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Pupil Size (pupil + size)

Distribution by Scientific Domains

Medical Sciences	88%

Selected Abstracts

Age-related lens yellowing per se contributes little to the increase in Farnsworth-Munsell 100 hue error scores with age

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 1 2008
Raymond O. Beirne
Purpose:, To investigate the effects of real and simulated age-related changes in crystalline lens yellowing on Farnsworth,Munsell (FM) 100 hue total and partial error scores. Methods:, FM 100 hue total and partial error scores were measured in a group of younger (n = 10, mean age 22.2 ± 2.65 years) and a group of older (n = 10, mean age = 54.5 ± 2.64 years) normal observers along with psychophysical estimates of crystalline lens optical density and pupil size measurements. Three younger observers underwent repeated FM 100 hue testing using a variety of simulated age-related lens yellowing conditions, using filters with well-defined absorption properties which mimicked the real age-related lens yellowing changes of the older group. FM 100 hue scores were also measured under different levels of background illumination and pupil size in the 3 younger observers. Results:, FM 100 hue total and partial error scores were significantly higher in the older age group compared to the younger group (p <0.01). Lens density measures were significantly higher in the older age group compared to the young group (p<0.01), but showed less scatter with age than FM 100 hue error scores. Pupil size was significantly larger in the younger group compared to the older group (p<0.01). Simulated lens yellowing in the three younger observers, equivalent to the level of that of the older observers, did not affect any of their FM 100 hue total or partial error scores. Reductions in pupil size and illumination significantly affected the younger observers' performance, with increases in error score equivalent to the observed age-related decline between the younger and older group. Conclusions:, Lens yellowing per se makes little contribution to the increase in Farnsworth,Munsell 100 hue error score with increasing age. Retinal illumination levels and pupil size can significantly affect the error score and should be considered when interpreting FM 100 hue error scores in older subjects. Clinicians should also consider iris colour and macular pigment density when interpreting FM 100 hue error scores. [source]

Continuous recording of accommodation and pupil size using the Shin-Nippon SRW-5000 autorefractor

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 2 2001
J. S. Wolffsohn
Summary A newly released commercial autorefractor, the Shin-Nippon SRW-5000 (Japan), has been found to be valid compared to subjective refraction and repeatable over a wide prescription range. Its binocular open field-of-view allows the accommodative state to be monitored while a natural environment is viewed. In conventional static mode, the device can take up to 45 readings in 1 min using digital image analysis of the reflected retinal image of a measurement ring. Continuous on-line analysis of the ring provides high (up to 60 Hz) temporal resolution of the refractive state to an accuracy of <0.001 D. Pupil size can also be analysed to a resolution of <0.001 mm. The measurement of accommodation and pupil size was relatively unaffected by eccentricity of viewing up to ±10° and instrument focusing inaccuracies of ±5 mm. The resolution properties of the analysis are shown to be ideal for measurement of dynamic accommodation and pupil responses. [source]

Normal values and standard deviations for pupil diameter and interpupillary distance in subjects aged 1 month to 19 years

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2002
Colleen MacLachlan
Normal values of pupil diameters and interpupillary distances (PDs) were measured in a population of 1311 subjects (in 4294 visits) ranging from 1 month of age to slightly over 19 years of age. Subjects in this study were recruited from birth announcements in a local newspaper for a developmental vision project. Pupil sizes were measured photographically when the corneas were illuminated by 15.9 ± 0.5 lux ambient illumination (i.e. under mesopic conditions). Interpupillary distance was measured with an interocular distance rule while the subject fixated an object at 0.66 m distance. These PD measurements were corrected for systematic measurement errors and to an infinite viewing distance using radii of ocular rotation based on age-dependent axial lengths. Means and S.D. were calculated for age, pupil diameter and PD for each 1-year group of male and female subjects. The second order regression equation for average pupil size as a function of age was determined: [males pupil diameter (in mm)=5.83 + 0.181*age in years , 0053*age in years2, r2=0.897; female pupil diameter=5.40 + 0.285*age in years , 0.0109*age in years2, r2=0.945]. The difference between male and female pupil sizes (mean male , female=0.13 mm) was marginally not significant (p < 0.054). The average corrected PDs as a function of age were found to approximate another second-order regression equation: (males PD=43.36 + 1.663*age in years , 0.034*age in years2, r2=0.986; females PD=41.76 + 1.891*age in years , 0.052*age in years2, r2=0.986). Male PD was wider than female PD by an average of 1.58 mm (p < 0.0003). As expected, the results of this study were similar to a preliminary investigation conducted by Thunyalukul et al. [Invest. Ophthalmol. Vis. Sci.37 (1996) S731] on a portion of the present data set, and also very similar to data from another study of comparable racial composition using a different measurement method [Pryor, Pediatrics44 (1969) 973]. It was concluded that pupil diameter and PD increase more gradually than axial length of the eye in the first few years of life. The normal values and S.D. for both pupil size and PD determined in this study have important clinical implications as well as applications in the optical industry. [source]

Maternal Oral Intake Mouse Model for Fetal Alcohol Spectrum Disorders: Ocular Defects as a Measure of Effect

ALCOHOLISM, Issue 10 2006
Scott E. Parnell
Background: This work was conducted in an effort to establish an oral intake model system in which the effects of ethanol insult that occur during early stages of embryogenesis can be easily examined and in which agents that may modulate ethanol's teratogenicity can be readily tested in vivo. The model system described utilizes the alcohol deprivation effect to obtain teratogenic levels of maternal ethanol intake on days 7 and 8 of pregnancy in C57Bl/6J mice. Ocular defects including microphthalmia and uveal coloboma, which have previously been shown to result from ethanol administered by gavage or via intraperitoneal injection on these days, served as the developmental end point for this study. The ocular defects are readily identifiable and their degree of severity is expected to correlate with concurrently developing defects of the central nervous system (CNS). Methods: Female C57Bl/6J mice were maintained on an ethanol-containing (4.8% v/v) liquid diet for 14 days and then mated during a subsequent abstinence period. Mice were then reexposed to ethanol on days 7 and 8 of pregnancy only. Control as well as ethanol-exposed dams were killed on their 14th day of pregnancy. Fetuses were then weighed, measured for crown rump length, photographed, and analyzed for ocular abnormalities. Globe size, palpebral fissure length, and pupil size and shape were noted for both the right and left eyes of all fetuses and informative comparisons were made. Results: This exposure paradigm resulted in peak maternal blood alcohol concentrations that ranged from 170 to 220 mg/dL on gestational day (GD) 8. Compared with the GD 14 fetuses from the normal control group, the pair-fed, acquisition controls, as well as the ethanol-exposed fetuses, were developmentally delayed and had reduced weights. Confirming previous studies, comparison of similarly staged control and treated GD 8 embryos illustrated reductions in the size of the forebrain in the latter. Subsequent ocular malformations were noted in 33% of the right eyes and 25% of the left eyes of the 103 GD 14 ethanol-exposed fetuses examined. This incidence of defects is twice that observed in the control groups. Additionally, it was found that the palpebral fissure length is directly correlated with globe size. Conclusions: The high incidence of readily identifiable ocular malformations produced by oral ethanol intake in this model and their relevance to human fetal alcohol spectrum disorders (FASD) makes this an excellent system for utilization in experiments involving factors administered to the embryo that might alter ethanol's teratogenic effects. Additionally, the fact that early ethanol insult yields ocular and forebrain abnormalities that are developmentally associated allows efficient specimen selection for subsequent detailed analyses of CNS effects in this in vivo mammalian FASD model. [source]

Limits of spherical blur determined with an adaptive optics mirror

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2009
David A. Atchison
Abstract We extended an earlier study (Vision Research, 45, 1967,1974, 2005) in which we investigated limits at which induced blur of letter targets becomes noticeable, troublesome and objectionable. Here we used a deformable adaptive optics mirror to vary spherical defocus for conditions of a white background with correction of astigmatism; a white background with reduction of all aberrations other than defocus; and a monochromatic background with reduction of all aberrations other than defocus. We used seven cyclopleged subjects, lines of three high-contrast letters as targets, 3,6 mm artificial pupils, and 0.1,0.6 logMAR letter sizes. Subjects used a method of adjustment to control the defocus component of the mirror to set the ,just noticeable', ,just troublesome' and ,just objectionable' defocus levels. For the white-no adaptive optics condition combined with 0.1 logMAR letter size, mean ,noticeable' blur limits were ±0.30, ±0.24 and ±0.23 D at 3, 4 and 6 mm pupils, respectively. White-adaptive optics and monochromatic-adaptive optics conditions reduced blur limits by 8% and 20%, respectively. Increasing pupil size from 3,6 mm decreased blur limits by 29%, and increasing letter size increased blur limits by 79%. Ratios of troublesome to noticeable, and of objectionable to noticeable, blur limits were 1.9 and 2.7 times, respectively. The study shows that the deformable mirror can be used to vary defocus in vision experiments. Overall, the results of noticeable, troublesome and objectionable blur agreed well with those of the previous study. Attempting to reduce higher-order aberrations or chromatic aberrations, reduced blur limits to only a small extent. [source]

On the compensation of horizontal coma aberrations in young human eyes

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2008
Fan Lu
Abstract The nature of the compensation of horizontal coma (Z31) between optical elements of the human eye has been studied and the compensative mechanism has been attributed to a passive process linked to angle kappa of the eye. We measured the horizontal coma in the anterior cornea, the whole eye and the internal optics for 221 young subjects. Thirty-three eyes with minimum angle lambda and 53 eyes with relatively large angle lambda were selected from these eyes to test the hypothesis that horizontal coma compensation is linked to angle kappa. Significant horizontal coma in the anterior cornea was observed for the group with minimum angle lambda in both the right (,0.12 ± 0.07 ,m) and left eyes (0.12 ± 0.10 ,m), and this was well compensated by the internal optics so that the level of horizontal coma in the whole eye over a 6-mm pupil size was very low (,0.05 ± 0.07 ,m for OD and 0.02 ± 0.08 ,m for OS). The horizontal coma in the anterior cornea was significantly correlated to the horizontal coma in the internal optics for both the right and the left eye. The results suggest that there is another source of horizontal coma, in addition to that linked to angle kappa, in the anterior cornea, and also a new compensative mechanism to balance the corneal coma, perhaps in the posterior cornea or the lens. [source]

Age-related lens yellowing per se contributes little to the increase in Farnsworth-Munsell 100 hue error scores with age

Normal values and standard deviations for pupil diameter and interpupillary distance in subjects aged 1 month to 19 years

Influence of chronic alcohol abuse and ensuing forced abstinence on static subjective accommodation function in humans

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2001
Hugh Campbell
Summary Purpose. Acute alcohol ingestion can change accommodation, but the long term effects of sustained alcohol consumption on accommodative function have not been studied in detail. This study was thus undertaken on individuals with a history of alcohol abuse. Methods. Thirty-seven male individuals aged 25,56 years (average 40 years) from an alcohol rehabilitation centre in Inverness, Scotland, were assessed on admission and after a week of forced abstinence. The results were compared to a paired age-matched set of control male subjects. The static amplitude of accommodation was measured by an RAF rule, and the pupil size measured with a pupil gauge. Results. On admission, the group mean measured amplitude of accommodation was 4.7±2.2 D (mean±SD). These values for the alcoholics were lower than age-matched controls (of5.9±2.9 D). The slope of the age-dependent decline in RAF rule accommodation measures was significantly smaller for the alcoholics compared to controls (at 0.215±0.027 D/year versus0.332±0.015 D/year, respectively; p <0.001), with the younger alcoholics showing a greater impairment. Following abstinence, there was no measurable change in accommodation measured, indicating the lower amplitude in the alcoholics was not attributable to circulatory alcohol levels. The resting pupil diameter in the alcoholics was4.37±0.63 mm compared to the controls of3.97±0.75 mm, with a higher incidence of small pupils (,3 mm) in the controls. Conclusions. The results indicate that chronic alcohol use can adversely affect subjective static accommodation, especially in younger alcoholics, as well as cause slight mydriasis. [source]

Continuous recording of accommodation and pupil size using the Shin-Nippon SRW-5000 autorefractor

Accommodation microfluctuations and pupil size during sustained viewing of visual display terminals

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 1 2000
L.S. Gray
Summary Accommodation microfluctuations comprise two dominant frequencies; a low frequency component (LFC0.6 Hz) and a high frequency component (1.0 Hz[source]

Virtual friend or threat?

PSYCHOPHYSIOLOGY, Issue 5 2009
The effects of facial expression, emotional experience, gaze interaction on psychophysiological responses
Abstract The present study aimed to investigate the impact of facial expression, gaze interaction, and gender on attention allocation, physiological arousal, facial muscle responses, and emotional experience in simulated social interactions. Participants viewed animated virtual characters varying in terms of gender, gaze interaction, and facial expression. We recorded facial EMG, fixation duration, pupil size, and subjective experience. Subject's rapid facial reactions (RFRs) differentiated more clearly between the character's happy and angry expression in the condition of mutual eye-to-eye contact. This finding provides evidence for the idea that RFRs are not simply motor responses, but part of an emotional reaction. Eye movement data showed that fixations were longer in response to both angry and neutral faces than to happy faces, thereby suggesting that attention is preferentially allocated to cues indicating potential threat during social interaction. [source]

4423: The limits of manifest refraction: visual performance under low light conditions

ACTA OPHTHALMOLOGICA, Issue 2010
J CABEZA
Purpose To present a method to optimize the prescription values of ophthalmic lenses based on ocular wavefront information. Those lenses provide improved vision under low light conditions to the patient. Methods We will show first the influence of ocular aberrations on visual performance, and how do they change with pupil size. We will also show the way higher order aberrations affect the manifest refraction procedure. Finally, we will present a method to optimize the prescription values of ophthalmic lenses based on ocular wavefront information. Results Independent studies have shown that such optimized ophthalmic lenses provide on average an improvement in visual acuity of almost one line under mesopic conditions, when compared to conventional opththalmic lenses. Conclusion Visual performance under low light conditions can be improved by ophthalmic lenses whose prescription was optimized taking into account ocular wavefront information. Commercial interest [source]

Evaluation of anterior segment parameter changes using the Pentacam after uneventful phacoemulsification

ACTA OPHTHALMOLOGICA, Issue 5 2010
Selim Doganay
Abstract. Purpose:, This study set out to evaluate the influences of uneventful phacoemulsification on the anterior segment parameters obtained with the Pentacam rotating Scheimpflug camera and intraocular pressure (IOP). Methods:, A total of 42 eyes of 34 patients (26 men, eight women) were evaluated preoperatively, and at 1, 3 and 6 months postoperatively with the Pentacam. Intraocular pressure was measured with the Goldmann applanation tonometer. The non-parametric paired t -test was used to compare preoperative and 1-, 3- and 6-month postoperative measurements of anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA) width, central corneal thickness (CCT), the central 3-, 5- and 7-mm corneal volume (CV), pupil size, and IOP. Pearson's correlation test was used to evaluate the relationships between IOP and ACD, ACV and ACA width. Results:, The differences between ACD, ACV, ACA and IOP values taken preoperatively and those taken postoperatively at 1, 3 and 6 months were statistically significant (p < 0.05). The differences between CCT, central 3-, 5- and 7-mm CV, and pupil size measurements taken preoperatively and those taken postoperatively at 1, 3 and 6 months were not statistically significant (p > 0.05). The decrease in IOP was not correlated with the changes in ACD, ACV and ACA (p > 0.05). Conclusions:, Uneventful phacoemulsification significantly reduced IOP, increased ACD and ACV, and widened the ACA. However, alterations in CV, CCT and pupil size values were not statistically significant. Alterations in ACD, ACV, ACA and IOP remain stable after the first month of surgery. [source]

Improving the optics of KPros

ACTA OPHTHALMOLOGICA, Issue 2009
C HULL
Purpose The purpose of this talk is to review the clinically relevant optical and visual requirements of keratoprostheses. Methods Modelling of designs using commerical and purpose-written optical design software as well as clinical measurments on a small number of patients implanted with the osteo-odonto keratprosthesis optical cylinder. Results The important visual optical proerties of any keratoprosthesis optic are the foveal image quality (affecting the acuity) and the field of view. These fundamentally depend upon the pupil size, and the length and diameter of the optic since the power must be fixed to give emmetropia. The axial image quality can be changed by controlling the spherical aberration. However, maximising axial (foveal) image quality causes poorer off-axis image quality potentially reducing the effective visual field. Shorter, larger diameter optics help improve the visual field as well as consideration of off-axis image quality. Conclusion The theoretical properties of keratoprosthesis optics must be balanced against other clinical requirements such as longterm complications and stability. The clinical requirements provide the constraints on the optical design. However, discussions can usefully happen between surgeons and those involved in the design of the optics to give the best possible visual rehabilitation. [source]

Slitlamp integrated OCT, what you can see, is what you can scan

ACTA OPHTHALMOLOGICA, Issue 2009
FD VERBRAAK
Purpose To present results of OCT images captured of the posterior and anterior segment of the eye using the SLSCAN-1, a new FD-OCT device integrated into a slit lamp. Methods Patients, seen in the outpatient clinic of the Academic Medical Center, were scanned with the SLSCAN-1, a newly developed OCT scanning device, integrated into a common slit lamp (figure 1). The OCT is a Fourier Domain OCT system (SLD light source, central wavelength 830 nm, bandwidth 30 nm, 1024 pixel CCD camera, scan speed 5k A-scans per second, 1024 A-scans per B-scan). The posterior segment scans have been captured using a standard indirect ophthalmic lens (Volk). A color fundus photography of the observed area is made at the same time (Topcon camera DC1, resolution = 3.24 Mp). Results For posterior segment imaging, the flexible optical arrangement of the slit lamp and the hand-held lens (Volk), allows the user to scan large areas of the retina (>45 degrees), depending on the pupil size of the patient. In all patients the macula and optic disk could be visualized without any difficulty. In the anterior segment mode, the SLSCAN-1 allows imaging of the cornea, anterior chamber, iris and parts of the lens. Conclusion The images made by the SLSCAN-, new slit lamp integrated FD-OCT, could be very useful to examine patients directly, both posterior and anterior, during regular slit lamp examinations. Commercial interest [source]

Aberration controll with contact lenses

ACTA OPHTHALMOLOGICA, Issue 2007
A LINDSKOOG PETTERSSON
Purpose: To investigate and compare the reduction in ocular aberrations with standard hydrogel contact lenses (i.e., lenses not designed to control aberrations) and with aberration controlled hydrogel and silicon-hydrogel contact lenses. Methods: The aberrations with and without contact lenses were measured in 42 subjects between 20 and 37 years of age using a Zywave wave front sensor (B&L). 22 subjects were fitted a standard contact lens and an aberration controlled hydrogel lens. The remaining 20 subjects were fitted aberration controlled silicon-hydrogel lenses Results: With the standard lens the aberrations were controlled (i.e., close to zero) with a 4.0 mm pupil. Whereas, with both the aberration control lenses the residual spherical aberrations became negative. The reduction in aberrations differed significantly (p<0.05) between all lenses. Conclusions: Since aberration controlled contact lenses in many subjects overcorrect the spherical aberrations when the pupil size is normal (~4.0 mm) we suggest measuring wave front aberrations in each patient both with and without contact lenses in order to achieve the desired effect. [source]

Use of pupil size and reaction to detect orbital trauma during and after surgery

CLINICAL OTOLARYNGOLOGY, Issue 3 2004
Farhan H. Zaidi
We describe how pupillary reactions, used as an index of optic nerve function, can be elicited using only one working pupil. This is to challenge the conclusion of a study that did not appreciate this physiological phenomenon and thus gave rise to erroneous conclusions that might otherwise limit the scope of pupil measurements during and after surgery. For suitable cases, non-opioid anaesthesia and further clinical development of pupillometry are suggested by us as measures to monitor optic nerve function. [source]

Use of pupil size and reaction to detect orbital trauma during and after surgery

CLINICAL OTOLARYNGOLOGY, Issue 3 2004
Andrew C. Swift
No abstract is available for this article. [source]

Normal values and standard deviations for pupil diameter and interpupillary distance in subjects aged 1 month to 19 years

The effect of Flash banners on multiattribute decision making: Distractor or source of arousal?

PSYCHOLOGY & MARKETING, Issue 5 2006
Rong-Fuh Day
The role of peripheral flash advertisements in decision making as a distractor or a source of arousal was examined. Participants were asked to perform multiattribute decision making in a display environment with or without banners of advertisement flashing occasionally in the peripheral region of the display. The flash banners accelerated the speed of decision making, although the participants rarely made eye movements in response to the banners or fixated their eyes on them. It was interesting to note that the participants' pupil sizes increased with the presence of flash banners. These findings suggest that rather than distracting participants' attention, flash banners appear to elevate the general level of arousal of the participants, which in turn led to making faster on-line decisions. © 2006 Wiley Periodicals, Inc. [source]

Effects of incentive on working memory capacity: Behavioral and pupillometric data

PSYCHOPHYSIOLOGY, Issue 1 2008
Richard P. Heitz
Abstract We evaluated the hypothesis that individual differences in working memory capacity are explained by variation in mental effort, persons with low capacity exerting less effort than persons with high capacity. Groups previously rated high and low in working memory capacity performed the reading span task under three levels of incentive. The effort hypothesis holds that low span subjects exert less effort during task performance than do high spans. Subjects' pupil sizes were recorded online during task performance as a measure of mental effort. Both recall performance and pupil diameter were found to be increased under incentives, but were additive with span (incentives increased performance and pupil diameter equivalently for both span groups). Contrary to the effort hypothesis, task-evoked pupillary responses indicated that if anything, low span subjects exert more effort than do high spans. [source]

4424: Visual acuity loss with healthy ageing: can it be reversed by wavefront laser?

ACTA OPHTHALMOLOGICA, Issue 2010
D ELLIOTT
Purpose To consider what levels of "super acuity" might be achieved by the correction of ocular aberrations in older patients by wavefront corrected ophthalmic surgery. Note that when comparing visual acuity (VA) of older patients with VA in the young, the average optimal monocular visual acuity of a young subject is about 6/4 (decimal VA 1.50) and not the often quoted ,normal' figure of 20/20 (6/6 or 1.0 decimal). Methods Studies that attempted to isolate the cause(s) of deterioration in visual function with age in normal, healthy eyes were reviewed. Results The majority of studies suggest that the deterioration in visual function with age is primarily due to changes within the neural system rather than optical factors. In addition, several studies have shown increases in ocular aberrations with age, but this is only found when comparisons are made across age groups with fixed pupil sizes. When natural pupil sizes are considered, there is no change in aberrations with age because of age-related pupillary miosis Conclusion There appears to be little scope for ocular aberration correction to be used to counteract the loss of vision with age. Reduced vision in patients with cataract is primarily due to increased forward light scatter, and aberrations play a minor role in reducing vision. Intra-ocular lenses (IOLs) should be designed to keep ocular aberrations at a minimum after cataract surgery, but given that vision loss with age appears to be primarily due to neural changes, there seems little scope for IOLs to improve on the vision of phakic subjects under natural pupil conditions. [source]

Preoperative topical cyclopentolate can be omitted when using intracameral lidocaine in phacoemulsification surgery

ACTA OPHTHALMOLOGICA, Issue 3 2009
Björn Lundberg
Abstract. Purpose:, To evaluate the mydriatic effect of topical cyclopentolate 1% when combined with topical phenylephrine 10% and intracameral lidocaine 1% in phacoemulsification cataract surgery. Methods:, We performed a prospective, double-masked, randomized trial including 20 patients with age-related cataract, who were scheduled for unilateral phacoemulsification and intraocular lens (IOL) implantation. Patients were given either two drops of phenylephrine 10% at 30 mins and 15 mins prior to surgery (group 1), or two drops each of cyclopentolate 1% and phenylephrine 10% at the same time points (group 2). All patients were also given lidocaine 1% intracamerally at the beginning of the procedure. Intraoperative pupil sizes were assessed from video-recordings. Results:, Initially, pupil sizes were significantly smaller in group 1 (4.8 ± 1.2 mm versus 6.5 ± 1.4 mm; p = 0.0098), but the lidocaine injection increased the pupil sizes in group 1 significantly, so that pupil sizes in both groups were equalized throughout the surgical procedure. Conclusions:, Preoperative topical cyclopentolate does not enhance mydriasis in phacoemulsification surgery when using intracameral lidocaine and can be omitted when intracameral lidocaine is used. [source]