Fiber Optic Light Source Research Articles

Retinal damage produced by intraocular fiber optic light

We exposed the maculas of owl monkey eyes to light from an intraocular fiber optic light source similar to that used for human pars plana vitrectomy. Retinal irradiance was calculated at 0.22 W/cm2. Eyes were exposed for time intervals ranging from 30 minutes to five minutes and were observed after light treatment by fundus photography and fluorescein angiography. Tissue was obtained for light and electron microscopy by animal killing at one hour, 24 hours, one week, and four weeks. Fundus lesions were seen ophthalmoscopically as early as five hours following 30 minutes of light exposure. Significant damage to the photoreceptor layer and less damage to the pigment epithelium was present by light and electron microscopy as early as one hour after 30 minutes of light exposure. By one month complete loss of photoreceptors with Muller cell junctions between inner retina and flattened abnormal retinal pigment epithelium cells was observed. Fluorescein angiography revealed significant staining of the pigment epithelium and outer retina 24 hours after 30 minutes of light exposure. No leakage from retinal vessels occurred. At one month following light treatment, transmission of choroidal fluorescein through window defects in the pigment epithelium was present with no retinal staining. The threshold for ophthalmoscopically visible fundus lesions in this study was 15 minutes of light exposure. Ten minutes of light treatment was the threshold for microscopic changes. Short light exposures damaged the outer retina and spared the pigment epithelium. Removing a substantial amount of the infrared light from our light source did not protect the retina from damage. Removal of light between 400 and 500 nm is probably more helpful in protecting the retina. Intermittent light exposure of the retina seemed as harmful as uninterrupted illumination for the same cumulative period of time. We speculate that the retinal damage caused by intraocular fiber optic light has primarily a photic mechanism. Damage to the retinal pigment epithelium may be secondary to outer retinal damage. The present levels of intraocular light used for human pars plana vitrectomy are probably safe in most instances. Lengthy preretinal membrane stripping procedures during vitrectomy, however, may pose a threat of light damage to the retina. This damage must be appreciated as continued efforts are made to produce brighter sources of intraocular light for human pars plana vitrectomy.

Otoscopy and photography: a new method.

A new hand-held otoscope photographic system, convenient and suitable for clinical application, is introduced. This instrument allows clear otoscopic examination in stenotic or tortuous ear canals, and photographs the subject in one procedure. The instrument consists of a rod-lens optical system, a fiberoptic light source, a camera, and exchangeable speculum and a strobe light. Color photographs of tympanic membranes and middle ear pathology are presented.

Retinal Damage Produced by Intraocular Fiber Optic Light

We exposed the maculas of owl monkey eyes to light from an intraocular fiber optic light source similar to that used for human pars plana vitrectomy. Retinal irradiance was calculated at 0.22 W/cm2. Eyes were exposed for time intervals ranging from 30 minutes to five minutes and were observed after light treatment by fundus photography and fluorescein angiography. Tissue was obtained for light and electron microscopy by animal killing at one hour, 24 hours, one week, and four weeks. Fundus lesions were seen ophthalmoscopically as early as five hours following 30 minutes of light exposure. Significant damage to the photoreceptor layer and less damage to the pigment epithelium was present by light and electron microscopy as early as one hour after 30 minutes of light exposure. By one month complete loss of photoreceptors with Müller cell junctions between inner retina and flattened abnormal retinal pigment epithelium cells was observed. Fluorescein angiography revealed significant staining of the pigment epithelium and outer retina 24 hours after 30 minutes of light exposure. No leakage from retinal vessels occurred. At one month following light treatment, transmission of choroidal fluorescein through window defects in the pigment epithelium was present with no retinal staining. The threshold for ophthalmoscopically visible fundus lesions in this study was 15 minutes of light exposure. Ten minutes of light treatment was the threshold for microscopic changes. Short light exposures damaged the outer retina and spared the pigment epithelium. Removing a substantial amount of the infrared light from our light source did not protect the retina from damage. Removal of light between 400 and 500 nm is probably more helpful in protecting the retina. Intermittent light exposure of the retina seemed as harmful as uninterrupted illumination for the same cumulative period of time. We speculate that the retinal damage caused by intraocular fiber optic light has primarily a photic mechanism. Damage to the retinal pigment epithelium may be secondary to outer retinal damage. The present levels of intraocular light used for human pars plana vitrectomy are probably safe in most instances. Lengthy preretinal membrane stripping procedures during vitrectomy, however, may pose a threat of light damage to the retina. This damage must be appreciated as continued efforts are made to produce brighter sources of intraocular light for human pars plana vitrectomy.

An Improved Microsurgical Ceiling-Mounted Unit and Automated Television

To increase the versatility of a ceiling-mounted microsurgical unit, we instructed an instrument company to redesign an existant unit according to our requirements. The modified instrument has improved microscope supporting arms capable of supporting an inserted X-Y translation stage. The unit houses diathermy, cautery, fiberoptic light source, and suction devices. Most of these devices can be exchanged for other to adapt to individual requirements. Mirror image design increases versatility. Floor-mounted outlets avoid a multitude of cables. A double color television system for automatic recording of surgery has been installed.

A review of laparoscopy

Although known since 1901 it is only since the development of a fiberoptic light source and a safe method of maintenance of the pneumoperit oneum that laparoscopy has been widely used. In addition to its use for diagnosis the laparoscope with added instruments is used to ligate fallopian tubes and to remove ovarian tissue for biopsy. For tubal ligation a 2nd incision is made several inches below the paraumbilical one and a cauterizing and cutting instrument introduced. In addition to understanding the procedure operating room nurses are required to care for the equipment and to be familiar with the use of each item. Proper grounding of the electrosurgical unit is necessary to prevent burns. Preoperative preparations are made according to the requirements of the surgeon and anesthesiologist. General anesthesia is used with intubation. A dilatation and curettage is first done and a Pratt dilator placed in the uterus. The tenaculum and dilator are taped together. This allows manipulation of the uterus. When carbon dioxide gas is pumped through the Verres needle the pressure should not exceed 30 mg of mercury. The patient is placed in the Trendelenberg position for the operation. In some cases a procedure called hydrotubation is done. In these instances 10 cc of a dye solution is introduced via the cannula in the uterus. If the fallopian tubes are patent the dye can be seen exuding from the tubes. The operator then proceeds with coagulating and resecting each tube. The resected section is removed for study and hemostasis is verified. An ovarian biopsy may also be done in the same way. Possible complications include injury to other viscera emphysema bleeding and cardiac arrhythmias. Constant monitoring by electrocardiogram will detect arrhythmias. In some newer instruments a 2nd puncture is not needed. Local anesthesia is used by some surgeons following Fentanyl citrate analgesia. This shortens hospital and convalescent time.

Transillumination Photography of the Eye

The essentials of this system consist of a bifurcated fiber optic bundle, a fiber optic light source, and an adapted Kowa RC-2 f undus camera with high-powered power unit (Figs, land 2) . One end of the fiber optic bundle is at­ tached to the light box and the other end is attached to the Kowa camera through a hole drilled into the Kowa flash tube housing. The joined end of the bifurcated bundle is then held by the examiner or photographer. By applying the joined bundle directly to the eye, transillumination can be obtained. In these cases, the bundle is used without modi­ fication (Fig. 3). However, with a lens sys­ tem attached, the bundle can be used as a fo­ cal illuminator with a slit beam through which a photographic flash can also be trans­ mitted. When the fiber optic bundle is to be ap­ plied directly to the globe, as in transillumi­ nation, the patient first receives a topical an­ esthetic. Then, in a darkened room, the pho­ tographer applies the joined end of the fiber optic bundle to the eye. By using the light from the light box which exits through half of the joined bundle, the precise view to be

Fiber optic cannula for the panculdoscope

W IT H T H E need for intense cold light for culdoscopic cinemaphotography and still photography, quartz fibers made up into a bundle have been introduced for this purpose. Endoscopic instruments adapt themselves well to this modality. Instead of including the fine fiber bundles within the optical telescope, as are presently available, a new cannula was devised that is compatible with the existing panculdoscope. An intense light source on the outside coupled with a 4 to 6 foot fiber optic bundle transmits a clear white light to the new cannula and is emitted at the distal end parallel to the face of the endoscopic optics (Fig, I). The cannula with the trocar in place is introduced in the same manner as previously described for cu1doscopy.l Upon removal of the trocar, the culdoscope is placed within the cannula and Iocked into position by a special device that permits adjustment so that the exit lens at the distal end of the scope is parallel to the surfaces of the emitting fibers. In this way maximum white light covers the entire visual field without any shadows. An intense fiber optic light source permits color cinemaphotography with ease. A new fiber optic cannula” for the panculdoscope has been presented and its use herein described.