Intracameral phenylephrine for surgical mydriasis and intraoperative floppy-iris syndrome: systemic adverse effects and optimal dose.

Phenylephrine, a potent sympathomimetic, induces mydriasis via iris dilator muscle contraction. Intracameral (IC) phenylephrine has been successfully used in cataract surgery for initial mydriasis, maintaining mydriasis, and management of intraoperative floppy-iris syndrome. Serious systemic adverse events (mainly cardiovascular) have been described with topical phenylephrine drops, but we found very little evidence of such adverse events associated with IC phenylephrine use. However, we suspect under-reporting of such adverse events, as they may instead be ascribed to anxiety, positioning, anesthesia, etc. Optimal dosage/concentrations for IC phenylephrine use in different purposes have not been fully studied. In the absence of robust evidence, we suggest that lower but effective IC phenylephrine concentrations are used: a lower concentration (0.31%), in conjunction with an anticholinergic and lidocaine, may be used for initial mydriasis. For management of intraoperative floppy-iris syndrome, 0.31% may be effective, though a higher concentration (1% to 1.25%) may be required.

Age-related results over 2 years of the multicenter Spanish study of atropine 0.01% in childhood myopia progression.

To evaluate the age-related efficacy and safety of atropine 0.01% eye drops over 2 years for myopia control in a multicentric pediatric Spanish cohort. A non-controlled, interventional, prospective multicenter study was conducted as an extension of the Spanish Group of Atropine Treatment for Myopia Control Study (GTAM 1). Children aged 6-14 years with myopia from - 2.00 to - 6.00 D, astigmatism < 1.50 D and documented annual myopic progression of at least - 0.50 D under cycloplegic examination were recruited. From the original cohort of 105 participants, 92 children who had been receiving atropine 0.01% eye drops once nightly in each eye for 1 year continued their participation in this extended study (GTAM 2). All the patients underwent a standardized quarterly follow-up protocol, which included measurements of best-corrected visual acuity (BCVA), cycloplegic autorefraction, axial length (AL), anterior chamber depth (ACD), and pupil diameter. The study sample was divided into three age groups: 6-8, 9-11, and 12-14 years old. The mean change in cycloplegic spherical equivalent (SE) and axial length (AL) during the 24 months of follow-up was analyzed. Correlations between SE and AL, as well as the distribution of annual progression, were evaluated. Adverse effects were recorded using a specific questionnaire. Finally, 81 children completed the follow-up and were included in the analysis. Over the 2-year period, the mean changes in SE and AL were - 0.88 ± 0.60 D and 0.49 ± 0.25 mm, respectively. Additionally, 51 patients (63%) experienced SE annual progression lower than - 0.50 D. The correlation between the progression of SE and AL during the total period of treatment was mild (r = - 0.36; p < 0.001). There were no differences between the first and the second year of treatment in the progression of SE (- 0.42 ± 0.41 D versus - 0.45 ± 0.39 D; p = 0.69) or AL (0.25 ± 0.16 mm versus 0.23 ± 0.14 mm; p = 0.43). Older patients (12-14 years old) showed less AL progression than younger children (6-8 years old): 0.36 ± 0.18 mm versus 0.59 ± 0.30 mm; p = 0.01. Adverse effects were mild, infrequent, and decreased over time. On average, the myopia progression in control groups from other published biannual studies exceeded that observed in our study. Over 2 years, atropine 0.01% demonstrated a safe treatment for controlling myopia progression in a multicentric cohort of Spanish children. The effect remained stable during this period. Older patients exhibited a more favorable response in terms of AL enlargement. However, further studies are needed to investigate the age-related effect of low-dose atropine in the Caucasian population.

Application of topical rocuronium bromide dosing by ocular size in four species of wild birds.

BACKGROUND: Rocuronium bromide has been evaluated as a mydriatic agent in birds, but the species applied were limited and the dose and effect were variable. OBJECTIVE: This study aims to evaluate the efficacy of topical rocuronium bromide as mydriatics in 4 species according to horizontal palpebral fissure length: Feral pigeon (Columba livia), Common kestrel (Falco tinnunculus), Northern boobook (Ninox japonica), and Eurasian eagle owl (Bubo bubo). METHODS: A total of 32 birds (8 for each species) were included as pre-releasing examination. Rocuronium bromide was instilled in one randomly selected eye of each bird based on palpebral fissure length criteria (0.5 mg/50 µL for pigeons, 1 mg/100 µL for kestrels and boobook owls, and 2 mg/200 µL for eagle owls). The contralateral eye was used as control and treated with normal saline. After instillation of the drug, pupil diameter, pupillary light reflex, intraocular pressure, heart rate, and respiratory rate were evaluated at 10 min intervals up to 180 min and at 30 min intervals up to 360 min. RESULTS: Statistically significant mydriasis was obtained in all birds (p < 0.001). However, in boobook and eagle owls, marked mydriasis persisted until 360 min. Side effects including corneal erosion and lower eyelid paralysis were common, which was observed in 26/32 birds. Blepharospasm was also noted during this study. No systemic adverse signs were observed. CONCLUSIONS: Rocuronium bromide could be a good mydriatics option for 4 species of birds, however, further studies are needed to find lowest effective dose to reduce drug-related side effects.

The effects of mydriatic eye drops on cerebral blood flow and oxygenation in retinopathy of prematurity examinations.

Mydriatic eye drops used during retinopathy examination have been associated with cardiovascular, respiratory, and gastrointestinal side effects. The aim of our study was to investigate the effects of the drops used for pupil dilatation on cerebral blood flow and cerebral oxygenation. The study included 62 infants who underwent retinopathy screening exams. Vital signs, heart rate (HR), arterial oxygen saturation (SpO2), and mean arterial pressure (MAP) were recorded. Cerebral oxygenation and middle cerebral artery blood flow velocity were evaluated using near-infrared spectroscopy (NIRS) and Doppler ultrasonography, respectively, and the cerebral metabolic rate of oxygen (CMRO2) was also calculated. The mean gestational age of the infants included was 31.29 ± 1.42 weeks, and the mean birth weight was 1620 ± 265 g. Heart rate was found to be significantly decreased after mydriatic eye drop instillation; however, there were no significant differences regarding blood pressure and oxygen saturation levels (HR: p < 0.001; MAP: p = 0.851; SpO2: p = 0.986, respectively). After instillation while cerebral regional oxygen saturation (rScO2) measurements were significantly decreased at the 60th minute (p = 0.01), no significant difference was found in Vmax and Vmean of MCA before and after mydriatic eye drop instillation (p = 0.755, p = 0.515, respectively). Regarding CMRO2 measurements, we also did not find any statistical difference (p = 0.442).    Conclusion: Our study has shown that although eye drops may affect heart rate and regional cerebral oxygen saturation, they do not alter cerebral blood flow velocities and metabolic rate of oxygen consumption. Current recommendations for mydriatic eye drop use in retinopathy exam appear to be safe. What is Known: • Mydriatic eye drop installation is recommended for pupil dilatation during ROP screening exams. • It's known that mydriatics used in ROP examination have affects on the vital signs, cerebral oxygenation and blood flow. What is New: • This is the first study evaluating the changes in cerebral oxygenation and blood flow velocity after mydriatic drop instillation using NIRS and Doppler US concomitantly. • While the eye drops may affect heart rate and regional cerebral oxygen saturation, they do not alter cerebral blood flow velocities and metabolic rate of oxygen consumption.

Incidence of Adverse Events Induced by Atropine in Myopic Children: A Meta-Analysis.

A large number of studies have evaluated the efficacy of low-dose atropine in preventing or slowing myopic progression. However, it is challenging to evaluate the ocular safety from these studies. We aimed to evaluate the incidence of adverse events induced by atropine in children with myopia. We performed a systematic literature search in several databases for studies published until November 2022. The incidence of adverse events induced by atropine was pooled by a common-effect (fixed-effect) or random-effects model. Subgroup analyses were conducted according to drug doses, types of adverse events, and ethnicity. A total of 31 articles were ultimately included in the study. The overall incidence of adverse events for atropine was 5.9%, and the incidence of severe adverse events was 0.0%. The most commonly reported adverse events were photophobia (9.1%) and blurred near vision (2.9%). Other adverse events including eye irritation/discomfort, allergic reactions, headache, stye/chalazion, glare, and dizziness occurred in less than 1% of the patients. The incidence of atropine-induced adverse events varied depending on the drug doses. A lower dose of atropine was associated with a lower incidence of adverse events. There was no significant difference in the incidence of adverse events for low-dose atropine between Asian and White children. Our study suggests photophobia and blurred near vision are the most frequently reported adverse events induced by atropine. Low-dose atropine is safer than moderate- and high-dose atropine. Our study could provide a safe reference for ophthalmologists to prescribe atropine for myopic children.

Effect of Low-Concentration Atropine Eyedrops vs Placebo on Myopia Incidence in Children: The LAMP2 Randomized Clinical Trial.

Importance: Early onset of myopia is associated with high myopia later in life, and myopia is irreversible once developed. Objective: To evaluate the efficacy of low-concentration atropine eyedrops at 0.05% and 0.01% concentration for delaying the onset of myopia. Design, Setting, and Participants: This randomized, placebo-controlled, double-masked trial conducted at the Chinese University of Hong Kong Eye Centre enrolled 474 nonmyopic children aged 4 through 9 years with cycloplegic spherical equivalent between +1.00 D to 0.00 D and astigmatism less than -1.00 D. The first recruited participant started treatment on July 11, 2017, and the last participant was enrolled on June 4, 2020; the date of the final follow-up session was June 4, 2022. Interventions: Participants were assigned at random to the 0.05% atropine (n = 160), 0.01% atropine (n = 159), and placebo (n = 155) groups and had eyedrops applied once nightly in both eyes over 2 years. Main Outcomes and Measures: The primary outcomes were the 2-year cumulative incidence rate of myopia (cycloplegic spherical equivalent of at least -0.50 D in either eye) and the percentage of participants with fast myopic shift (spherical equivalent myopic shift of at least 1.00 D). Results: Of the 474 randomized patients (mean age, 6.8 years; 50% female), 353 (74.5%) completed the trial. The 2-year cumulative incidence of myopia in the 0.05% atropine, 0.01% atropine, and placebo groups were 28.4% (33/116), 45.9% (56/122), and 53.0% (61/115), respectively, and the percentages of participants with fast myopic shift at 2 years were 25.0%, 45.1%, and 53.9%. Compared with the placebo group, the 0.05% atropine group had significantly lower 2-year cumulative myopia incidence (difference, 24.6% [95% CI, 12.0%-36.4%]) and percentage of patients with fast myopic shift (difference, 28.9% [95% CI, 16.5%-40.5%]). Compared with the 0.01% atropine group, the 0.05% atropine group had significantly lower 2-year cumulative myopia incidence (difference, 17.5% [95% CI, 5.2%-29.2%]) and percentage of patients with fast myopic shift (difference, 20.1% [95% CI, 8.0%-31.6%]). The 0.01% atropine and placebo groups were not significantly different in 2-year cumulative myopia incidence or percentage of patients with fast myopic shift. Photophobia was the most common adverse event and was reported by 12.9% of participants in the 0.05% atropine group, 18.9% in the 0.01% atropine group, and 12.2% in the placebo group in the second year. Conclusions and Relevance: Among children aged 4 to 9 years without myopia, nightly use of 0.05% atropine eyedrops compared with placebo resulted in a significantly lower incidence of myopia and lower percentage of participants with fast myopic shift at 2 years. There was no significant difference between 0.01% atropine and placebo. Further research is needed to replicate the findings, to understand whether this represents a delay or prevention of myopia, and to assess longer-term safety. Trial Registration: Chinese Clinical Trial Registry: ChiCTR-IPR-15006883.

Cyclopentolate eye drops-induced anaphylaxis in an infant.

BACKGROUND: Cyclopentolate is frequently used as a mydriatic agent during ophthalmological examinations in childhood and hypersensitivity reactions associated with this drug are rare. We aim to report an infant who experienced anaphylaxis due to cyclopentolate eye drops. CASE: A nine-month-old girl, who was being followed up with a diagnosis of retinoblastoma, presented for consultation for urticaria, cough, stridor, and dyspnea that developed after the administration of topical cyclopentolate to the eyes. The patient was diagnosed with anaphylaxis and treated with adrenaline. During the follow-up, tropicamide was used safely as an alternative drug. CONCLUSIONS: In children, hypersensitivity reactions due to cyclopentolate are very rare. Only four pediatric patients were reported in the literature to have developed an allergic reaction after the administration of cyclopentolate eye drops. We present here the youngest patient who developed anaphylaxis with cyclopentolate eye drops. Anaphylaxis due to cyclopentolate should be kept in mind, rapidly recognized, and treated when a reaction develops.

Trifascicular block with syncope triggered by preoperative mydriatic eye drops for cataract surgery.

We report the case of an 85-year-old patient who developed trifascicular block with syncope, triggered by preoperative eye drops for cataract surgery. This life-threatening situation reopens the debate over the necessity of having an anesthesiologist present during cataract surgery.

Acute drug reaction to phenylephrine and tropicamide collyrium in a late-preterm newborn: a case report.

BACKGROUND: Collyrium administration is a common procedure in the neonatal ward, both in preterm and at term babies. Various molecules are used to induce mydriasis and cycloplegia: among them, phenylephrine and tropicamide are the most popular, and their administration is generally considered safe. CASE PRESENTATION: A 35 + 2 weeks-old, 2510 g, well-appearing male newborn required an ophthalmologic evaluation after a doubtful red reflex test. A collyrium with 1% phenylephrine and 0.95% tropicamide was administered prior to the consult, one drop per eye. Two minutes after the administration, the baby developed a severe apnea that required tactile stimulation. Moreover, the area around his eyes became visibly pale. Three minutes later, the baby became severely bradycardic (59 bpm), but remained in good general condition, so that resuscitation maneuvers were not required. Bradycardia lasted for almost three hours and then gradually resolved. CONCLUSIONS: Cardiopulmonary manifestations, such as bradycardia and even cardiopulmonary arrest, are severe complications that can happen after phenylephrine collyrium administration in preterm newborns. However, they have been described in babies below 1500 g or with concurrent respiratory manifestations. Our patient, on the other hand, was late preterm, and never required a ventilatory support prior to the collyrium administration. Practitioners who deal with premature babies, even if late preterm, must be aware of these possible complications and administer phenylephrine collyrium carefully, where cardiopulmonary resuscitation equipment and personnel are available.

The safety of intracameral phenylephrine - A systematic review.

Intracameral phenylephrine is commonly used in ophthalmic surgery as an alternative or supplement to mydriatic eye drops; hence, the importance of an evidence-based understanding of its risk-benefit profile is vital. We performed a comprehensive search in the PubMed, Google Scholar, and Cochrane databases for published studies and case reports relating to the use of intracameral phenylephrine. Articles from 1958 to 2021 with the following keywords were used: "intracameral phenylephrine," "intracameral mydriatics," "phenylephrine," "pupil dilation," "complications." Intracameral phenylephrine was first used in 2003 as an alternative to topical mydriatics. Since then, it is being increasingly used with a variety of benefits, including rapid onset of mydriasis, and cost-effectiveness. There are various case reports, however, of ocular and systemic complications associated with intracameral phenylephrine such as generation of free radicals, toxic anterior segment syndrome, inconsistent pupillary dilation during surgery, and ventricular fibrillation. Alternatives to intracameral phenylephrine such as iris hooks, a Malyugin ring, intracameral epinephrine, and intracameral tropicamide were compared with intracameral phenylephrine. Intracameral phenylephrine appears to have a good safety profile.

Efficacy and safety of Mydriatic Microdrops for Retinopathy Of Prematurity Screening (MyMiROPS): study protocol for a non-inferiority crossover randomized controlled trial.

BACKGROUND: Retinopathy of prematurity (ROP) eye examination screening presupposes adequate mydriasis for an informative fundoscopy of preterm infants at risk, on a weekly basis. Systemic absorption of the instilled mydriatic regimens has been associated with various adverse events in this fragile population. This report aims to present the fully developed protocol of a full-scale trial for testing the hypothesis that the reduced mydriatic drop volume achieves adequate mydriasis while minimizing systemic adverse events. METHODS: A non-inferiority crossover randomized controlled trial will be performed to study the efficacy and safety of combined phenylephrine 1.67% and tropicamide 0.33% microdrops compared with standard drops in a total of 93 preterm infants requiring ROP screening. Primary outcome will be the pupil diameter at 45 (T45) min after instillation. Pupil diameter at T90 and T120 will constitute secondary efficacy endpoints. Mixed-effects linear regression models will be developed, and the 95% confidence interval approach will be used for assessing non-inferiority. Whole blood samples will be analyzed using hydrophilic liquid chromatography-tandem mass spectrometry method (HILIC-MS/MS), for gathering pharmacokinetic (PK) data on the instilled phenylephrine, at nine specific time points within 3 h from mydriasis. Pooled PK data will be used due to ethical restrictions on having a full PK profile per infant. Heart rate, oxygen saturation, blood pressure measurements, and 48-h adverse events will also be recorded. DISCUSSION: This protocol is designed for a study powered to assess non-inferiority of microdrops compared with standard dilating drops. If our hypothesis is confirmed, microdrops may become a useful tool in ROP screening. TRIAL REGISTRATION: ClinicalTrials.gov NCT05043077 . Registered on 2 September 2021.

Efficacy and safety of mydriatic microdrops for retinopathy of prematurity screening: an external pilot crossover randomized controlled trial.

OBJECTIVE: To study the efficacy and safety of mydriatic microdrops compared with standard drops for retinopathy of prematurity (ROP) screening. STUDY DESIGN: Preterm infants undergoing ROP screening received microdrops and standard drops of phenylephrine 1.67% and tropicamide 0.33% in a random allocation sequence at two consecutive weekly examinations. Primary outcome was pupil diameter measured by two masked observers at 45 (T45) and 90 (T90) minutes after instillation. RESULTS: Twenty-five infants were randomized. No differences observed in mean pupil diameter after either administration technique at all time points (T45 Mean Difference: -0.14; 95% Confidence Interval: -0.38, 0.09; p = 0.23). Heart rate values at T120 were lower after microdrop instillation (p = 0.046). Otherwise, adverse events did not differ after either administration technique. CONCLUSION: This pilot study provides evidence of microdrops mydriasis efficacy, while justifying a full-scale trial to confirm their non-inferiority compared with standard drops and provide more data about safety. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04623684.

A Survey of Neonatal Nurses on Mydriatic Regimens Used in Neonatal Retinopathy of Prematurity Eye Examinations.

OBJECTIVE: This study was aimed to determine mydriatic regimen(s) used in neonatal units in Aotearoa, New Zealand (NZ), and Australia and to estimate the frequency of adverse drug events following mydriatic administration in preterm neonates. STUDY DESIGN: A cross-sectional survey was sent to neonatal nursing staff listed in the Australian and New Zealand Neonatal Network contact list. Participants were asked to state what mydriatic regimen they use, and to estimate the frequency of adverse drug events when eye drops were administered for retinopathy of prematurity eye examinations (ROPEE). RESULTS: Thirteen different mydriatic regimens were identified; phenylephrine 2.5% and cyclopentolate 0.5% (1 standard drop of each) was the most commonly used regimen. Two of the regimens exceeded adult doses and five regimens included a mydriatic that is equivalent to an adult dose. Following mydriatic instillation, the three most common adverse effects were apnea, tachycardia, and periorbital pallor. CONCLUSION: Low-concentration single-microdrop regimens are currently in use and resulting in successful ROPEE, yet doses exceeding adult doses are in use throughout Aotearoa, NZ, and Australian units. We know from this dataset that neonates are experiencing unwanted and potentially preventable, adverse effects associated with mydriatics, and every effort should be made to minimize this risk. KEY POINTS: · Thirteen different regimens are in use in Aotearoa, NZ, and Australia.. · Three regimens use doses in excess of adult doses.. · Phenylephrine 2.5% and cyclopentolate 0.5% (one standard drop of each) is the most common regimen.

Safety and efficacy of 0.02% and 0.01% atropine on controlling myopia progression: a 2-year clinical trial.

Four hundred myopic children randomly received atropine 0.02% (n = 138) or 0.01% (n = 142) in both eyes once-nightly or only wore single-vision spectacles (control group) (n = 120) for 2 years. Spherical equivalent refractive error (SER), axial length (AL), pupil diameter (PD), and amplitude of accommodation (AMP) were measured every 4 months. After 2 years, the SER changes were - 0.80 (0.52) D, - 0.93 (0.59) D and - 1.33 (0.72) D and the AL changes were 0.62 (0.29) mm, 0.72 (0.31) mm and 0.88 (0.35) mm in the 0.02% and 0.01% atropine groups and control group, respectively. There were significant differences between changes in SER and AL in the three groups (all P < 0.001). The changes in SER and AL in the 2nd year were similar to the changes in the 1st year in the three groups (all P > 0.05). From baseline to 2 years, the overall decrease in AMP and increase in PD were not significantly different in the two atropine groups, whereas the AMP and PD in the control group remained stable (all P > 0.05). 0.02% atropine had a better effect on myopia control than 0.01% atropine, and its effects on PD and AMP were similar to 0.01% atropine. 0.02% or 0.01% atropine controlled myopia progression and AL elongation synchronously and had similar effects on myopia control each year.

Systemic adverse events after screening of retinopathy of prematurity with mydriatic.

PURPOSE: To evaluate systemic adverse events after screening for retinopathy of prematurity (ROP) performed with mydriatic. METHODS: This was a retrospective case series study. Medical records of consecutive patients who underwent screening for ROP with 0.5% phenylephrine and 0.5% tropicamide eyedrops were retrospectively reviewed. The score of abdominal distention (0-5), volume of milk sucked and volume of stool, along with systemic details (pulse and respiration rates, blood pressure and number of periods of apnea) were collected at 1 week and 1 day before ROP examination, and at 1 day after examination. Results were compared between the days before and after examination. Correlation between body weight at the time of examination and the score of abdominal distention was examined. The numbers of infants with abdominal and/or systemic adverse events were compared between pre- and post-examination periods. RESULTS: Eighty-six infants met the inclusion criteria. The score of abdominal distention increased from 2.0 at 1 day before examination to 2.3 at 1 day after examination (p = 0.005), and the number of infants who had worsened abdominal distension increased after examination (p = 0.01). Infants with lower body weight had a higher score of abdominal distention (p < 0.0001, r = -0.57). The number of infants with reduced milk consumption increased after examination (p = 0.0001), as did the number of infants with decreased pulse rate (p = 0.0008). CONCLUSIONS: Screening for ROP with mydriatic may have adverse effects on systemic conditions. Infants should be carefully monitored after ROP screening with mydriatic.

[The safety of atropine for myopia prevention and control].

Atropine is a classical drug with a wide use in clinical practice. In ophthalmology, atropine can be used for cycloplegia before optometry, and the treatment of amblyopia, iridocyclitis, malignant glaucoma, etc. In recent years, the "old drugs with new application " research and application of atropine for myopia prevention and control has become a hotspot and the efficacy of atropine has been preliminarily recognized. However, before the widely used in clinical, the safety of atropine draws attention. Researches concerning side effects of atropine were searched. The most common problem is photophobia due to dilated pupils, followed by poor near visual acuity, allergy and inflammation, local irritation. Other side effects include withdraw rebound, dry eyes, elevation of intraocular pressure, system reactions, photic damage and toxicity. Among them, some side effects are theoretical yet, and the long-term effects of some side reactions are not clear. Further research and exploration is needed to serve clinical evidence. At present, investigational usage for myopia prevention and control in clinical trials of atropine can be beneficial. Safety observation and efficacy evaluation are equally important in the course of application. (Chin J Ophthalmol, 2021, 57: 299-304).

Choroidal and Retinal Changes After Systemic Adrenaline and Photodynamic Therapy in Non-Human Primates.

Purpose: To determine the tomographic, angiographic, and histologic changes in the choroid and retina of cynomolgus monkeys after systemic adrenaline and verteporfin photodynamic therapy (vPDT). Methods: Six cynomolgus monkeys (12 eyes) were treated with vPDT only (n = 2), adrenaline only for eight weeks (n = 2), adrenaline for eight weeks with vPDT at week 4 (n = 4), and adrenaline for 12 weeks and vPDT at week 8 (n = 4). Spectral-domain optical coherence tomography, angiography, and autofluorescence were performed at baseline and every 14 days thereafter until 28 days after adrenaline therapy or vPDT. Choroid parameters included choroidal thickness (CT) changes and structural changes using semiautomated image binarization. Histology with light and electron microscopy was performed. Results: Adrenaline resulted in subfoveal CT increase at week 4 compared with baseline (3.4%, P = 0.010), with further increase at week 8 (3.9%, P = 0.007). This correlated with choroidal luminal area increase (16.0% at week 8 compared with baseline, P = 0.030). Outer retinal changes included subretinal fluid, ellipsoid zone (EZ) disruption, photoreceptor elongation, and sub/intraretinal bright dots. Hypocyanescent spots surrounded by leakage was observed. Histology showed dilated choroidal vessels, intracytoplasmic vacuoles, and retinal pigment epithelium (RPE) enlarged basal infoldings. The vPDT decreased subfoveal CT at four weeks after vPDT (-7.5%, P = 0.007). This correlated with choroidal stromal area decrease (-18.0%, P < 0.010). Within the treatment spot, there was outer retinal atrophy, EZ disruption, irregular RPE thickening, intense hypoautofluorescence, hyperfluorescence, and hypocyanescence. On histology, there were outer retina, RPE, and choroid changes. Conclusions: Adrenaline induces choroidal vessel dilation and CT increase. The vPDT decreases CT because of a reduction in choroidal stromal component.

Safety and efficacy of unilateral topical application of rocuronium bromide in healthy scops owls (Otus scops).

OBJECTIVE: To evaluate the safety and efficacy of unilateral topical application of rocuronium bromide in scops owls. ANIMALS STUDIED: Ten healthy adult scops owls. PROCEDURES: Birds weighting between 82-111 g were enrolled. Complete physical and ophthalmic examinations were performed. Each animal received a single dose of 0.15 mg of rocuronium bromide (30 µL) in a randomly selected eye. Static pupillometric evaluations were performed before and after drug instillation at 0, 30, 60, 90, and 120 minutes, in a room with fixed light intensity. Physical and ophthalmic examinations were carried out to evaluate possible adverse effects. RESULTS: Median pupil (95% CI) size at t0 was 7.10 mm (5.51-7.41) for placebo eyes and 7.22 mm (6.93-7.48) for treated eyes, showing no statistical differences (P > .05). When compared to the placebo eye, significant mydriasis was achieved at t30 [8.18 mm (7.22-9.00)] (P = .014) and lasting until t90 [7.35 mm (6.20-9.52)] (P = .004). Maximal mydriasis was obtained at t60 [8.63 mm (7.72-9.81)] (P = .001). During this period, the treated eye no longer responded to direct light stimulation. Complete mydriasis was observed in 5/10 birds (mean weight 97.4 g). Pupil size at t90 and t120 did not differ from baseline (P > .05) in treated eyes. No adverse effects were seen during the study period. CONCLUSION: Single-dose topical rocuronium bromide (0.15 mg) is a safe and effective medium duration mydriatic agent in scops owls. Further studies are needed to evaluate bilateral topical application and standardize the mydriatic protocol.

Randomised controlled pilot trial comparing low dose and very low- dose microdrop administration of phenylephrine and cyclopentolate for retinopathy of prematurity eye examinations in neonates.

AIMS: To determine ifVery low dose mydriatic eye microdrop regimen sufficiently dilates the pupil (above 4.1 mm) compared with the currently used low dose mydriatic eye microdrop regimen.Cardiovascular, gastrointestinal and respiratory adverse effects occur following eye drop instillation. METHODS: Seventeen premature infants were recruited into this prospective, randomised controlled pilot trial in January 2017 to November 2018. Data were collected from the single-centre Neonatal Intensive Care Unit, Dunedin Hospital, New Zealand. The inclusion criteria were birth weight less than 1500 g or gestational age less than 31 weeks, or any premature infant requiring red reflex testing. Infants were randomised to receive either phenylephrine 1% or 0.5% and cyclopentolate 0.2% or 0.1%, 1 microdrop in both eyes. Efficacy outcome measures were pupil size at retinopathy of prematurity eye examination (ROPEE) and ophthalmologist rating of ease of screen. RESULTS: All participants had sufficient pupillary dilation for a successful ROPEE. Ophthalmologists rated the ROPEE as easy for 90% of all examinations. Pupil dilation measurements at the time of examination, mean±SD, 4.8±0.2 (95% CI 4.5 to 5.2) mm for treatment A and 5±0.2 (95%CI 4.6 to 5.4) mm for treatment B (p=0.61). There were no statistically significant differences between the groups for safety data. CONCLUSIONS: Very low dose microdrop administration of phenylephrine and cyclopentolate appears to be effective at sufficiently dilating the neonatal pupil for ROPEEs. Low dose and very low dose microdrop mydriatic regimens may also reduce the risk of unwanted adverse effects associated with these medicines. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (reference ACTRN12616001266459p).