Ocular gels or hydrogels and microinjectors

A method of injecting a fluent material at a choroid of an eye comprising

• providing an injection device comprising a syringe and a needle, with the syringe comprising a reservoir in fluid communication with an outlet and a piston for expelling contents of the reservoir from the syringe through the outlet,
• forcing the needle into the eye to advance the needle through the sclera,
• wherein a force applied to move the needle applies a piston force to the piston is greater than a force required to move the needle through the sclera and, while the piston force is applied at the piston, the reservoir has a pressure that is less than a pressure required to inject a fluid from the syringe into a sclera and is at least equal to a pressure required to inject a fluid at a choroid, and
• stopping the advancement of the needle through the sclera when the fluent material leaves the needle, with the needle being at the choroid.

A method of injecting a fluent material at a choroid of an eye comprising

• providing an injection device comprising a syringe and a needle, with the syringe comprising a reservoir in fluid communication with an outlet and a piston for expelling contents of the reservoir from the syringe through the outlet,
• wherein the reservoir, before use, comprises the fluent material at a pressure that is less than a pressure required to inject the fluent material from the syringe into a sclera and is at least equal to a pressure required to inject the fluid at a choroid,
• forcing the needle into the eye through the sclera until the needle is at the choroid, and
• allowing the pressure of the reservoir to move the fluent material into the eye at the choroid.

A method of injecting a fluent material at a choroid of an eye comprising

• providing an injection device comprising a syringe and a needle, with the syringe comprising a reservoir in fluid communication with an outlet and a piston for expelling contents of the reservoir from the syringe through the outlet,
• the device further comprising a biasing member connected with the needle or a plunger, said plunger being connected to the piston,
• applying a force to the device to advance the needle into the eye through the sclera,
• with the biasing member translating variations in the force into a constant force.