Exhibit
10.13





Execution
Copy







THIRD
AMENDING AGREEMENT




THIS THIRD AMENDING AGREEMENT
is made as of the 25th day of
July, 2008 by and between Nozhat Choudry (the “Employee”), a resident of the
Province of Ontario, and OccuLogix, Inc. (the “Employer”), a corporation
incorporated under the laws of the State of Delaware, and having its executive
offices at 2600 Skymark Avenue, Building 9, Suite 201, Mississauga, Ontario, L4W
5B2.




WHEREAS, the Employer and the
Employee entered into a termination agreement dated as of January 31, 2008 (the
“Termination Agreement”)
pursuant to which the Employee’s employment with the Employer, as its Vice
President, Clinical Research, was terminated;




AND WHEREAS,capitalized terms
used in this Third Amending Agreement, but not otherwise defined, shall have the
respective meanings attributed to such terms in the Termination
Agreement;




AND WHEREAS,the Employer and
the Employee have entered into an amending agreement dated as of March 3, 2008
(the “Amending
Agreement”) pursuant to which they agreed that the Employer may pay the
Employee up to 50% of the Severance Balance by granting to the Employee stock
options under the Stock Option Plan;




AND WHEREAS,the Employer and
the Employee have entered into an amending agreement dated as of June 19, 2008
(the “Second Amending
Agreement”) pursuant to which they agreed to, among other things, an
amendment to the earliest date on which the Severance Balance will become due
and payable to the Employee;




AND WHEREAS,on May 20, 2008,
the Employer filed a preliminary proxy statement (the “Preliminary Proxy Statement”)
with the U.S. Securities and Exchange Commission (the “SEC”), which is currently the
subject of review by the SEC, proposinga number of transactions
for the approval of the Employer’s stockholders, including the approval and
adoption of a certain Securities Purchase Agreement pursuant to which the
Employer has agreed to sell shares of its common stock to the investors party
thereto, and the investors party thereto have agreed to purchase shares of the
Employer’s common stock, upon the terms and conditions provided for therein (the
“Private
Placement”);




AND WHEREAS,as part of the
SEC review process, the Employer will revise the Preliminary Proxy Statement to
have it reflect the current terms of the transactions proposed therein,
including the Private Placement;




AND WHEREAS,the Employer has
advised the Employee that, upon clearing the SEC review process, the Employer
will file and mail the final version of the Preliminary Proxy Statement (the
“Proxy Statement”) and
convene a meeting of its stockholders (the “Stockholders
Meeting”);







AND WHEREAS,the Employer has
advised the Employee that it will not be able to pay the Severance Balance on or
prior to September 1, 2008, and they mutually have agreed to extend the deadline
by which the Severance Balance must be paid;




NOW, THEREFORE,in
consideration of the mutual promises and covenants contained in this Second
Amending Agreement and the Termination Agreement, as amended by the Amending
Agreement, and the receipt and sufficiency of which are hereby acknowledged by
the parties hereto, the parties hereto agree as follows:




1.
            AMENDMENT




1.1           Notwithstanding
the first sentence of Section 3.2 of the Termination Agreement, as such Section
3.2 has been amended by the Second Amending Agreement, subject to Section 3.4 of
the Termination Agreement, as such Section 3.4 has been amended by the Amending
Agreement, on the earliest to occur of (i) October 31, 2008, (ii) the
termination of the Stockholders Meeting, provided that the requisite approval of
the Employer’s stockholders for the Private Placement or any of the proposed
transactions on which the Private Placement is conditioned, all as described and
provided for in the Proxy Statement, is not obtained at the Stockholders
Meeting, (iii) the closing of the Private Placement and (iv) a Change of
Control, the Employer shall pay the Employee, in a lump sum, the Severance
Balance.




1.2           Section
5.2 of the Termination Agreement, as such Section 5.2 has been amended by the
Second Amending Agreement, is hereby deleted in its entirety and replaced with
the following Section 5.2:




5.2
            The
      Employer shall use commercially reasonable efforts to obtain the Requisite
      Stockholder Approval, which covenant shall terminate and become null and
      void, and be of no more force or effect, upon the earlier to occur of (i)
      the date on which a meeting of the Employer’s stockholders may be convened
      to obtain the Requisite Stockholder Approval and (ii) October 31,
      2008.




1.3           The
Termination Agreement, as amended by the Amending Agreement and the Second
Amending Agreement, remains in full force and effect, unamended, other than as
specifically amended by this Third Amending Agreement.




2.
            ACKNOWLEDGEMENT




2.1           The
Employee hereby acknowledges that:




(a)
            She
      has had sufficient time to review and consider this Third Amending
      Agreement thoroughly;




(b)
            She
      has read and understands the terms of this Third Amending Agreement and
      her obligations hereunder;




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(c)
            She
      has been given an opportunity to obtain independent legal advice, or such
      other advice as she may desire, concerning the interpretation and effect
      of this Third Amending Agreement;
and




(d)
            She
      is entering this Third Amending Agreement voluntarily and without any
      pressure from the Employer.




3.
            MISCELLANEOUS




3.1           The
headings in this Third Amending Agreement are included solely for convenience of
reference and shall not affect the construction or interpretation
hereof.




3.2           The
parties hereto expressly agree that nothing in this Third Amending Agreement
shall be construed as an admission of liability.




3.3           This
Third Amending Agreement shall be binding upon, and inure to the benefit of, the
parties hereto and their respective heirs, trustees, administrators, successors
and assigns.




3.4           This
Third Amending Agreement and the Termination Agreement, as amended by the
Amending Agreement and the Second Amending Agreement, constitute the entire
agreement between the parties hereto pertaining to the subject matter of the
termination of the Employee’s employment with the Employer.  This
Third Amending Agreement, together with the Termination Agreement, as amended by
the Amending Agreement and the Second Amending Agreement, supersede and replace
all prior agreements, if any, written or oral, with respect to such subject
matter and any rights which the Employee may have by reason of any such prior
agreements or by reason of the Employee’s employment with the
Employer.  There are no representations, warranties or agreements
between the parties hereto in connection with the subject matter of this Third
Amending Agreement, except as specifically set forth herein.  No
reliance is placed on any representation, opinion, advice or assertion of fact
made by the Employer or any of its officers, directors, agents or employees to
the Employee, except to the extent that the same has been reduced to writing and
included as a term of this Third Amending Agreement or the Termination
Agreement, as amended by the Amending Agreement and the Second Amending
Agreement.  Accordingly, there shall be no liability, either in tort
or in contract, assessed in relation to any such representation, opinion, advice
or assertion of fact, except to the extent aforesaid.




3.5           Each
of the provisions contained in this Third Amending Agreement is distinct and
severable, and a declaration of invalidity or unenforceability of any provision
or part thereof by a court of competent jurisdiction shall not affect the
validity or enforceability of any other provision hereof.




3.6           This
Third Amending Agreement shall be governed by, and construed in accordance with,
the laws of the Province of Ontario and the federal laws of Canada applicable
therein.




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3.7           This
Third Amending Agreement may be signed in counterparts and delivered by
facsimile transmission or other electronic means, and each of such counterparts
shall constitute an original document, and such counterparts, taken together,
shall constitute one and the same instrument.






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REMAINDER OF THIS PAGE INTENTIONALLY LEFT BLANK]




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IN WITNESS WHEREOF,the
parties have executed this Third Amending Agreement as of the date set forth
above.




OCCULOGIX,
      INC.By:
            /s/
      Suh KimSuh
      KimGeneral
      Counsel







/s/
      Nozhat ChoudrySignature
      of Witness
            
            Nozhat
      ChoudryName
      of Witness (please
      print)