View clinical trials related to Mydriasis.
Filter by:Cataract surgery is one of the most frequently performed surgeries worldwide and complications are rare. However, there are factors that increase the risk of complications, such as poor pupil dilation and intra-operative floppy iris syndrome (IFIS). Reasons for a small pupil size are pseudoexfoliation syndrome (PXF) syndrome, uveitis or synechia and the use of pilocarpin drops. IFIS is a syndrome usually caused by systemic alpha1-blockers (foremost tamsulosin) used to treat benign prostatic hyperplasia.1,2 As described by Chang and Campbell3 IFIS is characterized by billowing of a flaccid iris stroma, a propensity for iris prolapse towards the phacoemulsification tip as well as towards the incisions and progressive intra-operative pupil constriction. Stopping tamsulosin pre-operatively did not show to effectively prevent IFIS.4,5 However, it is of high importance to identify patients prior to surgery, who are treated with alpha1-blockers, or patients with a small pupil size and poor pharmacological pupil dilation. Some methods, such as intracameral injection of phenylephrine is only sufficient in a few cases 6, and a disadvantage is the risk of a hypertensive episode.7 Another pharmacological method is the use of atropine drops pre-operatively, but this method did not show to sufficiently reduce IFIS.4 Different methods were shown to reduce intra-operative problems due to IFIS/small pupil size: The use of highly cohesive ophthalmic viscosurgical devices (OVD), also called viscoadaptives, such as sodium hyaluronate (e.g. AMO Healon5 or Croma Eyefill H.D.) help to viscodilate the pupil and by resting on the iris during the entire phacoemulsification procedure reduce the risk of iris prolapsing towards the incisions. This method is more dependent on a central phacoemulsification technique and low fluidic parameters to allow the OVD to stay on the iris during the entire procedure.8 In case of a small pupil, pupil stretching with 2 instruments can be used additively. Another option to stabilize the pupil size is the use of mechanical pupil expansion devices, such as 1. Iris retractors - these devices are routinely used to dilate the pupil intra-operatively. Typically, 4 or 5 iris retractors, also called iris hooks, are inserted through 4-5 incisions. Usually, the IFIS pupil is very elastic and the risk of overstretching is small.8 2. Pupil expansion rings, such as the Malyugin ring. This ring is placed on the pupil margin with an injector through the main incision. It eliminates the need of additional incisions and saves time.9 Rationale To compare different methods to manage IFIS and poor pupil dilation in cataract surgery: a pupil expansion ring (Malyugin Ring), iris retractors (iris hooks) and a viscoadaptive OVD.
The purpose of this study is to study the safety and efficacy of intracameral adrenaline for pupil dilation without topical mydriatics in refractive cataract surgery.
The purpose of this study is to determine if the mydriatic effect of intracameral lidocaine 1% is as effective as topical cyclopentolate 1% and phenylephrine 10% for achieving effective mydriasis during phacoemulsification surgery.
This study was done to compare efficacy, safety and efficiencies of various methods of pupil dilation prior to cataract surgery.
The purpose of this study is to compare the mydriatic effect of 2.5% phenylephrine and 1% tropicamide by conventional instillation and lower conjunctival fornix packing in premature infants.
The purpose is to determine if an intracameral solution of 0.2% tropicamide and 2% phenylephrine can dilate the pupil for cataract surgery as well as pre-operative topical 1% tropicamide and 5% phenylephrine. We will be looking at two separate groups of patients, those with and those without pseudoexfoliation syndrome. We will be looking at how each method affects the size of the pupil at the beginning and at the end of cataract surgery. In addittion, we will look at what effect the two different methods have on blood pressure and heart rate in the pre-operative, peri-operative and post-operative periods.
To compare the clinical efficacy and systemic side effects between 2.5% and 10% phenylephrine for mydriasis in diabetic patient with darkly pigmented irides.
The purpose of this study is to compare the efficacy on pupillary dilation between the single dose versus the three doses of 1% tropicamide with 10% phenylephrine for complete ocular examination.