Skip to content

Diagnosis and preoperative assessment

TL;DR — Diagnosing cataract is easy; deciding whether to operate is not, because visual acuity is a poor gauge of cataract disability and the decision is properly a function-and-preference judgement (See 2019, PMID 30489358; Steinberg 1994, PMID 8185520). Routine preoperative medical testing is settled evidence: across three randomised trials covering 21,531 cataract surgeries there were 353 medical adverse events in the tested group and 354 in the untested group (OR 1.00, 95% CI 0.86–1.16, high-certainty evidence), no reduction in intraoperative (OR 0.99, 0.71–1.38) or postoperative ocular events, no difference in cancellations (OR 0.97, 0.78–1.21) — and costs 2.55 times higher with testing (Keay 2019, PMID 30616299; Schein 2000, PMID 10639542). What does change outcomes is ocular assessment: the ocular surface, the cornea, the macula and optic nerve, and accurate biometry. Anticoagulants and antiplatelets need not be stopped (Katz 2003, PMID 13129878), but α1-antagonist exposure must be elicited because intraoperative floppy iris syndrome occurs in about 2% of cataract operations and raises complication risk (Enright 2017, PMID 27653607).

The indication problem

Cataract surgery is indicated when lens opacity impairs function enough that the patient wants the operation and the eye is likely to benefit. Every clause is contestable. Visual acuity alone is explicitly described in the review literature as a poor gauge of cataract disability, which is why aberrometry, lens densitometry and light-scatter measures are being explored as adjuncts (PMID 30489358). The VF-14 correlated more strongly with patients' own rating of trouble with their vision than any acuity measure did (PMID 8185520), and is about three times more responsive to surgery than a generic health-status instrument (Cassard 1995, PMID 7487617). Modern Rasch-scaled instruments (Cat-PROM5, Catquest-9SF) have person reliability 0.90 and 0.88 with standardised responsiveness 1.45 and 1.47 SD, and are brief enough for routine services (Sparrow 2018, PMID 29386619; Lundström 2009, PMID 19251145). Work on combining acuity with PROMs into an explicit appropriateness-and-prioritisation tool is under way (Schlenker 2023, PMID 36028007).

Timing matters beyond the eye. Cataract surgery is one of the few single interventions with trial-level evidence for reducing falls (Tinetti 2010, PMID 20085954), and surgery is associated with lower fall rates (>30%) and lower rates of dementia (20–30%) in clinical review summaries (Chen 2025, PMID 40227658). Delay is not neutral: on a rationed New Zealand waiting list, patients waited a mean of 18.2 ± 11.6 months, only 49% were ultimately operated in the public sector, 12% had died, and mean acuity deteriorated by 0.05 logMAR from 6/30 to 6/36 while waiting (Riley 2001, PMID 11778807). See outcomes and quality of life and patient experience and advocacy.

Preoperative medical testing: what the trials show

Outcome Testing vs no/selective testing Certainty Source
Medical adverse events (707 total: 353 tested, 354 untested) OR 1.00 (0.86–1.16) High Keay 2019, PMID 30616299
Intraoperative ocular events OR 0.99 (0.71–1.38) Moderate PMID 30616299
Postoperative ocular events OR 1.11 (0.74–1.67) Moderate PMID 30616299
Cancellation of surgery OR 0.97 (0.78–1.21) High PMID 30616299
Cost 2.55× higher with routine testing Moderate PMID 30616299
Complication rate in the largest trial (19,557 operations, 18,189 patients) 31.3 per 1,000 operations in both arms; intraoperative 19.2 vs 19.7 per 1,000 — Schein 2000, PMID 10639542

The three trials included 61 hospitalisations and 3 deaths across 21,531 operations; most events were cardiovascular and intraoperative (PMID 30616299). The clinical translation is that no preoperative test is indicated for the cataract operation itself — testing may still be indicated for a patient's other health needs (Rusk 2016, PMID 27542420; Macias 2024, PMID 38278587). Commentaries have described this as an unusually clear case where evidence and practice diverged for decades (Schein 2021, PMID 33485473; Date 2017, PMID 28590284; Dupps 2016, PMID 27113870). Routine preoperative viral serology has been questioned on the same grounds (Kukkala 2025, PMID 40719730). Guideline synthesis now converges on avoiding routine preoperative medical tests for surgery under local anaesthesia (García Anguas 2025, PMID 41027307), and outpatient pathways without dedicated anaesthesia support have been shown to be safe in observational cohorts (Koolwijk 2015, PMID 25444350).

Systemic medications that do matter

Antithrombotics: continue. In a prospective cohort of 19,283 cataract operations, 24.2% of patients routinely used aspirin and 4.0% warfarin; rates of stroke, TIA or DVT were 1.5/1,000 in non-users and 3.8/1,000 in continuing users, with no events among warfarin users who stopped, and myocardial events were not different between continuers and discontinuers (Katz 2003, PMID 13129878). In the UK Cataract National Dataset (48,862 operations with recorded drug history), 28.1% took aspirin, 5.1% warfarin, 1.9% clopidogrel and 1.0% dipyridamole; any local-anaesthetic block complication was more frequent with clopidogrel (8.0%, P < 0.0001) or warfarin (6.2%, P = 0.0026) than in non-users (4.3%), and subconjunctival haemorrhage was commoner (clopidogrel 4.4%, warfarin 3.7% vs 1.7%) — but potentially sight-threatening haemorrhagic complications were not increased (Benzimra 2009, PMID 18259210). Practical perioperative guidance for traditional and newer agents is reviewed in (Kong 2015, PMID 25425711).

α1-antagonists: ask, don't stop reflexively. Intraoperative floppy iris syndrome occurs in about 2% of cataract operations and is associated with increased complication risk; tamsulosin carries the highest risk, but antipsychotics and hypertension are also implicated and women are susceptible, so screening should cover both sexes and current or prior exposure (PMID 27653607). Some surgeons temporarily discontinue tamsulosin preoperatively (PMID 40227658), but the pupil changes are not reliably reversible on withdrawal; the practical response is a graded set of intraoperative measures.

Diabetes. Fixed HbA1c thresholds should not by themselves determine timing; a macula-first approach integrating OCT and retinal co-management is now recommended, with lens choice avoiding multifocal optics in eyes with diabetic macular disease (Garcia-Cabrera 2026, PMID 41343850; Xia 2022, PMID 35445624).

The ocular examination that changes management

Domain What is assessed Why it changes the plan Source
Ocular surface Tear film, dry eye disease, epithelial basement membrane dystrophy, Salzmann nodules, pterygium Erroneous keratometry → refractive surprise; surgery itself induces or worsens OSD Venkateswaran 2022, PMID 36211316; Sarnicola 2024, PMID 38018802
Cornea Endothelial cell count and guttata, irregular astigmatism, keratoconus, prior refractive surgery Determines decompensation risk, formula choice and whether toric or premium optics are viable Sarnicola 2026, PMID 41175387; Ting 2024, PMID 37962882
Macula and optic nerve OCT for macular disease; disc and field for glaucoma Determines achievable acuity and contraindicates multifocal optics PMID 41343850; Grzybowski 2020, PMID 31955239
Pupil, zonules and lens position Dilation, phacodonesis, pseudoexfoliation, lens decentration Predicts zonular complications and need for capsular support Crandall 2018, PMID 29965904; Hayashi 2024, PMID 38290806
Axial length extremes Very short or very long eyes; high myopia Changes formula choice and complication profile; only 63% of eyes with axial length >26 mm achieve ≥20/40 Elhusseiny 2023, PMID 36473016
Functional vision PROM, glare/contrast, driving and reading needs Establishes whether operating is likely to help this person PMID 29386619; PMID 36028007

Pseudoexfoliation deserves specific mention: in 315 consecutive PXF eyes, 9.84% required scleral IOL fixation or a capsular tension ring, and the risk was stratified by mydriasis <6.30 mm, anterior chamber depth <2.074 mm and lens decentration >0.260 mm — with odds ratios of 4.81 for poor mydriasis alone, 23.99 with a shallow chamber added, and 287.39 with all three (PMID 38290806).

Biometry

Accurate biometry is the single technical determinant of the refractive result. Swept-source OCT biometers show excellent repeatability and reproducibility across keratometry, central corneal thickness, white-to-white, anterior chamber depth, lens thickness, axial length and pupil diameter, and are described as likely to become the gold standard — with the caveat that between-device agreement for some parameters is not good enough to treat devices as interchangeable (Montés-Micó 2021, PMID 33315731). Even in routine practice, systematic between-centre differences exist: in 2,143 consecutive eyes across 12 Japanese sites, axial length (P = 0.003), anterior chamber depth, lens thickness and central corneal thickness all differed significantly between sites, while mean keratometry (P = 0.587) and corneal astigmatism (P = 0.304) did not; and formula choice mattered — SRK/T gave significantly more hyperopic and larger absolute error than Barrett Universal II (P = 0.016) (Kamiya 2022, PMID 34108223).

Two preoperative situations demand special handling because ordinary keratometry is invalid: prior corneal refractive surgery, where total keratometry, ray tracing, intraoperative aberrometry and machine-learning formulas are needed (PMID 37962882), and keratoconus, where keratoconus-specific formulas with measured posterior corneal curvature improve accuracy but prediction errors remain higher than in normal eyes (PMID 41175387). Both are developed in IOL power calculation.

Ocular-surface optimisation before biometry is not cosmetic. Dry eye, epithelial basement membrane dystrophy, Salzmann nodules and pterygia all distort keratometry, and treating them before measurement is the recommended sequence (PMID 36211316); the relationship is bidirectional, since surgery induces or exaggerates ocular surface disease which then degrades the refractive outcome (PMID 38018802). Optimising the tear film, integrating topography and tomography, and using advanced formulas are presented as the practical route to hitting target refraction (Narang 2024, PMID 37962881; Khoramnia 2022, PMID 35204334).

How risk is presented changes how it is perceived. In a randomised study of 100 patients referred for cataract surgery, framing the same information positively ("99% chance of no adverse effects") versus negatively ("1% chance of adverse effects") produced median risk-perception scores of 2 (IQR 1–2) versus 3 (1–3) (p < 0.0001), and framing was the only significant factor — no patient demographic or clinical characteristic mattered (Martinez 2024, PMID 38729627). There is no recommended standard way to communicate cataract surgical risk (PMID 38729627).

Consent also covers who operates. In a prospective survey of 330 consecutive patients, 71% consented to resident participation; a prior negative experience with any medical trainee independently predicted refusal (OR 3.10, 95% CI 1.32–7.28, p = 0.009) (Pur 2023, PMID 35623411). Decision-making context shifts over time within the same service (Weingessel 2019, PMID 30284377).

Where premium optics are being considered, the expectation conversation must be explicit about spectacle independence, photic phenomena, contrast and the effect of co-pathology — see intraocular lenses. Artificial-intelligence decision support is beginning to appear both in surgical decision-making for complex eyes (Su 2025, PMID 40977894) and in preoperative anaesthetic assessment (Guerrier 2025, PMID 40973582), without prospective outcome evidence.

Open questions

  • Can a PROM-based indication rule outperform an acuity threshold? Rasch-validated instruments exist and perform well (PMID 29386619; PMID 19251145), and prototype appropriateness tools have been described (PMID 36028007), but no health system has published a prospective comparison against acuity criteria for equity of access, outcome and cost.
  • What replaces routine testing? The Cochrane review explicitly proposes self-administered health questionnaires as a substitute for history and physical examination (PMID 30616299); no trial has evaluated such a substitution.
  • Should tamsulosin be stopped? IFIS risk is established and guidelines have been revised (PMID 27653607), yet no randomised comparison of continuation versus preoperative discontinuation with complication endpoints was identified in this session's searches.
  • How much does ocular-surface optimisation improve refractive outcomes? A prospective self-controlled study in 55 treated eyes with moderate-to-severe dry eye reported an increase from 66% to 94% within ±0.50 D after cryopreserved amniotic membrane treatment (p < 0.001) (Wongskhaluang 2025, PMID 40589536). The result is not a randomised effect estimate: 95% of participants were female, 9 of 64 enrolled eyes did not complete, and the before-treatment prediction was compared with the achieved refraction after treatment.
  • Are biometers interchangeable? SS-OCT devices are highly repeatable but agreement between devices is flagged as insufficient for interchangeability in some parameters (PMID 33315731), and inter-centre biometric differences are real (PMID 34108223); no consensus minimum dataset for reporting device and constant has been adopted.

References

  1. See CW, Iftikhar M, Woreta FA. Preoperative evaluation for cataract surgery. Current opinion in ophthalmology. 2019;30:3-8. PMID 30489358
  2. Steinberg EP, Tielsch JM, Schein OD, et al. The VF-14. An index of functional impairment in patients with cataract. Archives of ophthalmology (Chicago, Ill. : 1960). 1994;112:630-8. PMID 8185520
  3. Keay L, Lindsley K, Tielsch J, et al. Routine preoperative medical testing for cataract surgery. The Cochrane database of systematic reviews. 2019;1:CD007293. PMID 30616299
  4. Schein OD, Katz J, Bass EB, et al. The value of routine preoperative medical testing before cataract surgery. Study of Medical Testing for Cataract Surgery. The New England journal of medicine. 2000;342:168-75. PMID 10639542
  5. Katz J, Feldman MA, Bass EB, et al. Risks and benefits of anticoagulant and antiplatelet medication use before cataract surgery. Ophthalmology. 2003;110:1784-8. PMID 13129878
  6. Enright JM, Karacal H, Tsai LM. Floppy iris syndrome and cataract surgery. Current opinion in ophthalmology. 2017;28:29-34. PMID 27653607
  7. Cassard SD, Patrick DL, Damiano AM, et al. Reproducibility and responsiveness of the VF-14. An index of functional impairment in patients with cataracts. Archives of ophthalmology (Chicago, Ill. : 1960). 1995;113:1508-13. PMID 7487617
  8. Sparrow JM, Grzeda MT, Frost NA, et al. Cataract surgery patient-reported outcome measures: a head-to-head comparison of the psychometric performance and patient acceptability of the Cat-PROM5 and Catquest-9SF self-report questionnaires. Eye (London, England). 2018;32:788-795. PMID 29386619
  9. Lundström M, Pesudovs K. Catquest-9SF patient outcomes questionnaire: nine-item short-form Rasch-scaled revision of the Catquest questionnaire. Journal of cataract and refractive surgery. 2009;35:504-13. PMID 19251145
  10. Schlenker MB, Sayal AP, Yang M, et al. Visual acuity, patient-reported outcome measures, or both? The development of an evidence-based appropriateness and prioritization tool for cataract surgery patients. Canadian journal of ophthalmology. Journal canadien d'ophtalmologie. 2023;58:e74-e76. PMID 36028007
  11. Tinetti ME, Kumar C. The patient who falls: "It's always a trade-off". JAMA. 2010;303:258-66. PMID 20085954
  12. Chen SP, Woreta F, Chang DF. Cataracts: A Review. JAMA. 2025;333:2093-2103. PMID 40227658
  13. Riley AF, Grupcheva CN, Malik TY, et al. The waiting game: natural history of a cataract waiting list in New Zealand. Clinical & experimental ophthalmology. 2001;29:376-80. PMID 11778807
  14. Rusk MH. Avoiding Unnecessary Preoperative Testing. The Medical clinics of North America. 2016;100:1003-8. PMID 27542420
  15. Macias AA, Goldfarb J. Preoperative Evaluation of Patients Undergoing Eye Surgery. Anesthesiology clinics. 2024;42:159-168. PMID 38278587
  16. Schein OD. Preoperative Medical Evaluation for Cataract Surgery: Finally an Opportunity for Common Medical Sense to Prevail. Ophthalmology. 2021;128:216-217. PMID 33485473
  17. Date RC, Al-Mohtaseb ZN. Advances in Preoperative Testing for Cataract Surgery. International ophthalmology clinics. 2017;57:99-114. PMID 28590284
  18. Dupps WJ. Preoperative screening for occult disease in cataract surgery candidates. Journal of cataract and refractive surgery. 2016;42:513-4. PMID 27113870
  19. Kukkala A, Vardhan A. Preoperative viral screening in cataract surgery: Essential or excessive?. Indian journal of ophthalmology. 2025;73:1221-1222. PMID 40719730
  20. García Anguas M, Seva-Llor AM, Cabrera Beyrouti R. Cataract care process: Systematic review of clinical guidelines and synthesis of recommendations. Journal of healthcare quality research. 2025;40:101161. PMID 41027307
  21. Koolwijk J, Fick M, Selles C, et al. Outpatient cataract surgery: incident and procedural risk analysis do not support current clinical ophthalmology guidelines. Ophthalmology. 2015;122:281-7. PMID 25444350
  22. Benzimra JD, Johnston RL, Jaycock P, et al. The Cataract National Dataset electronic multicentre audit of 55,567 operations: antiplatelet and anticoagulant medications. Eye (London, England). 2009;23:10-6. PMID 18259210
  23. Kong KL, Khan J. Ophthalmic patients on antithrombotic drugs: a review and guide to perioperative management. The British journal of ophthalmology. 2015;99:1025-30. PMID 25425711
  24. Garcia-Cabrera CR, Afshari NA. Cataract surgery in patients with diabetes mellitus: preoperative, intraoperative, and postoperative considerations. Current opinion in ophthalmology. 2026;37:42-47. PMID 41343850
  25. Xia Y. The management of cataract surgery in diabetic patients. Journal of perioperative practice. 2022;32:361-367. PMID 35445624
  26. Venkateswaran N, Luna RD, Gupta PK. Ocular surface optimization before cataract surgery. Saudi journal of ophthalmology : official journal of the Saudi Ophthalmological Society. 2022;36:142-148. PMID 36211316
  27. Sarnicola E, Sarnicola C, De Bernardo M, et al. Cataract surgery in setting of ocular surface disease. Current opinion in ophthalmology. 2024;35:155-162. PMID 38018802
  28. Sarnicola C, Sarnicola E, Sarnicola V. Cataract surgery in keratoconus: current challenges and future directions. Current opinion in ophthalmology. 2026;37:11-15. PMID 41175387
  29. Ting D, Gatinel D, Ang M. Cataract surgery after corneal refractive surgery: preoperative considerations and management. Current opinion in ophthalmology. 2024;35:4-10. PMID 37962882
  30. Grzybowski A, Kanclerz P, Tuuminen R. Multifocal intraocular lenses and retinal diseases. Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie. 2020;258:805-813. PMID 31955239
  31. Crandall AS. Exfoliation Syndrome and Cataract Surgery. Journal of glaucoma. 2018;27 Suppl 1:S102-S104. PMID 29965904
  32. Hayashi K, Yoshida M, Manabe SI, et al. High-risk factors for zonular complications during cataract surgery in eyes with pseudoexfoliation syndrome. The British journal of ophthalmology. 2024;108:1193-1199. PMID 38290806
  33. Elhusseiny AM, Salim S. Cataract surgery in myopic eyes. Current opinion in ophthalmology. 2023;34:64-70. PMID 36473016
  34. Montés-Micó R, Pastor-Pascual F, Ruiz-Mesa R, et al. Ocular biometry with swept-source optical coherence tomography. Journal of cataract and refractive surgery. 2021;47:802-814. PMID 33315731
  35. Kamiya K, Hayashi K, Tanabe M, et al. Nationwide multicentre comparison of preoperative biometry and predictability of cataract surgery in Japan. The British journal of ophthalmology. 2022;106:1227-1234. PMID 34108223
  36. Narang R, Agarwal A. Refractive cataract surgery. Current opinion in ophthalmology. 2024;35:23-27. PMID 37962881
  37. Khoramnia R, Auffarth G, Łabuz G, et al. Refractive Outcomes after Cataract Surgery. Diagnostics (Basel, Switzerland). 2022;12. PMID 35204334
  38. Martinez DL, Ahmed IIK, Schlenker MB. Risk communication in cataract surgery. BMJ open ophthalmology. 2024;9. PMID 38729627
  39. Pur DR, Lin T, Iordanous Y, et al. Patient perspective on the participation of ophthalmology residents in their cataract surgery. Canadian journal of ophthalmology. Journal canadien d'ophtalmologie. 2023;58:443-448. PMID 35623411
  40. Weingessel B, Wahl M, Huf W, et al. Decision-making for cataract surgery: Changes within 7 years. Acta ophthalmologica. 2019;97:e139-e140. PMID 30284377
  41. Su K, He W, Jiang H, et al. Artificial intelligence applications facilitate decision-making in cataract surgery for highly myopic patients. Frontiers in cell and developmental biology. 2025;13:1613634. PMID 40977894
  42. Guerrier G, Cargeac A, Courtois F, et al. Effectiveness of artificial intelligence as a support tool in preoperative anaesthesia assessments for cataract surgery: a step towards enhancing patient management. British journal of anaesthesia. 2025;135:1383-1385. PMID 40973582
  43. Wongskhaluang J. Optimization of the Ocular Surface Prior to Cataract Surgery Using Cryopreserved Amniotic Membrane. Clinical ophthalmology (Auckland, N.Z.). 2025;19:1975-1983. PMID 40589536