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Recent advances in retinal detachment and vitreous surgery
Recent advances in retinal detachment and vitreous surgery H MacKenzie Freeman, MD
During the past ten years there has been an impressive improvement in the surgical results in the treatment of retinal detachment. Exciting developments in surgical instrumentation and operative techniques within the past five years offer hope for vision in cases that were considered inoperable only a short time ago. This report will describe the pathogenesis, incidence, symptoms, diagnosis and recent advances in the surgical management of retinal detachment.
Pathogenesis of retinal detachment. The eye may be compared to a camera, where the lens focuses the H MacKenzie Freeman. MD, is an assistant clinical professor of ophthalmology a t Harvard Medical School, assistant surgeon a t the Massachusetts Eye and Ear Infirmary and a clinical senior scientist at the Retina Foundation, Boston. Dr Freeman received his MD degree from the University of Alberta, Edmonton. For the past I I years he has specialized in retinal detachment surgery. D r Freeman spoke on retinal detachment and vitreous surgery a t the 1973 AORN Congress.
896
picture on a sensitive film (Fig 1). In the human eye, the cornea (transparent tissue resembling a watch crystal) and the lens focus images on the retina, which is a thin light-sen& tive film located at the back of the eye (Fig 2). The picture which is registered in the retina is transmitted to the brain by the optic nerve. The space between the lens and retina is filled with a transparent jelly called vitreous body. Aging and other damage may cause the vitreous body to shrink. If, in the process of shrinking, the vitreous body remains attached to the retina in one area, it may tear the retina (Fig 3). A retinal tear is often the prelude to a retinal detachment. Fluid which has replaced the shrunken jelly of the vitreous body floats off the retina and accumulates between it and the wall of the eye (Fig 4). The detached retina, being separated from part of its blood supply, becomes insensitive to light, thus resulting in gradual blindness.
AORN Journal, November 1973, Vol18, No 5
Incidence of retinal detachment. Retinal detachment occurs in one of eight thousand persons each year. Persons that develop a retinal detachment have approximately a 25 Sb chance of developing one in the other eye, although the retinal detachments do not necessarily develop simultaneously. Most retinal detachments develop spontaneously and a small percentage occur following head or eye injury. Retinal detachment may occur at any age, however it occurs most commonly during the ages of 55 to 65 years in males and between 60 and 70 years of age in females. Symptoms. Retinal detachment results in a painless loss of vision. The shrinkage of vitreous often produces extensive flashes of light in the eye. Sudden floaters or specks moving around in the eye may also be noted, but fortunately vitreous shrinkage is seldom followed by further difficulties. A retinal break may develop spontaneously, or it may m u r as a result of injury. Many retinal breaks develop without any warning signs. However, a retinal tear or a very
Fig 1 . The human eye is like a camera lens which focuses an image on film. The cornea a n d crystalline lens, f i g 2, focus an image on the light sensitive retina.
early retinal detachment is sometimes accompanied by a limited flicker of light which remains in a definite location in the field of vision. reak in retina
umulates
tic nerve \
Fig 3. A retinal break caused by shrinkage of the vitreous body is often the prelude t o a retinal detachment.
Fig 4. Fluid which replaces the vitreous g e l floats off the retina a n d detaches it from the w a l l of the eye.
AORN Journal, November 1973, Vol18, N o 5
897
Break in extreme peripklery is hard to see More posterior break is easier to see Fig 5. Two retinal breaksone in the posterior section which is easier to see, and one in the extreme periphery which is impossible to see without the aid of a scleral depressor. Failure to treat both breaks would result in surgical failure to reattach the retina.
Fig 6. The small pupil ophfhalmoscdpe has improved examination and diagnostic procedures for retinal detachment.
Fig 7. Using a scleral depressor, the eye surgeon presses gently on the patient's eyeball in order t o push the peripheral areas info view.
Tearing of the retina may also be accompanied by bleeding which causes brown or black specks inside the eye. Patients often compare this with falling soot or looking through a cobweb. When the retina starts detaching, a definite curtain may appear on one side in the field of vision. Later, when the central portion of the retina becomes affected by an early retinal detachment, vision is distorted and it seems as though the patient is looking through water.
Diagnosis. The diagnosis of a retinal detachment is made with a binocular indirect ophthalmoscope which permits a three dimensional view of the retina. This instrument enables the ophthalmologist to detect the elevation of retina from its normal attachment and find the retinal breaks which cause the retina to detach. Once the diagnosis has been made, the importance of a thorough preoperative ophthalmoscopic examination cannot be overemphasized. With a retinal detachment, the exact location, number, and nature of retinal breaks are essential factors which must be learned before the proper type of surgery can be determined. Retinal breaks are generally small and located in the periphery of the retina (Fig 5) where the retina is thinner and examination is often difficult. Therefore, detection may require a long and diligent search. A new refined instrument called the small pupil ophthalmoscope (Fig 6 ) , along with a scleral depressor (Fig 7), has now made it possible for the eye surgeon to obtain a binocular view of the total fundus of the eye from the optic nerve to the far periphery with a maximum possible il-
lumination. The new ophthalmoscope has the additional advantage of being useful even when the patient’s pupil is small or clouded by opacities. With the aid of these devices, the physician makes a precise mapping of the patient’s retina which serves as a blueprint for his surgery.
Treatment. A. Treatment of retinal detach-
ment before retinal detachment develops. If a retinal break is discovered before it has a chance to cause a retinal detachment, this break can be sealed nonsurgically, ie, without having to cut the eye tissues. Preventive surgery often avoids more extensive types of operations that are necessary for the repair of a retinal detachment. Photoeoagulation and cry0 applications are methods which can be used to seal retinal breaks before the retina becomes detached. Photocoagulation is a method of making a small, controlled burn in the retina by
Fig 8. The useful range of preventive cryosurgery is anterior to globe.
the equator of fhe
shining a very bright relatively strong light through the patient’s pupil. These tiny burns heal with a
AORN Journal, November 1973, V o l 1 8 , N o 5
899
f
Light
Fig 9. The useful range of photocoagulation is the posterior half of the globe (arrows).
scar which tends to seal the retinal break. This treatment “spot welds” the retina back to the wall of the eye. Another method for scarring the retina to seal the retina1 break is to cause small, controlled frostbite damage to the retina by applying cry0 applications with a cold probe to the outer wall of the eye. Cryosurgery is preferred for the preventive treatment of retinal breaks located in the front half of the eyeball (Fig 8 ) . The tip of the cold probe, where freezing occurs, can be applied to the outside of the eyeball in the areas corresponding to the anterior half of the eye. The recess existing between the eyeball and the eyelid allows the cryoprobe tip to be applied t o the eyeball as far back as its equator. As shown in Fig 9, light from a photocoagulator is easily focused on those portions of the retina located in the back half of the eyeball. Due to the curvature of the eyeball and the presence of the colored iris, light cannot be focused efficiently on the front half of the retina. For each patient the method preferred may depend on the location of the retinal breaks to be treated.
B. Treatment of retinal detachment. The aim in retinal detachment surgery is to seal the retinal break, reattach the retina, and prevent the
900
retina from redetaching. One technique of retinal detachment surgery is termed scleral buckling. The area of the retinal break is first treated with diathermy or cryosurgery. Then fluid that accumulated under the retina is released and the wall of the eye is indented or buckled t o bring i t in contact with the detached retina. The internal hump or “buckle” is created by means of a tiny piece of silicone rubber implanted in or on the sclera a t points corresponding to the breaks in the retina (Fig 10). Scleral buckling creates a high and permanent ridge in the eye which facilitates sealing of the retinal breaks, and minimizes traction exerted on the retina. This is particularly useful when vitreous traction holds the retina in a detached position. In cases where the vitreous gel is exerting traction on the retina, the silicone implanted in the sclera is placed under a silicone belt, called a circling element. The fluid under the retina is released by perforating the sclera with a fine needle a t a point posterior to the retinal break. Once the fluid has been drained, the circling element is gently tightened (Fig 11).The purpose of this tiny belt is to permanently maintain the indentation of the eye’s configuration, thereby relieving any internal traction caused by stretched vitreous bands and membranes (Fig 12). If the buckle is correctly placed,
AORN Journal, November 1973, Vol 18, N o 5
Silicone rubber
Fig 10. After placement of diathermy over the location of refinal breaks, a small piece of specially moJded silicone rubber is embedded in the sclera and maintained in place with a tiny belt. Subretinal fluid is released.
Sutures are gently tightened after release of subretinal fluid Point posterior to the retinal break,where subretinal fluid is released
Fig 7 1 . Side view showing how circling band is used to permanently maintain the indented configuration.
Fig 12. Following the release of the subretinal fluid, the sutures on the sclera over the plastic implant and the circling element are gently tightened, thereby reattaching the retina.
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Fig 73. The torn retina (from 9 t o 3 o'clock) is folded over on top of itself (see arrow), and cannot be reaftached as long as it remains in that position.
Fig 74. Gravify is used to' unfold a giant retinal tear by anchoring the patient to a motor driven operating table that can be tilted in multiple positions, even upside down. Dr Freeman is shown preoperatively determining the position that will be most likely to unfold the tear. (Ralph Morse, Time/Life Picture Agency, 7969 Time, Inc.)
the membranes that pull on the retina exert less traction and there is less chance that the retina will detach. C. Mctnagcment of a giant retinal tcar. 1. The giant tear operating table.
Most retinal tears are about the size of the tip of a lead pencil. In some cases, however, the retina becomes extensively torn to produce a “giant retinal tear,” which is 100 to 200 times larger than in the usual case. Gravity causes the upper edge of a giant tear to become folded over on top of itself, and the torn retina cannot be reattached as long as it remains in that position (Fig 13). The treatment of a giant retinal tear continues to be one of the most difficult and challenging problems in eye surgery. A special motor-driven giant tear operating table was developed a t the Retina Foundation. This table utilizes the force of gravity to unfold the retina of a giant tear. The patient is anchored to the table with straps placed across his legs, abdomen, and chest. These straps are similar to safety belts used in automobiles (Fig 14). The first part of
the operation is performed with the patient in the face-up position. Midway through the operation the table is raised and turned so that the patient is rotated around 180 degrees to the face-down position. In that position, gravity acts to unfold the retina so that it can be reattached surgically. Beneath the inverted patient, the surgeon and his assistants operate either sitting on stools or kneeling on the floor. It takes about 45 minutes to surgically secure the unfolded retina in place. After this critical period the patient is rotated back to the face-up position for completion of the operation. The entire operation may last as long as seven hours. 2. The intraocular balloon. In some cases of giant retinal tears, scar tissue develops between the folded retina of a giant tear and the underlying retina. When this happens, use of the giant tear (“upside down”) operating table is not sufficent to unfold the retina. It was necessary for surgeons to find a technique of breaking through the adhesions formed by scar tissue
Fig 75. W h e n the torn retina is folded over and stuck down to the underlying retina, it cannot be unfolded by gravity. A tiny rubber balloon is inserted into the eye beneath the fold. The balloon is further inflated and used a s a soft tissue probe to break adhesions which immobilize the retina.
903
3. Vitreous scissors. In some cases of retinal detachment the vitreous will give rise to Scar tissue-like bands which exert traction on the retina preventing it from being reattached by scleral buckling. These bands accounted for many failures in retinal detachment surgery. A pair of miniaturized Scissors was developed for cutting the vitreous bands (Fig 17). The part of the scissors that enters the eye is thinner than a dime. Once the vitreous bands are cut the retina can be reattached in many cases. Fig 76. Once the adhesions have been broken, the balloon is used to unfold the retina.
without destroying or harming the delicate retina. For this purpose, a soft tissue probe in the form of a tiny intraocular balloon was developed. The balloon was first tested successfully in blind collie dogs which are well cared for and studied a t the Retina Foundation’s farm in Townsend, Mass. A survey of 14,000 collie dogs in the United States revealed that giant retinal tears are 85 times more common in collies than in humans. Some collies were successfully treated and, most important, it was learned that the fragile retina was not damaged by gentle contact with the balloon. Today the balloon is used in human cases of giant retinal tears which only a few years ago were considered hopeless and inoperable. The balloon is carefully slipped underneath the overlapped retina (Fig 15) and then inflated and gently used to break through the adhesions and unfold the retina back into place (Fig 16).
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4. Vitreous nibbler (vitreous infusion suction cutter). The normal
vitreous is transparent, permitting the passage of light rays to stimulate the retina and produce vision. In some persons the vitreous will lose its transparency as a result of membranes, hemorrhage from the retinal blood vessels, or chemical changes resulting in loss of vision. An article in this JournaZ on pars plana vitrectomy describes an instrument developed by Dr Machemer which grinds up the opaque vitreous or blood and suctions it from the eye while simultaneously refilling the vitreous cavity with physiologic saline. The instrument is like a “RotoRooter” which suctions out clogged drains. Results with this instrument are impressive. Research at the Retina Foundation with vitreous nibblers may have application for the removal of cataracts in underdeveloped nations. Surgeons from India asked us to adapt the “RotoRooter” instrument for use in cataract extraction. In India, with a population of about 550 million people, cataracts are very common. Literally millions of Indians are blind because there are not enough hospital beds, surgeons, or operating rooms.
AORN Journal, November 1973, Vol 18, N o 5
Many who develop cataracts in both eyes cannot see to carry on their work, to farm their little plots of land, and they die of malnutrition in about 18 months. Surgeons in India now conduct eye camps which move from city to city. Public buildings, such as schools, are used for the operations. The blind are brought to the eye camps by guides who charge a penny for the service. Many Indians do not have even that penny, and may not receive eye care. As news of the eye camp spreads, one side of the road near it is lined for a mile with male patients waiting to have cataracts removed; the other side contains a mile-long line of female patients. The blind hold onto the person in front of them forming a human chain. When the eye camp is out of supplies, and when it has treated all the patients it can, those in the lines are told to come back next year. Surgeons operate in school rooms with a flashlight. Ten surgical teams work simultaneously devoting about six minutes to each operation. Since current cataract procedures involve a
Fig 77. The slippery vitreous band-like membrane that prevents the retina from being reattached may be cut more easily with a miniaturized scissors than with a knife. The scissors used is so small that the part that enters the eye is thinner than a dime.
relatively large incision and sutures are often not available, the patient must lie very still after surgery. The patient goes to a large room where he must lie still for three or four days on a mat on the floor in eight square feet of space. Thus, valuable “hospital beds” are used because hospitals do not have enough money to pay for sutures to close this incision. The immediate solution for this great problem is not t o build more hospitals; that would cost billions of dollars which India cannot afford. One solution may be to develop cataract extraction techniques which surgeons can use to help the greatest number of people possible within existing conditions of a shortage of operating rooms and hospital beds. Using the vitreous suction cutter for cataract removal would eliminate the need for a large incision in the eye and help Indian surgeons serve more patients. The cataract could be removed through a tiny incision and the patient could go home to recuperate. Though such a technique would probably not give as good a visual result as conventional techniques of cataract extraction currently used in
North America, it would make possible the restoration of some useful vision in a greater number of those blind in India.
Summary. Pathogenesis: Retinal detachment is caused by a tear or hole in the retina which allows fluid vitreous to pass behind the retina to detach it from the inside of the back of the eye.
Symptomatobgy: Symptoms of retinal detachment are a painless loss of vision which may be preceded by floaters, black specks, flashes'of light or distorted vision in the affected eye.
Diagnosis: The diagnosis is made using the binocular indirect ophthalmoscope and scleral depressor which pushes the hidden areas of the retina into the view of the ophthalmoscope. Preventive Treatment: If a retinal tear is discovered before i t produces a retinal detachment, the tear may be sealed nonsurgically with photocoagulation or cry0 (freezing) applications. Surgical Treatment of Retinal Detachment: The aim of treatment is to find all the retinal tears, seal them and attempt to prevent additional tears from developing. One method to accomplish this is the scleral buckling operation. Fluid is drained from behind the retina, then the wall of the eye is buckled inwards by implanting a plastic rubber implant within or on the surface of the x l e r a (white fibrous outer coat of the eye).
Giant Retinal Tears: Giant retinal tears can be unfolded by turning the patient upside down on a special
906
rotating operating table or with a tiny balloon used as a probe.
Vitreous Nibbler: Vitreous opacities or blood which obliterate vision may be successfully removed from the eye using a vitreous nibbler. ACKNOWLEDGMENTS The development and refinements o f surgical techniques were done as a joint effort b y the Retina Associates-Charles L Schepens, lchiro D Okarnura, Robert J Brockhurst, Wallace J McMeel, H MacKenzie Freeman, Felipe I Tolentino.
MD, Ronald C Pruett, and
Clinical and basic research leading t o the development o f the surgical advances described was carried out b y a team o f investigators o f the Department o f Retina Research o f the Retina Foundation stimulated and guided by i t s director, Charles L Schepens, MD. The group includes Angelica Anastopoulou, MD, Mohammad Ashrafzadeh, MD, Muhammad Chishti, MD, Ian Constable, MD, Glynne Coulvillion, MD, Sachico Hamada, MD, Felipe Huamonte, MD, Chan-bok Lee, MD, Pei-fei Lee, MD, Hsiao-su Liu, MD. Gustavo Morales, MD, Felipe Tolentino, MD, O l e g Pornerantzeff, D Eng, Anton Banko and Robert Thompson. Illustrations were prepared by David Tilden; photography was done by Roger Lancaster.
A AN A officers elec+ed Newly elected officers of the American Association of Nurse Anesthetists, announced at its recent national meeting in Chicago, are: president, Goldie D Brangman; president-elect, Mildred C Rumpf; vice-president, Dolores E Biggins; treasurer, Alverna M Skoog; trustee region 1, Miriam H Hagy, trustee region 4, Helen H Hart; trustee region 5, Ronald F Caulk. Officers serving for the second term are: trustee region 2, Pauline W Hester; trustee region 3, Ruth E Ecklund; trustee region 6, E Jean Duwall.
AORN Journal, November 1973, Vol 18, N o 5
During the past ten years there has been an impressive improvement in the surgical results in the treatment of retinal detachment. Exciting developments in surgical instrumentation and operative techniques within the past five years offer hope for vision in cases that were considered inoperable only a short time ago. This report will describe the pathogenesis, incidence, symptoms, diagnosis and recent advances in the surgical management of retinal detachment.
Pathogenesis of retinal detachment. The eye may be compared to a camera, where the lens focuses the H MacKenzie Freeman. MD, is an assistant clinical professor of ophthalmology a t Harvard Medical School, assistant surgeon a t the Massachusetts Eye and Ear Infirmary and a clinical senior scientist at the Retina Foundation, Boston. Dr Freeman received his MD degree from the University of Alberta, Edmonton. For the past I I years he has specialized in retinal detachment surgery. D r Freeman spoke on retinal detachment and vitreous surgery a t the 1973 AORN Congress.
896
picture on a sensitive film (Fig 1). In the human eye, the cornea (transparent tissue resembling a watch crystal) and the lens focus images on the retina, which is a thin light-sen& tive film located at the back of the eye (Fig 2). The picture which is registered in the retina is transmitted to the brain by the optic nerve. The space between the lens and retina is filled with a transparent jelly called vitreous body. Aging and other damage may cause the vitreous body to shrink. If, in the process of shrinking, the vitreous body remains attached to the retina in one area, it may tear the retina (Fig 3). A retinal tear is often the prelude to a retinal detachment. Fluid which has replaced the shrunken jelly of the vitreous body floats off the retina and accumulates between it and the wall of the eye (Fig 4). The detached retina, being separated from part of its blood supply, becomes insensitive to light, thus resulting in gradual blindness.
AORN Journal, November 1973, Vol18, No 5
Incidence of retinal detachment. Retinal detachment occurs in one of eight thousand persons each year. Persons that develop a retinal detachment have approximately a 25 Sb chance of developing one in the other eye, although the retinal detachments do not necessarily develop simultaneously. Most retinal detachments develop spontaneously and a small percentage occur following head or eye injury. Retinal detachment may occur at any age, however it occurs most commonly during the ages of 55 to 65 years in males and between 60 and 70 years of age in females. Symptoms. Retinal detachment results in a painless loss of vision. The shrinkage of vitreous often produces extensive flashes of light in the eye. Sudden floaters or specks moving around in the eye may also be noted, but fortunately vitreous shrinkage is seldom followed by further difficulties. A retinal break may develop spontaneously, or it may m u r as a result of injury. Many retinal breaks develop without any warning signs. However, a retinal tear or a very
Fig 1 . The human eye is like a camera lens which focuses an image on film. The cornea a n d crystalline lens, f i g 2, focus an image on the light sensitive retina.
early retinal detachment is sometimes accompanied by a limited flicker of light which remains in a definite location in the field of vision. reak in retina
umulates
tic nerve \
Fig 3. A retinal break caused by shrinkage of the vitreous body is often the prelude t o a retinal detachment.
Fig 4. Fluid which replaces the vitreous g e l floats off the retina a n d detaches it from the w a l l of the eye.
AORN Journal, November 1973, Vol18, N o 5
897
Break in extreme peripklery is hard to see More posterior break is easier to see Fig 5. Two retinal breaksone in the posterior section which is easier to see, and one in the extreme periphery which is impossible to see without the aid of a scleral depressor. Failure to treat both breaks would result in surgical failure to reattach the retina.
Fig 6. The small pupil ophfhalmoscdpe has improved examination and diagnostic procedures for retinal detachment.
Fig 7. Using a scleral depressor, the eye surgeon presses gently on the patient's eyeball in order t o push the peripheral areas info view.
Tearing of the retina may also be accompanied by bleeding which causes brown or black specks inside the eye. Patients often compare this with falling soot or looking through a cobweb. When the retina starts detaching, a definite curtain may appear on one side in the field of vision. Later, when the central portion of the retina becomes affected by an early retinal detachment, vision is distorted and it seems as though the patient is looking through water.
Diagnosis. The diagnosis of a retinal detachment is made with a binocular indirect ophthalmoscope which permits a three dimensional view of the retina. This instrument enables the ophthalmologist to detect the elevation of retina from its normal attachment and find the retinal breaks which cause the retina to detach. Once the diagnosis has been made, the importance of a thorough preoperative ophthalmoscopic examination cannot be overemphasized. With a retinal detachment, the exact location, number, and nature of retinal breaks are essential factors which must be learned before the proper type of surgery can be determined. Retinal breaks are generally small and located in the periphery of the retina (Fig 5) where the retina is thinner and examination is often difficult. Therefore, detection may require a long and diligent search. A new refined instrument called the small pupil ophthalmoscope (Fig 6 ) , along with a scleral depressor (Fig 7), has now made it possible for the eye surgeon to obtain a binocular view of the total fundus of the eye from the optic nerve to the far periphery with a maximum possible il-
lumination. The new ophthalmoscope has the additional advantage of being useful even when the patient’s pupil is small or clouded by opacities. With the aid of these devices, the physician makes a precise mapping of the patient’s retina which serves as a blueprint for his surgery.
Treatment. A. Treatment of retinal detach-
ment before retinal detachment develops. If a retinal break is discovered before it has a chance to cause a retinal detachment, this break can be sealed nonsurgically, ie, without having to cut the eye tissues. Preventive surgery often avoids more extensive types of operations that are necessary for the repair of a retinal detachment. Photoeoagulation and cry0 applications are methods which can be used to seal retinal breaks before the retina becomes detached. Photocoagulation is a method of making a small, controlled burn in the retina by
Fig 8. The useful range of preventive cryosurgery is anterior to globe.
the equator of fhe
shining a very bright relatively strong light through the patient’s pupil. These tiny burns heal with a
AORN Journal, November 1973, V o l 1 8 , N o 5
899
f
Light
Fig 9. The useful range of photocoagulation is the posterior half of the globe (arrows).
scar which tends to seal the retinal break. This treatment “spot welds” the retina back to the wall of the eye. Another method for scarring the retina to seal the retina1 break is to cause small, controlled frostbite damage to the retina by applying cry0 applications with a cold probe to the outer wall of the eye. Cryosurgery is preferred for the preventive treatment of retinal breaks located in the front half of the eyeball (Fig 8 ) . The tip of the cold probe, where freezing occurs, can be applied to the outside of the eyeball in the areas corresponding to the anterior half of the eye. The recess existing between the eyeball and the eyelid allows the cryoprobe tip to be applied t o the eyeball as far back as its equator. As shown in Fig 9, light from a photocoagulator is easily focused on those portions of the retina located in the back half of the eyeball. Due to the curvature of the eyeball and the presence of the colored iris, light cannot be focused efficiently on the front half of the retina. For each patient the method preferred may depend on the location of the retinal breaks to be treated.
B. Treatment of retinal detachment. The aim in retinal detachment surgery is to seal the retinal break, reattach the retina, and prevent the
900
retina from redetaching. One technique of retinal detachment surgery is termed scleral buckling. The area of the retinal break is first treated with diathermy or cryosurgery. Then fluid that accumulated under the retina is released and the wall of the eye is indented or buckled t o bring i t in contact with the detached retina. The internal hump or “buckle” is created by means of a tiny piece of silicone rubber implanted in or on the sclera a t points corresponding to the breaks in the retina (Fig 10). Scleral buckling creates a high and permanent ridge in the eye which facilitates sealing of the retinal breaks, and minimizes traction exerted on the retina. This is particularly useful when vitreous traction holds the retina in a detached position. In cases where the vitreous gel is exerting traction on the retina, the silicone implanted in the sclera is placed under a silicone belt, called a circling element. The fluid under the retina is released by perforating the sclera with a fine needle a t a point posterior to the retinal break. Once the fluid has been drained, the circling element is gently tightened (Fig 11).The purpose of this tiny belt is to permanently maintain the indentation of the eye’s configuration, thereby relieving any internal traction caused by stretched vitreous bands and membranes (Fig 12). If the buckle is correctly placed,
AORN Journal, November 1973, Vol 18, N o 5
Silicone rubber
Fig 10. After placement of diathermy over the location of refinal breaks, a small piece of specially moJded silicone rubber is embedded in the sclera and maintained in place with a tiny belt. Subretinal fluid is released.
Sutures are gently tightened after release of subretinal fluid Point posterior to the retinal break,where subretinal fluid is released
Fig 7 1 . Side view showing how circling band is used to permanently maintain the indented configuration.
Fig 12. Following the release of the subretinal fluid, the sutures on the sclera over the plastic implant and the circling element are gently tightened, thereby reattaching the retina.
901
Fig 73. The torn retina (from 9 t o 3 o'clock) is folded over on top of itself (see arrow), and cannot be reaftached as long as it remains in that position.
Fig 74. Gravify is used to' unfold a giant retinal tear by anchoring the patient to a motor driven operating table that can be tilted in multiple positions, even upside down. Dr Freeman is shown preoperatively determining the position that will be most likely to unfold the tear. (Ralph Morse, Time/Life Picture Agency, 7969 Time, Inc.)
the membranes that pull on the retina exert less traction and there is less chance that the retina will detach. C. Mctnagcment of a giant retinal tcar. 1. The giant tear operating table.
Most retinal tears are about the size of the tip of a lead pencil. In some cases, however, the retina becomes extensively torn to produce a “giant retinal tear,” which is 100 to 200 times larger than in the usual case. Gravity causes the upper edge of a giant tear to become folded over on top of itself, and the torn retina cannot be reattached as long as it remains in that position (Fig 13). The treatment of a giant retinal tear continues to be one of the most difficult and challenging problems in eye surgery. A special motor-driven giant tear operating table was developed a t the Retina Foundation. This table utilizes the force of gravity to unfold the retina of a giant tear. The patient is anchored to the table with straps placed across his legs, abdomen, and chest. These straps are similar to safety belts used in automobiles (Fig 14). The first part of
the operation is performed with the patient in the face-up position. Midway through the operation the table is raised and turned so that the patient is rotated around 180 degrees to the face-down position. In that position, gravity acts to unfold the retina so that it can be reattached surgically. Beneath the inverted patient, the surgeon and his assistants operate either sitting on stools or kneeling on the floor. It takes about 45 minutes to surgically secure the unfolded retina in place. After this critical period the patient is rotated back to the face-up position for completion of the operation. The entire operation may last as long as seven hours. 2. The intraocular balloon. In some cases of giant retinal tears, scar tissue develops between the folded retina of a giant tear and the underlying retina. When this happens, use of the giant tear (“upside down”) operating table is not sufficent to unfold the retina. It was necessary for surgeons to find a technique of breaking through the adhesions formed by scar tissue
Fig 75. W h e n the torn retina is folded over and stuck down to the underlying retina, it cannot be unfolded by gravity. A tiny rubber balloon is inserted into the eye beneath the fold. The balloon is further inflated and used a s a soft tissue probe to break adhesions which immobilize the retina.
903
3. Vitreous scissors. In some cases of retinal detachment the vitreous will give rise to Scar tissue-like bands which exert traction on the retina preventing it from being reattached by scleral buckling. These bands accounted for many failures in retinal detachment surgery. A pair of miniaturized Scissors was developed for cutting the vitreous bands (Fig 17). The part of the scissors that enters the eye is thinner than a dime. Once the vitreous bands are cut the retina can be reattached in many cases. Fig 76. Once the adhesions have been broken, the balloon is used to unfold the retina.
without destroying or harming the delicate retina. For this purpose, a soft tissue probe in the form of a tiny intraocular balloon was developed. The balloon was first tested successfully in blind collie dogs which are well cared for and studied a t the Retina Foundation’s farm in Townsend, Mass. A survey of 14,000 collie dogs in the United States revealed that giant retinal tears are 85 times more common in collies than in humans. Some collies were successfully treated and, most important, it was learned that the fragile retina was not damaged by gentle contact with the balloon. Today the balloon is used in human cases of giant retinal tears which only a few years ago were considered hopeless and inoperable. The balloon is carefully slipped underneath the overlapped retina (Fig 15) and then inflated and gently used to break through the adhesions and unfold the retina back into place (Fig 16).
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4. Vitreous nibbler (vitreous infusion suction cutter). The normal
vitreous is transparent, permitting the passage of light rays to stimulate the retina and produce vision. In some persons the vitreous will lose its transparency as a result of membranes, hemorrhage from the retinal blood vessels, or chemical changes resulting in loss of vision. An article in this JournaZ on pars plana vitrectomy describes an instrument developed by Dr Machemer which grinds up the opaque vitreous or blood and suctions it from the eye while simultaneously refilling the vitreous cavity with physiologic saline. The instrument is like a “RotoRooter” which suctions out clogged drains. Results with this instrument are impressive. Research at the Retina Foundation with vitreous nibblers may have application for the removal of cataracts in underdeveloped nations. Surgeons from India asked us to adapt the “RotoRooter” instrument for use in cataract extraction. In India, with a population of about 550 million people, cataracts are very common. Literally millions of Indians are blind because there are not enough hospital beds, surgeons, or operating rooms.
AORN Journal, November 1973, Vol 18, N o 5
Many who develop cataracts in both eyes cannot see to carry on their work, to farm their little plots of land, and they die of malnutrition in about 18 months. Surgeons in India now conduct eye camps which move from city to city. Public buildings, such as schools, are used for the operations. The blind are brought to the eye camps by guides who charge a penny for the service. Many Indians do not have even that penny, and may not receive eye care. As news of the eye camp spreads, one side of the road near it is lined for a mile with male patients waiting to have cataracts removed; the other side contains a mile-long line of female patients. The blind hold onto the person in front of them forming a human chain. When the eye camp is out of supplies, and when it has treated all the patients it can, those in the lines are told to come back next year. Surgeons operate in school rooms with a flashlight. Ten surgical teams work simultaneously devoting about six minutes to each operation. Since current cataract procedures involve a
Fig 77. The slippery vitreous band-like membrane that prevents the retina from being reattached may be cut more easily with a miniaturized scissors than with a knife. The scissors used is so small that the part that enters the eye is thinner than a dime.
relatively large incision and sutures are often not available, the patient must lie very still after surgery. The patient goes to a large room where he must lie still for three or four days on a mat on the floor in eight square feet of space. Thus, valuable “hospital beds” are used because hospitals do not have enough money to pay for sutures to close this incision. The immediate solution for this great problem is not t o build more hospitals; that would cost billions of dollars which India cannot afford. One solution may be to develop cataract extraction techniques which surgeons can use to help the greatest number of people possible within existing conditions of a shortage of operating rooms and hospital beds. Using the vitreous suction cutter for cataract removal would eliminate the need for a large incision in the eye and help Indian surgeons serve more patients. The cataract could be removed through a tiny incision and the patient could go home to recuperate. Though such a technique would probably not give as good a visual result as conventional techniques of cataract extraction currently used in
North America, it would make possible the restoration of some useful vision in a greater number of those blind in India.
Summary. Pathogenesis: Retinal detachment is caused by a tear or hole in the retina which allows fluid vitreous to pass behind the retina to detach it from the inside of the back of the eye.
Symptomatobgy: Symptoms of retinal detachment are a painless loss of vision which may be preceded by floaters, black specks, flashes'of light or distorted vision in the affected eye.
Diagnosis: The diagnosis is made using the binocular indirect ophthalmoscope and scleral depressor which pushes the hidden areas of the retina into the view of the ophthalmoscope. Preventive Treatment: If a retinal tear is discovered before i t produces a retinal detachment, the tear may be sealed nonsurgically with photocoagulation or cry0 (freezing) applications. Surgical Treatment of Retinal Detachment: The aim of treatment is to find all the retinal tears, seal them and attempt to prevent additional tears from developing. One method to accomplish this is the scleral buckling operation. Fluid is drained from behind the retina, then the wall of the eye is buckled inwards by implanting a plastic rubber implant within or on the surface of the x l e r a (white fibrous outer coat of the eye).
Giant Retinal Tears: Giant retinal tears can be unfolded by turning the patient upside down on a special
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rotating operating table or with a tiny balloon used as a probe.
Vitreous Nibbler: Vitreous opacities or blood which obliterate vision may be successfully removed from the eye using a vitreous nibbler. ACKNOWLEDGMENTS The development and refinements o f surgical techniques were done as a joint effort b y the Retina Associates-Charles L Schepens, lchiro D Okarnura, Robert J Brockhurst, Wallace J McMeel, H MacKenzie Freeman, Felipe I Tolentino.
MD, Ronald C Pruett, and
Clinical and basic research leading t o the development o f the surgical advances described was carried out b y a team o f investigators o f the Department o f Retina Research o f the Retina Foundation stimulated and guided by i t s director, Charles L Schepens, MD. The group includes Angelica Anastopoulou, MD, Mohammad Ashrafzadeh, MD, Muhammad Chishti, MD, Ian Constable, MD, Glynne Coulvillion, MD, Sachico Hamada, MD, Felipe Huamonte, MD, Chan-bok Lee, MD, Pei-fei Lee, MD, Hsiao-su Liu, MD. Gustavo Morales, MD, Felipe Tolentino, MD, O l e g Pornerantzeff, D Eng, Anton Banko and Robert Thompson. Illustrations were prepared by David Tilden; photography was done by Roger Lancaster.
A AN A officers elec+ed Newly elected officers of the American Association of Nurse Anesthetists, announced at its recent national meeting in Chicago, are: president, Goldie D Brangman; president-elect, Mildred C Rumpf; vice-president, Dolores E Biggins; treasurer, Alverna M Skoog; trustee region 1, Miriam H Hagy, trustee region 4, Helen H Hart; trustee region 5, Ronald F Caulk. Officers serving for the second term are: trustee region 2, Pauline W Hester; trustee region 3, Ruth E Ecklund; trustee region 6, E Jean Duwall.
AORN Journal, November 1973, Vol 18, N o 5