Targeting better and less invasive therapies to restore vision



3T's unique platform can be implanted under the conjunctiva in a minimally invasive—non-ocular penetrating—procedure



A review of ocular drug delivery modalities



The episcleral implant (D, in the figure below) is intended for periocular use by placement under the conjunctiva in contact with the episclera—the outer side of the sclera. It neither penetrates the sclera or the eye.





Diagram of common ocular drug delivery methods discussed at the ARVO 2009 Summer Eye Research Conference including various adjuvant implant devices. Adapted with permission from Lee SS, Robinson MR. Novel drug delivery systems for retinal diseases. Ophthalmic Res. 200941:124 –135. © 2009 S. Karger AG, Basel.


A 44-fold increase in the bioavailability of molecules to the retina could be achieved by the episcleral selective delivery in comparison to periocular injections.



Ricardo A. Pontes de Carvalho et al: Investigative Ophthalmology & Visual Science, October 2006, Vol. 47, No. 10


In this proof of concept study while preserving all the dynamic ocular barriers, it was demonstrated that a significant (44-fold) improvement in the drug delivery to the retina could be achieved by the use of the selective episcleral drug delivery system.



Sustained and targeted episcleral delivery of celecoxib in a rabbit model of retinal and choroidal neovascularization





Luiz H. Lima, Michel E. Farah, Glenwood Gum, Pamela Ko and Ricardo A. P. de Carvalho. Int J Retin Vitr (2018) 4:3



In an animal model of retinal and subretinal neovascularization, episcleral celecoxib delivery was demonstrated to significantly inhibit neovascularization. It was also noticed, although not statistically significant, an apparent effect of episcleral celecoxib on preventing tractional retinal detachment secondary to epiretinal fibrovascular proliferation. The transscleral delivery of celecoxib combined with sustained-release strategy may have impact in the treatment of retinal and choroidal proliferative diseases.



episcleral delivery for the treatment of ocular cancers: The safety and distribution of anti-cancer drugs in the eye





R. A. P de Carvalho et al.: Investigative Ophthalmology & Visual Science September 2016, Vol.57, 4007



The Preclinical Safety, Toxicity and Pharmacokinetics (Pk) of Targeted Episcleral Delivery of Topotecan, Melphalan and Its Combination with Dexamethasone.

In this study, conducted under Good Laboratory Practices to support Investigational New Drug Application (IND) scientists at 3T characterized the safety and Pk of topotecan, melphalan and combinations with dexamethasone in support of its clinical development.for the treatment of retinoblastoma and uveal melanoma.

Both INDs are open at the Food and Drug Administration



targeted episcleral delivery of a neuroprotective drug for the treatment of traumatic and neurodegenerative ocular diseases





Manders et al. Investigative Ophthalmology & Visual Science September 2016, Vol.57



Selective Episcleral Drug Delivery of Neuroprotective Drugs. Toxicokinetics of a Neuroprotective Estradiol Analog and Implications for Treatment of Traumatic and Neurodegenerative Ocular Conditions



Selective episcleral delivery of anti-glaucoma drugs is efficacious in lowering Intraocular pressure



R. A. P. de Carvalho et al.Investigative Ophthalmology & Visual Science April 2009, Vol.50, 5969.


3T's episcleral system was used to facilitate the diffusion of large molecules into the eye





R. A. P de Carvalho et al. Investigative Ophthalmology & Visual Science May 2007, Vol.48, 3193


Targeted episcleral delivery of monoclonal antibodies and macromolecules: in vivo studies. 3T investigators have presented results of in vivo study showing that proteins and large molecules can diffuse through the sclera and the targeted episcleral delivery can facilitate its delivery to the eye.



COMBINING SUSTAINED DRUG-RELEASE FORMULATION TO THE EPISCLERAL SYSTEMS MAY SIGNIFICANTLY PROLONG DRUG EXPOSURE IN THE EYE



R. A. P. de Carvalho et al.: Investigative Ophthalmology & Visual Science May 2006, Vol.47, 5111.