Ophthalmic Imaging

What it is — light-based, non-contact cross-sections of retina and optic nerve at micron resolution. No dye, no needles; a chin rest and steady fixation.

Macular OCT — thickness maps plus anatomy: intraretinal and subretinal fluid, macular holes, epiretinal membranes; the injection-clinic scorecard.

Glaucoma OCT — peripapillary RNFL and ganglion-cell scans quantify nerve-fiber loss before fields change.

OCT-A — repeated scans turn moving blood into contrast: retinal flow maps with zero dye.

Quality discipline — check signal strength before saving. Low signal and blurred layers usually mean media opacity, a dried-out tear film, or movement: blink, artificial tears, re-align, rescan. Small pupils and dense cataract may still force dilation. Quality problems recognized at the chair never get misread as disease later.

Fluorescein angiography (FA) — IV dye photographed through timed phases: choroidal flush → arterial → arteriovenous/venous → late. Missed phases can't be re-shot. Prep: consent, IV access, explain the sequence and the darkness, coach fixation. Warn about expected effects — brief nausea, yellow skin and urine for a day — while the emergency kit stays ready for the rare true allergic reaction.

ICG angiography — infrared dye imaging of the CHOROIDAL circulation; allergy screening classically includes iodine sensitivity.

Fundus autofluorescence — the RPE's own glow maps its health, dye-free.

Color and stereo disc photography — the glaucoma baseline every future visit compares against; stereo pairs add cup depth.

Red-free (green) filter — darkens blood and reveals vessels, hemorrhages, and nerve-fiber striations.

Anterior segment and widefield — slit-lamp photos date-stamp lid and corneal findings; ultra-widefield systems sweep the periphery, sometimes without full dilation.

The photographer's craft — focus, alignment, lid/lash/blink artifact control — and the non-negotiable: verify patient, eye (OD/OS), and date on every saved image.