Cataracts — master index¶
Last curated: 2026-08-31 · status: rebuilt at audit; all pages remain draft pending independent re-audit by a different engine
The condition in five sentences. Cataract is loss of crystalline-lens transparency — nuclear, cortical or posterior subcapsular, often mixed — and its molecular core is oxidation of crystallin protein once a transport barrier isolates the lens nucleus in middle age (Truscott 2005, PMID 15862178; Chylack 1993, PMID 8512486). It is the single largest cause of blindness in the world: 15.2 million blind and 78.8 million with moderate-or-severe vision impairment among adults aged ≥50 in 2020, and 17.0 million blind (39.6% of all blindness) on the all-ages cataract-specific model, 60% of them women (GBD Vision Loss Expert Group 2021, PMID 33275949; Vision Loss Expert Group 2024, PMID 38461217). Surgery is the only established treatment and among the most cost-effective operations in medicine, yet age-standardised cataract blindness fell 27.5% between 1990 and 2020 while the absolute cataract-blind count rose 29.7%, because ageing and population growth outran surgical capacity (PMID 38461217; Lansingh 2007, PMID 17383730). The World Health Assembly's replacement target — a 30-percentage-point rise in effective cataract surgical coverage by 2030 — is not on track, with a modelled rise of 8.4 points (95% CI 8.1–8.6) between 2020 and 2030 (McCormick 2026, PMID 41687671). The field's two recurring intellectual problems are therefore that visual acuity is a poor measure of what cataract takes away, and that rare surgical harms need denominators no trial can supply.
Start here: overview.md. Research frontier: OPEN-QUESTIONS.md. Growth history: LOG.md.
At a glance¶
| Layer | Built content |
|---|---|
| Canonical wiki pages | 22/22 written; all draft |
| Distinct live-verified PMIDs cited | 447 |
| Citations per page | 22–55 (median 40) |
| Landmark paper notes | 6 |
| Tiered open questions | 23, plus a 12-row "dots not yet connected" table |
| ClinicalTrials.gov records verified and displayed | 25 |
Reading paths¶
| Reader goal | Path |
|---|---|
| Understand the condition | overview → classification and grading → lens biology and pathogenesis → risk factors |
| Plan adult surgery | diagnosis and preoperative assessment → IOL power calculation → intraocular lenses → anaesthesia and perioperative care → surgical technique → complications |
| Compare lenses | intraocular lenses → IOL power calculation → posterior capsule opacification → outcomes and quality of life |
| Operate on a difficult eye | surgery with coexisting eye disease → secondary and traumatic cataract → complications |
| Study global delivery | epidemiology and global burden → access, equity and service delivery → patient experience and advocacy |
| Review safety | complications → red flags and safety concerns → guidelines |
| Understand children's disease | congenital and paediatric cataract → IOL power calculation → posterior capsule opacification |
| Find research gaps | clinical trials landscape → non-surgical and preventive approaches → open questions |
Pages¶
| File | Scope | Refs | Status |
|---|---|---|---|
| overview.md | What cataract is, the burden, what surgery does and does not fix, map of the knowledge base | 40 | draft |
| classification-and-grading.md | Nuclear/cortical/PSC phenotypes, LOCS III and its predecessors, WHO simplified system, objective and deep-learning grading | 26 | draft |
| epidemiology-and-global-burden.md | Definitions that control the numbers, global counts, the rate-versus-count paradox, incidence, regional concentration, the 2030 target | 27 | draft |
| lens-biology-and-pathogenesis.md | Crystallin packing and chaperones, the glutathione barrier hypothesis, oxidative markers, aggregation reversal, lens epithelial cells | 25 | draft |
| risk-factors.md | Age, sex, smoking, corticosteroids, diabetes, UV, drugs, alcohol, nutrition — with effect sizes and their confounding | 30 | draft |
| congenital-and-paediatric-cataract.md | Prevalence, genetics, detection and timing, IATS and TAPS, glaucoma risk, myopic shift, optical correction, cost | 40 | draft |
| secondary-and-traumatic-cataract.md | Trauma, uveitis, post-vitrectomy and post-injection cataract, drugs, radiation, retinitis pigmentosa | 32 | draft |
| diagnosis-and-preoperative-assessment.md | The indication problem, the negative preoperative-testing evidence, medications that matter, the ocular examination, biometry, consent | 42 | draft |
| iol-power-calculation.md | Prediction error as endpoint, biometry inputs, formula generations, short and long eyes, post-refractive and irregular corneas, paediatric eyes | 41 | draft |
| intraocular-lenses.md | Optical classes, comparative evidence, toric correction, dysphotopsia, material and edge design, selection and economics | 35 | draft |
| anaesthesia-and-perioperative-care.md | Anaesthetic options and their complication associations, systemic risk, antithrombotics, perioperative drugs, ISBCS, process safety | 49 | draft |
| surgical-technique.md | Phacoemulsification, MSICS, ECCE, femtosecond assistance, difficult eyes, learning curve, setting and cost | 35 | draft |
| complications.md | Frequency table, posterior capsule rupture, dropped nucleus, endophthalmitis, CME, corneal and IOP problems, retinal detachment, risk-adjusted audit | 53 | draft |
| posterior-capsule-opacification.md | Mechanism, endpoint definitions, incidence, edge and material effects, drugs, Nd:YAG and its costs, special populations | 33 | draft |
| surgery-with-coexisting-eye-disease.md | Glaucoma, AMD, diabetic retinopathy, corneal endothelial disease, pseudoexfoliation, uveitis, previous vitrectomy | 55 | draft |
| outcomes-and-quality-of-life.md | The six outcome domains, PROMs and their minimum important differences, falls and driving, registry benchmarks and risk adjustment | 44 | draft |
| access-equity-and-service-delivery.md | CSR/CSC/eCSC, the 2030 target trajectory, affordability, workforce and technique, equity gradients, implementation | 41 | draft |
| non-surgical-and-preventive-approaches.md | Why no reversing drug exists, the negative randomised record, aggregation reversal, delivery chemistry, behavioural prevention | 35 | draft |
| guidelines.md | The main documents, where guidance converges and diverges, NICE recommendations verified live, guideline quality | 41 | draft |
| clinical-trials-landscape.md | Landmark randomised trials, what is registered now, why cataract trials are hard, trial-shaped gaps | 36 | draft |
| red-flags-and-safety-concerns.md | Postoperative emergencies, endophthalmitis vs TASS vs HORV, preoperative flags, drug safety, unvalidated products | 48 | draft |
| patient-experience-and-advocacy.md | Experience before surgery, waiting, consent and expectations, satisfaction and its exceptions, access as experience, organisations | 39 | draft |
Literature layer¶
| Resource | Contents | Status |
|---|---|---|
| BIBLIOGRAPHY.md | 447 records grouped by canonical page, cited-by lines generated from the page files | verified at audit |
| notes/ | Six landmark notes: LOCS III, the ESCRS endophthalmitis trial, FACT, the GBD cause analysis, IATS at 10.5 years, and the Study of Medical Testing for Cataract Surgery | rewritten at audit |
| guidelines/REGISTRY.md | Guideline catalogue with per-entry HTTP re-verification results; geographically incomplete by its own statement | re-verified at audit |
| statistics/STATISTICS.md | Source-specific quantitative tables; one numeric error corrected at audit | re-verified at audit |
| patient-voice/ | Method and ethics, verified organisations, aggregate themes, annotated sources | re-verified at audit |
Search and verification provenance¶
- PubMed E-utilities, 2026-08-31 (audit session): all 363 previously cited identifiers re-fetched and confirmed; ~40 additional topic searches run to fill gaps; 447 distinct records now cited, every one retrieved live in this session.
- ClinicalTrials.gov API v2, 2026-08-31: all 25 cited NCT records retrieved individually and confirmed, plus a status-filtered sweep of the "cataract" condition.
- Web endpoints, 2026-08-31: eight patient-organisation URLs re-requested (all HTTP 200); guideline endpoints re-requested with per-entry results recorded in the registry — two did not return HTTP 200 and are marked unconfirmed rather than removed.
- Status: no page was promoted to
curated. The audit found the authored pages unusable and rewrote them, so the current text has not been checked by an engine other than its author. A fresh independent audit by a different engine is required before promotion.