[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Ophthalmology](https://durgical.com/en/ophthalmology/) › [The eye exam](https://durgical.com/en/ophthalmology/areas/exam/) › OCT, fundus photography and angiography # OCT, fundus photography and angiography - Examination OCT gives a cross-section of the retina, photographs screen and document it, and angiography shows how blood flows and leaks. Each answers a different question. Updated Nov 5, 2026 **See it in 3D:** [Retina](https://durgical.com/en/anatomy/retina/) · [Macula](https://durgical.com/en/anatomy/macula/) · [Optic disc](https://durgical.com/en/anatomy/optic-disc/) ## Key points - OCT = cross-section of the retina, no contact, no dye. - Fluorescein angiography = leakage, non-perfusion, new vessels. - Yellow skin and urine after fluorescein are expected. - Retinal photography enables diabetic screening by telemedicine. ## What it is Ophthalmology relies on imaging that the general doctor rarely orders but often reads in reports. Optical coherence tomography (OCT) uses light to make micrometre-scale cross-sections of the retina and optic nerve. Fundus photography records the retina and is the basis of diabetic retinopathy screening and telemedicine. Fluorescein angiography, with dye injected into a vein, shows leakage, blocked capillaries and new vessels. OCT angiography shows vessels without dye. ## Normal values and scales - OCT shows macular oedema, fluid in neovascular macular degeneration, macular holes and the thickness of the nerve fibre layer in glaucoma. - Fluorescein angiography shows capillary non-perfusion, new vessels and leakage. - After fluorescein the skin and urine turn yellow for a day; nausea is common and severe allergic reactions are rare. - Retinal photographs graded remotely allow diabetic screening where there are few ophthalmologists. ## How it is done - OCT: the patient looks at a target while a scan of the macula or optic disc is taken in seconds, without contact or dye. - Fundus photography: one or more images of the posterior pole, through dilated or undilated pupils; wide-field cameras capture the periphery. - Fluorescein angiography: dye is injected into an arm vein and serial photographs record its passage through the retinal and choroidal vessels. - The ophthalmologist compares the images with previous ones to judge change. ## How to interpret it - Anti-VEGF treatment of macular degeneration and diabetic macular oedema is guided by repeated OCT. - Thinning of the nerve fibre layer on OCT can precede field loss in glaucoma. - OCT of the optic disc helps follow papilloedema and separate it from disc drusen. ## Next step / Initial management - Report of new fluid or haemorrhage at the macula: ophthalmology within days. - Abnormal diabetic screening photograph: refer according to the grade (urgent for proliferative disease). - Before fluorescein angiography: ask about allergy, pregnancy and kidney disease, and have resuscitation available. - Imaging complements the clinical exam; it does not replace measuring acuity and examining the eye. ## Test yourself Think of the answer, then tap the question to see it. ## Which test shows macular oedema as a cross-section without dye? Optical coherence tomography (OCT). ## What does fluorescein angiography show that OCT does not? The dynamic passage of dye through the vessels: leakage, non-perfused capillaries and new vessels. ## What expected effects follow fluorescein angiography? Yellow discoloration of skin and urine for about a day, and sometimes nausea. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/ophthalmology/oct-fundus-photography-and-angiography/) ## Connections ## See it in 3D 3 The structures of Durgical's 3D anatomy where it is found. - [Retina](https://durgical.com/en/anatomy/retina/) - [Macula](https://durgical.com/en/anatomy/macula/) - [Optic disc](https://durgical.com/en/anatomy/optic-disc/) ## Related 4 - [The retina and macula as seen on OCT](https://durgical.com/en/ophthalmology/the-retina-and-macula-as-seen-on-oct/) - [Intravitreal anti-VEGF injections](https://durgical.com/en/ophthalmology/intravitreal-anti-vegf-injections/) - [Diabetes and the eye: screening and grading](https://durgical.com/en/ophthalmology/diabetes-and-the-eye-screening-and-grading/) - [The optic disc: cup, rim and colour](https://durgical.com/en/ophthalmology/the-optic-disc-cup-rim-and-colour/) ## Related conditions 4 - [Age-related macular degeneration](https://durgical.com/en/conditions/age-related-macular-degeneration/) - [Diabetic retinopathy](https://durgical.com/en/conditions/diabetic-retinopathy/) - [Open-angle glaucoma](https://durgical.com/en/conditions/open-angle-glaucoma/) - [Central retinal vein occlusion](https://durgical.com/en/conditions/central-retinal-vein-occlusion/) ## In Pharmacology 1 - [Fluorescein](https://durgical.com/en/pharmacology/fluorescein/) [← All of ophthalmology](https://durgical.com/en/ophthalmology/) Educational content; not a clinical guideline and no substitute for assessment by a health professional. For sudden visual loss, severe eye pain, a chemical burn or an eye injury, go to an emergency department at once. Sources: [Optical Coherence Tomography](https://www.ncbi.nlm.nih.gov/books/NBK606122/) (StatPearls Publishing (NCBI Bookshelf), 2024); [Fluorescein Angiography](https://www.ncbi.nlm.nih.gov/books/NBK576378/) (StatPearls Publishing (NCBI Bookshelf), 2023); [Fundus Camera](https://www.ncbi.nlm.nih.gov/books/NBK585111/) (StatPearls Publishing (NCBI Bookshelf), 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/ophthalmology/oct-fundus-photography-and-angiography/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/ophthalmology/oct-fundus-photography-and-angiography/