<title>New stroboscopic light source and technique for intraoperative retinal fluorescein angiography during penetrating keratoplasty</title>

Abstract

ABSTRACt Purpose: We report the development of a new stroboscopic light source system and technique forperforming intraoperative fluorescein angiography during penetrating keratoplasty for aphakic orpseudophakic bullous keratopathy. Method: A controllable pulse xenon light source system(Strobex lamp; Chadwick-Helmuth mc, El Monte, CA) with a fiberoptic endoilluminator probe isused to perform high quality intraoperative fluorescein angiography during penetrating keratoplastyin pigmented rabbits and human subjects. Following corneal trephination and extraction of theintraocular lens (crystalline lens in rabbits), a temporary Cobo keratoprosthesis is secured while a20 gauge endoilluminator is inserted into the vitreous cavity through a limbal incision. Theendoilluminator is advanced to a retinal illumination area of DD and 10% fluorescein is injectedintravenously. A microscope camera coupled to a 50:50 beamsplitter photographs the passage offluorescein dye while the surgeon maintains an unaltered view through the operating microscope.Results: Angiograms through a keratoprosthesis show excellent contrast and resolution,comparable to standard fluorescein angiography. Fine peripapillary vessels are seen reproduciblyand with great detail in the rabbits. All the phases ofretinal angiography can be seen, includingarteriolar constriction and capillary nonperfusion in one of four human subjects examined.Conclusions: High quality intraoperative fluorescein angiography can be performed in patientsundergoing penetrating keratoplasty for aphakic/ pseudophakic bullous keratopathy. With thistechnology, pre-existing retinal disorders such as cystoid macular edema might be identified in theperioperative setting allowing for imponant management decisions to be made intraoperatively.1. INTRODUCTIONCME remains the leading cause of best corrected poor visual acuity following penetrating