<PAGE>   1
                                 EXHIBIT 10.11A

<PAGE>   2
                           LOAN MODIFICATION AGREEMENT

     This Loan Modification Agreement is entered into as of November 26, 1997,
by and between Laserscope ("Borrower") whose address is 3052 Orchard Drive, San
Jose, CA 95134 and Silicon Valley Bank ("Bank") whose address is 3003 Tasman
Drive, Santa Clara, CA 95054.

1. DESCRIPTION OF EXISTING INDEBTEDNESS: Among other indebtedness which may be
owing by Borrower to Bank, Borrower is indebted to Bank pursuant to, among other
documents, an Amended and Restated Loan and Security Agreement, dated November
27, 1996, as may be amended from time to time, (the "Loan Agreement"). The Loan
Agreement provided for, among other things, a Committed Line in the original
principal amount of Five Million Dollars ($5,000,000.00),(the "Revolving
Facility"). Defined terms used but not otherwise defined herein shall have the
same meanings as in the Loan Agreement.

Hereinafter, all indebtedness owing by Borrower to Bank shall be referred to as
the "Indebtedness."

2. DESCRIPTION OF COLLATERAL AND GUARANTIES. Repayment of the Indebtedness is
secured by the Collateral as described in the Loan Agreement.

Hereinafter, the above-described security documents and guaranties, together
with all other documents securing repayment of the Indebtedness shall be
referred to as the "Security Documents". Hereinafter, the Security Documents,
together with all other documents evidencing or securing the Indebtedness shall
be referred to as the "Existing Loan Documents".

3. DESCRIPTION OF CHANGE IN TERMS.

   A. Modification(s) to Loan Agreement.

      1.  The following Definition as set forth in Section 1.1 is hereby amended
as follows:

          "Maturity Date" means November 25, 1998.

      2.  Subsection (a) of Section 2.1 entitled "Advances" is hereby amended to
          read, in its entirety as follows:

          (a) Subject to and upon the terms and conditions of this Agreement,
          Bank agrees to make Advances to Borrower in an aggregate outstanding
          amount not to exceed (i) the Committed Line, minus the Credit Card
          Sublimit or the Borrowing Base, whichever is


                                        1
<PAGE>   3
          less, minus (ii) the face amount of all outstanding Letters of Credit
          (including drawn but unreimbursed Letters of Credit) and minus (iii)
          the Foreign Exchange Reserve. Subject to the terms and conditions of
          this Agreement, amounts borrowed pursuant to this Section 2.1 may be
          repaid and reborrowed at any time during the term of this Agreement.
          For purposes of this Agreement, "Borrowing Base" means an amount equal
          to (i) Seventy Five Percent (75%) of Eligible Accounts, as determined
          by Bank with reference to the most recent Borrowing Base Certificate
          delivered by Borrower.




      3.  Subsection (a) of Section 2.3 entitled "Interest Rates" is hereby
          amended to read, in its entirety, as follows:

(a)  Interest Rate. Except as set forth in Section 2.3(b), any Advances shall
          bear interest, on the Average Daily Balance thereof, at a per annum
          rate equal to three-quarters of one (.75) percentage point above the
          Prime Rate, effective as of the date hereof.

      4.  Subsection (b) of Section 2.5 entitled "Letters of Credit" is hereby
          amended as follows:

          An issuance fee for each Letter of Credit of One and one half (1.50)
          percent of the amount of each Letter of Credit shall be due upon the
          issuance of such Letter of Credit.

      5.  Section 6.8 entitled "Quick Ratio" is hereby amended to read, in its
          entirety, as follows:

          Borrower shall maintain, as of the last day of each of Borrower's
          fiscal quarters, a ratio of Quick Assets to Current Liabilities of at
          least .80 to 1.00.

      6.  Section 6.9 entitled "Debt-Net Worth Ratio" is hereby amended to read,
          in its entirety, as follows:


                                        2
<PAGE>   4
          Borrower shall maintain, as of the last day of each of Borrower's
          fiscal quarters, a ratio of Total Liabilities less Subordinated Debt
          to Tangible Net Worth plus Subordinated Debt of not more than 1.00 to
          1.00.

      7.  Section 6.10 entitled "Tangible Net Worth" is hereby amended to read,
          in its entirety, as follows:

          Borrower shall maintain, as of the last day of each of Borrower's
          fiscal quarters, a minimum Tangible Net Worth of $24,000,000 plus 75%
          of net profits (excluding losses) for the prior quarter, on a
          consolidated basis, plus 100% of new equity or Subordinated Debt
          received after the date hereof.

      8.  Section 6.11 entitled "Profitability" is hereby amended to read, in
          its entirety, as follows:

          Borrower shall have a net profit of One Dollar ($1.00) in each fiscal
          quarter.

      9.  The following Section entitled "Credit Card Sublimit" is hereby
          incorporated as 2.1.4 into the Loan Agreement:

      Borrower may utilize up to an aggregate amount not to exceed $100,000.00
          for cash management services provided by Bank, which services will
          include business credit cards for the executives of Borrower as
          described in certain cash management service agreements provided to
          Borrower from time to time in connection herewith (a "Credit Card
          Service", or the "Credit Card Services"). All amounts actually paid by
          Bank in respect of a Credit Card Service or Credit Card Services, when
          paid, constitute an Advance under the Committed Line.

4. CONSISTENT CHANGES. The Existing Loan Documents are hereby amended wherever
necessary to reflect the changes described above.

5. PAYMENT OF LOAN FEE. Borrower shall pay to Bank a fee in the amount of Twenty
Thousand Dollars ($20,000.00) (the "Loan Fee") plus all out-of-pocket expenses.

6. NO DEFENSES OF BORROWER. Borrower (and each guarantor and pledgor signing
below) agrees that, as of the date hereof, it has no defenses against the
obligations to pay any amounts under the Indebtedness.


                                        3
<PAGE>   5
7. CONTINUING VALIDITY. Borrower (and each guarantor and pledgor signing below)
understands and agrees that in modifying the existing Indebtedness, Bank is
relying upon Borrower's representations, warranties, and agreements, as set
forth in the Existing Loan Documents. Except as expressly modified pursuant to
this Loan Modification Agreement, the terms of the Existing Loan Documents
remain unchanged and in full force and effect. Bank's agreement to modifications
to the existing Indebtedness pursuant to this Loan Modification Agreement in no
way shall obligate Bank to make any future modifications to the Indebtedness.
Nothing in this Loan Modification Agreement shall constitute a satisfaction of
the Indebtedness. It is the intention of Bank and Borrower to retain as liable
parties all makers and endorsers of Existing Loan Documents, unless the party is
expressly released by Bank in writing. No maker, endorser, or guarantor will be
released by virtue of this Loan Modification Agreement. The terms of this
paragraph apply not only to this Loan Modification Agreement, but also to all
subsequent loan modification agreements.

8. CONDITIONS. The effectiveness of this Loan Modification Agreement is
conditioned upon Borrower's payment of the Loan Fee.

   This Loan Modification Agreement is executed as of the date first written
above.

BORROWER:                                   BANK:

LASERSCOPE                                  SILICON VALLEY BANK

By:  /s/Dennis LaLumandiere                 By: /s/Gary Reagan
   -------------------------                   ---------------------------------
Name: Dennis LaLumandiere                   Name: Gary Reagan
      ---------------------------------          -------------------------------
Title:Vice President of Finance and         Title:Vice President - Life Sciences
      ---------------------------------           ------------------------------
      Chief Financial Officer                     and Health Care Practice
      ---------------------------------           ------------------------------


                                       4