Evaluation of a patient for retinal detachment includes a thorough history and a complete ocular exam, including measurement of visual acuity, external examination, ocular motility testing, testing of pupillary reactions, anterior-segment biomicroscopy, tonometry, and binocular indirect ophthalmoscopy with scleral depression. Posterior-segment biomicroscopy, perimetry, and ultrasonography are also sometimes required. Rhegmatogenous retinal detachment is a diagnosis generally made by clinical examination of the retina alone, but a full history, ocular examination, and sometimes selected ancillary tests are also important parts of the evaluation (Figure 4–1). The symptoms of retinal detachment include fl ashes of light, new floaters, visual Field defect, decreased visual acuity, metamorphopsia, and rarely, defective color vision. The perception of light fl ashes, or photopsia, is due to the production of phosphenes by pathophysiologic stimulation of the retina. The retina is activated by light but is also capable of responding to mechanical disturbances. In fact, the most common cause of light fl ashes is posterior vitreous detachment. As the vitreous separates from the retinal surface, the retina is disturbed mechanically, stimulating a sensation of light. This perception is more marked if there are focal vitreoretinal adhesions. Generally, vitreous separation is benign and may almost be regarded as normal in the senescent eye. In approximately 12% of symptomatic posterior vitreous detachments, however, a careful search of the periphery reveals a tear of the retina. If the fl ashes are associated with floaters, it is wise to assume that a retinal tear exists, until proved otherwise. These symptoms demand a prompt and careful examination of the periphery with binocular indirect ophthalmoscopy and scleral indentation. The patient’s localization of the photopsia is of little value in predicting the location of the vitreoretinal pathology. If no breaks are evident in the first examination after symptomatic vitreous detachment, they rarely appear at a later date. If there is no associated hemorrhage or other pathologic condition, the patient needs counseling only. However, if pigment or blood is detected in the vitreous, a follow-up examination is often required. It is prudent to forewarn patients about the symptoms of retinal detachment. Flashes alone or floaters alone are less significant than if they occur together, in which case they are more likely to be associated with a retinal break.
Perioperative Complications of Surgery for Hypertrophic Pyloric Stenosis