Horizontal Pupil Diameter Research Articles

Efficacy and Safety of Mydriatic Microdrops for Retinopathy of Prematurity Screening

Commercial mydriatics administered in preterm infants during retinopathy of prematurity (ROP) screening have been associated with various cardiorespiratory and gastrointestinal adverse events. To examine whether microdrops of a combined mixture of 1.67% phenylephrine and 0.33% tropicamide are noninferior to standard drops regarding mydriatic efficacy at 45, 90, and 120 minutes. The occurrence of systemic adverse events and systemic absorption of phenylephrine eyedrops were additional secondary outcomes. This randomized clinical trial with a double-masked, noninferiority, crossover design included infants undergoing ROP screening at a tertiary center in Northern Greece from September 2021 to January 2023. Eligible participants were infants with gestational age below 32 weeks and/or birthweight under 1501 g, or infants beyond these thresholds referred by an attending neonatologist due to comorbidities. Either microdrops or standard drops of the diluted mixture were administered at a random allocation sequence with a 1-week washout period. The horizontal pupil diameter at 45, 90, and 120 minutes was measured using a customized ruler in 0.5-mm increments. Mixed-effects linear regression models were developed, and the confidence interval (CI) approach was used for assessing noninferiority. The predefined noninferiority margin was -0.4 mm. Heart rate; oxygen saturation; blood pressure measurements at 45, 90, and 120 minutes; 24-hour hypertensive episodes; and 48-hour systemic adverse events were assessed. Phenylephrine concentration in peripheral blood within 3 hours postinstillation was measured using hydrophilic liquid chromatography-tandem mass spectrometry. Pooled pharmacokinetic parameters were calculated based on a developed mathematical model. A total of 83 infants were randomized (mean [SD] gestational age, 29.7 [2.0] weeks; mean [SD] birth weight, 1277 [374] g). Microdrops proved to be superior regarding mydriatic efficacy at 45 minutes (mean difference, 0.12; Bonferroni-corrected 95% CI, 0.01 to 0.23; P = .008) and noninferior at 90 minutes (Bonferroni-corrected 95% CI, -0.10 to 0.17) and 120 minutes (Bonferroni-corrected 95% CI, -0.18 to 0.14). Lower levels of oxygen saturation at 45 minutes (mean difference, 0.66; 95% CI, 0.09 to 1.24; P = .03) and 90 minutes (mean difference, 0.58; 95% CI, 0.03 to 1.14; P = .04) and higher percentage of 24-hour hypertensive episodes (median [IQR] percentage of hypertensive episodes: microdrops, 0.10% [0.02%-0.19%] vs standard drops, 0.14% [0.06%-0.40%]; P = .01) were observed after standard drops. A 1-compartment model with first-order absorption best described the pharmacokinetic data. To our knowledge, this is the first study establishing noninferiority of microdrops compared with standard drops of a diluted mydriatic mixture, showing reduced systemic adverse events after microdrops and determining the pharmacokinetic profile of phenylephrine eyedrops in preterm infants. ClinicalTrials.gov Identifier: NCT05043077.

Evaluation of 0.1% and 1% atropine eyedrops in cats: A comparative study of tolerance, stability, and efficacy.

Investigate the tolerance, stability, and efficacy of topical 0.1% and 1% atropine in cats. Six cats underwent two trials separated by a 2-week washout period. One drop of artificial tears was placed in one randomly selected eye (control), and one drop of either 0.1% atropine (Trial I) or 1% atropine (Trial II) was placed in the other eye. Immediate adverse effects were recorded for severity (0-3) and duration (seconds). Horizontal pupil diameter (HPD), pupillary light reflexes (PLRs), intraocular pressure (IOP), Schirmer tear test-1 (STT-1), and heart rate (HR) were monitored at baseline then 8 h post-administration. PLRs were assessed for a total of 72 h. Stability was assessed weekly for 1 month in room temperature and refrigerated conditions, evaluating solution clarity, pH, and drug concentrations. Adverse effects had a significantly lower severity score and shorter duration with 0.1% versus 1% atropine (severity 1.2 ± 0.4 vs. 2.5 ± 0.5, p = .010; duration 107.5 ± 53.3 vs. 293.3 ± 106.5 s, p = .009). HPD was significantly greater than baseline measurements as early as 40 min for both atropine formulations. Pupils were non-responsive for a significantly shorter duration with 0.1% versus 1% atropine (median 7 h vs. 47.5 h, p = .031). Compared with control eyes, IOP was significantly elevated by 1% atropine (p = .021) but not 0.1% atropine (p = .502). No significant differences were noted in STT-1 and HR measurements. Both solutions were stable in room temperature and refrigerated conditions for 1 month. Diluted 0.1% atropine was stable and better tolerated by cats, offering a potential alternative to feline patients that experience adverse effects from topical 1% atropine.

Postmortem sympathomimetic iris excitability

Background:A reliable estimation of time since death can be important for the law enforcement authorities. The compound method encompassing supravital reactions such as the chemical excitability of the iris can be used to further narrow intervals estimated by temperature-based methods. Postmortem iris excitability was mostly assessed by parasympatholytic or parasympathomimetic substances. Little is known regarding sympathomimetic agents. The present study aims to describe the postmortem iris excitability using the sympathomimetic drug phenylephrine. Methods:Cadavers were included after body donors gave written informed consent during lifetime. Exclusion criteria were known eye disease, or a postmortem interval exceeding 26 hours. A pupillometer with a minimum measurement range of 0.5 mm was used to determine the horizontal pupil diameter before and 20 minutes after the application of phenylephrine. Increase in pupil diameter was labeled as positive reaction, unchanged pupil diameter was labeled as negative reaction, and decrease in pupil diameter was labeled as paradox reaction. Results:30 eyes from 16 cadavers (median age = 80.0; 9 males, 7 females) were examined. Initial pupil size was in median 3.5 mm (interquartile range [IQR]: 3.0–4.5 mm) and progressed to 4.0 mm (IQR: 3.5–5.0 mm) 20 minutes after drug instillation. The achieved pupil diameter difference comprised in median 0.5 mm (IQR: 0.0–1.0 mm). A positive reaction was observed in 21 cases. Negative reactions were observed in 5 cases and paradox reactions in 4 cases. Overall, there was a statistically significant difference in diameter between the initial and the reactive pupil (P = 0.0002). Conclusion:Although relatively rarely used, sympathomimetic drugs seem to be eligible for chemical postmortem iris excitability. Currently, assessment of postmortem iris excitability usually only involves parasympatholytic and parasympathomimetic agents. The findings of the present study give a hint that the application of a third agent with a sympathomimetic mechanism of action could provide additional information. Further studies assessing such a triple approach in the compound method in comparison with the current gold standard for estimation of time since death are mandatory to ensure reliable results.

Effects of gabapentin on intraocular pressure, tear production and horizontal pupil diameter in New Zealand White rabbits.

This study aimed to investigate the effects of gabapentin on various ocular parameters in New Zealand White rabbits. A randomised, placebo-controlled crossover study design was employed. Eight New Zealand White rabbits were randomly assigned to receive either oral gabapentin at a dosage of 15mg/kg or an oral placebo, with a 1-week washout period between treatments. Intraocular pressure, tear production and horizontal pupil diameter were measured at baseline (T0) and at 30, 60, 90, 120, 180, 240 and 360 minutes after drug administration. Physiological and behavioural changes were also recorded for both treatments following drug administration. The administration of gabapentin did not have any significant effects on the ocular parameters measured in this study. However, the rabbits exhibited some muscle relaxation with partially closed eyes during handling, and they were slightly easier to remove from the cage when treated with gabapentin compared to the placebo treatment. In this study, the ocular effects of gabapentin were assessed in only a small number of healthy rabbits. These effects may differ in rabbits with pre-existing eye conditions or in those receiving other medications. Our findings suggest that gabapentin treatment does not have a significant impact on intraocular pressure, tear production or horizontal pupil diameter in rabbits.

Effect of gentamicin on mydriasis in rabbit’s eye

Background: In our ophthalmology outpatient department, routinely to observe the posterior segment of the eye and the fundus of the eye, we use various mydriatics such as atropine, cyclopentolate, and tropicamide for various indications. As there are a lot of mydriatics clinically used, taking much time for dilation, any add-on drug can be used for dilatation of pupils helping the underlying drugs for a better outcome. This study provides information regarding the effect of topical administration of gentamicin on horizontal pupillary diameter (HPD) over and above use of other mydriatics in rabbit’s eye. There are no similar studies in the past. Aims and Objectives: The aim of this study was to evaluate the effect of gentamicin on the HPD of rabbit’s eye. Materials and Methods: After taking the Institutional Ethics Committee clearance, 48 rabbits were taken into this study and were divided into 2 groups of 24 rabbits each. HPD was measured in both eyes before starting the experiment. Gentamicin eye drops were instilled in the right eye (test) and normal saline in the left eye (control) in both groups of 24 each. HPD was measured in both eyes after 30 min of instilling drops, and readings were noted. Thereafter, homatropine hydrobromide was instilled in both eyes in the first group (24 rabbits), and phenylephrine hydrochloride in the second group (24 rabbits). HPD in both eyes was measured every 5 min for 30 min. Results: After 30 min of instilling gentamicin eye drops in the test eye, there was no change in HPD; however, after instilling a mydriatic agent (homatropine or phenylephrine), there was an early onset of mydriasis as well as marked mydriasis in test eye compared to control eye in both groups. Hence, the differences in HPD between both eyes (test and control eye) were statistically not significant (P = 0.083). Conclusion: Topical application of gentamicin does not have a mydriatic effect, but it potentiates the mydriatic effect of homatropine and phenylephrine in rabbit’s eye.

Gabapentin reduces stress and does not affect ocular parameters in clinically normal cats.

To describe the effects of gabapentin on ocular and behavioral parameters following oral administration in healthy cats. Masked, placebo-controlled, randomized crossover-design study. Ten young, healthy cats were scheduled for two veterinary visits 7 days apart and randomly assigned to receive a compounded capsule containing 100 mg of gabapentin or placebo (100 mg lactose powder) at the first visit and the opposite treatment at the second visit. Respiratory rate, heart rate, stress score, sedation score, compliance score, horizontal pupil diameter, intraocular pressure, and Schirmer tear test-1 were measured prior to and 1.5, 3, and 6h following capsule administration. Stress score, sedation score, and compliance score were assigned based on established behavioral scales. Results of the two treatments were statistically compared with a p-value <0.05 considered significant. Respiratory rate was significantly reduced at 1.5 (p=0.049) and 3 (p=0.03) hours following gabapentin administration. Stress score was significantly reduced at 1.5 (p=0.01) hours following gabapentin administration. Sedation score was significantly increased at 1.5 (p=0.015) and 3 (p=0.03) hours following gabapentin administration. Gabapentin had no significant effect on heart rate, compliance score, or ocular values measured in this study. Gabapentin reduces stress and increases sedation at 1.5h after treatment, with no significant effect on horizontal pupil diameter, intraocular pressure or Schirmer tear test-1 results.

Effects of medetomidine/ketamine and xylazine/ketamine anesthesia and their reversal by atipamezole on ocular parameters and monitored anesthesia care in cats

The aim of this study was to investigate the impact of the general anesthetic drug ketamine and premedication agents medetomidine and xylazine, and their reversal by atipamezole, on monitored anesthesia care values and ocular parameters such as intraocular pressure, horizontal pupillar diameter, and Schirmer tear test in cats. A randomized, single-blinded study was conducted. Twenty intact female cats (weiging between 2.2 and 3.6 kg, and 0.5 to 5.5 years of age) referred for ovariohysterectomy (OHE) procedure by the owners at regular intervals over 4 months were included in the study. The cats were randomly divided into two groups containing 10 animals in each group. The cats were premedicated with medetomidine 80 µg/kg intramuscular in group 1 while the cats in the 2nd group were premedicated with xylazine hydrochloride 2 mg/kg intramuscular. After the OHE procedure was ended, anesthesia regimes were reversed by using atipamezole 200 µg/kg intramuscularly. Monitoring of respiration rate, heart rate, mean arterial pressure, peripheral arterial oxygen saturation, and body temperature were conducted using a patient monitor at T0, T1, T2, T3, and T4 time points. Both groups showed declines in intraocular pressure and increases in horizontal pupil diameter after anesthesia induction (T0 vs. T1, all, P&amp;lt;0.05); however, the chancing and recovery pattern of intraocular pressure and horizontal pupil diameter showed intergroup difference. In conclusion, xylazine/ketamine is more effective than medetomidine/ketamine in attenuating the intraocular pressure, increasing the horizontal pupil diameter, and alteration the monitored anesthesia care response in the general anesthesia.

Pupil Dilation by Intracameral Injection of Preservative Free 1% Lidocaine and Topical Mydriatics in Phacoemulsification Cases: A Comparative Study

Purpose: To compare the results of pupil dilation by an intracameral injection of preservative free 1% lidocaine with conventional topical mydriatics during phacoemulsification cataract surgery. Comparison was also done for simultaneous anaesthetic effect between intracameral lidocaine and topical mydriatics. Methods: A randomized, comparative interventional study was conducted. The study included 50 patients who underwent phacoemulsification and intraocular lens implantation surgery and were divided in two groups. One group was given topical mydriatics (25 eyes) preoperatively and other intracameral lidocaine (25 eyes) at commencement of surgery to dilate the pupil. The topical group received 3 drops of tropicamide 0.8% and phenylephrine 5% eye drops 15 minutes apart starting 45 minutes before surgery. The intracameral group received preservative-free lidocaine 1% (0.2 to 0.3 mL) injected just before the procedure began. In both groups, the horizontal pupil diameter was measured before and after pupil dilation using the same caliper. Total surgical time, need for a supplement mydriatic agent during the surgery and subjective surgical performance were recorded. Any adverse ocular and systemic effects between two groups were also compared. Results: The mean age, sex, cataract grading, baseline horizontal pupil diameter and mean surgerical time were similar between the topical and intracameral group. The mean pupil dilation was 4.62 ± 0.96 mm in the intracameral group and 4.76 ± 0.75 mm in the topical group. There was no statistically significant difference between the two groups (P value =0.57).There was no significant difference between groups in the overall subjective surgical performance (P=0.72). No patient in any group required supplementary intracameral mydriatic injection. Conclusion: Intracameral lidocaine is a safe, effective and reliable alternative to topical mydriatic for pupil dilation with added advantages of fast postoperative recovery and is also ....

The Impact of Clinical Atropine Use in Taiwanese Schoolchildren: Changes in Physiological Characteristics and Visual Functions.

Taiwan is commonly noted for its high prevalence of myopia, as well as a long history of more than 20 years of using atropine to control myopia. However, the clinical implications are rarely discussed. This is a cross-sectional study investigating the influence of topical atropine instillation on ocular physiology, visual function, and visual discomfort in children. Aged 7 to 12 years, 212 schoolchildren were recruited and divided into the atropine group and the non-atropine group. Physiological characteristics such as pupil size and intraocular pressure were measured, and a variety of visual functions was also evaluated. A questionnaire was used to investigate the side effects and visual complaints caused by atropine treatment. There was a significant difference in pupil size (OD: 5.40 ± 0.90 vs. 6.60 ± 1.01 mm; OS: 5.42 ± 0.87 vs. 6.64 ± 1.00 mm, p < 0.001) between the two groups. Reductions in near visual acuity, accommodation, convergence ability, and stereopsis were observed in the atropine group. The horizontal pupil diameter enlarged, and visual functions were greatly affected after administration of topical atropine. The changes in visual function during atropine therapy need to be carefully monitored by clinicians, while patient compliance is usually the key to success.

Effect of Topical Cyclopentolate 1% on Ocular Ultrasonographic Features, Intraocular Pressure, Tear Production, and Pupil Size in Normal Donkeys (Equus Asinus)

This study was performed to investigate the effects of cyclopentolate on ultrasonographic parameters of eye structures, intraocular pressure (IOP), tear production, and pupil size in normal donkeys. Sixteen eyes of eight clinically healthy adult donkeys (2–2.5 years old) weighing 295 ± 34 kg (mean ± standard deviation) were used in this study. Cyclopentolate hydrochloride 1% was instilled in a randomly selected eye and the other eye received normal saline drops as a control. The effect of cyclopentolate was evaluated by ultrasonography. Additionally, changes in IOP and tear production were evaluated for 2 hours post-instillation by tonometry and Schirmer tear test (STT), respectively. Vertical and horizontal pupil diameters were recorded pre-instillation (0), and 15, 30-, 45-, 60-, and 120-minutes post-instillation. After cyclopentolate 1% instillation, iridocorneal angle and width of the entry of ciliary cleft were significantly increased as observed by ultrasonography. IOP was significantly increased starting from 30 minutes till 60 minutes post-instillation of cyclopentolate 1%. Non-significant alteration in the STT was observed in the cyclopentolate-treated eyes compared to the control eyes. Both vertical and horizontal pupil diameters began to significantly increase 30 minutes after cyclopentolate 1% instillation compared to the control saline group. In conclusion, cyclopentolate 1% could be used as a potent cycloplegic drug in donkeys without systemic or ocular side effects.

Efficacy of Nepafenac versus Flurbiprofen in Maintaining Intraoperative Mydriasis During Phacoemulsification: A Comparative Study.

PurposeTo compare the efficacy of topical nepafenac (0.1%) with flurbiprofen (0.03%) in maintaining intra-operative mydriasis during phacoemulsification surgery.Patients and MethodsThis study comprised of 160 patients, who were divided into two arms of 80 each (arms A and B) after randomisation. Pre-operatively, all patients received one drop of tropicamide 0.8% and phenylephrine 5% (combination), 4 times, at an interval of 15 minutes on the day of surgery. Thereafter, Nepafenac drop in arm A/Flurbiprofen drop in arm B was administered 4 times, at an interval of 15 minutes keeping a gap of 10 minutes between tropicamide-phenylephrine and any of the experimental drugs. Phacoemulsification was performed one hour after the administration of last drop. Both vertical and horizontal pupillary diameter were measured at three steps; immediately before the surgical incision (baseline), at the end of emulsification of nucleus (before irrigation and aspiration) and at the end of surgery (after stromal hydration).ResultsThe difference in pupillary diameter between two groups, was statistically insignificant for vertical diameter (P = 0.08) and horizontal diameter (P = 0.28) at the start of surgery. On the other hand, pupillary diameter difference was statistically significant after emulsification of nucleus and at the end of surgery as well when both vertical (P < 0.05) and horizontal diameter (P < 0.05) were considered. The total reduction in pupillary diameter (both vertically and horizontally) was significantly less in the Nepafenac as compared to Flurbiprofen group (P < 0.05). Analysis of mean cumulative dissipated energy did not document any appreciable difference between the two groups. Phacoemulsification time analysis yielded statistically significant results (P = 0.004) between the Nepafenac and Flurbiprofen group.ConclusionIn the present study, topical Nepafenac (0.1%) proved to be more efficacious in maintaining intra-operative mydriasis during phacoemulsification surgery as compared to topical Flurbiprofen (0.03%).

Mesure du diamètre pupillaire chez les patients diabétiques et non diabétiques : étude cas-témoins

To study the effect of type 2diabetes on pupil diameter. We carried out a case-control study at the Douala Obstetrics, Gynecology and Pediatric Hospital over a 5-month period. The cases were type 2diabetic patients, and the controls were non-diabetic patients paired for age and gender. We studied the correlation between the duration of diabetes, fasting blood sugar and the horizontal pupil diameter. We included 35patients in each group. The mean age was 56.6±10.01years. Both groups included 17males and 18females. The mean duration of diabetes was 2.72±4.31years, and the mean fasting blood sugar was 2.02±0.69g/L. The mean pupil diameter was similar in the two groups. On the right side, it was 4.75±0.73mm for controls and 4.52±0.69mm for cases (P=0.179). On the left side, it was 4.70±0.68mm and 4.42±0.73mm respectively for each group (P=0.101). The duration of diabetes was correlated to pupil diameter in the right eye (r=-0.43; P=0.01) and left eye (r=-0.45; P<0.01). No additional risk was found to be associated with diabetes for right pupil diameters (OR=0.79; P=0.33), or for left ones (OR=0.76; P=0.24). Pupil diameter is similar in diabetic and non-diabetic patients. However, the duration of diabetes appears to affect pupil diameter.

Experimental Model of Far Temporal Field Negative Dysphotopsia Generated in Phakic Eyes.

PurposeThe axial separation between the iris and the intraocular lens (IOL) in pseudophakic eyes can cause rays originating from the far temporal field to miss the IOL, resulting in negative dysphotopsia (ND). We developed an experimental model to test the hypothesis that obstruction of rays from the far temporal field can generate ND and an accompanying loss of visual sensitivity in the far temporal field.MethodsThe right eyes of 10 phakic subjects were fitted with soft contact lenses containing a 5.50-mm central clear zone and a 12-mm outer diameter opaque annulus. In three of the subjects, eyes were dilated with 1% tropicamide solution, and effective aperture diameters were determined optically (pupil camera) and psychophysically (narrow beam detection). Visual field extent (Goldmann bowl) and temporal and inferotemporal meridian sensitivities (Octopus perimeter) were measured. A wide-angle model was constructed to quantify the impact of the annular opacity on retinal illuminance.ResultsAll 10 subjects observed a dark crescent in the far temporal and inferotemporal fields. The opaque annulus reduced effective horizontal pupil diameters from 8 mm to 5.5 mm on-axis and from >2 mm to <1 mm at 90°. Perimetry revealed a 10° reduction in temporal and inferotemporal field extent and increasing loss of sensitivity beyond 70°. The wide-angle model confirmed significant vignetting (>50% beyond 70°), approaching zero retinal illuminance beyond 85°.ConclusionsVignetting of rays originating from the far temporal field by axially separated apertures can create symptoms mirroring perceptual reports of negative dysphotopsia in symptomatic pseudophakic patients.

Changes in intraocular pressure, horizontal pupil diameter, and tear production during the use of topical 1% cyclopentolate in cats and rabbits.

Background:Cyclopentolate is not commonly used as mydriatic drug in veterinary medicine because of limited data on the local and systemic effects in animals.Aim:To determine the effects of topical 1% cyclopentolate hydrochloride on intraocular pressure (IOP), horizontal pupil diameter (HPD) and tear production in the cat and rabbit’s eye during the first hour and up to 36 hours after treatment.Methods:One drop of 1% cyclopentolate hydrochloride was used in the left eye in 10 clinically and ophthalmologically healthy domestic cats and 10 rabbits. IOP and HPD were recorded every 5 minutes during the first hour, then every 2 hours during the following 12-hour period, and at 24 and 36 hours after application. Schirmer tear test (STT) was measured at 30 and 60 minute after treatment, then in same time points as IOP and HPD. Rebound tonometer (TonoVet®) was used to assess IOP, Jameson calliper to measure HPD and STT to determine the tear production.Results:1% cyclopentolate increased IOP in cats, reaching a maximum (28.1 ± 5.4 mmHg) at T50 and in rabbits at T25 (16.7 ± 1.3 mmHg). Maximal mydriasis in cats was observed at T40 and lasted 24–36 hours, but in rabbits at T25, and returned to pre-treatment values at T10h–T12h. In cats, STT decreased in both eyes 30 minutes after treatment and remained lower throughout the 36-hour period. In rabbits, STT decreased in the treated eye 30 minutes after treatment, but all following STT measurements returned to normal pre-treatment levels.Conclusion:Study showed novel data about the effects of 1% cyclopentolate to IOP, HPD, STT in cats and rabbits. Cyclopentolate in cats caused mydriasis 20–40 minutes after the treatment by increasing IOP, at the same time, pupil diameter reached pre-treatment values 24–36 hours after treatment. In rabbit’s mydriasis occurred faster, 10–25 minutes after treatment without significant IOP increase and mydriasis lasted 10–12 hours. Significant STT decrease was recorded in cats, but more likely were connected to stress factors. This drug could be considered as a therapeutical alternative in rabbit more than in cats.

Subconjunctival 0.1% epinephrine versus placebo in maintenance of mydriasis during vitrectomy: a randomized controlled trial

BackgroundPupil dilation and mydriasis maintenance throughout vitreoretinal surgeries are important to allow satisfactory fundus visualization and reduce risk of complications. The purpose of this study is to evaluate the role of subconjunctival epinephrine 0.1% injection in mydriasis maintenance during vitrectomy.MethodsNinety-nine consecutive patients undergoing vitrectomy were enrolled. All subjects were preoperatively dilated with tropicamide 1%. Each patient was randomly allocated either in the epinephrine or placebo group. In epinephrine group, patients were submitted to a 0.2 cc subconjunctival injection of a 0.1% epinephrine solution just before first incisions. In placebo group, the same procedure was performed with 0.2 cc of saline 0.9%. Horizontal pupil diameter was measured with calipers before and in the end of the procedure.ResultsPatients in the epinephrine group showed a significantly larger mean pupil diameter in the end of the surgery compared to placebo. There was a significant increase of mean pupil diameter from the beginning to the end of the surgery in such patients. Blood pressure was significantly higher in the epinephrine group than in placebo group. No other adverse effects were noted.ConclusionSubconjunctival epinephrine is effective for maintaining and increasing pupil size during vitrectomy, compared to placebo. Caution should be taken regarding intraoperative blood pressure levels.Trial registrationRBR; RBR-3qzhvg; Registered 8 May 2018—Retrospectively registered, http://www.ensaiosclinicos.gov.br/rg/RBR-3qzhvg/.

Pupillary Responses to Full-Field Chromatic Stimuli Are Reduced in Patients with Early-Stage Primary Open-Angle Glaucoma

To evaluate the ability of chromatic pupillometry to reveal abnormal pupillary responses to light in patients with early-stage primary open-angle glaucoma (POAG) and to test whether the degree of pupillometric impairment correlates with structural hallmarks of optic nerve damage in the disease. Cross-sectional study. Forty-six patients with early-stage POAG (63.4±8.3 years, 63% male, 87% ethnic-Chinese) and 90 age-matched healthy controls (61.4±8.6 years, 34% male, 89% ethnic-Chinese). Patients with POAG had a visual field mean deviation (VFMD) of-6 decibels or better on automated perimetry. Each participant underwent a monocular 2-minute exposure to blue light (462 nm) followed by another 2-minute exposure to red light (638 nm) using a modified Ganzfeld dome equipped with a light-emitting diode lighting system. The light stimuli intensity was increased logarithmically to evaluate the combined extrinsic and intrinsic response of intrinsically photosensitive retinal ganglion cells (ipRGCs). Light-induced changes in horizontal pupil diameter were assessed monocularly using infrared pupillography. Baseline-adjusted, light-induced pupillary constriction amplitudes were calculated, and individual irradiance-response curves were constructed for each stimulus. Pupillary constriction amplitudes were compared between groups and across light intensities using a linear mixed model analysis. The linear relationship between pupillometric parameters and different structural and functional features of glaucoma was assessed using Pearson's correlation analysis. Light-induced pupillary constriction was reduced in patients with early-stage POAG compared with controls at moderate to high irradiances (≥11 Log photons/cm2/s) of blue (P= 0.003) and red (P < 0.001) light. Maximal pupillary constriction amplitude was correlated with retinal nerve fiber layer thickness (RNFL) thickness (blue: r= 0.51, P < 0.001; red: r= 0.45, P= 0.002) in patients with POAG but not in controls. Conversely, pupillometric parameters were not correlated with visual field scores in patients with early-stage POAG. Patients with early-stage POAG exhibit reduced pupillary responses to moderate and high irradiances of blue and red lights. This wavelength-independent functional alteration correlates with structural thinning of the RNFL and could be the consequence of dysfunction or loss of melanopsin expressing ipRGCs in the early stages of the disease.

Efficacy of the Canabrava Ring (pupil expansion device) in cataract surgery for eyes with small pupils: the first 30 cases.

To evaluate the outcomes of the first 30 cataract surgeries performed with a new disposable, injector-free, small-pupil expansion device. This consecutive case series included 30 eyes from 29 patients who underwent cataract surgery using a new disposable small-pupil expansion device called the Canabrava Ring (AJL Ophthalmic S.A, Spain). It is the first iris expansion ring produced with indents that do not align with each other in the superior and inferior regions, resulting in a small vertical length (0.4 mm) that minimizes the risk of endothelial contact. All eyes had poorly dilated pupils of less than 5 mm preoperatively. Fifteen eyes had significant infective or traumatic pathologies preoperatively. Vertical and horizontal pupil diameters were evaluated preoperatively, intraoperatively, and 1 month postoperatively. The mean patient age was 64 ± 11.8 (standard deviation) years. The Canabrava Ring remained engaged throughout all surgeries, except one. All pupils were intraoperatively expanded to a diameter of 6.3 mm. Although preexisting pathology on the innervation of the pupils, the mean pupil diameter returns to a close preoperative size after 1 month surgery. The mean pupil diameters postoperatively and preoperatively were 4.41 and 3.77 mm, respectively (p<0.05). Postoperative complications occurred in eight eyes (one toxoplasmosis reactivation, one retinal detachment, one posterior capsule rupture, one posterior capsule opacification, and four posterior synechiae). These complications occurred in eyes with preexisting traumatic or infective pathologies or synechiae. The Canabrava Ring is effective for expanding and maintaining expansion of small pupils in cataract surgery. The increase in postoperative pupil diameter is clinically diminutive and can most likely be attributed to preexisting pathologies affecting pupil innervation. Further large-scale studies are required to support the present findings.

Slit lamp assessment of relative afferent pupillary defect

PurposeTo demonstrate the accuracy of slit lamp assessment of relative afferent pupillary defect (RAPD) in patients with asymetric optic neuropathy.Methods40 eyes of 20 patients with asymetric optic neuropathy and no obvious RAPD in swinging flashlight test were evaluated on slit lamp. The asymetric optic neuropathy was confirmed by fundus examination, retinal nerve fiber layer thikness on OCT, visual field examination, visual potentials and/or brain and orbit MRI.The horizontal pupillary diameter in the affected (or more affeted) eye was measured and compared to the horizontal pupillary diameter of the fellow eye using the width of the slit lamp beam. Both diameters were measured in millimeters and compared.ResultsThere was a quantified anisocoria and RAPD each time when asymetric optic neuropathy was present. In other words, with the same slit lamp beam width (the same light intensity) the affected (or more affected eye) had a larger pupillary horizontal diameter.ConclusionsSlit lamp assessment of RAPD is simpler, quicker and more accurate than standard assessment using swinging flashlight test especially when anisocoria is not obvious.

Changes in intraocular pressure and horizontal pupil diameter during use of topical mydriatics in the canine eye.

The objective of this study was to determine the effects of topical 0.5% tropicamide, 1% atropine sulphate and 10% phenylephrine hydrochloride ophthalmic solutions on intraocular pressure (IOP) and horizontal pupil diameter (HPD) in the dog during the first hour after treatment. Forty clinically and ophthalmologically normal canine patients (between the ages of 2 and 6 years) of varying breed and sex were used in this study. Animals were randomly divided into four groups of ten and given one drop of tropicamide, atropine, phenylephrine or saline into one eye. IOP and HPD were measured in both eyes every 5 minutes for 60 minutes. Tropicamide increased IOP by 8.8±4.0 mmHg 35 minutes post-treatment compared to pre-treatment (P<0.01) only in treated eye. IOP in the contralateral eye did not increase. With atropine the maximum increase in IOP was 2.6±2.8 mmHg at 20 minutes post treatment in the treated eye (P<0.01). IOP in the contralateral eye did not increase. Phenylephrine increased IOP by 2.3±2.1 mmHg (P<0.05) 10 minutes after treatment. Also in the untreated eye IOP increased by 2.3±2.1 mmHg, 20 minutes post-treatment. Maximum HPD in eyes treated with tropicamide occurred at 55 minutes and with atropine at 60 minutes. There were no HPD changes in the contralateral, untreated eye. Topical 10% phenylephrine showed maximal pupil dilation 60 minutes after treatment, but the HPD of the – untreated eye slightly decreased at 15 minutes, but this change only reached statistical significance at 40 min post- treatment (P<0.05). Normal saline showed no influence on IOP or HPD. The drugs investigated here show a significant increase in IOP after mydriatics.

The effect of intracameral epinephrine on pupil size during phacoemulsification and its postoperative effect on specular findings and macular thickness

Objective: To evaluate pupillary size and vital signs following intraoperative intracameral adrenaline during phacoemulsification and postoperative effect of on co specular microscopy findings and macular thickness by OCT. Methods: A prospective interventional study carried out from December 2014 to December 2015 on 90 eyes. They were divided randomly into further 6 groups (15 each). The inclusion criteria consisted of no history of ocular pathologic conditions, trauma, previous ocular surgery, or recent ocular medication use. All patients were dilated preoperatively by phenylephrine 10% and operated under local peribulbar anesthesia. Then systemic monitoring regarding (pulse rate, blood pressure) and measurement of the horizontal pupil diameter by a caliper to the nearest 0.25mm pre and post intracameral adrenaline injection. Results: In our study there were great effect for intracameral epinephrine, with concentrations used, in dilatation and maintainance of papillary dilatation, The mean pre intracameral epinephrine was 4.53± 1.27 mm.The mean post epinephrine papillary diameter was 6.46± 1.00 mm. Three cases from group 1/10000 weren't dilated properly. Also three cases from group 1/9000 weren't dilated properly after intracameral epinephrine. Conclusion: Intracameral epinephrine even in higher concentrations is effective in papillary dilatation especially in cases with long duration and poorly dilated cases by usual topical mydriatics.