Arora KS, Robin AL, Corcoran KJ, Corcoran SL, Ramulu PY Use of Various Glaucoma Surgeries and Procedures in Medicare Beneficiaries from 1994 to 2012. Ophthalmology. 2015 Aug;122(8):1615-24. doi: 10.1016/j.ophtha.2015.04.015. Epub 2015 Jun 16.
Francis BA, Kawji AS, Vo NT, Dustin L, Chopra V Endoscopic cyclophotocoagulation (ECP) in the management of uncontrolled glaucoma with prior aqueous tube shunt. J Glaucoma. 2011 Oct;20(8):523-7. doi: 10.1097/IJG.0b013e3181f46337.
Gabelt BT, Kaufman PL Changes in aqueous humor dynamics with age and glaucoma. Prog Retin Eye Res. 2005 Sep;24(5):612-37. Review.
Ko SJ, Hwang YH, Ahn SI, Kim HK Surgical Outcomes of Additional Ahmed Glaucoma Valve Implantation in Refractory Glaucoma. J Glaucoma. 2016 Jun;25(6):e620-4. doi: 10.1097/IJG.0000000000000298.
Schaefer JL, Levine MA, Martorana G, Koenigsman H, Smith MF, Sherwood MB Failed glaucoma drainage implant: long-term outcomes of a second glaucoma drainage device versus cyclophotocoagulation. Br J Ophthalmol. 2015 Dec;99(12):1718-24. doi: 10.1136/bjophthalmol-2015-306725. Epub 2015 May 29.
Semchyshyn TM, Tsai JC, Joos KM Supplemental transscleral diode laser cyclophotocoagulation after aqueous shunt placement in refractory glaucoma. Ophthalmology. 2002 Jun;109(6):1078-84.
Smith M, Buys YM, Trope GE Second Ahmed valve insertion in the same eye. J Glaucoma. 2009 Apr-May;18(4):336-40. doi: 10.1097/IJG.0b013e318182edfb.
Sood S, Beck AD Cyclophotocoagulation versus sequential tube shunt as a secondary intervention following primary tube shunt failure in pediatric glaucoma. J AAPOS. 2009 Aug;13(4):379-83. doi: 10.1016/j.jaapos.2009.05.006.
The AGS Second Aqueous Shunt Implant vs. Transscleral Cyclophotocoagulation Treatment Study
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.