Method For Delivering A Substance To An Eye

Abstract

An ophthalmic delivery device includes a body defining a fluid reservoir and a pump in fluid communication with the reservoir. The delivery device also includes a nozzle that includes a dosage chamber for holding a dosage of fluid, a valve seat, and a valve cover. The valve cover extends about the valve seat and forms an interface therebetween and the valve seat includes an outlet aperture. The interface is in fluid communication with the outlet aperture and the dosage chamber, and at least part of the valve cover is movable between (i) a closed position with the valve cover engaging the valve seat to close the interface and form a fluid-tight seal therebetween, and (ii) an open position with at least part of the valve cover spaced away from the valve seat in response to fluid flowing through the outlet aperture at a pressure greater than a valve opening pressure to allow the passage of pressurized fluid therebetween. The valve seat and the valve cover are dimensioned to dispense the dosage of fluid through the interface at a velocity of equal to or less than 6 meters per second.

1 .- 20 . (canceled) 
     
     
         21 . A method for delivering a substance to an eye and treating dry eye, comprising:
 (i) storing multiple doses of the substance hermetically sealed in a variable-volume chamber connectible in fluid communication with a one-way valve defining a normally closed valve opening that opens in response to the substance at an inlet to the valve opening exceeding a valve opening pressure;   (ii) metering a dose of substance from the variable-volume storage chamber at a volume within the range of about 15 micro liters to about 25 micro liters and pressurizing the metered dose above the valve opening pressure;   (iii) introducing the pressurized metered dose through the one-way valve;   (iv) delivering the metered dose to the eye; and   (v) repeating steps (ii) through (iv) at spaced time intervals relative to each other per day such that the total volume of doses delivered per day is equal to an approximate amount of a person's tear production per day to thereby treat a dry eye.   
     
     
         22 . A method as defined in  claim 21 , wherein the delivering step includes delivering the metered dose from the one way valve in a plurality of micro droplets at a velocity of less than approximately 10 meters per second and into the eye 
     
     
         23 . A method as defined in  claim 22 , wherein the delivering step includes delivering the metered dose at a velocity of less than approximately 6 meters per second. 
     
     
         24 . A method as defined in  claim 21 , further comprising engaging with a tissue-engaging member facial tissue adjacent to the eye to at least partially expose a conjunctiva cul-de-sac of the eye, and wherein the delivering step includes delivering the metered dose to the conjunctiva cul-de-sac. 
     
     
         25 . A method as defined in  claim 21 , wherein the delivering step includes delivering the metered dose at an energy upon impacting the eye that is equal to or less than approximately 40 micro-joules. 
     
     
         26 . A method as defined in  claim 21 , wherein the delivering step includes delivering the metered dose in a plume of micro droplets that extend through an approximately semi-circular arc that substantially conforms to the angular extent of a conjunctiva cul-de-sac of the eye. 
     
     
         27 . A method as defined in  claim 21 , wherein the delivering step is performed approximately four (4) times per day. 
     
     
         28 . A method as defined in  claim 21 , wherein the delivering step includes delivering the metered dose to a cul-de-sac of the eye without overflowing the cul-de-sac with the delivered substance.