Prescriber FAQ

VES (Vision Enhancing System) is Ocutech’s trademarked and patented terminology for its innovative Keplerian optical design that combines a telescope and periscope into one optical assembly. This innovative design provides the wide field of view of Keplerian systems in a lightweight, compact and ergonomic design.

Ocutech offers diagnostic testing and demonstration systems of all of its low vision products. Ocutech offers complete prescribing guides, fitting charts, DVDs and videos, and convenient step-by-step ordering forms. Technical support is always available.

Why choose which telescope? Where do I start?
Dr. Greene’s clinical pearls:

I usually start with the 4x power. If your patient needs a lot of light, choose the VES-Sport which produces the brightest image, otherwise the VES-K may be fine. The VES-K is better for small faces (kids, small adults) while the VES-Sport is a bit more modern looking and is available in colors which kids especially enjoy.

The VES-Mini (available in 3x only) offers the widest field of view of any high power telescope available and can be prescribed for one or two eyes and for distance and near and is quite helpful for reading and music. It can also be prescribed in a “full diameter”(straight ahead) position for individuals who want to use it for TV or the computer. For driving, some states require that only monocular telescopes that don't cover the other eye be allowed. The mini is perfect for this application.

If 4x power doesn't provide ample visual acuity try the VES-Sport or VES-K in the 6x power. If field of view is an issue try the mini 3x. If the user had difficulty finding the target while looking through a monocular telescope, try the mini prescribed for both eyes.

Ocutech bioptic telescope systems are indicated for all central vision, macular and retinal disorders where visual acuity is responsive to magnification. Individuals with vision as poor as 20/400 have benefited from Ocutech devices.

Responsive visual diagnoses include macular degeneration, diabetic retinopathy, Stargardt's Disease, Hereditary macular degeneration, albinism, high myopia, nystagmus, coloboma, optic atrophy, macula holes, achromatopsia as well as many other vision disorders.

Ocutech systems are appropriate for all bioptic telescope applications for far, intermediate and near distances, and for a full range of visual activities. The individual's specific visual needs, established in consultation with their low vision specialist, will determine which Ocutech device, if any, will be most appropriate to achieve their functional goals.

Ocutech systems are appropriate for all bioptic telescope applications. These include television, travel, classroom, signs, faces, theater, sporting events, shopping, computer use, table top activities including games and card playing. Bioptic telescopes can be used for driving where legal and with appropriate state licensure when required.

The innovative bridge and bracket mounting designs of many of Ocutech’s products allow its systems to be easily and conveniently demonstrated to patients during the evaluation visit. There is little prescribing risk as all critical telescope positioning can be readjusted at any time, even after dispensing. With Ocutech Low Vision Aids you can achieve a level of control never before available with a high quality low vision optical system. Even challenging eccentric viewing and nystagmus patients can be fit with ease. Call or email Ocutech for a complete professional catalog.

For general, non-demanding visual activities telescope power should be selected to provide at least 20/50 (6/15) acuity through the device. For more demanding, higher resolution activities telescope power should be selected to provide at least 20/40 (6/12) or even 20/30 (6/9) through the device.

An easy way to determine what power to prescribe is the multiply the acuity goal by the power of the telescope. For instance if the acuity goal is 20/40 (6/12), than a 3x telescope will provide at least that acuity for individuals with best corrected visual acuity (BCVA) of 20/120 (6/40).

Why not prescribe a higher power? If we prescribe a higher power than is needed to provide the desired acuity through the device, than the field of view of the telescope will be narrower than necessary and there will be greater demand on the user to keep their head still to stabilize the image. So, while it’s not unreasonable to prescribe a higher telescope power than the minimum required, it may make adaptation to the telescope more challenging for the user.

For acuity goal of 20/50 (6/15):	Snellen	Metric
3x power indicated for BCVA up to:	20/150	6/45
4x power	20/200	6/60
6x power	20/300	6/90

For acuity goal of 20/40 (6/12):
3x power indicated for BCVA up to:	20/120	6/40
4x power	20/160	6/48
6x power	20/240	6/72

For acuity goal of 20/30 (6/9):
3x power indicated for BCVA up to:	20/90	6/27
4x power	20/120	6/40
6x power	20/180	6/54

All Ocutech VES bioptics provide internal Rx correction for a large range of spherical refractive errors (consult tech sheets for full ranges) and usually do not require additional eyepiece corrections. Cylinder corrections are not usually indicated when below 3 diopters. Auxiliary eyepiece corrections are not necessary if the patient can achieve their acuity goal through an equivalent testing telescopic device without such a correction.

It is desirable to prescribe for the dominant eye, so long as the acuity through the Ocutech is significantly better than the acuity of the non-dominant eye with the normal distance correction if any. If the non-dominant eye is the significantly better seeing eye, it is often necessary to at least partially occlude the dominant eye to aid sighting through the telescope

Individuals with macular degeneration or other central vision disorders may not fixate normally and as such using the traditional methods of measuring a monocular PD may not provide the optimum eyepiece position. Slight modifications to the eyepiece position may provide a fuller field of view and brighter image, so taking the few extra moments to confirm the ideal eyepiece correction can be quite valuable to insure the best performance of the device.

First, position the eyepiece directly above the eye that will be sighting through the telescope.

Second, have the patient dip their head and sight through the telescope to look at an acuity chart or other target across the room, and have them focus the telescope until it’s as clear as possible.

Third, while the patient is looking through the telescope, move the telescope right and left slightly to confirm whether a slight reposition of the eyepiece can provide a fuller field of view and brighter image.

Lastly, take the bioptic off the user’s head and using a millimeter ruler, measure from the center of the eyepiece to the center of the bridge to determine the ideal PD to position the telescope eyepiece.

For more information regarding fitting each of Ocutech’s bioptic telescope designs, please visit the individual product page for each device.

We recommend prescribing the normal distance Rx in the carrier lenses including a bifocal if it is habitually used. We recommend conventional flat-top or round-segment bifocals rather than progressive lenses. If no distance Rx is normally worn, plano lenses should be ordered.

We recommend at least 10mm between the bottom of the eyepiece and the top of the bifocal segment. Please see our frame catalog tech sheet that lists recommended maximum segment heights for all OCUTECH FRAMES.

Ocutech offers informational and instructional DVDs, patient information brochures and an active referral system for Ocutech prescribers. Ocutech also operates the Ocutech Ambassador Program which connects your prospective bioptic patients with experienced users so they can share their personal experiences using Ocutech Bioptic telescopes.