To Loupe or Not To Loupe? That is the Question!

Is magnification really, really necessary for successful strabismus surgery? May be not….. Does magnification benefit the surgeon who performs strabismus surgery? Yes!!

Advantages of Magnification

The surgeon sees the anatomy in more detail in the operative field – enabling more focused attention to finer detail – and contributing to:

• Accurate suture placement
• Awareness of small vessels making it easier to control bleeding
• Accurate identification of tissue layers
• Better visualization of sutures and needles
• Accurate needle placement, enabling a shallow “scleral tunnel” – avoiding scleral perforation

Methods to Achieve Magnification with Loupes

• Power 2.5x to 4.5x (2.5 okay for “younger eyes” but eventually 3.5x to 4.0x is the choice for older surgeons)
• Working Distance + 16″
• A light mounted on a head band and placed between the eyepieces of the loupe is an option many surgeons prefer – this light is especially useful for working in a “hole” such as when doing orbit surgery.

Types of Loupes

• A headband mounted light is a very useful adjunct to loupe magnification in that it improves the view when working in a “hole” and in cases where the surgeon’s or the assistant’s head blocks the fixed operating lights.
• Spectacle mounted loupes are the most popular. They should include distance correction and may have a small bifocal add.
• Presbyopic surgeons benefit from a small bifocal to see at near when looking around loupes
• Head band mounted loupes may be used while the surgeon wears spectacles. They may also be used by several different surgeons. Most surgeons who use loupes purchase the spectacle mounted type.

Want to know more or order magnification loupes? Contact AdmetecVision at www.admetec-vision.com, or call us at our toll-free number: 1-888-670-5063. Prefer to email? You can reach us at contact@admetec-vision.com.

Ready to make your purchase? You can order now online!

(Image courtesy of Wikipedia)

Why Loupes are a wise long-term investment

Since the 1980s, TV series such as Chicago Hope, Grey’s Anatomy, ER, and House M.D. have been featuring surgeons operating while wearing loupes. It makes the show look authentic and the doctors in it as highly regarded professionals. They use of the best equipment available in order to provide excellent care to their patients.

When it is time to buy loupes, an appealing frame looks is part of it. But the major consideration is how the optical equipment will perform and how will it stand up to everyday use.

The two most common types of loupe configurations available are flip-up and through-the-lens (TTL). Through-the-lens optics are customized to meet the clinician’s individual needs. They are permanently glued in place. The main advantages of using TTL loupes (compared to flip-ups) are:

1. The optics stay aligned
2. They are well-balanced
3. They are light-weight
4. They provide a wider field of vision (the optics are close to the eyes)

The TTL setup is similar to top-lined reading glasses where the wearer looks over the optic to view the room using distance vision and though the optic when viewing the patient’s mouth at close range.

Flip-up telescopes are adjustable. Some clinicians with strong prescriptions or bifocals therefore prefer flip-up telescopes because the optics can be flipped up and out of the way. When wearing flip-up telescopes, it is advised to use a head strap that is fastened securely around the wearer’s head. Flip-up loupes are adjustable and can be changed to different frames if wanted. It is easy to change a prescription in a flip-up loupe if the vision of the clinician changes.

Choosing a lower magnification level offers a wider field of vision and a more forgiving depth of field when looking through the optic area than higher magnification. Stronger telescopes zoom in to a narrow field and are difficult to work with independently.

When choosing optics make sure your loupes are:  light-weight, have a wide field of vision, have three-dimensional image qualities,and have very sharp high-resolution image. For these reasons, Admetec-Vision is often the preferred choice.

Good frames are made of titanium to pass the test of time and to ensure daily use. The purchase of a loupe is a long-term investment. It is important to buy a quality product that will stand up to daily use to prevent the need to repurchase in a short period of time.

Editorial note: The full  article was originally published in Hygiene Tribune US, Vol. 2, Issue 1, 2009.

The Use of Loupe Magnification In Microsurgery In The Third World: A Trinidad Experience

By: Maniram Ragbir, Consultant, Surgery, Plastic Surgery, General Hospital, POS, Trinidad

A  retrospective analysis was conducted of 38 patients in whom microvascular techniques were used for reconstruction at the General Hospital, Port-of-Spain.

Microsurgical techniques are applied to many aspects of reconstructive surgery. However, the operating microscope is still a very expensive piece of equipment and may not be readily available in the third world.

Microsurgical success with loupe magnification is well documented. In their publication, the authors analyze the effectiveness of microsurgical procedures performed in Trinidad over a 15 year period with the use of loupe magnification. Aim was to determine the effectiveness of microsurgery in the third world.

Methods and Results:

• A 15 year retrospective analysis of microsurgical procedures performed with the aid of loupe magnification was done at the General Hospital, Port-of-Spain, Trinidad.

•  There were a total of 38 cases, which included 12 replant surgeries; 12 free tissue transfers; 5 supercharged TRAM flaps; 4 facial nerve repairs; 5 peripheral nerve repairs with grafts.

•  The age range was 12 to 65 years with 23 males and 15 females. All procedures were performed by one of two trained microvascular surgeons with the aid of loupe magnification.

Complications included two failed hand replants, partial necrosis of one TRAM which was salvaged with a pedicled latissimus dorsi and minor necrosis of one latissimus dorsi flap.

Conclusion:
With appropriate training microsurgical procedures can be successfully performed with loupe magnification in the third world.

The use of loupe magnification in microsurgery was well justified in trained hands. Its use at this center is advocated on the grounds of cost effectiveness, portability, efficiency, and operator freedom. The purchase price of the instruments is nominal in comparison with the operating microscope.

(Source and image: Internet Scientific Publications http://www.ispub.com)

How to Choose Your Magnification Loupes – Part II

This blog post is an continuation of our previous post.

Test the working distance
The working distance refers to the distance between your eyes, and the patient’s mouth. You can measure this while assuming your normal working position, making sure you are: comfortable, that your back is straight, and that you are not leaning forward too much.

Perhaps you could ask someone to assist you in this procedure. You can also use the following overview to help determine the best working distance for your personal needs:

Height:
<170 cm (5ft 7 in) 170-190 cm (5ft 7 in to 6ft 4 in) >190 cm (6ft 4 in)

Sitting:
340 mm (14 in) 420 mm (16 in) 500 mm (20 in)

Standing:
420 mm (16 in) 500 mm (20 in) 550 mm (22in)

Check the field of view.
The field of view is the area that is visible and in focus, while looking through the loupes. A larger field of view is preferred, as there is a larger area visible through the loupes, and there is less need to move your head around . The size of the “field of view” also corresponds directly to the magnification factor.

A loupe with a lower magnification factor will have a larger field of view, and vice versa. All loupes utilize high performance lens systems that provide an extra wide field of view (up to 125mm / 4.9 inch).

Check the depth of view.
The depth of field is the depth of the area that is visible as well as  in-focus, while looking through the loupes. A larger depth of field is preferred, as there is a deeper area visible through the loupes. The size of the “depth of field” corresponds directly to the “working distance”.

A loupe with a longer working distance, will have a larger depth of field, and vice versa. The size of the “depth of field” also corresponds directly to the magnification factor.

A loupe with a lower magnification factor, will have a larger depth of field, and vice versa. All loupes utilize high performance lens systems that provide an extra large depth of field (up to 120mm / 4.7 inch).

Test the weight of the loupes.
Weight is an important factor when choosing a new loupe, especially if the loupe is to be used for longer periods of time. Lightweight loupes are more comfortable, and in the long term, will reduce tension and other complications. Ultra light weight loupes, offer the maximal comfort. All loupes utilize extremely light weight materials.

Regarding the Keperlilean loupes, these loupes are heavy. When choosing these, opt for the headband style, which will be comfortable for using a long time.

How to Choose Your Magnification Loupes – Part I

The first step is to choose the correct magnification and working distance to ensure that that you will work in ergonomically with your new loupe. Only with the correct working posture can you reduce eye strain, back / shoulder / neck tension, and stress-induced headaches. Furthermore, good ergonomics have shown to improve information processing and decision-making.

Low resolution, color distortion and flatness of the image should be avoided. Resolution is defined as the optical system’s ability to form distinguishable images of objects separated by small distances, or to recognize fine detail.

Looking with loupes at the testing objects and selecting an area of tiny details that can only be seen with magnification, is an excellent way to test loupes.

Chromatic aberration is an often-used term, referring to color distortion. Each color has a different wavelength and the first color that generally comes out of focus is blue. Quality loupes such as AdmetecVision’s do not show any blue haze just to the side of black lines on white paper.

Spherical aberration is another term that is often used. It refers to the flatness of the image. When viewed through quality loupes, an object will not exhibit any spherical aberrations as curved or spherical.

To evaluate loupes for their true optical performance, one must be trained to see the differences on such complex images. For most users, a simple piece of graph paper with black lines will suffice to reveal the difference between mediocre and high quality loupes.

The level of magnification used is mainly based on personal preferences. However, there are a few guidelines that are helpful for choosing the best magnification.  The lowest comfortable magnification level must be selected, since this will provide the widest field of view. There is some commonly used and recommended magnification for loupes:

Spectacle Surgical Loupes: An Essential Piece of Equipment for Surgeons

Over the years, we have seen a breakthrough in many surgical procedures. Surgeons nowadays need to work with precision where during an operation intricate details can be observed. In order to be sure that surgeons can meticulously observe all relevant details, spectacle surgical loupes are used. These are magnifying aids that are used without the using hands.

Loupes used by dentists as well as surgeons for during vascular, plastic and ENT surgery. In those cases, loupes are needed to view small arteries, nerves and tendons.

Surgical loupes have a range of magnifying degrees and the amount of magnifying necessary is dependent on the type of surgery being performed.

In general surgery, the degree of magnification required is around 2.5x. In specialized surgery, a higher magnification loupe of 5.5x is normally used. In general cardiac surgery, a loupe of 3.5x is common, while 4.5x to 5.5x loupes arte used in neurosurgery or tendon and hand operations. Loupes are also an integral part for screening sutures in micro surgery,

Magnification in loupes ranges from 2.5x to 5.5x with options for even higher degrees of magnification. All surgical loupes of AdmetecVision have exceptionally high resolution which enables surgeons to have a clear picture of the affected area when operating. This is possible due to the high grade lenses which are an integral part of the loupe. Light weight loupes are popular since they are more comfortable to wear during operations.

Surgeons and dentists are always checking the intensity of vision of their loupes. Although a wider field allows more clarity, any increase in loupe magnification also lowers the area of vision. Surgeons and dentists also have to decide how they want their loupes be mounted, e.g., spectacle, flip-up or head band.

Today surgeons need surgical loupe, regardless of the kind of surgery they are engaged in. They therefore need to conduct research on loupe manufacturers such as AdmetecVision before deciding which loupes will suit  their particular expertise.

Ideale Werkhoogte voor Tandartsen die een Loepbril Gebruiken

Voor het bepalen van de werkhoogte moet de werkstoel de houding van de tandarts goed ondersteunen. De hoofdsteun wordt verschillend ingesteld voor behandeling in de onderkaak of bovenkaak – immers, bij behandeling in de bovenkaak is indirect zicht vanaf de achterzijde van de patiënt. Voor een rechtshandige tandarts is de zitlocatie dan ook tussen 10.30 en 11.30 uur. Het occlusievlak van de bovenkaak wordt 20º/25º naar achteren gekanteld ten opzichte ten opzichte van de verticaal.

Bij de behandeling in de onderkaak vanaf de achterzijde van de patiënt wordt het occlusievlak van de onderkaak in een hoek van ca. 40º geplaatst ten opzichte van de horizontaal.

Plaatsing van armen en handen is van groot belang. De bovenarmen zijn naast de romp en mogen tijdens het werk maximaal 10º naar voren gaan om de belasting op de armen en de schoudergordel tot een minimum te beperken.

Uitgaande van een horizontale lijn is de hoek 90º tussen boven- en onderarmen. De onderarmen worden tijdens het werk minimaal 10º en maximaal 25º omhoog geheven. Voor het bepalen van de werkhoogte zijn de onderarmen ca. 10-15º omhoog t.o.v. de horizontaal.

De plaats waar de handen zich nu bevinden wordt ook wel de boekleesstand genoemd. De kijkafstand is comfortabel en het is mogelijk vanuit een optimale lichaamshouding zicht te verkrijgen op het werkveld.

De afstand van de ogen tot het werkveld is hierbij 35-40 cm voor een tandarts met een gemiddelde lengte. Bij gebruik van een werkbril/loepbril moet de bril dus op deze werkafstand aangemeten zijn. Vaak worden werkbrillen op een te kleine werkafstand aangemeten waardoor de tandarts gedwongen wordt in een ongunstige houding te werken. Dit is eenvoudig zelf na te gaan door op te meten op welke afstand men scherp zicht heeft met de werkbril.

Bij veel brillen ter correctie van bijziendheid wordt een extra positieve correctie toegepast om een vergroting van het werkveld te verkrijgen. Dit heeft ten gevolge een kortere werkafstand wat ongunstig is voor de werkhouding.

(Bron en afbeelding: Medisch Ondernemen)

A Short History of Surgical Loupes

In their book The History of Modern Cataract Surgery, Marvin L. Kwitko and Charles D. Kelman describe the history of surgical loupes.

The first surgical loupes date back to 1876 and consisted of simple loupes attached to a spectacle frame or a headband. These were made of convex lenses that were decentered to allow convergence and to use the prismatic effects of the periphery. Carl von Hess used such a loupe together with an electrical illumination device attached to a headband.

In 1886, a mechanic named Westien constructed a binocular instrument from two loupes to be used by a zoologist. Von Zehender later attempted to modify these loupes for use in ophthalmology, and the Zehender-Westien double loupe was born. It had a firm base and a lens for lateral focal illumination.

Further development of a binocular magnifying instrument progressed along two pathways: one for diagnostic purposes and one for surgical use, leading to the eventual development of the slit-lamp and the corneal microscope.

By 1912, Von Rohr and Stock had constructed a spectacle loupe that was lighter and less magnifying than Westien’s. It had a working distance of 25 cm and a magnification of 2X. Gullstrand was the first to use these loupes starting the development of a binocular loupe that could be attached to spectacles and bifocals. This model is still used today by ophthalmic surgeons for a variety of surgical procedures. By simply tilting his or her head, the surgeon can view the field either through the spectacle lens or through the loupes. This allows for only using the magnification when needed. However, It a magnification of more than 2X was not practical, due to the fact that the slightest movement of the head would cause large movements of the image in high magnification. Furthermore, optical principles prevented a magnification of more than 2X with these loupes.

For years, the selection of loupes was limited, but loupes from innovators such as Admetec-Vision are lightweight and have stylish frames.  Magnification loupes range from entry-level models to loupes with highly sophisticated optical systems. So the choice is yours.

(To read the original chapter online on Google books, please click here)

Operation Loupes and Headlight Were Used as Visual Aids during Cauda Equina Syndrome Operations

Cauda Equina Syndrome (CES) appeared as a postoperative complication in five patients that were operated on for lumbar disc herniation.

The study consisted of a retrospective analysis of records and radiographs in five patients who developed acute cauda equina syndrome after surgery for lumbar disc herniation.

The objective of the study was to postulate as a possible pathophysiologic mechanism the venous congestion caused by preexisting spinal stenosis and to present a management plan: extended decompression within 48 hours.

Cauda equina syndrome is reported as a sequela in 0.2%–1% of the surgeries for lumbar disc herniation. There is, however, no consensus on the possible pathophysiologic mechanism to the complication or to its management.

Methods uses for preoperative investigations consisted of magnetic resonance imaging, or myelography and computed tomography. There was a good correlation between clinical appearance and radiographic findings in all patients. When the complication became apparent in four of the patients, they were investigated with magnetic resonance imaging and reoperated on within 48 hours with wide decompressions.

During the operation, surgical loupes and headlights were used as visual aids. The index operation was reported uneventful in all patients. Postoperative magnetic resonance imaging did not show the cause of the cauda equina syndrome, nor could this be established at the reoperation.

Before surgery, all five patients had preexisting narrowing of the spinal canal. In no case was the lumbosacral disc the index level. Two patients recovered fully, whereas the other three experienced varying degrees of residual symptoms. There was no correlation between the end result and the delay until secondary decompression.

The researchers concluded that relative spinal stenosis may contribute to the development of cauda equina syndrome after surgery for lumbar disc herniation. A venous congestion can be triggered by postoperative edema, leading to nerve root ischemia. The treatment of choice seems to be extended decompression within 48 hours.

(Source: Henriques, Thomas MD*; Olerud, Claes MD, PhD*; Petrén-Mallmin, Marianne MD, PhD†; Ahl, Torbjörn MD, PhD Spine Journal Volume 26 – Issue 3 – pp 293-297)

About Telescopes-Through-The- Lens or TTL Loupes

TTL (telescopes through the lens) means that the telescopes are positioned in the lens of the spectacles supporting it in such a way that the eyepiece is at an optimal distance from the pupil with nothing in-between. This gives excellent optical quality and a wide field of vision.

Opting for TTL loupes comes down to a personal preference.  TTL loupes are usually lighter and less bulky than flip-up loupes. In contrast to flip-ups, TTL loupes cannot be moved out of the line of sight. The main benefit of TTL loupes is their closer position to the eye. This enables a wider field of view. The only disadvantage is that peripheral vision is less when reaching for instruments. TTL loupes are customized to the needs of the individual dentist, surgeon, veterinarian, or dental hygienist.

AdmetecVision’s loupes are highly customizable, e.g., for inter-pupil distance, working distance and declination angle. Other custom design settings include dioptric correction which is a demand from any medical professional using his/her magnification tool for long periods of time.

What are the main benefits of dental or surgical loupes? To quote dentist Dr. Jörg Werner:

1)         to see more is to know more

2)         to see more enables more accurate treatment

3)         to see more translates into crystal clear precision

4)         to see more leads to higher quality

5)         to see more means better control

6)         to see more enables application of the latest treatment methods

7)         to see more benefits patients

Want to know more?

Contact AdmetecVision at www.admetec-vision.com, or call us at our toll-free number: 1-888-670-5063. You can also email us at contact@admetec-vision.com. Ready to make a purchase? You can order now online!