Site of potential operating microscope light-induced phototoxicity on the human retina during temporal approach eye surgery
| Autor: | Roy D. Brod, Mark A. Pavilack |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Microscope
Light genetic structures medicine.medical_treatment Iatrogenic Disease Cataract Extraction Retina Pupil Foveola law.invention Optics Retinal Diseases law Cornea Microscopy medicine Humans Eye surgery Radiation Injuries business.industry eye diseases Ophthalmology medicine.anatomical_structure sense organs Operating microscope business |
| Zdroj: | Ophthalmology. 108:381-385 |
| ISSN: | 0161-6420 |
| DOI: | 10.1016/s0161-6420(00)00536-4 |
| Popis: | Objective To determine the site of focal illumination on the retina of phakic human cadaver eyes from an operating microscope positioned for temporal approach eye surgery. Design Experimental study. Methods A Zeiss OPMI-6SFR operating microscope (Zeiss Humphrey Systems, Dublin, CA) was positioned over two phakic human cadaver eyes to measure the site of the focal illumination on the retina by directly observing the illumination on the posterior scleral surface of the globe. External localization of the foveola was made by direct observation using scleral indentation and indirect ophthalmoscopy. Various combinations of microscope angulation and field of view were analyzed. Main outcome measures Distance of focal illumination from the operating room microscope relative to the foveola was measured. Results The diameter of the "hot spot" of focal illumination on the retina was 4.0 mm. With the eye positioned straight ahead and the level operating room microscope positioned for temporal approach eye surgery, the center of retinal illumination was 0.9 and 1.4 mm nasal relative to the foveola when the microscope field of view was centered over the cornea and temporal limbus, respectively. With the microscope angled 5, 10, 15, and 20° temporally (oculars tilted toward surgeon), the center of the illumination was displaced nasal to the foveola by 1.1, 1.5, 3.8, and 5.1 mm, respectively, when the field of view was centered over the cornea and 1.5, 2.6, 4.7, and 6.0 mm, respectively, nasal to the foveola when centered over the temporal limbus. Conclusions Retinal illumination from an operating microscope positioned for temporal approach eye surgery has the potential for light-induced injury to the fovea. Angulation of the operating microscope by up to 10° temporally when the microscope field of view was centered over the cornea and up to 5° temporally when centered over the temporal limbus was not adequate to displace the focal illumination off the foveola when the eye was in the straight-ahead position. Tilting the operating microscope 15° or more temporally when centered on the pupil and 10° or more when centered over the temporal limbus should safely displace the retinal light exposure away from the fovea during temporal approach surgery. Suggestions for reducing the risk of iatrogenic phototoxicity are reviewed. |
| Databáze: | OpenAIRE |
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