For an otherwise healthy adult with age‑related cataract, what are the indications for intra‑ocular lens implantation, required pre‑operative evaluation, preferred IOL choice and surgical technique, postoperative medication regimen and follow‑up, and non‑surgical alternatives if surgery is contraindicated?

Intraocular Lens Implantation for Age-Related Cataract

Indications for Surgery

Cataract extraction with IOL implantation is medically necessary when lens opacity causes visual decline that no longer meets the patient's daily functional needs and surgery offers reasonable likelihood of improvement. 1, 2, 3

The primary surgical indication is functional visual impairment affecting activities such as reading, driving, or work tasks, even when visual acuity measurements appear adequate. 3, 4 Surgery is also indicated when cataract prevents adequate visualization of posterior segment pathology requiring diagnosis or management, regardless of visual potential. 2

Do not perform surgery if tolerable refractive correction already provides satisfactory vision and no other indication exists for lens removal. 3, 4

Absolute Contraindications

• Patient cannot safely undergo surgery due to coexisting medical or ocular conditions 3
• Surgery will not improve visual function and no other indication for lens removal exists 3
• Active or recently active uveitis requiring ongoing treatment 1
• Uncontrolled glaucoma 1
• Corneal endothelial disease including Fuchs dystrophy 1

Required Preoperative Evaluation

Essential Testing

• B-scan ultrasonography is mandatory to exclude posterior segment pathology that could affect surgical planning and prognosis, particularly when cataract obscures fundus visualization. 2
• IOL power calculation using standard biometry; when corneal irregularity exists, employ multiple biometry methods to improve accuracy. 2
• Potential acuity testing has limited predictive value when anterior segment pathology obstructs the optical pathway but should be performed. 2

Medical Clearance

Routine preoperative medical testing (ECG, chest radiography, laboratory studies) is not required for cataract surgery in otherwise healthy adults. 1 Focus evaluation on ocular factors affecting surgical risk and visual prognosis. 1

Preferred IOL Choice and Surgical Technique

Standard Surgical Approach

Sutureless small-incision phacoemulsification with foldable IOL implantation is the preferred technique, producing superior uncorrected distance visual acuity and lower complication rates compared to other methods. 3, 4 This approach allows smaller incisions with faster healing. 2

IOL Selection

• Standard monofocal IOLs remain the most predictable option for most patients 1
• Trifocal IOLs provide good visual acuity at far, intermediate, and near distances (0.1 logMAR or better at all ranges) with high patient satisfaction despite some optical phenomena 5
• Phakic IOLs are approved only for refractive correction in patients without visually significant cataract and are not indicated for standard cataract surgery 1

Special Circumstances

When anterior segment complexity exists (corneal scarring, posterior synechiae, inflammatory history), phacoemulsification with foldable IOL remains preferred despite technical challenges. 2 For secondary IOL implantation after complications, retropupillary iris-claw IOLs provide the lowest prediction error and absolute error. 6

Postoperative Medication Regimen

Standard Protocol

• Topical antibiotic: Moxifloxacin 0.5% (preservative-free) three times daily for 7 days 2
• Topical corticosteroid: Prednisolone acetate 1% (preservative-free) four times daily, with extended taper over 4-6 weeks 2
• NSAID: Consider adding preservative-free ketorolac 0.45% for the first postoperative month to manage inflammation and reduce cystoid macular edema risk 2

High-Risk Patients

Preservative-free formulations are mandatory for patients with corneal scarring, history of corneal ulcer, or compromised corneal integrity. 2 Extend corticosteroid duration beyond standard taper when inflammatory history exists. 2

Follow-Up Schedule

Schedule postoperative examinations at day 1, week 1, and month 1 to monitor for complications including endophthalmitis, elevated intraocular pressure, corneal edema, and cystoid macular edema. 1 Visual rehabilitation typically shows improvement by 4 months with maintained gains at 1 year. 7

Non-Surgical Alternatives

No pharmacological treatments exist to eliminate cataracts or retard their progression. 3 When surgery is contraindicated or deferred:

• Update refractive correction as needed to accommodate refractive shifts during cataract development 4
• Provide UV-B protection (brimmed hats, UV-blocking sunglasses) as a measure that may slow progression 4
• Advise smoking cessation, as tobacco use accelerates lens opacity formation 4
• Schedule regular monitoring to detect functional decline warranting reconsideration of surgery 4

Critical Pitfalls to Avoid

• Do not defer surgery based solely on uncertain visual potential when diagnostic necessity exists (inability to visualize retina for management of posterior pathology). 2
• Do not skip B-scan ultrasonography—retinal pathology must be excluded before proceeding. 2
• Do not use standard postoperative taper in patients with inflammatory history; extend corticosteroid duration. 2
• Do not wait more than 4 months after surgery is clearly indicated, as delays increase risk of vision-related falls and accidents. 4
• Do not operate on asymptomatic patients with good visual acuity, as this exposes them to surgical risks (endophthalmitis, retinal detachment, posterior capsule rupture) without meaningful benefit. 4

Expected Outcomes

Up to 90% of patients undergoing first-eye cataract surgery report improvement in functional status and satisfaction with vision. 3, 4 Mean visual acuity typically improves from 20/100 preoperatively to 20/40 at 4 months, with maintained improvement at 1 year. 7 Objective measures show dramatic improvement in timed manual performance and mental status. 7