Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statements of Operations
Collaboration revenue	$ 41,259us-gaap_SalesRevenueServicesNet
Costs and expenses:
Research and development	88,385us-gaap_ResearchAndDevelopmentExpense	33,215us-gaap_ResearchAndDevelopmentExpense	6,792us-gaap_ResearchAndDevelopmentExpense
General and administrative	33,387us-gaap_GeneralAndAdministrativeExpense	14,210us-gaap_GeneralAndAdministrativeExpense	6,889us-gaap_GeneralAndAdministrativeExpense
Total costs and expenses	121,772us-gaap_CostsAndExpenses	47,425us-gaap_CostsAndExpenses	13,681us-gaap_CostsAndExpenses
Income (loss) from operations	(80,513)us-gaap_OperatingIncomeLoss	(47,425)us-gaap_OperatingIncomeLoss	(13,681)us-gaap_OperatingIncomeLoss
Interest income (expense)	217	(1,454)	(507)
Loss on extinguishment of debt		(1,091)
Other loss		(1,175)opht_OtherLoss	(374)opht_OtherLoss
Loss before income tax provision	(80,296)	(51,145)	(14,562)
Income tax provision	(17,892)us-gaap_IncomeTaxExpenseBenefit
Net loss	(98,188)us-gaap_NetIncomeLoss	(51,145)us-gaap_NetIncomeLoss	(14,562)us-gaap_NetIncomeLoss
Add: accretion of preferred stock dividends		(5,891)	(7,063)
Net income (loss) attributable to common stockholders	$ (98,188)	$ (57,036)	$ (21,625)
Net income (loss) attributable to common stockholders per share :
Basic and diluted (in dollars per share)	$ (2.95)us-gaap_EarningsPerShareBasicAndDiluted	$ (6.34)us-gaap_EarningsPerShareBasicAndDiluted	$ (14.89)us-gaap_EarningsPerShareBasicAndDiluted
Weighted average common shares outstanding:
Basic and diluted (in shares)	33,258	9,003	1,452

Amount of expense (income) related to adjustment to fair value of warrant liability, and other misc income or expense.

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Total costs of sales and operating expenses for the period.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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Accretion of temporary equity during the period due to cash, stock, and in-kind dividends. This item is an adjustment to net income necessary to derive net income apportioned to common stockholders and is to be distinguished from Temporary Equity, Accretion of Dividends (Temporary Equity, Accretion of Dividends).

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Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

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