Abstract
Purpose::
A NEW REGIMEN FOR THE TREATMENT OF CNV IN AMD HAS BEEN SHOWN TO HAVE PROMISING LONG TERM VISUAL OUTCOMES. THIS NEW QUADRUPLE THERAPY CONSISTS OF A CORE PARS PLANA VITRECTOMY (cPPV). VISUDYNE (PDT) , INTRAVITREAL AVASTIN(BEVACIZUMAB) AND INTRAVITREAL DEXAMETHASONE.A NEWLY DESIGNED 23 GAUGE VITRECTOR (INTRECTOR) WAS USED TO PERFORM A SEQUENTIAL DRUG INJECTION AND A cPPV.
Methods::
A PDT (72 SECONDS) TREATMENT ON DAY ONE PRECEDED THE COMBINED cPPV(0.35 CC) BY THE "INTRECTOR", AND SEQUENTIAL INJECTIONS OF AVASTIN(1.25 MG IN 0.125 CC) AND DEXAMETHASONE (800 UG IN 0.2 CC)ON DAY TWO THROUGH THE SAME SITE. ALL EYES (N=50) HAD EITHER AN OCCULT OR CLASSIC MEMBRANE AS SHOWN ON THE INITIAL FLUORESCEIN ANGIOGRAPHY. INTRAVITREAL SURGERY (cPPV) WAS PERFORMED SOLELY WITH THE "INTRECTOR" AND AIDED BY AN OPERATING MICROSCOPE OR BY AN INDIRECT OPHTHALMOSCOPE . ALL EYES HAD FOLLOWUP EVERY 6 WEEKS AFTER THE QUADRUPLE THERAPY WITH FOLLOWUP FOR AT LEAST 11 MONTHS.
Results::
11 MONTHS AFTER THE INITIAL QUADRUPLE THERAPY THE MEAN VISUAL THERAPY INCREASED FROM BASELINE (20/100) FOR AN AVERAGE OF 2 LINES OF VISUAL IMPROVEMENT (20/80). NONE OF THE 50 EYES HAD REGRESSED TO PRETREATMENT LEVELS NOR WERE THERE ANY ADVERSE EVENTS. SEVEN OF THE INITIAL 50 EYES, IN THE FIRST 9-11 MONTHS ,REQUIRED RETREATMENT WITH cPPV AND REPEATED DRUG INJECTIONS ALONE ,WITHOUT PDT. THESE 7 EYES HAD BECOME SYMPTOMATIC AND OCT DEMONSTRATED RETINAL PIGMENT EPITHELIUM COMPLEX THICKENING. HOWEVER, ALL 50 EYES EXCEPT ONE SHOWED NO EVIDENCE OF A RECURRENCE ON ANGIOGRAPHY.
Conclusions::
WE HAVE SHOWN THAT MULTIPLE DRUG REGIMENS ALONG WITH A cPPV ACHIEVED LONG TERM SIGNIFICANT VISUAL RESULTS IN OUR PATIENTS .THIS WAS ACHIEVED WITH MINIMAL RETREATMENTS ONLY AFTER THE FIRST 9-11 MONTHS (14%).EACH DRUG HAS THE ABILITY TO CLOSE OFF AND RETARD THE UNDERLYING NEOVASCULAR PROCESS .THE VITRECTOMY INCREASES THE OXYGEN LEVEL IN THE VITREOUS.WE DO NOT KNOW HOW MUCH OXYGEN REACHES THE CHORIORETINAL COMPLEX. THIS MIGHT IN AND OF ITSELF TURN OFF THE HYPOXIC STIMULUS THAT DRIVES THE ANGIOGENESIS. THESE INITIAL RESULTS LEAVE MANY QUESTIONS UNANSWERED. DO THE SYNERGISTIC EFFECTS OF PDT AND THE COMBINED INJECTIONS OF AVASTIN AND DEXAMETHASONE EXPLAIN IT? WHAT IMPACT AND HOW MUCH DOES THE cPPV HAVE? EQUAL VOLUME OF DRUG WAS SUBSTITUTED BY THE VOLUME OF VITREOUS REMOVED. THIS SAFE 23 GAUGE SELF SEALING SUTURELESS EXCHANGE WITH THE "INTRECTOR" CERTAINLY ALLOWS FOR AN EXACT AND KNOWN CONCENTRATION OF DRUG INJECTION. WITH THE NEXT GENERATION OF INTRAVITREAL DRUGS IN THE PIPELINE (VEGF-TRAP, CAND-3, SiRNA, ENZYMES), COMBINATIONS MIGHT BE OUR FUTURE.
Keywords: age-related macular degeneration • choroid: neovascularization • vitreoretinal surgery