Risks of cataract surgery
Modern cataract surgery is highly successful, but it is still eye surgery. This page outlines the main risks, why they occur, and how they are typically managed.
Common & expected
Uncommon
Rare but serious
Key idea
Most “complications” are either temporary side‑effects (e.g., dry/gritty eye) or treatable issues (e.g., inflammation, pressure rise). The small set of vision‑threatening events are uncommon but worth understanding.
Common, usually temporary
- Scratchy / dry eye (often worse for weeks; can be long‑term in some people).
- Light sensitivity, mild ache, watering.
- Corneal swelling (blur early; usually clears over days to weeks).
- Inflammation (treated with anti‑inflammatory drops).
- Floaters (often pre‑existing; new floaters should be reviewed).
- Posterior capsular opacification (“secondary cataract”) months/years later; usually treated with YAG laser.
Visual symptoms that can persist
- Dysphotopsias: haloes, glare, starbursts, edge shadows.
- Residual refractive error: under/over‑correction, astigmatism, “refractive surprise”.
- Reduced contrast (more noticeable with multifocal/EDOF lenses).
- Night‑driving difficulties (especially in the early adaptation period).
Uncommon intra‑operative complications
| Issue | What it means | Typical management |
|---|---|---|
| Posterior capsular rupture | Tear in the thin “bag” that holds the IOL; may allow vitreous to come forward. | May require anterior vitrectomy and a different IOL placement strategy. |
| Zonular weakness / lens instability | Support fibres are weak (e.g., pseudoexfoliation, trauma). | Capsular tension ring, alternative IOL fixation, or staged approach. |
| Dropped nucleus / lens fragments | Lens pieces fall posteriorly. | May need vitrectomy by a retinal surgeon (same day or later). |
| Suprachoroidal haemorrhage | Rare bleeding behind the retina/choroid; can threaten vision. | Immediate wound closure, pressure control; later retinal specialist care. |
Rare but serious post‑operative risks
- Endophthalmitis (intraocular infection): severe pain, marked redness, rapidly worsening vision.
- Retinal detachment: flashes, a “curtain”, shower of floaters; risk is higher with high myopia.
- Cystoid macular oedema (CME): blurred/distorted central vision weeks after surgery.
- Retinal vascular occlusion (artery/vein thrombosis): sudden vision loss.
- Corneal decompensation (e.g., in Fuchs dystrophy): persistent corneal swelling and haze.
Pressure and glaucoma‑related issues
- IOP spikes in the first day(s) can occur (often treatable with drops/tablets).
- Angle closure / narrow angles may improve after lens removal, but monitoring continues.
- Glaucoma progression remains possible independent of cataract surgery.
- If you already have glaucoma, ask whether you need combined surgery (e.g., MIGS) or staged procedures.
When to seek urgent review
Same day / emergency if you have any of the following after surgery:
- Severe pain or a rapidly worsening “deep ache”
- Sudden drop in vision
- Marked redness with discharge
- New flashes, a curtain/shadow, or many new floaters
- Nausea/vomiting with eye pain (possible pressure rise)
- Persistent severe photophobia
This is educational content and not personal medical advice. Always follow your surgeon’s specific post‑op instructions.