Optohood reduces ambient light to facilitate mydriasis, reducing small pupil-related artifact. With its built in occluders , Optohood is able to reduce near point accommodation and consensual pupillary reflexes. By reducing reflective lights and accommodative reflexes Optohood is able to increase pupil size.
The result? Better patient care due to improved diagnosis, better image quality, shorter dilation time, and reduced practitioner frustration.
Save time, see more patients
Optohood reduces the wait time for full dilation, hence being able to see more patients per day.
OptoHood, with its occluder system, forces the pupil to dilate to its maximum, thereby allowing more light into the eye. When the pupil is not dilated large enough, the smaller opening creates the dark spot artifact, which makes it very difficult for the eye care professional to diagnose what is in that area. The enlarged opening of the pupil eliminates that problem, as seen in Fig 1b and 2b. This saves the 5 to 10 minutes that the doctor will need to take to check that area by having to use a 90 or 78 diopter lens with a slit lamp.
Busy eye care practices often dilate patients for OCT and nerve fiber layer assessment. Due to irregular and inconsistencies in pupil sizes many practitioners often are forced to dilate their patients in order to obtain gradable images. There is debate about the effect of pupil dilation on RNFL thickness measurements by Stratus OCT: Some studies reported that the difference is little or even not statistically significant, while other studies found that measurements before and after dilation are not interchangeable.
OCT scans without mydriasis enables the operator to save time in a busy practice, would not cause annoying visual disturbances for the patients, and removes the risk of angle closure. OptoHood would allow for consistency and standardization in the process.
Diabetic Retinal Screening
10-30% of fundus images are unreadable due to small pupil size and cataracts. Optohood can significantly reduce those unreadable images.
Diabetic screenings have been successfully implemented in most of Europe and now catching on in the US.
All diabetic screenings are performed undilated so Optohood becomes a vital part of obtaining good quality readable images.
As primary care physicians are slowly becoming required to screen for diabetes as part of a regular annual checkup, the concern for light control in their offices while using a retina camera is becoming more frequent. PCPs typically have a lot of light in their exam rooms, as they require much light to do an exam. Their primary concern is not light control, unlike eye care physicians. Hence, their diabetic screening retinal images will have a considerably higher percentage of them being unreadable. Optohood allows for taking optimal retinal images without compromising or modifying the PCP's exam room.
Consistently equal-sized pupils
Maximum pupil size
The normal pupil size in adults varies from 2-4mm in diameter in bright light, to 4-8mm in the dark. The pupils are generally equal in size. They constrict to direct illumination (direct response) and to illumination of the opposite eye (consensual response). The pupil dilates in the dark. Both pupils constrict when the eye is focused on a near object (accommodative response). When the non-occluded eye is looking straight ahead, it will receive visual stimulus of near objects, such as equipment, technician, walls, etc., which would result in pupil constriction of both pupils (consensual response). With the use of OptoHood, both light and accommodation stimulus are reduced, thus resulting in larger pupil size. Most ophthalmic cameras require minimum pupil size for quality images. OptoHood can help technicians produce high quality and consistent images.
By having a larger pupil size, the camera will increase the angle of view. Data from various manufacturer's fundus camera specifications indicate that as the pupil size increases, the viewing angle increases as well.
A 3.3mm pupil size produces a 33 degree viewing angle.
A 4mm pupil size produces a 45 degree viewing angle.
Larger Viewing Angle
Use with ocular wavefront aberrometer
Wavefront aberration of the eye, as derived from Shack-Hartmann images is determined with a certain degree of accuracy that varies considerably with pupil position. Zernike expansion coefficients are determined with less accuracy when recalculated at "cropped" pupils with the use of the algorithm employed in COAS. This study shows that these errors attributed to the reduced number of sensor elements could be, at least partially, overcome using an appropriate algorithm that calculates the aberration coefficients for smaller pupils based on full-size pupil set of data. Moreover, micro-fluctuations observed in the corresponding to defocus, are probably inherent characteristics of the eye and therefore show no improvement when the algorithm is applied. Consequently, it must be emphasised that wavefront aberration data used in clinical care should not be extracted from a single measurement, which represents only a static snapshot of a dynamically changing aberration pattern. - http://www.biomedcentral.com/1471-2415/4/1
Ocular wavefront aberrometers benefit from OptoHood by having the pupil dilate as large as possible, thus reducing errors and increasing accuracy. The picture above, taken from a vision conference, depicts how blocking the above light provides a much better result for the instrument.