<PAGE>

                                                                    EXHIBIT 10.8

                      PATENT LICENSE AND ROYALTY AGREEMENT

            THIS AGREEMENT (the "Agreement") is made by and between OccuLogix
Corporation. a Florida Corporation (the "Licensee"), and Prof Dr. Richard
Brunner ("Brunner) living in Germany and listed as inventor [along with Prof.
Dr. Helmut Borberg ("Borberg") but who is not yet or currently a party to this
Agreement or other license agreement with OccuLogix] in US patent application
09/000,917, which is the parent application of US letters patent 6,245,038
issued June 12, 2001 (the "Patent").

            WHEREAS, Brunner [and Borberg] are the sole owners of the Patent and
enjoy all of the rights, title and interests therein, and

            WHEREAS, Brunner desires to license any and all of his rights, title
and interests to the Patent and the Patent Rights derived therefrom to Licensee,
and

            WHEREAS, Licensee desires to obtain an exclusive license to all of
Brunner's interests in the Patent and. the Patent Rights derived therefrom and
to exclusively own the License to any and all of his rights, title, interests
and ownership to the Patent and any and all related patents, rights and
inventions that specifically relate to the Patent whether owned now or at any
time in the future by Brunner (the "License"), and

            WHEREAS, Brunner shall be eligible to receive any and all
consideration and compensation from the Licensee, such as those pledged to be
made by the Licensee to Brunner under the terms of this Agreement

            NOW THEREFORE, in consideration for guaranteed Advance Royalty
Payments and Royalty Payments as described below, and other good and valuable
consideration, Brunner does hereby exclusively license, in accordance with the
terms set forth below, unto Licensee, its successors and assigns, Brunner's
entire undivided right, title, ownership and interest in and to the Patent and
the invention(s) therein contained (the "Patent Rights"), throughout the
Territory, to be held and enjoyed by Licensee its successors and assigns, the
same as it would have been held and enjoyed by Brunner if this Exclusive License
and Royalty Agreement had not been made and entered into.

            Brunner recognizes that by signing this Agreement, the combination
of this Agreement and the Agreement between Professor Dr. Helmut Borberg and
Licensee attached as Exhibit A will collectively constitute an EXCLUSIVE PATENT
LICENSE AND ROYALTY AGREEMENT by which Borberg and Brunner grant an exclusive
license in the patent to Licensee including the right to sue for past
infringement

1.    Patent Rights. Shall mean any and all of Brunner's rights, title,
      ownership and interests in and to US letters patent 6,245,038 and any and
      all inventions, modifications, continuations-in-part, extensions,
      divisions, improvements, etc. made by Brunner or his agents, in any and
      all areas that relate directly to the Patent, regardless of whether such
      inventions or improvements are patentable or may become parented; all
      inventions. modifications, continuations-in-part, extensions, divisions,
      improvements, etc. shall

<PAGE>

                                      -2-

      automatically be incorporated herein without the payment of any additional
      fees, royalties or any other compensation or considerations of any kind.

2.    Representation by Brunner. Brunner warrants that he, along with Borberg as
      the joint inventor of United States Patent 6,245,038, exclusively owns and
      possesses the Patent and the Patent Rights, and has all right and title
      thereto and that this Patent License and Royalty Agreement is made without
      encumbrance or threat of future interference by others claiming ownership
      therein and that no security interests to any third party exists therein
      or any other agreement to the contrary.

3.    Representation by Licensee. Licensee represents that it is a bona fide
      corporation in good standing in Florida.

4.    Advance Royalty Payments. Licensee agrees to pay Brunner Fifty Thousand
      Dollars ($50,000 USD) annually as an advance and credited against any and
      all Royalty Payments paid in accordance with this License. Such Advance
      Royalty Payments shall be paid to Brunner and in equal payments of Twelve
      Thousand Five-hundred Dollars ($12,500 USD), made quarterly, on or before
      the expiration of Forty-five (45) days after the reporting close of each
      prior calendar quarter. The initial payment of Twelve Thousand
      Five-hundred Dollars ($12,500 USD) shall be due and payable within
      Forty-five (45) Days of the Effective Date herein.

5.    Royalty Payments. Licensee agrees to pay royalties to Brunner totaling
      One-Half Percent (0,5% in USD). Royalty Payments shall be calculated and
      paid based upon Total Net Revenues that Licensee receives from the bona
      fide commercial sales of its Products sold in reliance and dependence upon
      the validity of the Patent's claims and of the Patent Rights in the
      Territory.

6.    Accounting and Timing of Royalty Payments. Upon making each Royalty
      Payment, Licensee shall provide Brunner with a summary of the accounting
      used to determine the amount of Royalty Payment due. Royalty Payments
      shall be made by wire transfer and shall be computed on Total Net Revenues
      received by the Licensee by the reporting close of each calendar quarter
      and distributed and paid to Brunner and on a quarterly basis, on or before
      the expiration of Forty-five (45) days after the reporting close of each
      prior calendar quarter.

7.    Failure to Pay by Licensee. Should Licensee fail to make any payments as
      required herein, and should the Licensee fail to cure the breach created
      thereby, any and all rights, title and ownership to the License provided
      to the Licensee under this Agreement shall be forfeited and any and all
      such rights, title and ownership to the License shall, upon notice of the
      failure to cure the breach, immediately revert to Brunner, and all monies
      paid by Licensee until such date shall be retained by him without
      forfeiture.

8.    Territory. Shall mean the United States and any other jurisdictions
      subject to recognizing any valid claims of the Patent or of the Patent
      Rights.

9.    Total Net Revenues. Shall mean total gross revenues less any discounts,
      rebates, shipping costs, handling costs, transportation insurance costs,
      importation fees, and duties

<PAGE>

                                      -3-

      on any and all Products sold by the Licensee in the Territory and which
      are sold in reliance upon and specifically used in accordance with or
      subject to any of the valid claims of the Patent.

10.   Records. Licensee agrees to keep complete and correct books, accounts and
      records according to Generally Accepted Accounting Principles (GAAP)
      regulations to facilitate computation of Royalty Payments. Brunner or his
      representatives acceptable to Licensee, shall have a full right of
      accounting including the right to confidentially examine Licensee's books
      and records, at all reasonable times and upon reasonable notice, for the
      purpose of verifying the amount of Royalty Payments due.

11.   Products. Shall mean any of Licensee's products, goods or technologies
      sold to unaffiliated third parties in the Territory for the purposes of
      providing extracorporeal therapies for the treatment of the ophthalmic
      diseases as defined by any valid claim(s) of the Patent. In this case,
      Licensee's sale of extracorporeal filters and tubing sets for use in any
      and all ophthalmic indications.

12.   Term. The Royalty Payments shall be due to Brunner beginning with the
      first bona fide commercial sale of any Product in the Territory and may,
      at the discretion of Licensee terminate upon the first of any of the
      following three events to occur: a) All patents of the Patient Rights
      expire, b) All patent claims of the Patent Rights are invalidated, or c) A
      similarly fashioned competitive extracorporeal product, method or
      technology is commercially introduced in the Territory for use in
      ophthalmic indications that could not be deterred by best-efforts
      enforcement/infringement proceedings brought by Licensee against the
      competitive product, method or technology where such proceedings are made
      in reliance in full or in part upon the Patent's claims and or the Patent
      Rights.

13.   Patent Defense. Licensee shall pay for any and all costs incurred for
      patent maintenance, enforcement and defense of the Patent or the Patent
      Rights in the Territory.

14.   Participation. Brunner agrees, in consideration of the premises herein,
      that his executors and administrators will, at any time upon request,
      communicate to the Licensee, its successors and assigns, any facts
      relating to said Patent and Patent Rights, and the history thereof known
      to him or his successors and assigns, and that he will testify as to the
      same in any interference or other proceeding when requested to do so by
      the Licensee, its successors and assigns. Any and all costs of such
      participation by Brunner or his successors and assigns shall be borne by
      Licensee.

15.   Succession. Brunner binds himself and his heirs, executors,
      administrators, employees and legal representatives, as the case may be,
      to execute and deliver to the Licensee, its successors and assigns, any
      further documents or instruments and to do any and all further acts that
      may be deemed necessary by the Licensee, its successors and assigns to
      file applications for improvements and inventions in any country where
      Licensee may elect to file such application(s), and that may be necessary
      to vest in the Licensee, its successors and assigns, the license, rights
      or title herein conveyed, or intended so to be, and to enable such title
      to be recorded in the United States and or foreign countries where

<PAGE>

                                      -4-

      such application(s) may be filed. Any and all costs of such participation
      by Brunner or his successors and assigns shall be borne by Licensee.

16.   Relationship of the Parties: Indemnification. It is agreed that this
      Agreement does not make any Party herein a general or special agent, legal
      representative, subsidiary, joint venturer, partner, employee or servant
      of any other Party herein for any purpose.

17.   Breach and Disputes. Any breaching Party shall have Thirty (30) Days from
      the date of notification to cure such breach. Any dispute between the
      Parties to this Agreement shall be resolved through binding arbitration,
      which shall be governed under the rules and regulations of the American
      Arbitration Association.

18.   Forum, Venue and Governing Law. This agreement shall be governed and
      interpreted under Delaware law (without applying its conflict of law
      principles). Exclusive venue for legal proceedings arising hereunder shall
      be in Hillsborough County, Florida.

19.   Entire Agreement. This Agreement supersedes any prior understanding that
      may have been reached between the Parties and encompasses the entire
      agreement between the Licensee and Brunner with respect to the Patent and
      the Patent Rights. The terms of this Agreement are confidential and shall
      be maintained by the Parties in accordance thereby.

20.   Modification. This Agreement cannot be modified except in writing executed
      mutually between the Parties.

21.   Additional Consideration. This Agreement shall be transformed into an
      EXCLUSIVE PATENT LICENSE and ROYALTY AGREEMENT under the provision that a
      separate Agreement with substantially identical terms and conditions shall
      be concluded with Prof. Dr. Helmut Borberg (Borberg) on or before May 31,
      2002. If such Agreement is not concluded by such date, this Agreement
      shall remain in full force and effect as a NONEXCLUSIVE PATENT LICENSE and
      ROYALTY AGREEMENT between Brunner and Licensee.

            IN WITNESS WHEREOF, the Parties have signed and executed this
Agreement and have caused this Agreement to become effective as of the Effective
Date last executed below.

            OCCULOGIX CORPORATION                 prof. Dr. RICHARD BRUNNER


            By: /s/ Richard Davis                 By:  /s/ Dr. Richard Brunner
               -------------------------------         ------------------------



            Title: Chairman, President and CEO    Title:
                  ----------------------------          -----------------------



            Date: May 6, 2002                     Date: May 6, 2002
                 ---------------------------           -------------------------

<PAGE>

                PATENT LICENSE AND ROYALTY AGREEMENT (EXHIBIT A)

            THIS AGREEMENT (the "Agreement") is made by and between OccuLogix
Corporation, a Florida Corporation (the "Licensee"), and living in Germany and
listed as inventor [along with Prof. Dr. Richard Brunner ("Brunner") in US
patent application 09/000,917, which is the parent application of US letters
patent 6,245,038 issued Jane 12, 2001 (the "Patent").

            WHEREAS, Borberg [and Brunner] are the sole owners of the Patent and
enjoy all of the rights, title and interests therein, and

            WHEREAS Borberg is aware of the attached NON EXCLUSIVE PATENT
LICENSE and ROYALTY AGREEMENT made between Brunner and Licensee.

            WHEREAS , Borberg desires to license any and all of his rights,
title and interests to the Patent and the Patent Rights derived therefrom to
Licensee, and

            WHEREAS, Borberg recognizes that by signing this Agreement, the
combination of this Agreement and the agreement between Brunner and Licensee
together will become an EXCLUSIVE PATENT LICENSE and ROYALTY AGREEMENT by which
Brunner and Borberg assign an exclusive license in the patent to Licensee.

            WHEREAS, Licensee desires to obtain an exclusive license to all of
Borberg's interests in the Patent and the Patent Rights derived therefrom and to
exclusively own the License to any and all of their rights, title, interests and
ownership to the Patent any and all related patents, rights and inventions that
specifically relate to the Patent whether owned now or at any tame in the future
by Borberg (the "License"), and

            WHEREAS, Borberg shall be eligible to receive any and all
consideration and compensation from the Licensee, such as those pledged to be
made by the Licensee to Borberg under the terms of this Agreement.

            NOW THEREFORE in consideration for guaranteed Advance Royalty
Payments and Royalty Payments as described below, and other good and valuable
consideration, Borberg does hereby exclusively license, in accordance with the
terms set forth below, unto Licensee, its successors and assigns, Borberg's
entire undivided right, title, ownership and interest in and to the Patent and
the invention(s) therein contained (the "Patent Rights"), throughout the
Territory to be held and enjoyed by Licensee its successors and assigns, the
same as it would have been held and enjoyed by Borberg if this License and
Royalty Agreement had not been made and entered into.

1.    Patent Rights. Shall mean any and all of Borberg rights, title, ownership
      and interests in and to US letters patent 6,245,038 and any and all
      inventions, modifications, continuations-in-part, extensions, divisions,
      improvements, etc. made by Borberg or his agents, in any and all areas
      that relate directly to the Patent, regardless of whether such inventions
      or improvements are patentable or may become patented; all inventions,
      modifications, continuations-in-part, extensions, divisions, improvements,
      etc. shall

<PAGE>

                                      -6-

      automatically be incorporated herein without the payment of any additional
      fees, royalties or any other compensation or considerations of any kind.

2.    Representation by Borberg. Borberg warrants that he, along with Brunner,
      exclusively owns and possesses the Patent and the Patent Rights, and has
      all right and title thereto and that this Patent License and Royalty
      Agreement is made without encumbrance or threat of future interference by
      others claiming ownership therein and that no security interests to any
      third party exists therein or any other agreements to the contrary.

3.    Representation by Licensee. Licensee represents that it is a bona fide
      corporation in good standing in Florida.

4.    Advance Royalty Payments. Licensee agrees to pay Borberg Fifty Thousand
      Dollars ($50,000 USD) annually as an advance and credited against any and
      all Royalty Payments paid in accordance with this License. Such Advance
      Royalty Payments shall be paid to Borberg and in equal payments of Twelve
      Thousand Five-hundred Dollars ($12,500 USD), made quarterly, on or before
      the expiration of Forty-five (45) days after the reporting close of each
      prior calendar quarter. The initial payment of Twelve Thousand
      Five-hundred Dollars ($12,500 USD) shall be due and payable within
      Forty-five (45) days of the Effective Date herein.

5.    Royalty Payments. Licensee agrees to pay royalties to Brunner totaling
      One-Half Percent (0,5% in USD). Royalty Payments shall be calculated and
      paid based upon Total Net Revenues that Licensee receives from the bona
      fide commercial sales of its Products sold in reliance and dependence upon
      the validity of the Patent's claims and of the Patent Rights in the
      Territory.

6.    Accounting and Timing of Royalty Payments. Upon making each Royalty
      Payment, Licensee shall provide Brunner with a summary of the accounting
      used to determine the amount of Royalty Payment due. Royalty Payments
      shall be made by wire transfer and shall be computed on Total Net Revenues
      received by the Licensee by the reporting close of each calendar quarter
      and distributed and paid to Brunner and on a quarterly basis, on or before
      the expiration of Forty-five (45) days after the reporting close of each
      prior calendar quarter.

7.    Failure to Pay by Licensee. Should Licensee fail to make any payments as
      required herein, and should the Licensee fail to cure the breach created
      thereby, any and all rights, title and ownership to the License provided
      to the Licensee under this Agreement shall be forfeited and any and all
      such rights, title and ownership to the License shall, upon notice of the
      failure to cure the breach, immediately revert to Brunner, and all monies
      paid by Licensee until such date shall be retained by him without
      forfeiture.

8.    Territory. Shall mean the United States and any other jurisdictions
      subject to recognizing any valid claims of the Patent or of the Patent
      Rights.

9.    Total Net Revenues. Shall mean total gross revenues less any discounts,
      rebates, shipping costs, handling costs, transportation insurance costs,
      importation fees, and duties on any and all Products sold by the Licensee
      in the Territory and which are sold in

<PAGE>

                                      -7-

      reliance upon and specifically used in accordance with or subject to any
      of the valid claims of the Patent.

10.   Records. Licensee agrees to keep complete and correct books, accounts and
      records according to Generally Accepted Accounting Principles (GAAP)
      regulations to facilitate computation of Royalty Payments. Brunner or his
      representatives acceptable to Licensee, shall have a full right of
      accounting including the right to confidentially examine Licensee's books
      and records, at all reasonable times and upon reasonable notice, for the
      purpose of verifying the amount of Royalty Payments due.

11.   Products. Shall mean any of Licensee's products, goods or technologies
      sold to unaffiliated third parties in the Territory for the purposes of
      providing extracorporeal therapies for the treatment of the ophthalmic
      diseases as defined by any valid claim(s) of the Patent. In this case,
      Licensee's sale of extracorporeal filters and tubing sets for use in any
      and all ophthalmic indications.

12.   Term. The Royalty Payments shall be due to Brunner beginning with the
      first bona fide commercial sale of any Product in the Territory and may,
      at the discretion of Licensee terminate upon the first of any of the
      following three events to occur: a) All patents of the Patient Rights
      expire, b) All patent claims of the Patent Rights are invalidated, or c) A
      similarly fashioned competitive extracorporeal product, method or
      technology is commercially introduced in the Territory for use in
      ophthalmic indications that could not be deterred by best-efforts
      enforcement/infringement proceedings brought by Licensee against the
      competitive product, method or technology where such proceedings are made
      in reliance in full or in part upon the Patent's claims and or the Patent
      Rights.

13.   Patent Defense. Licensee shall pay for any and all costs incurred for
      patent maintenance, enforcement and defense of the Patent or the Patent
      Rights in the Territory.

14.   Participation. Borberg agrees, in consideration of the promises herein,
      that he and any of his executors and administrators will, at any time upon
      request, communicate to the Licensee, its successors and assigns, any
      facts relating to said Patent and Patent Rights, and the history thereof,
      known to him or his successors and assigns, and that he will testify as to
      the same in any interference or other proceeding when requested to do so
      by the Licensee, its successors and assigns. Any and all costs of such
      participation by Borberg or his successors and assigns shall be borne by
      Licensee.

15.   Succession. Borberg binds himself and his heirs, executors,
      administrators, employees and legal representatives, the case may be, to
      execute and deliver to the Licensee, its successors and assigns, any
      further documents or instruments and to do any and all further acts that
      may be deemed necessary by the Licensee, its successors and assigns to
      file applications for improvements and inventions in any country where
      Licensee may elect to file such application(s) and that may be necessary
      to vest in the Licensee, its successors and assigns, the license, rights
      or title herein conveyed, or intended so to be, and to enable such title
      to be recorded in the United States and or foreign countries where such
      application(s) may be filed. Any and all costs of such participation by
      Borberg or his successors and assigns shall be borne by Licensee.

<PAGE>

                                      -8-

16.   Relationship of the Parties; Indemnification. It is agreed that this
      Agreement does not make any Party herein a general or special agent, legal
      representative, subsidiary, joint venturer, partner, employee or servant
      of any other Party herein for any purpose.

17.   Breach and Disputes. Any breaching Party shall have Thirty (30) Days from
      the date of notification to cure sure breach. Any dispute between the
      Parties to this Agreement shall be resolved through binding arbitration,
      which shall be governed under the rules and regulations of the American
      Arbitration Association. .

18.   Forum, Venue and Governing Law. This agreement shall be governed and
      interpreted. under Delaware law (without applying its conflict of law
      principles). Exclusive venue for legal proceedings arising hereunder shall
      be in Hillsborough County, Florida.

19.   Entire Agreement. This Agreement supersedes any prior understanding that
      may have been reached between the Parties and encompasses the entire
      agreement between the Licensee and Borberg with respect to the Patent and
      the Patent Rights. The terms of this Agreement are confidential and shall
      be maintained by the Parties in accordance thereby.

20.   Modification. This Agreement cannot be modified except in writing executed
      mutually between the Parties.

            IN WITNESS WHEREOF, the Partise have signed and executed this
Agreement and have caused this Agreement to become affective as of the Effective
Date Last executed below.

            OCCULOGIX CORPORATION                 prof. Dr. RICHARD BRUNNER


            By: /s/ Richard Davis                 By:  /s/ Dr. Richard Brunner
               -------------------------------         ------------------------


            Title:                                Title:
                  ----------------------------          -----------------------
            Date:                                 Date:
                 ---------------------------           -------------------------