Pharmacological Pupil Dilation Research Articles

Web-Based Screening for Diabetic Retinopathy in a Primary Care Population: The EyeCheck Project

The objective of this study was to evaluate the feasibility of ATA category 2 Web-based screening for diabetic retinopathy in a primary care population in the Netherlands. A total of 1,676 patients in a primary care setting, with diabetes, without known diabetic retinopathy, and without previous screening by an ophthalmologist, were included between January 1 and December 31, 2003. Patients underwent a brief questionnaire and two field retinal photography. Photographs were independently read by two ophthalmologists. Outcome measures were gradability of the photographs, need for pharmacologic pupil dilation, assessment as suspect for presence of diabetic retinopathy, of neovascularization and of diabetic retinopathy, and agreement between graders. Of the population studied, 11.3% of patients required pupil dilation, average transmission time of images was 73 sec, 12.0% of patients had ungradable photographs, 10.4% of the patients with gradable photographs were assessed as "suspect for diabetic retinopathy," and 2.0% were assessed to need urgent referral. Red lesions were present in 3.5% and bright lesions were present in 1.6% of all gradable patients. Neovascularization of the disk was found in one patient. Type 1 patients had much higher rates of "suspect for diabetic retinopathy" (34.5%) than type 2 patients (9.4%). Interrater agreement kappa was 0.93. Web-based screening, using open source technology and uncompressed images, is feasible in a primary care setting, with a high rate of inter-rater agreement. Dilate-as-needed may be a sensible approach for retinal photography. The high incidence of "suspect for diabetic retinopathy" in type 1 diabetes patients illustrates that web-based diabetic retinopathy screening programs for these patients may detect diabetic retinopathy that would otherwise have gone undetected.

Diabetic retinopathy screening using digital non‐mydriatic fundus photography and automated image analysis

To investigate the use of automated image analysis for the detection of diabetic retinopathy (DR) in fundus photographs captured with and without pharmacological pupil dilation using a digital non-mydriatic camera. A total of 83 patients (165 eyes) with type 1 or type 2 diabetes, representing the full spectrum of DR, were photographed with and without pharmacological pupil dilation using a digital non-mydriatic camera. Two sets of five overlapping, non-stereoscopic, 45-degree field images of each eye were obtained. All images were graded in a masked fashion by two readers according to ETDRS standards and disagreements were settled by an independent adjudicator. Automated detection of red lesions as well as image quality control was made: detection of a single red lesion or insufficient image quality was categorized as possible DR. At patient level, the automated red lesion detection and image quality control combined demonstrated a sensitivity of 89.9% and specificity of 85.7% in detecting DR when used on images captured without pupil dilation, and a sensitivity of 97.0% and specificity of 75.0% when used on images captured with pupil dilation. For moderate non-proliferative or more severe DR the sensitivity was 100% for images captured both with and without pupil dilation. Our results demonstrate that the described automated image analysis system, which detects the presence or absence of DR, can be used as a first-step screening tool in DR screening with considerable effectiveness.

Screening for diabetic retinopathy using a digital non‐mydriatic camera compared with standard 35‐mm stereo colour transparencies

To investigate the use of a digital non-mydriatic camera for determining the ETDRS clinical level of diabetic retinopathy, and to evaluate its use in a screening setting to appropriately determine the need for referral to an ophthalmologist (ETDRS level > or = 35). A total of 83 patients with diabetes were photographed with and without pharmacological pupil dilation at an ophthalmology department using a digital non-mydriatic camera, obtaining two sets of five non-stereoscopic, 45 degree field images of each eye. ETDRS seven standard field, 35-mm stereoscopic colour fundus photographs were also obtained. A subgroup of 59 patients was photographed at an optician's shop using the digital non-mydriatic camera without pupil dilation. There was substantial agreement between the clinical level of diabetic retinopathy assessed from the 35-mm photographs and the digital images: the ophthalmology department (kappa = 0.76) with pupil dilation and (kappa = 0.66) without pupil dilation, respectively, and at the optician's (kappa = 0.60 without pupil dilation). With respect to the need for referral to an ophthalmologist, there was almost perfect agreement in the ophthalmology department (kappa = 0.88) with pupil dilation and (kappa = 0.84) without pupil dilation, respectively, and those taken at the optician's (kappa = 0.87 without pupil dilation). A digital non-mydriatic camera may be used in a screening situation to appropriately determine the need for referral to an ophthalmologist (ETDRS level > or = 35).

Le segment antérieur de l’œil des diabétiques

To study the damage to the anterior segment of the eye during mellitus diabetes. We prospectively studied the anterior segment of the eye in 200 diabetic patients and 200 patients with no history of diabetes (control group). Parameters included the corneal curvature radius, corneal thickness, central corneal sensitivity (Cochet Bonnet esthesiometer), pupil diameter before and after dilation using tropicamide and phenylephrine eye drops, delay for maximal pupil dilation, lens transparency, and intraocular pressure. The damage to the anterior segment was compared in both groups and was correlated with the parameters of diabetes (type, duration, and equilibration), retinopathy grade, and peripheral neuropathy. Corneal geometry (i.e., curvature radius and thickness) and intraocular pressure did not correlate with diabetes. Cataract was significantly influenced by diabetes (p<0.001). The duration needed to obtain pharmacological maximal mydriasis significantly correlated with iris color (rs=0.47, p<0.001), patient age (rs=0.28, p<0.001) and diabetes (rs=0.25, p<0.001). Dilation was significantly longer in the diabetic patient than in those of the control group (36.5 min vs 30.7 min, p<0.001). Corneal sensitivity significantly correlated with age (rs=0.48, p<0.001) and diabetes (rs=0.53, p<0.001). Corneal sensitivity was decreased in the diabetic group (5.42 vs 5.94, p<0.001) and it correlated with retinopathy grade (rs=0.47, p<0.001) and with peripheral neuropathy (rs=0.15, p<0.001). Sensitivity and specificity of hypoesthesia in detecting peripheral neuropathy were 67.4% and 49.4%, respectively. Among the parameters of diabetes, duration of progression showed the strongest correlation with damage to anterior segment (rs > or = 0.25, p<0.001). Diabetes influences lens transparency, pharmacological pupil dilatation and corneal sensitivity. In spite of the unspecific character of the damage and the subjectivity of the measurement, corneal sensitivity is an interesting parameter to take into consideration among diabetic patients.

Effect of pharmacological dilation and constriction of pupil on corneal topography.

A prospective study was undertaken to investigate the effect of pharmacological pupillary dilation and constriction on corneal topography. Corneal topography was performed using the EyeSys system on 28 normal subjects before and after pupil dilation, constriction, and then with the pupil intact (no medication). Our results show that both flattening and steepening of the corneal curvature were found in all three examination periods. The numbers of corneas with flattening and steepening in each examination period were compared and found not to be statistically different. Mean change of corneal flattening was compared with mean change of corneal steepening in each examination period and again no significant difference was found. These results indicate that the slight changes in corneal power and radius following pharmacological pupillary dilation or constriction may be due to either the inability to repeat by the subjects, or error by observers or instrument.

The effectiveness of papilledema as an indicator of raised intracranial pressure in children with craniosynostosis.

Craniosynostosis management partially depends on the detection and treatment of elevated intracranial pressure (ICP). Examination for papilledema is considered to be the most reliable screening method for identifying raised ICP, but its effectiveness has not been defined. One hundred and twenty-two children with craniosynostosis who underwent funduscopic examinations and then Camino ICP monitoring were studied. All eye examinations were performed by an ophthalmologist after pharmacological pupillary dilation. Fifteen patients (12%) had papilledema. Subsequent ICP monitoring showed that the median ICP was 12.7 mm Hg, with 41 patients (34%) having elevated ICPs (> 15 mm Hg). Those with papilledema had higher ICPs (17.5 +/- 3.2 versus 12.7 +/- 5.5 mm Hg), were older (5.9 +/- 4.7 versus 1.9 +/- 2.6 years), and were more likely to have craniofacial syndromes (73 versus 41%) than those without papilledema (P < 0.05). Patients with both elevated ICPs and papilledema were older (5.9 +/- 4.7 versus 1.6 +/- 1.4 years) and more likely to have multiple-suture synostosis (92 versus 61%) than those with elevated ICPs and no papilledema (P < 0.05). The presence of papilledema was a specific (98%) indicator of raised ICP, but its sensitivity was age-dependent. It was 100% sensitive in children older than 8 years, but it indicated elevated ICP in only 22% of younger patients. These results suggest that ICP monitoring to document elevated ICP is unnecessary in children older than 8 years who have detailed ophthalmological examinations. In the younger child, the presence of papilledema reliably indicates elevated ICP but its absence does not rule out elevated ICP; formal ICP measurement has a greater role in detecting elevated ICP in these patients.

Accidental mydriasis from blue nightshade ‘lipstick’

A 7-year-old girl presented with bilaterally dilated pupils, nausea, and vomiting 2 days after head trauma. Pilocarpine pupil testing led to the correct diagnosis of pharmacologic pupillary dilation from an unexpected and unusual source of plant poisoning, Solanum dulcamara (blue nightshade). In patients with internal ophthalmoplegia, awareness of the possibility of pharmacologic mydriasis and correct use of topical pilocarpine testing can preclude the necessity for neuroradiologic and invasive diagnostic studies, even in cases with atypical or complex presentations.

Anisocoria and Aerosolized Anticholinergics

The use of aerosolized anticholinergics has not previously been emphasized as a cause of pharmacologic pupillary dilation. The diagnosis can be confirmed by instillation of 1 percent pilocarpine hydrochloride in the affected eye, thereby preventing needless neurologic studies and evaluation. We report one patient who had transient asymmetric pupillary dilation secondary to aerosolized anticholinergic treatment. Also, we looked at the incidence of the above complication in 40 outpatients who were treated for acute asthmatic exacerbation.

Prevention of latrogenic acute narrow-angle glaucoma

The pathophysiology of glaucoma is reviewed, and the risks of pharmacologic pupillary dilation are discussed. A simple transillumination screening test for identifying patients in whom mydriasis presents a risk is described.