<PAGE>   1
                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                 AMENDMENT NO. 2
                                       TO
                                    FORM 10-K


[X]  Annual report pursuant to Section 13 or 15(d) of the Securities Exchange
     Act of 1934

                   For the fiscal year ended June 30, 1996, or

[ ]  Transition report pursuant to Section 13 or 15(d) of the Securities
     Exchange Act of 1934 

        For the transition period from _____________ to _______________

                         COMMISSION FILE NUMBER: 0-10640

                              COLLAGEN CORPORATION
             (Exact name of Registrant as specified in its charter)

<TABLE>
<S>                                                          <C>
            DELAWARE                                            94-2300486
(State or other jurisdiction of                              (I.R.S. Employer
 incorporation or organization)                              Identification No.)

    2500 Faber Place, Palo Alto, CA                               94303
(Address of principal executive offices)                        (Zip Code)
</TABLE>
       Registrant's telephone number, including area code: (415) 856-0200

        Securities registered pursuant to Section 12(b) of the Act: None

           Securities registered pursuant to Section 12(g) of the Act:
                          Common Stock, $.01 par value


Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 month (or such shorter period that the registrant was required
to file such reports), and (2) has been subject to such filing requirements for
the past 90 days.  Yes  X    No
                       ---      ---

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of Registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [ ]

The aggregate market value of the voting stock held by non-affiliates of the
Registrant, based upon the closing price of the Common Stock on September 6,
1996, on the Nasdaq Stock Market, was approximately $128,272,131. Shares of
Common Stock held by each officer and director and by each person who owns 5% or
more of the outstanding Common Stock have been excluded in that such persons may
be deemed to be affiliates. This determination of affiliate status is not
necessarily a conclusive determination for other purposes.

As of September 6, 1996, Registrant had 8,690,110 shares of Common Stock
outstanding.
<PAGE>   2

The Registrant hereby amends its Annual Report on Form 10-K/A for the fiscal
year ended June 30, 1996 to refile Exhibit 10.83 and 10.84 pursuant to a grant
of confidential treatment with respect to such Exhibits.


                                     PART IV

ITEM 14.  EXHIBITS, FINANCIAL STATEMENTS, SCHEDULES, AND REPORTS ON FORM 8-K

(a)  The following documents are filed as a part of this report:

     2.   Exhibits
<TABLE>
<CAPTION>
          EXHIBIT
           NUMBER          NOTES                                    DESCRIPTION
          -------          -----                                    -----------
          <S>              <C>         <C>
              3.1            (9)       Certificate of Incorporation of Collagen Subsidiary, Inc.
              3.2            (9)       Certificate of Merger of Collagen Corporation, a California corporation,
                                       into Collagen Subsidiary, Inc., a Delaware corporation
              3.3           (12)       By-Laws, as amended
             10.24           (1)       Collaborative Research and Distribution Agreement with Zimmer, Inc.
                                       dated as of June 26, 1985
             10.27           (1)       Distribution Agreement between Registrant and Lederle (Japan), Ltd.
                                       dated as of June 26, 1985
             10.34           (2)       Agreement for Sale and Leaseback of Manufacturing Facility between
                                       Registrant and Heleasco Seven, Inc.
             10.36           (3)       Amended and Restated Development and Distribution Agreement with C.R.
                                       Bard, Inc., dated as of August 4, 1989
             10.38           (4)       Agreement for Sale and Leaseback of Manufacturing Facility between
                                       Registrant and Heleasco Seven, Inc. dated September 25, 1989
             10.39           (4)       Agreement for Sale and Leaseback of Manufacturing Facility between
                                       Registrant and Heleasco Seven, Inc. dated December 29, 1989
             10.40           (4)       Amended and Restated Promissory Note of Dale A. Stringfellow, dated
                                       September 7, 1990
             10.41           (4)       Amended and Restated Promissory Note Secured by Deed of Trust by Dale A.
                                       Stringfellow, dated September 7, 1990
             10.42           (4)       1984 Incentive Stock Option Plan, as amended
             10.43           (4)       1985 Employee Stock Purchase Plan, as amended
             10.44          (12)       1990 Directors' Stock Option Plan, as amended
</TABLE>

<PAGE>   3

<TABLE>
          <S>              <C>         <C>
             10.46           (5)       Agreement between Registrant and Essex Chemie, A.G. dated November 19,
                                       1990
             10.56           (6)       Lease Agreement dated June 1, 1992 by and between Registrant and
                                       Harbor Investment Partners
             10.58           (6)       License and Option Agreement dated June 30, 1992 between Registrant
                                       and Research Development Foundation
             10.60           (7)       Amendments dated February 16, 1993 and February 18, 1993 respectively,
                                       to the Product Development and Distribution Agreement dated January 18,
                                       1985 by and between Registrant and Zimmer, Inc., originally filed
                                       as Exhibit 10.24 to Registrant's Form 10-K for the fiscal year ended
                                       June 30, 1985
             10.61*          (7)       Letter Agreement, dated April 26, 1991 and May 21, 1993 by and between
                                       Collagen Corporation and A. Neville Pelletier
             10.62           (8)       1994 Stock Option Plan
             10.63           (9)       Renewed Lease for 2500 Faber  Place, Palo Alto, California dated
                                       December 1, 1992 between Registrant and Leonard Ely, Shirley Ely, Carl
                                       Carlsen and Mary L. Carlsen
             10.65*          (9)       Promissory Note of Howard D. Palefsky dated August 3, 1994
             10.66           (9)       Revised Form of Agreement Regarding Proprietary Information and
                                       Inventions between Registrant and all employees or consultants
             10.67          (10)       Credit Agreement, dated November 15, 1994, by and between the Bank of
                                       New York and the Registrant, as amended January 24, 1995
             10.67(a)       (13)       Second  Amendment, Third Amendment and Fourth Amendment dated June 30,
                                       1995, September 30, 1995, and December 26, 1995, respectively, to
                                       Credit Agreement dated November 15, 1994 by and between the Bank of
                                       New York and the Registrant
             10.67(b)       (14)       Fifth  Amendment, dated March 29, 1996, to Credit Agreement dated
                                       November 15, 1994 by and between the Bank of New York and the Registrant
             10.67(c)                  Sixth Amendment, dated June 28, 1996, to Credit Agreement dated
                                       November 15, 1994 by and between the Bank of New York and the Registrant
</TABLE>

<PAGE>   4

<TABLE>
          <S>              <C>         <C>
             10.68          (10)       Letter Agreement, dated October 7, 1994,  by and between C.R.  Bard.
                                       Inc. and the Registrant, amending the Amended and Restated Development
                                       and  Distribution Agreement dated August 4, 1989 between the Parties
                                       originally filed as Exhibit 10.36 to the Registrant's Form 10-K for
                                       the fiscal year ended June 30, 1989
             10.70*         (12)       Letter of Acceptance of Employment by and between Gary Petersmeyer and
                                       the Registrant, dated December 19, 1994
             10.71**        (12)       License, Supply and Option Agreement, dated March 24, 1995 by and
                                       between LipoMatrix, Incorporated and Registrant
             10.72**        (12)       Distributor Agreement dated March 24, 1995 by and between LipoMatrix,
                                       Incorporated and Registrant
             10.73**        (12)       Coordination Agreement dated March 24, 1995, by and between LipoMatrix
                                       Incorporated and Registrant's wholly owned subsidiary, Collagen
                                       International Incorporated
             10.74*         (12)       Promissory Note of Howard D. Palefsky dated June 5, 1995
             10.75**        (12)       Letter Agreement, dated July 10, 1995 by and between C.R. Bard, Inc.
                                       and the Registrant, amending the Amended and Restated Development and 
                                       Distribution Agreement dated August 4, 1989 between the Parties 
                                       originally filed as Exhibit 10.36 to the Registrant's Form 10-K for
                                       the fiscal year ended June 30, 1989
             10.76          (11)       Stock Purchase Agreement dated August 22, 1995 between the Registrant
                                       and certain stockholders of LipoMatrix, Incorporated
             10.77*         (13)       Promissory Note between Howard D. Palefsky and the Registrant dated
                                       December 11, 1995
             10.78*         (15)       Bonus Agreement between Howard D. Palefsky and the Registrant dated
                                       February 20, 1996
             10.79*         (15)       Promissory Note between Howard D. Palefsky and the Registrant dated
                                       February 20, 1996
             10.80*         (14)       Amended and Restated Secured Loan Agreement between Ross R. Erickson
                                       and the Registrant dated December 31, 1995
             10.81*                    Letter of Acceptance of Employment by and Pierre Comte and the
                                       Registrant dated March 21, 1995
             10.82                     Loan Agreement between the Registrant and Cohesion Corporation dated
                                       May 24, 1996
             10.83**                   Worldwide Medical Product Distribution Agreement between Registrant
                                       and Tissue Technologies, Inc. dated June 4, 1996
             10.84**                   Distribution Agreement between Registrant and Biomatrix, Inc. dated
                                       June 17, 1996
             10.87**                   Distribution Agreement between Registrant and Lederle (Japan), LTD.
                                       dated January 1, 1996
             11.1                      Statement Regarding Weighted Average Common and Common Equivalent
                                       Shares Used in Computation of Per Share Income
             21.1                      List of Subsidiaries
             23.1                      Consent of Ernst & Young LLP, Independent Auditors
             24.1                      Power of Attorney (see page 42)
             27.1                      Financial Data Schedule (EDGAR version only)
</TABLE>
------------------
 * Constitutes a management contract or compensatory contract, plan or
   arrangement.
** Confidential treatment has been granted for a portion of this document.

Notes to Exhibits:

     (1)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1985.

     (2)  Incorporated by reference to the same exhibits filed with Registrant's
          Current Report on Form 8-K dated March 31, 1989.

     (3)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1989.

     (4)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1990.

     (5)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1991.

     (6)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1992.

     (7)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1993.

     (8)  Incorporated by reference to Exhibit 4.1 filed with Registrant's
          Registration statement of Form S-8 (No. 33-80038) which became
          effective June 9, 1994.

     (9)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1994

     (10) Incorporated by reference to the same exhibits filed with Registrant's
          Quarterly Report on Form 10-Q for the fiscal quarter ended December
          31, 1994.

     (11) Incorporated by reference to exhibit 2.1 filed with Registrant's
          Current Report on Form 8-K dated September 6, 1995.

     (12) Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1995

     (13) Incorporated by reference to the same exhibits filed with Registrant's
          Quarterly Report on Form 10-Q for the fiscal quarter ended December
          31, 1995

     (14) Incorporated by reference to exhibit 10.76 originally filed with
          Registrant's Quarterly Report on Form 10-Q for the fiscal quarter
          ended December 31, 1995

     (15) Incorporated by reference to the same exhibits filed with Registrant's
          Quarterly Report on Form 10-Q for the fiscal quarter ended March 31,
          1996
<PAGE>   5

                                   SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange
Act of 1934, the Registrant has duly caused this Report to be signed on its
behalf by the undersigned, thereunto duly authorized.


                                       COLLAGEN AESTHETICS, INC.
                                       (FORMERLY COLLAGEN CORPORATION)


                                       /s/ MICHAEL A. BATES
                                       --------------------------------
                                       Michael A. Bates
                                       Vice President, Finance and
                                       Chief Financial Officer



Dated: March 15, 1999

<PAGE>   6



                                POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears below
constitutes and appoints Gary S. Petersmeyer and Michael A. Bates, jointly and
severally, his attorneys-in-fact, each with the power of substitution, for him
in any and all capacities, to sign any amendments to this Amendment No. 2 to
Form 10-K, and to file the same, with exhibits thereto and other documents in
connection therewith, with the Securities and Exchange Commission, hereby
ratifying and confirming all that each of said attorneys-in-fact, or his
substitute or substitutes, may do or cause to be done by virtue hereof. Pursuant
to the requirements of the Securities Exchange Act of 1934, this Report has been
signed below by the following persons on behalf of the Registrant and in the
capacities and on the dates indicated.

<TABLE>
<CAPTION>
               Signature                                     Title                                  Date
------------------------------------------------------------------------------------------------------------
<S>                                     <C>                                                   <C>
/s/ GARY S. PETERSMEYER                 President, Chief Executive Officer, and               March 18, 1999
-----------------------------           Director (Principal Executive Officer)
Gary S. Petersmeyer                     

/s/ MICHAEL A. BATES                    Vice President Finance and Chief Financial            March 18, 1999
-----------------------------           Officer (Principal Financial and Accounting 
Michael A. Bates                        Officer)

/s/ ANNE L. BAKAR                       Director                                              March 18, 1999
-----------------------------
Anne L. Bakar

/s/ WILLIAM G. DAVIS                    Director                                              March 18, 1999
-----------------------------
William G. Davis


-----------------------------           Director
Gerald Lazarus, M.D.

</TABLE>

<PAGE>   7

                              COLLAGEN CORPORATION

                   AMENDMENT NO. 2 TO FORM 10-K ANNUAL REPORT
                        FOR THE YEAR ENDED JUNE 30, 1996

                                INDEX TO EXHIBITS


<TABLE>
<CAPTION>
EXHIBIT
 NUMBER      NOTES                                   DESCRIPTION
-------      -----                                   -----------
<S>          <C>        <C>
    3.1        (9)      Certificate of Incorporation of Collagen Subsidiary, Inc.
    3.2        (9)      Certificate of Merger of Collagen Corporation, a California corporation,
                        into Collagen Subsidiary, Inc., a Delaware corporation
    3.3       (12)      By-Laws, as amended
   10.24       (1)      Collaborative Research and Distribution Agreement with Zimmer, Inc.
                        dated as of June 26, 1985
   10.27       (1)      Distribution Agreement between Registrant and Lederle (Japan), Ltd.
                        dated as of June 26, 1985
   10.34       (2)      Agreement for Sale and Leaseback of Manufacturing Facility between
                        Registrant and Heleasco Seven, Inc.
   10.36       (3)      Amended and Restated Development and Distribution Agreement with C.R.
                        Bard, Inc., dated as of August 4, 1989
   10.38       (4)      Agreement for Sale and Leaseback of Manufacturing Facility between
                        Registrant and Heleasco Seven, Inc. dated September 25, 1989
   10.39       (4)      Agreement for Sale and Leaseback of Manufacturing Facility between
                        Registrant and Heleasco Seven, Inc. dated December 29, 1989
   10.40       (4)      Amended and Restated Promissory Note of Dale A. Stringfellow, dated
                        September 7, 1990
   10.41       (4)      Amended and Restated Promissory Note Secured by Deed of Trust by Dale A.
                        Stringfellow, dated September 7, 1990
   10.42       (4)      1984 Incentive Stock Option Plan, as amended
   10.43       (4)      1985 Employee Stock Purchase Plan, as amended
   10.44      (12)      1990 Directors' Stock Option Plan, as amended
</TABLE>
<PAGE>   8

<TABLE>
<CAPTION>
EXHIBIT
 NUMBER      NOTES                                   DESCRIPTION
-------      -----                                   -----------
<S>          <C>        <C>
   10.46       (5)      Agreement between Registrant and Essex Chemie, A.G. dated November 19,
                        1990 
   10.56       (6)      Lease Agreement dated June 1, 1992 by and between Registrant and
                        Harbor Investment Partners
   10.58       (6)      License and Option Agreement dated June 30, 1992 between Registrant
                        and Research Development Foundation
   10.60       (7)      Amendments dated February 16, 1993 and February 18, 1993 respectively,
                        to the Product Development and Distribution Agreement dated January 18,
                        1985 by and between Registrant and Zimmer, Inc., originally filed
                        as Exhibit 10.24 to Registrant's Form 10-K for the fiscal year ended
                        June 30, 1985
   10.61*      (7)      Letter Agreement, dated April 26, 1991 and May 21, 1993 by and between
                        Collagen Corporation and A. Neville Pelletier
   10.62       (8)      1994 Stock Option Plan
   10.63       (9)      Renewed Lease for 2500 Faber  Place, Palo Alto, California dated
                        December 1, 1992 between Registrant and Leonard Ely, Shirley Ely, Carl
                        Carlsen and Mary L. Carlsen
   10.65*      (9)      Promissory Note of Howard D. Palefsky dated August 3, 1994
   10.66       (9)      Revised Form of Agreement Regarding Proprietary Information and
                        Inventions between Registrant and all employees or consultants
   10.67      (10)      Credit Agreement, dated November 15, 1994, by and between the Bank of
                        New York and the Registrant, as amended January 24, 1995
   10.67(a)   (13)      Second  Amendment, Third Amendment and Fourth Amendment dated June 30,
                        1995, September 30, 1995, and December 26, 1995, respectively, to
                        Credit Agreement dated November 15, 1994 by and between the Bank of
                        New York and the Registrant
   10.67(b)   (14)      Fifth  Amendment, dated March 29, 1996, to Credit Agreement dated
                        November 15, 1994 by and between the Bank of New York and the Registrant
   10.67(c)             Sixth Amendment, dated June 28, 1996, to Credit Agreement dated
                        November 15, 1994 by and between the Bank of New York and the Registrant
</TABLE>

<PAGE>   9
<TABLE>
<CAPTION>
EXHIBIT
 NUMBER      NOTES                                   DESCRIPTION
-------      -----                                   -----------
<S>          <C>        <C>
   10.68      (10)      Letter Agreement, dated October 7, 1994,  by and between C.R.  Bard.
                        Inc. and the Registrant, amending the Amended and Restated Development
                        and  Distribution Agreement dated August 4, 1989 between the Parties
                        originally filed as Exhibit 10.36 to the Registrant's Form 10-K for
                        the fiscal year ended June 30, 1989
   10.70*     (12)      Letter of Acceptance of Employment by and between Gary Petersmeyer and
                        the Registrant, dated December 19, 1994
   10.71**    (12)      License, Supply and Option Agreement, dated March 24, 1995 by and
                        between LipoMatrix, Incorporated and Registrant
   10.72**    (12)      Distributor Agreement dated March 24, 1995 by and between LipoMatrix,
                        Incorporated and Registrant
   10.73**    (12)      Coordination Agreement dated March 24, 1995, by and between LipoMatrix
                        Incorporated and Registrant's wholly owned subsidiary, Collagen
                        International Incorporated
   10.74*     (12)      Promissory Note of Howard D. Palefsky dated June 5, 1995
   10.75**    (12)      Letter Agreement, dated July 10, 1995 by and between C.R. Bard, Inc.
                        and the Registrant, amending the Amended and Restated Development and 
                        Distribution Agreement dated August 4, 1989 between the Parties 
                        originally filed as Exhibit 10.36 to the Registrant's Form 10-K for
                        the fiscal year ended June 30, 1989
   10.76      (11)      Stock Purchase Agreement dated August 22, 1995 between the Registrant
                        and certain stockholders of LipoMatrix, Incorporated
   10.77*     (13)      Promissory Note between Howard D. Palefsky and the Registrant dated
                        December 11, 1995
   10.78*     (15)      Bonus Agreement between Howard D. Palefsky and the Registrant dated
                        February 20, 1996
   10.79*     (15)      Promissory Note between Howard D. Palefsky and the Registrant dated
                        February 20, 1996
   10.80*     (14)      Amended and Restated Secured Loan Agreement between Ross R. Erickson
                        and the Registrant dated December 31, 1995
   10.81*               Letter of Acceptance of Employment by and Pierre Comte and the
                        Registrant dated March 21, 1995
   10.82                Loan Agreement between the Registrant and Cohesion Corporation dated
                        May 24, 1996
   10.83**              Worldwide Medical Product Distribution Agreement between Registrant
                        and Tissue Technologies, Inc. dated June 4, 1996
   10.84**              Distribution Agreement between Registrant and Biomatrix, Inc. dated
                        June 17, 1996
   10.87**              Distribution Agreement between Registrant and Lederle (Japan), LTD.
                        dated January 1, 1996
   11.1                 Statement Regarding Weighted Average Common and Common Equivalent
                        Shares Used in Computation of Per Share Income
   21.1                 List of Subsidiaries
   23.1                 Consent of Ernst & Young LLP, Independent Auditors
   24.1                 Power of Attorney (see page 42)
   27.1                 Financial Data Schedule (EDGAR version only)
</TABLE>

------------------
 * Constitutes a management contract or compensatory contract, plan or
   arrangement.
** Confidential treatment has been granted for a portion of this document.


Notes to Exhibits:

     (1)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1985.

     (2)  Incorporated by reference to the same exhibits filed with Registrant's
          Current Report on Form 8-K dated March 31, 1989.

     (3)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1989.

     (4)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1990.

     (5)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1991.

     (6)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1992.

     (7)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1993.

     (8)  Incorporated by reference to Exhibit 4.1 filed with Registrant's
          Registration statement of Form S-8 (No. 33-80038) which became
          effective June 9, 1994.

     (9)  Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1994

     (10) Incorporated by reference to the same exhibits filed with Registrant's
          Quarterly Report on Form 10-Q for the fiscal quarter ended December
          31, 1994.

     (11) Incorporated by reference to exhibit 2.1 filed with Registrant's
          Current Report on Form 8-K dated September 6, 1995.

     (12) Incorporated by reference to the same exhibits filed with Registrant's
          Annual Report on Form 10-K for the fiscal year ended June 30, 1995

     (13) Incorporated by reference to the same exhibits filed with Registrant's
          Quarterly Report on Form 10-Q for the fiscal quarter ended December
          31, 1995

     (14) Incorporated by reference to exhibit 10.76 originally filed with
          Registrant's Quarterly Report on Form 10-Q for the fiscal quarter
          ended December 31, 1995

     (15) Incorporated by reference to the same exhibits filed with Registrant's
          Quarterly Report on Form 10-Q for the fiscal quarter ended March 31,
          1996