ocular, corneal and internal HOAs were measured with a Hartmann–Shack wavefront aberrometer (KR-1W, Topcon Co., Tokyo, Japan). Results522 eyes of 263 consecutive subjects with severe high myopia (defined as spherical equivalent refraction [SER] ≤ −10.00D) in at least one eye, and high myopia (SER ≤ −6.00D) in the fellow eye, [mean (SD) SER −11.85 (2.03D)] were analysed. The mean (SD) age of subjects was 18.5 (1.6) years. Chinese eyes had significantly greater internal total HOA root-mean-square (RMS) compared to Malay eyes [mean difference (SD) 0.0246 (0.007) μm, p < 0.001). More negative SER was associated with greater ocular total HOA (p = 0.038), primary coma (p = 0.003) and tetrafoil (p = 0.025) RMS, as well as more positive ocular (p = 0.003) and internal primary spherical aberration (p = 0.009). Greater ocular total HOAs was associated with reduced visual acuity in simulated night conditions and low contrast, decreased contrast sensitivity under mesopic and simulated night conditions (all p < 0.05). ConclusionsGreater HOAs were associated with Chinese ethnicity and more negative SER in a young Asian population with high myopia. Greater HOAs were associated with poorer visual performance in low luminance and reduced contrast conditions.

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.

Evaluation of Static and Dynamic Pupillary Functions in Early-Stage Primary Open Angle Glaucoma.

The dynamic parameters of the pupil, evaluated with an automated pupillometry device, differ in newly diagnosed early-stage primary open angle glaucoma (POAG) patients compared with healthy individuals, and this may guide us in early diagnosis and follow-up of glaucoma. To quantitatively determine static and dynamic pupillary functions in treatment-naive, newly diagnosed early-stage POAG patients and compare them with healthy controls. Forty eye of forty subjects with early POAG were compared with 71 eye of 71 age- matched and sex-matched healthy controls in terms of static and dynamic pupillary functions in this prospective and cross-sectional study. Static and dynamic pupillary functions were obtained with an automated pupillometry device. Static pupillometry parameters are pupil diameter (mm) in high photopic (100cd/m 2 ), low photopic (10cd/m 2 ), mesopic (1cd/m 2 ), and scotopic (0.1cd/m 2 ) light conditions. Dynamic pupillometry parameters are resting diameter (mm), amplitude (mm), latency (ms), duration (ms), and velocity (mm/s) of pupil contraction and dilation. Measured data were evaluated and compared with t test for independent groups. Duration of pupil contraction was lower, ( P =0.04) latency of pupil dilation time was longer, ( P =0.03) duration of pupil dilation was shorter ( P =0.04) and velocity of pupil dilation was lower ( P =0.02) in the POAG group. There was no significant difference between the 2 groups in terms of static pupillometry characteristics and the resting pupil diameter ( P >0.05 for all values). These results suggest that dynamic pupillary light responses may be affected in early-stage POAG compared with the normal population. Longitudinal studies with larger series are needed to better understand the quantitative changes in dynamic pupillometry functions in early-stage POAG.

Relationship Between Autonomic Nervous System Activity and Axial Length in Children.

BACKGROUND The aim of this work was to compare autonomic nervous system activity between eyes with axial and non-axial myopia and to investigate the relationship between autonomic nervous system activity and axial length (AL) in children. MATERIAL AND METHODS Seventy-eight eyes of 78 children were included in this study. Static and dynamic pupillary responses, including pupil diameter, latency, and velocity of pupil contraction and dilation, were recorded using automatic pupillometry to evaluate autonomic nervous system activity. AL was measured using the IOL-Master device. RESULTS In terms of static pupillary responses, the pupil diameter at mesopic condition (1 candelas/m²) (PD1) (4.06±0.64 vs 3.80±0.87 mm, P=0.045) and pupil diameter at low photopic condition (10 candelas/m²) (PD10) (3.40±0.49 vs 3.22±0.66 mm, P=0.046) were significantly larger in axial myopic eyes than in non-axial myopic eyes. In terms of dynamic pupillary responses, velocity of pupil contraction (Vel-C) (5.93±0.89 vs 6.75±1.60 mm/s, P=0.019) and velocity of pupil dilation (Vel-D) (2.28±0.38 vs 2.89±1.17 mm/s, P=0.002) were significantly slower in axial myopic eyes than in non-axial myopic eyes. Moreover, PD1 and PD10 were significantly and positively associated with AL, while Vel-C and Vel-D were significantly and negatively associated with AL (all P<0.05). CONCLUSIONS There was significant decrease in autonomic nervous system activity in axial myopia compared with non-axial myopia, and autonomic nervous system activity was significantly and negatively associated with AL in children. Decreases in autonomic nervous system activity in axial myopia may contribute to the excessive axial elongation in pediatric axial myopia.

A Mathematical Model for the Action Spectrum of Steady-State Pupil Size in Photopic Vision with Insight into Healthful Lighting

The pupillary light reflex, which has been seen as an important noninvasive and objective indicator of autonomic nervous system function, can be used for evaluating the impact of different lighting conditions in buildings on circadian behaviors, assessing ipRGC function in healthy and diseased retinas, and explaining luminance adaptation. However, the mechanism by which the intrinsic and extrinsic signals of ipRGCs regulate the steady-state pupil size under continuous lighting stimuli is still not clearly understood after decades of exploration. This paper presents a new experimental protocol with a large hemisphere LED screen as the stimulation device, allowing for a more realistic and comprehensive study in architectural spaces, which can potentially inform the design of lighting systems in buildings that promote healthy vision and comfort. Results reveal that both intrinsic and extrinsic signals participated in the process of regulating pupil size under continuous lighting conditions. Based on the findings, a new mathematical model was further proposed to calculate the contribution of these two signal sources to the changing intensity of melanopic radiance. The research outcomes also provide new insight into the mechanism of visual perception and adaptation and the nonvisual effect of eyes under different light conditions. Results suggest that the contribution of extrinsic signals may have been underestimated in previous studies since the extrinsic signal increases with reducing intensity in photopic conditions with lower melanopic radiance.

Preliminary characterization of a novel form of progressive retinal atrophy in the German Spitz dog associated with a frameshift mutation in GUCY2D.

To describe the clinical, preliminary electroretinographic and optical coherence tomography features of a newly identified form of progressive retinal atrophy (PRA) in German Spitzes, and identify the causal gene mutation. Thirty-three client-owned German Spitz dogs were included. All animals underwent a full ophthalmic examination, including vision testing. In addition, fundus photography, ERG, and OCT were performed. A DNA-marker-based association analysis was performed to screen potential candidate genes and the whole genomes of four animals were sequenced. Initial fundus changes were pale papilla and mild vascular attenuation. Oscillatory nystagmus was noted in 14 of 16 clinically affected puppies. Vision was impaired under both scotopic and photopic conditions. Rod-mediated ERGs were unrecordable in all affected dogs tested, reduced cone-mediated responses were present in one animal at 3months of age and unrecordable in the other affected animals tested. Multiple small retinal bullae were observed in three clinically affected animals (two with confirmed genetic diagnosis). OCT showed that despite loss of function, retinal structure was initially well-preserved, although a slight retinal thinning developed in older animals with the ventral retina being more severely affected. Pedigree analysis supported an autosomal recessive inheritance. A mutation was identified in GUCY2D, which segregated with the disease (NM_001003207.1:c.1598_1599insT; p.(Ser534GlufsTer20)). Human subjects with GUCY2D mutations typically show an initial disconnect between loss of function and loss of structure, a feature recapitulated in the affected dogs in this study. We identified early-onset PRA in the German Spitz associated with a frameshift mutation in GUCY2D.

Light- and drug-induced pupillary dynamics in eyes with a retropupillary iris-claw intraocular lens.

We evaluated the pupillary characteristics and response to light and drugs in eyes with posterior chamber (PC) placement of iris-claw intraocular lens (IC-IOL). In this cross-sectional, comparative study, we included adults with an IC-IOL implanted in the PC of a single eye. We excluded patients with ocular trauma, postoperative IC-IOL displacement or complications, and extended iris atrophy. We used anterior segment optical coherence tomography to perform light-controlled pupillography, measure the pupil diameter (PD), and estimated the pupil circularity under mesopic conditions. PD was also assessed under photopic, scotopic, pharmacological mydriasis, and miosis conditions. The results were compared to those of the fellow eye, phakic, or regular pseudophakic. The IC-IOL and control groups included 30 eyes each. The most frequent reasons for IC-IOL implantation were complicated cataract (37%) and dislocated/luxated prior IOL (33%). Compared to the control group, the IC-IOL group had lower visual acuity, a smaller PD under scotopic conditions (p = 0.0010) and after pharmacological mydriasis (p < 0.0001), and a larger PD after pharmacological miosis (p < 0.0001). Mesopic pupil circularity was comparable between the groups. We also considered ongoing extraocular treatments with possible effects on iris motility. The pupillary size and profile were similar between the groups in mesopic light. Reduced mydriasis was noted in response to light and drugs, while the degree of miosis was reduced in response to inducing drugs in the IC-IOL compared to the control group. This study complements previous results concerning the PC placement of IC-IOLs by adding original observations on drug-induced pupil motility.

Long Term Clinical Outcomes of Hydrophilic and Hydrophobic Versions of a Trifocal IOL with the Same Optical Design.

To show the visual and refractive outcomes in Asian eyes with cataract when bilaterally implanted with either a hydrophobic FineVision POD F GF or a hydrophilic FineVision POD F intraocular lens (IOL). Forty-six patients were randomized to receive POD F GF or POD F IOLs. Visual and refractive outcomes were assessed up to 24 months post-surgery. Measurements included uncorrected-distance visual acuity, corrected-distance visual acuity (CDVA), distance-corrected intermediate visual acuity (DCIVA), distance-corrected near visual acuity (DCNVA), refraction, defocus curve, photopic and mesopic contrast sensitivity, and patient-reported outcomes. Mean spherical equivalent was close to emmetropia for both groups and stable across postoperative visits. Overall, 97.73% and 100% of eyes in the POD F GF IOL group and 95.65% and 100%, of eyes in the POD F IOL group were within ±1.00D of the target refraction at 12 and 24 months, respectively. All patients showed a CDVA of ≥20/25 at 12- and 24-months post-surgery. In both groups, 24 months post-surgery 91% of patients presented a DCIVA of ≥20/25 and 83.3% of patients had a DCNVA of ≥20/25. Defocus curve showed continuous visual acuity, being 20/32 or better in both groups over a 4.00D range between 1.00D and -3.00/-3.50D. Both groups showed good contrast sensitivity values for photopic and mesopic conditions. Overall, 86.4%, 86.4%, and 72.7% of patients implanted with the POD F GF IOL reported not wearing glasses at all for distance, intermediate, and near vision, respectively. These values were 81.8%, 86.4%, and 90.9% for patients implanted with the POD F IOL. Both groups of patients reported similar satisfaction percentages (100% very satisfied/satisfied) and would recommend the procedure (100% definitively yes/probably yes). This study demonstrates good visual and refractive outcomes for both the FineVision POD F GF and the FineVision POD F IOLs when implanted in Asian eyes.

Reproducibility of Mesopic and Photopic Pupil Sizes in Myopic Children Using a Dedicated Pupillometer with Human-Assisted or Automated Reading.

This study aimed to investigate the reproducibility of pupil size measurements over time and between reading methods when comparing human-assisted reading to automated reading. Pupillary data were analyzed on a subset of myopic children enrolled in a multicenter randomized clinical trial on myopia control with low-dose atropine. Pupil size measurements were obtained prior to randomization at two time points (screening and baseline visits) using a dedicated pupillometer under mesopic and photopic conditions. A customized algorithm was built to perform automated readings, allowing comparisons between human-assisted and automated readings. Reproducibility analyses followed the principles of Bland and Altman and included the calculation of the mean difference between measurements and limits of agreement (LOA). We included 43 children. Mean (standard deviation) age was 9.8 (1.7) years and 25 (58%) children were girls. Using human-assisted readings, reproducibility over time showed mesopic mean difference of 0.02 mm with LOA from -0.87 mm to 0.91 mm, whereas photopic mean difference was -0.01 mm with LOA from -0.25 mm to 0.23 mm. Reproducibility between human-assisted and automated readings was also higher under photopic conditions, with mean difference of 0.03 mm and LOA from -0.03 mm to 0.10 mm at screening and mean difference of 0.03 mm and LOA from -0.06 mm to 0.12 mm at baseline. Using a dedicated pupillometer, we found that examinations performed under photopic conditions demonstrated higher reproducibility over time and between reading methods. We speculate whether mesopic measurements are sufficiently reproducible to be monitored over time. Furthermore, photopic measurements may be of greater relevance when evaluating the side effects of atropine treatment, such as photophobia.

Trifocal intraocular lenses versus bifocal intraocular lenses after cataract extraction among participants with presbyopia.

Trifocal intraocular lenses versus bifocal intraocular lenses after cataract extraction among participants with presbyopia.

Effect of monocular sensitivity on binocular summation of luminance-modulated flicker.

Binocular summation of luminance contrast signals in the spatial domain has been investigated in many studies, but less attention has been paid to the analogous interactions in the temporal domain. The present study determined the impact of monocular sensitivity on the binocular detection of luminance-modulated flickering stimuli. Binocular summation ratios (BSRs) were determined in 13 visually-normal adults for a range of monocular flicker modulation thresholds (FMTs), generated by changing stimulus size (7'- 60') and luminance (mesopic and photopic). Monocular and binocular FMTs were measured at the point of regard and in each of the four quadrants at 5° eccentricity for each target size and luminance using the Flicker-Plus test. Monocular and binocular FMT's increased with decreasing target size for all retinal locations (p<0.001), and were overall larger for mesopic than for photopic condition (p<0.001). BSRs for mesopic (mean±SD: 1.50±0.21) and photopic (1.60±0.24) stimuli were greater than unity (p<0.001), with the latter showing larger estimates than former (p<0.001). BSRs showed no significant trend across target sizes for both luminance conditions (p>0.12). The results demonstrate that the visual system successfully summates inputs from the two eyes to enhance flicker detection, independent of their absolute monocular detection thresholds. These findings may serve as a predictive baseline for further experiments designed to determine how other stimulus properties and interocular differences in monocular thresholds may affect the binocular perception of flicker.

Analysis of Daily Visual Habits in a Presbyopic Population.

To evaluate and report the visual habits and requirements of a sample of presbyopic patients using an advanced sensor. Transversal study collecting clinical data from 40 presbyopes candidates for presbyopia-correction intraocular lens (IOL) implantation with mean age of 61.0 years (43-80 years). A complete ophthalmological examination was performed in all patients including visual, refractive, an ocular biometric analysis. Furthermore, patients were instructed about the use of the Vivior Monitor system (Vivior AG, Zürich, Switzerland), which consists of a series of sensors attached to the rim of the patient's glasses that capture information about the visual behavior of the patient. This device was worn for a period of 36 hours or more. The data collected were transferred to a database and analyzed. Mean percentages of time dedicated to distance, intermediate, and near vision were 27.25 ± 11.93% (5-65%), 30.23 ± 9.36% (12-50%), and 42.53 ± 14.96% (13-78%), respectively. Mean percentages of time performing activities under photopic, mesopic, and scotopic conditions were 37.08 ± 23.20% (5-87%), 33.65 ± 13.84% (6-67%), and 29.28 ± 17.03% (4-65%). The percentage of time with digital screens ranged from 2% to 48%. Age was significantly correlated with the percentage of time dedicated to distance vision (r = 0.317, p=0.047) and to activities performed under photopic conditions (r = -0.344, p=0.030). Distance and illumination conditions used to perform different daily life visual activities vary significantly among presbyopes, with a trend to the dedication of more time to intermediate and near visual activities performed under photopic and mesopic conditions. Data interpretation should be done with care until a proper validation of the device used.

The Effect of Photochromic Contact Lenses on Pupil Size.

Photochromic contact lenses (PCL) are designed to increase the comfort of patients, in bright light conditions. The aim of the study was to evaluate the effect of PCL on pupil size. The study was conducted with 30 patients who were admitted to the contact lens department. Automated pupilography images of the right eyes of patients were obtained without contact lenses (group 1) in scotopic (S: 0.4 lux), mesopic (M: 4.0 lux), and photopic (p=40 lux) conditions. The procedures were repeated with silicone hydrogel contact lenses (Group 2) and with silicon hydrogel PCL (group 3). Mean age was 23.87±3.27 (17-30) years and male/female ratio was 10/20. The mean spheric equivalent of their right eyes was -3.60±1.73 (-0.50--7.50). Pupil diameters of Group 3, under scotopic conditions, were larger than Group 1 and 2 (p=0.001, p=0.044). There was no difference between groups under mesotopic and photopic conditions. Pupil diameters at the different illumination levels were similar regarding gender. Similarity in mesotopic and photopic pupil sizes compared to all groups may be a result of insignificant pupil changes of photochromic lenses in indoor conditions or insufficient time for lens activation.

Contrast Sensitivity and Patient Reported Outcomes After Bilateral Implantation of a Bi-Aspheric Hydrophobic Trifocal Diffractive Intraocular Lens

To assess contrast sensitivity and patient reported outcomes after uncomplicated cataract surgery with a new bi-aspheric diffractive trifocal intraocular lens (IOL) implantation. Twenty-five patients who underwent bilateral implantation with the Asqelio Trifocal TFLIO130C IOL (AST Products Inc., Billerica, MA, USA) were analyzed at 6 months post-surgery. Binocular contrast sensitivity with and without glare was measured under photopic conditions (85 cd/m2) and mesopic conditions (3 cd/m2). Patients were asked to complete the Catquest-9SF patient outcomes questionnaire and a visual symptoms questionnaire. Photopic contrast sensitivity values were either within or above normal levels without glare; when glare was induced, the mean sensitivity values dropped just below normal range. Mesopic contrast sensitivity values were above or within normal range both with and without glare, except for 12 cpd with glare, where the mean fell just below the normal range. Differences in binocular contrast sensitivity threshold values with and without glare were significant for all spatial frequencies tested under both photopic and mesopic conditions (p<0.05). The Catquest-9SF questionnaire outcomes showed that 88% of patients were either satisfied or very satisfied with their sight after the surgery, and in all cases, the results indicated no difficulty in performing different daily activities. The visual symptoms questionnaire indicated no relevant visual symptoms regarding frequency, intensity, or bothersomeness after implantation of the trifocal IOL. This novel bi-aspheric diffractive trifocal IOL provides good contrast sensitivity outcomes under bright and dim lighting conditions. Patients were satisfied with the surgery, with no relevant visual symptoms.

Reliability and agreement of apparent chord mu measurements between static and dynamic evaluations.

To assess the repeatability and agreement of Cartesian coordinates and the length of apparent chord mu and pupil diameter measurements during static (Galilei G4) and dynamic (Topolyzer Vario) evaluations. IOBA-Eye Institute, Valladolid, Spain. Case series. 3 consecutive measurements per scenario (Galilei G4 and Topolyzer Vario under low mesopic and photopic conditions) were performed by the same clinician. The intrasession repeatability was assessed using the within-subject SD (Sw), the precision, the coefficient of variation, and the intraclass correlation coefficient (ICC). The agreement was analyzed using repeated-measures analysis of variance and the Bland-Altman method. Thirty-seven healthy participants were recruited. The Sw values for chord mu parameters and pupil diameter ranged from 0.01 to 0.03 and 0.08 to 0.21, respectively. The ICC was ≥0.89 for all parameters. Galilei G4 and Topolyzer Vario under low mesopic and photopic conditions provided significantly different measures of apparent chord mu length (0.23 ± 0.11 mm, 0.30 ± 0.10 mm, and 0.25 ± 0.11 mm, respectively, P ≤ .02), X-coordinate (-0.18 ± 0.12 mm, -0.27 ± 0.11 mm, and -0.21 ± 0.12 mm, respectively, P < .001), and pupil diameter (3.38 ± 0.50 mm, 6.29 ± 0.60 mm, and 3.04 ± 0.41 mm, respectively, P < .001). Y-coordinate values obtained by Galilei G4 and Topolyzer Vario under low mesopic conditions were significantly different (0.06 ± 0.13 mm vs 0.03 ± 0.11 mm, respectively, P = .02), in contrast to Galilei G4 and Topolyzer Vario under photopic conditions (0.05 ± 0.13 mm, P = .82) and both illumination conditions of Topolyzer Vario (P ≥ .23). Galilei G4 and Topolyzer Vario provide consistent measurements of apparent chord mu Cartesian coordinates and length, as well as pupil diameter; however, the measurements are not interchangeable. Ophthalmic surgeons should consider these findings when planning customized intraocular lens implantation and refractive surgery procedures.

Evaluating Changes in Apparent Chord Mu after Pharmacological Pupil Dilatation

Introduction: Preoperative measurements of apparent chord mu length above 0.6 mm have been associated with higher risks for photic phenomena after cataract surgery with multifocal intraocular lenses (MFIOLs). Methods: This retrospective study evaluated patients scheduled for elective cataract surgery at a single tertiary medical center between 2021 and 2022. Pupil diameter and apparent chord mu length were analyzed for eyes with biometry measurements from IOLMaster 700 (Carl Zeiss Meditec, AG) under photopic light conditions, before and after pharmacological pupil dilatation. Exclusion criteria were visual acuity worse than 20/100, prior intraocular surgery, refractive surgery, iris-related procedures, or pupil abnormalities affecting dilatation. Apparent chord mu lengths before and after pupil dilatation were compared. In addition, multivariate linear regression analysis, using a stepwise method, was conducted to assess possible predictors of apparent chord values. Results: Included were 87 eyes of 87 patients. Mean chord mu length increased after pupillary dilatation from 0.32 ± 0.17 mm to 0.41 ± 0.17 mm for right eyes (p < 0.001) and from 0.29 ± 0.16 mm to 0.40 ± 0.22 mm for left eyes (p < 0.001). Seven eyes (8.0%) had an apparent chord mu of 0.6 mm and above pre-dilatation. Fourteen eyes (16.1%) with an apparent chord mu under 0.6 mm pre-dilatation had apparent chord mu of 0.6 mm or above post-dilatation. Conclusion: Apparent chord mu length significantly increases after pharmacological pupillary dilatation. Pupil size and dilatation status should always be considered during patient selection for a planned MFIOL using apparent chord mu length as a reference marker.

Analysis of the effects of visual quality under different light conditions in different intraocular lenses: Study pilot

AbstractPurpose: To compare the effects on visual function and quality of life in cataract patients undergoing cataract surgery between different extended depth of focus (EDOF) lenses, when subjected to different illumination conditions.Methods: Observational, prospective, cross‐sectional pilot study with a total of 31 eyes of 15 patients undergoing uncomplicated phacoemulsification cataract surgery with Tecnis Eyhance, Isopure1.2.3 and Vivity intraocular lenses. All patients underwent a complete preoperative examination. They were also evaluated on different days under mesopic and photopic conditions.Results: Thirty‐one eyes of 15 patients (70.5 ± 8.6) were included in the study. Statistically significant values were obtained when comparing intermediate visual acuity (VA) between mesopic and photopic illumination conditions for the Isopure and Eyhance lenses with a value of 0.021 and the Isopure lens with Vivity with 0.001. In photopic conditions at intermediate distance a significant value was obtained between Vivity and Eyhance with a value of 0.02 and in mesopic conditions at intermediate distance between Vivity and Isopure with a value of 0.001. Between the different lenses, no significant values were obtained between the photopic and mesopic conditions. No significant values were found for pupillometry and halometry in mesopic conditions either.Conclusions: All three intraocular lenses provided excellent distance vision in both photopic and mesopic conditions with no statistically significant differences. But in intermediate distance, significant differences were found between photopic and mesopic conditions between the Isopure lens and the Vivity and Eyhance lenses. Therefore, the Isopure lens has worse intermediate VA values in mesopic than the other lenses. There were also no significant differences in near vision in pupillometry and halometry.

Pupillary light responses after uncomplicated cataract surgery

AbstractPurpose: To study the effect of standard cataract surgery in the static and dynamic pupillary light responses.Methods: An observational prospective study was carried out in patients scheduled for cataract surgery. Exclusion criteria were previous ocular surgeries or diseases or intraoperative complications. Cataract surgery was done using phacoemulsification and intrasaccular monofocal intraocular lens implantation. Monocular infrared dynamic pupillometry was performed using white light (Corneal Analyser CA‐800, Topcon) just before surgery (same day), and at 1 week and 1 month after surgery. Pupil diameter was analysed under scotopic (SPD) and photopic (PPD) conditions, and latency to constriction (LC), latency to plateau (LP) and duration of constriction (DC) were also analysed. Statistical analysis was carried out with One Way ANOVA for paired data.Results: Twenty‐seven eyes from 27 patients (10 males and 17 females) were included. The mean age was 69.5 ± 9 years. Preoperative SPD and PPD values were 5.21 ± 1.1 mm and 2.78 ± 0.8 mm and decreased significantly by 1 week and 1 month after surgery (p = 0.0002 and p = 0.012, respectively). Preoperative LC, LP and DC values were 2.52 ± 0.09 s, 4.84 ± 0.35 s, and 10.9 ± 1.71 s and these values did not change significantly after surgery.Conclusions: Cataract surgery decreases the pupillary diameter both in photopic and scotopic conditions but does not modify the pupillary responses to light.

Occipital cortex activity in response to melanopsin in healthy humans

AbstractPurpose: Melanopsin‐expressing retinal ganglion cells (mRGCs) signal light information to the brain and mediate non‐visual physiologic responses. Animal studies suggest that melanopsin also influences the visual pathway via synaptic contacts in the lateral geniculate nucleus and the superior colliculus. In healthy and blind humans, blue light exposure results in modulation of occipital activity in neuroimaging studies, presumably from melanopsin interaction with photoreceptors. This study examined if melanopsin activation influences the visual evoked potential (VEP).Methods: We recorded VEPs to light flash stimuli to activate cones, rods and melanopsin in 30 healthy volunteers (red: 630 nm, blue: 445 nm, intensities: 0.00003 to 150 cd/m2). Dark adaptation was used to sensitize rods. At 2 log cd/m2, rods are saturated, and bright blue lights are considered more melanopsin activating. Under photopic conditions, red light activates M‐L cones. Amplitude and latency of the N2 and P2 components of the VEP were evaluated.Results: P2 obtained from the melanopsin stimulus presented under dark‐adaptation (MEL1) had the largest amplitude and shortest latency of all VEPs including the melanopsin stimulus presented non‐dark adapted condition (MEL2). There was no difference of N2 between MEL1 and MEL2 conditions. The latency of N2 and P2 from rods was longer than that from MEL1 and MEL2. P2 from MEL2 was equivalent in amplitude and latency to the P2 of the brightest cone stimulus (30 cd/m2 red light).Conclusion: Under non‐dark‐adapted conditions, bright blue light evokes a similar VEP as bright red light, suggesting that cones are the predominant influence in these conditions. However, bright blue light presented under dark adaptation modified the VEP latency and amplitude. As rod VEPs are distinguished by slow latencies, then we propose that these changes arise from mRGCs influence on cone‐mediated visual pathways to the occipital cortex.