Intangible Assets

6 Months Ended

Jun. 30, 2020

Goodwill And Intangible Assets Disclosure [Abstract]

Intangible Assets

5. Intangible Assets

The reconciliation of intangible assets for the six months ended June 30, 2020 and 2019 was as follows (in thousands):

	June 30,			June 30,
	2020			2019
Patented technologies
Gross carrying cost at beginning of period	$	68,322		$	68,322
Gross carrying cost at end of period		68,322			68,322
Accumulated amortization at beginning of period		(40,653	)		(38,193	)
Amortization expense		(1,230	)		(1,230	)
Accumulated amortization at end of period		(41,883	)		(39,423	)
Net book value at end of period	$	26,439		$	28,899

The Company amortizes intangible assets with finite lives on a straight-line basis over their respective estimated useful lives. Amortization of intangible assets totaled $615,000 and $1.2 million for each of the three and six months ended June 30, 2020 and 2019, respectively.  

In connection with the Icon Acquisition in March 2018, the initial purchase price was attributed to the DEXYCU product intangible asset. This finite-lived intangible asset is being amortized on a straight-line basis over its expected remaining useful life of 10.75 years at the rate of approximately $2.5 million per year. Amortization expense was reported as a component of cost of sales for the three and six months ended June 30, 2020 and 2019, respectively.