EFFECTS OF 0.1% CYCLOPENTOLATE OR 10% PHENYLEPHRINE ON PUPIL DIAMETER AND ACCOMMODATION

The mydriatic and cycloplegic effects of either one drop of 0.1% cyclopentolate or two drops of 10% phenylephrine were studied over a period of up to 6 hours after drug instillation, using 5 subjects aged between 25 and 43 years. The extent of mydriasis was determined from the horizontal diameter of the pupil. Dynamic accommodation responses were monitored with an infra-red, continuously recording optometer. Static measurements of the accommodation response/stimulus curve were made with a laser optometer. With either drug, dilation of the pupil occurred more rapidly than recovery of normal pupil diameter. Both drugs caused alterations in the dynamic and static accommodation responses. Response times were generally slowed, and the slope of the accommodation response/stimulus curve and the amplitude of accommodation were reduced. The time course of these changes was broadly similar to that of the pupil dilation. Cyclopentolate hydrochloride was more efficient as a mydriatic but exercised a greater unwanted cycloplegic effect.     

Clinical use of reversal of mydriasis by dapiprazole

Background: Dapiprazole hydrochloride is an alpha-1-adrenergic inhibitor that anticipates the mydriatic effect of phenylephrine in dilator muscle receptors in a competitive way. The aim of this study was to determine for which indications for mydriasis pupil dilation by phenylephrine alone is sufficient and if the reversal by dapiprazole is convenient and the practical.     

Stimulation of adrenergic β‐receptors enhances mydriasis in a porcine eye model

Purpose: To compare the mydriatic effect of intracamerally injected isoprenaline plus phenylephrine to phenylephrine alone and to epinephrine in a porcine eye model, aiming to eventually find the best combination of adrenergic substances for surgical mydriasis in humans. Methods: In this study, we used 89 intact eyes from newly slaughtered pigs, pretreated with 2.0 mg of intracameral acetylcholine. After waiting 60 seconds for miosis to develop, 0.15 ml 0.3% isoprenaline and 0.15 ml 3.0% phenylephrine were injected sequentially with a 90‐second interval in 21 eyes. In another 22 eyes, the same substances were given in the reverse order. In 20 eyes, 0.15 ml of 0.025% epinephrine was injected, and as a negative control 0.15 ml of balanced salt solution was injected in 26 eyes. The pupils were filmed during the treatments, and the mean pupil diameters were measured every 15 seconds from the video recordings. Results: Phenylephrine injected after isoprenaline had a larger mydriatic effect than epinephrine (p < 0.01). Without isoprenaline pretreatment, the mydriatic effect of phenylephrine was significantly smaller than that of epinephrine (p < 0.05). Isoprenaline also exhibited a small mydriatic effect of its own. Conclusions: The β‐receptor stimulator isoprenaline enhances the mydriatic effect of intracameral phenylephrine, indicating a role for the β‐receptor in the mydriatic response. Mydriasis mediated by β‐receptors may explain why nonspecific adrenergic stimulators such as epinine and epinephrine can have larger mydriatic effects than the specific α₁‐receptor stimulator phenylephrine.     

Intraoperative mydriasis by intracameral injection of mydriatic eye drops: in vivo efficacy and in vitro safety studies

Background: This study investigated the efficacy and safety of intracameral injection of commercially available eye drops containing 0.5% tropicamide and 0.5% phenylephrine hydrochloride (Mydrin‐P, Santen Pharmaceutical, Osaka, Japan). Design: In vitro experiment and prospective clinical study at a private hospital. Participants and Samples: Mydrin‐P was applied to confluent cultured human corneal endothelial cells, and the cellular morphology was examined. Clinical study subjects were 65 eyes of 65 patients that underwent phaco‐emulsification and aspiration with intraocular lens implantation and received intracameral injection of Mydrin‐P for poor mydriasis after preoperative topical instillation of mydriatics (intraocular mydriasis group; with five subgroups based on cause: diabetes, pseudo‐exfoliation, post‐surgery, uveitis, unknown). Controls, comprising 39 eyes of 39 patients, were not injected with Mydrin‐P. Methods: The ratio of pupillary diameter to corneal diameter was determined before and after injection of Mydrin‐P. Corneal endothelial density was measured preoperatively and 3 months and 1 year postoperatively. Main Outcome Measures: Pupillary diameter and corneal endothelial density. Results: Human corneal endothelial cell morphology was unaltered after Mydrin‐P injection. The mean ratio of the pupillary diameter to corneal diameter increased in the intraocular mydriasis group (before: 54.2 ± 4.8%, after: 58.4 ± 6.6%; P < 0.001) and in the diabetes and unknown subgroups. The corneal endothelial cell density reduction rate 3 months and 1 year after surgery was not significantly different between the intraocular mydriasis group and controls. Conclusion: Intracameral injection of Mydrin‐P appears to be effective and safe for dilating the pupil in cases with poor mydriasis after preoperative instillation of mydriatics.     

Driving ability after reversal of phenylephrine 10% induced mydriasis by dapiprazole 0.5%; a prospective study on 65 eyes

BACKGROUND: Particularly outpatients want to reach the ability for driving a car as soon as possible after pupillary dilatation. Dapiprazole is an alpha-1 adrenergic inhibitor that antagonizes the mydriatic effect of phenylephrine in a direct competitive way. The aim of this study was to determine restoration of traffic related functions after dapiprazole application in accordance with the guidelines of the German Society of Ophthalmology (DOG). SUBJECTS: 65 eyes of 33 subjects were tested (17 females, 16 males). All had driving licenses without restrictions. Before mydriasis and after reversal with dapiprazole traffic-related functions were evaluated (photopic visual acuity, mesopic vision, sensitivity to glare, colour vision, accommodation, visual field). RESULTS: No relevant changes of the parameter responsible for the ability to drive a motor vehicle could be shown after reaching premydriatic pupil diameters. CONCLUSIONS: There is evidence that reaching normal pupil diameters after reversal of mydriasis by dapiprazole is a valid sign of restoration of traffic related functions.     

Separate and additive mydriatic effects of lidocaine hydrochloride, phenylephrine, and cyclopentolate after intracameral injection

PURPOSE: To assess the separate mydriatic effect of lidocaine hydrochloride (Xylocaine), cyclopentolate, and phenylephrine after intracameral injection and evaluate whether intracameral Xylocaine and phenylephrine without cyclopentolate provide sufficient pupil dilation for cataract surgery. SETTING: Department of Clinical Science/Ophthalmology, Ume? University Hospital, Ume?, Sweden. METHODS: This prospective randomized double-masked study included 56 patients with age-related cataract scheduled for unilateral phacoemulsification. In 16 patients, Xylocaine 1%, phenylephrine 1.5%, and cyclopentolate 0.1% were injected one after the other. Phenylephrine and cyclopentolate were randomized to switch in order, creating 2 study groups. An additional 40 patients were randomized to receive intracameral Xylocaine 1%, phenylephrine 1.5%, and cyclopentolate 0.1% or intracameral Xylocaine 1% and phenylephrine 1.5% only. RESULTS: Xylocaine alone caused significant pupil dilation (mean 4.9 +/- 0.6 mm). In the group in which cyclopentolate was injected next, the pupil size increased 1.3 +/- 0.6 mm (P<.001). When phenylephrine was added, the pupil increased an additional 0.7 +/- 0.4 mm (P = .003). In the second group, in which phenylephrine was the second injection, the pupil size increased 2.1 +/- 0.5 mm (P<.001). When cyclopentolate was added, no significant change in size occurred. No statistically significant differences in pupil size were observed between the 40 patients who were given intracameral mydriatics with or without cyclopentolate. CONCLUSIONS: Xylocaine plus phenylephrine injected intracamerally gave adequate intraoperative pupil dilation in routine phacoemulsification surgery. Cyclopentolate administrated intracamerally had no immediate additive mydriatic effect to intracameral Xylocaine combined with phenylephrine.     

A combination solution for routine pupillary dilation.

BACKGROUND: This study investigated the ability of a combination drop containing reduced concentrations of tropicamide and phenylephrine to produce pupillary dilation adequate for routine fundoscopy. METHODS: One eye of each subject (N = 28; age range, 21 to 40 years; median, 23 years) was dilated with 1 drop of a solution containing 0.5% tropicamide and 2.5% phenylephrine (0.5T/2.5P). The other eye was dilated with 1 drop of either of 2 mixtures: 0.5% tropicamide and 1.25% phenylephrine (0.5T/1.25P, N = 15; median age, 23 years), or 0.25% tropicamide and 1.25% phenylephrine (0.25T/1.25P, N = 13; median age, 23 years). A topical anesthetic was administered before instilling the mydriatic agents. Pupil diameter was measured from a flash photograph taken every 15 minutes for 3 hours. There was no significant difference in pupil diameter between eyes dilated with the 0.5T/1.25P test solution and the 0.5T/2.5P control solution for the first 75 minutes after instillation (P = 0.41). All pupils reached their maximum diameter 60 minutes after drop instillation; where no significant difference was observed between the 3 mydriatic solutions (P = 0.81). All pupils were at least 7 mm in diameter 30 minutes after drop instillation, and this size was maintained for at least another 75 minutes for all solutions. CONCLUSIONS: Combination preparations of reduced concentrations of tropicamide and phenylephrine can produce clinically adequate mydriasis.     

Effect of pharmacologic pupil dilation with tropicamide and phenylephrine on wavefront measurements

PurposeTo investigate the influence of tropicamide 1% (as a cycloplegic mydriatic) and phenylephrine 10% (as a noncycloplegic mydriatic) on mydriasis, wavefront refraction, and wavefront aberrations.MethodsIn this prospective study, 31 myopic eyes with a large mesopic pupil size were evaluated with an Allegretto Wave analyzer in a natural dilated state, after instillation of tropicamide 1% or phenylephrine 10%. Aberrations expressed as Zernike polynomials up to the sixth order were analyzed. Wavefront refractions were compared with subjective manifest refraction.ResultsBoth tropicamide and phenylephrine cause significant mydriasis (p < 0.001), but phenylephrine induced a larger pupil size than tropicamide under mesopic conditions (p = 0.029). Compared with the natural state, tropicamide induced a significant hyperopic shift in wavefront refraction (by +0.27 ± 0.09 D; p = 0.002). In contrast, wavefront refraction did not significantly change when using phenylephrine as the mydriatic (+0.03 ± 0.10 D; p = 0.75). Compared with the subjective manifest refraction, wavefront refraction before mydriatics and after phenylephrine showed a significant myopic shift (p < 0.0125), whereas the wavefront refraction after tropicamide was not significantly different from subjective refraction. Zernike coefficient C4 showed a less positive defocus after application of tropicamide (p = 0.0017). Other aberration coefficients of Zernike polynomials up to the sixth order did not change significantly from before to after tropicamide application. There was no significant difference in Zernike coefficients up to C27 before and after phenylephrine.ConclusionPhenylephrine preserves accommodation and provides a larger pupil under mesopic conditions, whereas tropicamide relaxes accommodation and provides an objective wavefront refraction that is closer to the subjective manifest refraction. Neither phenylephrine nor tropicamide causes a significant change in high-order aberrations from the natural state.     

Pupil dilation using drops vs gel: a comparative study

Purpose

To compare the efficacy in pupil dilation and degree of discomfort between topical instillation of mydriatic drops and gel.

Methods

The study included 60 patients with no previous ocular history of trauma and surgery. One eye was dilated with two drops (tropicamide 0.5% and phenylephrine 10%), and the other with one drop of gel (tropicamide 0.5%+phenylephrine 5%). Pupil size was measured by a Colvard pupillometer at baseline and 5, 15, 30, and 45 min following instillation. Pain upon instillation was measured by visual analog scale (VAS).

Results

There was no difference in pupil size at baseline. Use of the gel achieved greater mydriasis than drops (P=0.01), and was also associated with lower pain scores (P=0.003). In diabetic patients, pupil size was smaller at baseline and following instillation of drops and gel. Use of the gel achieved an even greater degree of pupil dilation in this subset of patients than drops (P=0.019).

Conclusions

Gel formulation achieved significantly greater pupil dilation than drops, despite a lower concentration of phenylephrine, and was also associated with significantly lower patient discomfort. This study is the first report of improved mydriatic efficacy in diabetic patients.     

国产散瞳药在白内障超声乳化术前准备及术中散瞳效果的临床观察

目的:比较国产散瞳药卓比安与进口散瞳药美多丽在老年性白内障超声乳化联合人工晶状体植入术前及术中的散瞳效果。方法:患者200例术前1d随机分为两组,每组各100例:试验组为卓比安组和对照组美多丽组。点眼前测量两组双侧瞳孔大小并记录,共3次点药,每隔5min1次,点药结束后15,20,25min观察并记录瞳孔直径大小,及瞳孔开始回缩时间。卓比安组和美多丽组于术前1h点药3次,每次间隔5min,白内障超声乳化术中,观察并记录术前,注入黏弹剂后,超声乳化完成后瞳孔直径及有效超声乳化时间,并进行统计学比较。结果:卓比安组与美多丽组术前1d间隔5min3次点药,于点药结束后20min左右均能达到最大瞳孔直径,且两组最大瞳孔直径无统计学差异;卓比安组与美多丽组瞳孔开始回缩时间(h)分别为2.49±0.75h与2.85±0.74h,且两者有统计学差异。超声乳化过程中国产散瞳药卓比安与美多丽维持散瞳效果相同。结论:国产散瞳药卓比安组与进口散瞳药美多丽组相比术前与术中散瞳效果无统计学差异,但术前瞳孔维持最大直径时间(h)卓比安组要比美多丽时间短,且两者有统计学差异。     

Clinical use of reversal of mydriasis by dapiprazole

Background: Dapiprazole hydrochloride is an alpha-1-adrenergic inhibitor that anticipates the mydriatic effect of phenylephrine in dilator muscle receptors in a competitive way. The aim of this study was to determine for which indications for mydriasis pupil dilation by phenylephrine alone is sufficient and if the reversal by dapiprazole is convenient and the practical. Material and method: In 286 eyes of 147 outpatients, the pupil was dilated for fluorescein angiography – FLA (100 eyes of 50 patients), examination of the fundus – Fd (99 eyes of 52 patients), central argon laser coagulation – cALC (64 eyes of 32 patients), peripheral argon laser coagulation – pALC (16 eyes of 9 patients) and Nd:YAG capsulotomy (7 eyes of 4 patients) with phenylephrine 10 % eye drops, followed by reversal by dapiprazole 0.5 %. The width and mobility of the pupil were tested at intervals of 10 min. When mydriasis by phenylephrine was insufficient, tropicamide was applied additionally. Results: In 98 % of FLA with scanning laser ophthalmoscope, 75 % of cALC, 76 % of Fd, 62 % FLA with fundus camera and 38 % of pALC, mydriasis could be reached that was sufficient for the indication. Diabetics showed significantly more sluggish pupil mobility (t1/2: P < 0.05 mydriasis, P < 0.005 reversal). The mean duration after using dapiprazole until reaching the starting value ( ± 1 mm) of the pupil was 44.3 ± 26.3 min. In 86 % of the examined eyes, the pupil reached its starting value within 1 h. The subjective degree of satisfaction with the application of dapiprazole was “satisfied” to “very satisfied” (5.4 ± 1.4 points on a scale from 1 to 7 points). Discussion and conclusion: In fundus examination, fluorescein angiography by a laser scanner, diagnostic retinal examination and central laser coagulation, the combination phenylephrine/dapiprazole was most suitable. In our opinion, the combination is less suitable for peripheral argon laser coagulation and fluorescein angiography using a fundus camera.      

Randomized clinical trial of the efficacy and safety of tropicamide and phenylephrine in preoperative mydriasis for phacoemulsification

Purpose: To compare the mydriatic effect and safety between different concentrations of tropicamide and phenyle­phrine in preoperative mydriasis for phaco­emulsification. Methods: Two hundred and seventeen consecutive eyes in the same number of Chinese patients undergoing phaco­emulsification under local or topical anaesthesia in a university‐based eye hospital were analyzed. Patients were randomized into two groups by cluster randomization, each group receiving a different preoperative mydriatic regimen. Regimen A consisted of tropicamide 1.0% with phenylephrine 2.5%, and Regimen B consisted of tropicamide 0.5% with phenylephrine 0.5%. The main outcome measures were horizontal pupillary diameter, systolic, diastolic and pulse pressure and pulse rate. Results: The group who received Regimen A attained a mean horizontal pupillary diameter of 7.00 ± 1.06 mm. Their pupils were significantly larger than those receiving Regimen B (6.61 ± 1.03 mm, P = 0.007). No untoward cardiovascular effects were noted in either groups. Conclusion: Regimen A attained better preoperative mydriasis for phacoemulsification than Regimen B. Both regimens were safe with regard to their cardiovascular effects. The combination of tropicamide 1.0% and phenylephrine 2.5% is recommended as preoperative mydriatic for phacoemulsification in Chinese patients who have darkly pigmented irides.     

Evaluation of a new preoperative ophthalmic solution

BACKGROUND: Maximum mydriasis and corneal clarity during intraocular surgery are important to ensure operational safety. However, repeated instillation of mydriatic and anti-inflammatory ophthalmic solutions during surgery may affect compliance and may damage the corneal epithelium. We developed an ophthalmic solution containing tropicamide, phenylephrine hydrochloride and diclofenac sodium, and compared the properties and effect on corneal epithelial barrier function and on mydriasis of the solution and of its individual components. METHODS: We developed the ophthalmic solution by mixing 10 mL of 0.5% tropicamide/0.5% phenylephrine, 10 mL of 5% phenylephrine and 10 mL of 0.1% diclofenac (TPD). We determined the stability of the chemicals in solution using high-performance liquid chromatography immediately, 1 week and 1 month after mixing. Corneal epithelial barrier function was assessed before and after instillation of the solutions in 26 eyes of 17 patients (5 with proliferative diabetic retinopathy or diabetic maculopathy, 8 with cataract and 4 with no eye disease). The fluorescent intensity was measured 10 times at the central cornea 30 minutes after instillation of 3 mL of 0.5% fluorescein solution and the average value calculated. Finally, the pupil diameter of 50 eyes of 38 patients undergoing cataract surgery was measured before and immediately after the operation. RESULTS: No remarkable changes in the pH or pharmacologic activity of the TPD solution were observed at any time after mixing. In the patients with diabetic retinopathy or cataract, the increase in mean fluorescent intensity was significantly greater with the individual solutions than with the TPD solution (p < 0.01); there was no significant difference in mean fluorescent intensity in the subjects with no eye disease. No statistically significant difference in pupil diameter was observed between the eyes that received the TPD solution and those that received the individual solutions. INTERPRETATION: TPD ophthalmic solution is simple to prepare and use. The TPD solution had a similar effect on mydriasis as the three individual solutions but was less destructive to the corneal epithelium.     

Posterior chamber injection of intracameral mydriatics increases the durability of the mydriatic response

Purpose: To compare the mydriatic effect of intracameral mydriatics injected into the anterior or the posterior chamber in routine phacoemulsification cataract surgery. Methods: Forty‐four patients planned for unilateral phacoemulsification surgery were included after informed consent. Mydriasis was achieved by injecting 150 μl of a mixture of phenylephrine 1.5% and lidocaine 1.0% at the beginning of the procedure. The patients were randomly assigned to injection into the anterior or the posterior chamber. The pupils were filmed during the procedures, and the mean pupil diameters were measured at predetermined intervals from the video recordings by an independent observer. Results: Immediately after the injection, the pupils were larger after posterior chamber injection (3.8 ± 0.8 versus 3.1 ± 0.7 mm; p = 0.004). A similar difference was seen after the phacoemulsification (6.4 ± 0.7 versus 5.9 ± 1.0 mm; p = 0.031). The mydriatic durability was also better after posterior injection (p = 0.004–0.041). Conclusions: Apart from immediately after the injection, the initial mydriatic response was similar with both injection techniques, but the durability of the mydriasis was slightly better after a posterior chamber injection of ICM.     

Pupil dilation with intracameral lidocaine during phacoemulsification

PURPOSE: To evaluate pupil dilation by an intracameral injection of nonpreserved lidocaine 1% during phacoemulsification cataract extraction and compare the results with those using conventional topical mydriatics. SETTING: Department of Ophthalmology, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. METHODS: A prospective comparative case series study was conducted. The study included 57 patients who were given topical mydriatics (30 eyes) or intracameral lidocaine (27 eyes) to dilate the pupil for phacoemulsification and intraocular lens implantation. The topical group received 3 drops of cyclopentolate 1% and phenylephrine 5% given 5 minutes apart starting 60 minutes before surgery. The intracameral group received preservative-free lidocaine 1% (0.2 to 0.3 mL) injected just before the procedure began. No epinephrine was added to the irrigating solution. In both groups, the horizontal pupil diameter was measured before and after pupil dilation using the same caliper. Total surgical time, need for a mydriatic agent during the procedure, and subjective surgical performance were recorded. RESULTS: The mean age, sex, cataract density, baseline horizontal pupil diameter, and mean duration of the surgery were the same between the topical group and intracameral group. The mean pupil dilation was 4.52 mm +/- 0.08 (SD) in the intracameral group and 4.06 +/- 0.09 mm in the topical group; the difference between groups was statistically significant (P = .001). There was no significant difference between groups in the overall subjective surgical performance (P = .74). No patient in the intracameral group and 2 patients in the topical group required an intracameral mydriatic injection. CONCLUSION: During phacoemulsification, intracameral preservative-free lidocaine 1% provided rapid, effective mydriasis comparable that of topical mydriatics.     

Hydroxyamphetamine mydriasis in normal subjects

Hydroxyamphetamine eyedrops are used to help localize the lesion in Horner's syndrome. Because normal variability in the response to the eyedrops may influence the interpretation of test results in patients with Horner's syndrome, we studied both the interocular variability of the drug's mydriatic effect within each normal subject and the variation between individuals. We used photographs to document the variability among 26 normal subjects. Hydroxyamphetamine hydrobromide 1% eyedrops (Paredrine) were placed in both eyes of normal subjects in the same way that patients with Horner's syndrome are tested. The drug produced a mean increase in pupil size of 1.96 mm (+/- 0.61 S.D.) in the 52 eyes tested. In normal subjects, the mydriatic effect of hydroxyamphetamine was symmetric in each pair of eyes. The mean interocular asymmetry of mydriasis as measured by the difference in dilation (right eye dilation minus left eye dilation) was -0.087 mm (+/- 0.29 S.D.). Thus, the variability of hydroxyamphetamine mydriasis from one eye to the other in a single subject was much lower than the variability between subjects.     

Einfluss von Phenylephrin und Tropicamid auf Aberrationen höherer Ordnung

BACKGROUND: For wave-front guided corneal surgery, measuring higher order monochromatic aberrations in mydriasis is needed. However, a potential influence of mydriatic drugs on such aberrations could distort the ablation profile. METHOD: Wave-front analysis was carried out on 20 (tropicamide) and 19 (phenylephrine) eyes after dark adaptation, followed by measurement after the instillation of the mydriatics one after another. RESULTS: Phenylephrine had no significant influence on the wave-front; neither sphere nor RMS data differed from those taken after dark adaptation. After instilling tropicamide, significant changes in Z(2) (0) and, in parallel, also of the sphere were found. The RMS showed no significant difference, only the spherical aberration Z(4) (0) was reduced by an average of 0.035 microm. CONCLUSION: The wave-front changes individually through the mydriasis due to phenylephrine and tropicamide. In the case of tropicamide, the deviation is statistically significant. Therefore, abandonment of these mydriatics before refractive surgery can be recommended, as can the use physiological pupil dilatation. Because of its lower influence, phenylephrine should be the first choice if dimout effects no adequate mydriasis.     

Aberrometry due dilated pupils--Which mydriatic should be used?

BACKGROUND: For a wavefront-based LASIK procedure aberrometric measurements are necessary via a dilated pupil. The more dilated the pupil is the more aberrations can be identified. There are different mydriatic eyedrops used to dilate the pupil. It is unclear so far which mydriatic is best for measuring aberrations before LASIK. METHODS: We performed aberrometry measurements on 50 eyes under the following different conditions: physiological mydriasis under mesopic environment, tropicamide-induced dilation, phenylephrine-induced dilation, and cyclopentolate-induced dilation. The wavefront measurements were compared with the respective subjective refraction (sr). RESULTS: The refractive myopic error measured by aberrometry was less than after subjective refraction depending on the mydriatic used. Phenylephrine-induced mydriasis resulted in 0.19 D less myopia, tropicamide induced 0.35 D less myopia, and cyclopentolate 0.42 D less on the average. The aberrometry measurements under mesopic conditions led to 0.24 D less myopia than measured subjectively. CONCLUSION: Using cyclopentolate eyedrops wavefront analysis results in a considerable difference in the preoperative refractive error compared to the standard subjective refraction. Regarding the average differences in refraction the aberrometry measurements after neosynephrine-induced dilation of the pupil usually resemble the subjective refractive error. For practical reasons we would like to recommend aberrometry measurements under mesopic conditions without applying mydriatics provided the pupillary diameter is at least 6 mm.