Finding closest points without duplicates and given distance threshold

Given a bunch of latitudes and longitudes stored as Points, I would like to determine the points that are closest to each point given some maximum threshold in meters. This is my first stab at this:

DECLARE @ThresholdInMeters FLOAT = 1000000.0;

IF OBJECT_ID('tempdb..#Points1') IS NOT NULL
    DROP TABLE #Points1
CREATE TABLE #Points1
    (
      PointId INT IDENTITY(1, 1) ,
      Point GEOGRAPHY NULL
    ) 

DECLARE @LowerLatitude FLOAT;
DECLARE @UpperLatitude FLOAT;
DECLARE @RandomLatitude FLOAT;
DECLARE @LowerLongitude FLOAT;
DECLARE @UpperLongitude FLOAT;
DECLARE @RandomLongitude FLOAT;
DECLARE @Counter INT;

SET @LowerLatitude = -90 
SET @UpperLatitude = 90 
SET @LowerLongitude = -180
SET @UpperLongitude = 180

SET @Counter = 100;
WHILE ( @Counter > 0 )
    BEGIN
        SELECT  @RandomLatitude = ( ( @UpperLatitude - @LowerLatitude - 1 )
                                    * RAND() + @LowerLatitude );
        SELECT  @RandomLongitude = ( ( @UpperLongitude - @LowerLongitude - 1 )
                                     * RAND() + @LowerLongitude );

        INSERT  INTO #Points1
                SELECT  GEOGRAPHY::Point(@RandomLatitude, @RandomLongitude,
                                         4326)

        SET @Counter = @Counter - 1;
    END 

SELECT  
    Points1.PointId AS StartPointId,
    Points2.PointId AS EndPointId,
    Points1.Point.STDistance(Points2.Point) AS Distance
FROM #Points1 AS Points1
INNER JOIN #Points1 AS Points2 ON Points1.PointId <= Points2.PointId
WHERE Points1.Point.STDistance(Points2.Point) < @ThresholdInMeters

Any ideas on how to potentially improve this, especially in performance? All indices are already set.