Hamad Hejazi

Cataract remains the world’s leading cause of blindness. According to the World Health Organization, an estimated 94 million people live with vision impairment attributable to cataract, yet one in two people globally who require cataract surgery cannot access it (1). This does not resemble a disease problem but a systems problem, and surgical technique sits at its centre.

As an aspiring Ophthalmologist, one of the major draws to this brilliant speciality for me is the ability to do good on a large scale. Lower and middle income countries especially draw me in as there is evident scope to help a lot of patients by restoring their most prominent of the five senses – vision.

Effective cataract surgical coverage rates vary dramatically between nations, ranging from as low as 4% in some countries to 70% in others. This disparity reflects differences in disease burden but also disparities in infrastructure, cost, and postoperative support capacity (2).  Prompted by discussions at the UK & Ireland Society of Cataract and Refractive Surgeons (UKISCRS) Cataract and Cornea Day that I attended earlier this month, this article examines two techniques that receive attention in global ophthalmology: manual small incision cataract surgery (MSICS) and dropless cataract surgery.

MSICS: Appropriate Technology for a Global Burden

Phacoemulsification dominates surgical training in high-income settings, and rightly so for the populations we primarily serve. Yet the evidence base for MSICS in resource-limited contexts is compelling. A Cochrane systematic review of eight randomised controlled trials found no significant difference in best-corrected visual acuity between MSICS and phacoemulsification, and reported the cost of phacoemulsification to be more than four times that of MSICS in the one study where costs were directly compared (3).  MSICS offers lower cost and shorter operating times, with complication rates comparable to phacoemulsification across multiple systematic reviews (4).  This solves for scale in a manner that seems logical from a health economics view through a humanitarian lens.

MSICS avoids dependency on costly phacoemulsification machinery and is particularly well-suited for dense, brunescent cataracts disproportionately common in LMIC populations (3).  For patients presenting late (as can be common in sub-Saharan Africa and South Asia), MSICS may be technically preferable, as advanced cataracts carry a higher complication risk when phacoemulsification is attempted. MSICS appears more advantageous in terms of speed, cost, and independence from technology, and more suitable for high-volume surgical delivery in developing contexts (5).

Dropless Surgery: Removing a Barrier Hiding in Plain Sight

Even where surgery is accessible, postoperative drop regimens introduce a second barrier. Traditional protocols require patients to instill antibiotic, steroid, and NSAID drops multiple times daily for weeks. In camp-style delivery settings, where patients may travel hours for surgery and return to areas without pharmacy access, this expectation is frequently unmet. Not to mention, the adherence issues with drops postoperatively remain pertinent as fewer than 50% of patients appropriately use their prescribed drops post-operatively in the UK, even with advanced accessibility and patient education.

Dropless cataract surgery replaces this regimen with a single intraoperative injection, typically a combination of intracameral antibiotics like Cefuroxime and subconjunctival or intravitreal steroid. A 2024 cost analysis found that an injection-based prophylaxis regimen reduces overall healthcare system costs by 84.7% and eliminates patient out-of-pocket medication expenses entirely compared with topical regimens (6).  Studies have shown that combined steroid and antibiotic injections reduce rates of infection and inflammation and may reduce occurrences of cystoid macular oedema (7).  Compliance, which tends to be the Achilles heel of postoperative drop therapy, becomes irrelevant when medication delivery rests with the surgeon.

Limitations must be acknowledged. The technique is contraindicated in glaucoma patients and known steroid responders. Transient floaters and visual disturbance are reported following triamcinolone-containing preparations (8).  The ESCRS randomised controlled trial of intracameral cefuroxime remains the only level I evidence demonstrating the prophylactic benefit of any injected antibiotic, and long-term comparative data on dropless regimens in LMIC settings specifically remain limited (9). These can be viewed as calls for continued rigorous study and not necessarily arguments against the technique’s promise.

A Note for Residents

For UK residents, exposure to MSICS is uncommon. Phacoemulsification rightly dominates our curricula, but global ophthalmology demands a broader surgical expertise. Familiarity with MSICS principles need not replace phacoemulsification training. The two techniques can go hand-in-hand and enrich each other. Moreover, dropless protocols are gaining traction in the UK for reasons of patient preference and compliance, independent of any global health argument. Improved compliance and better patient satisfaction outcomes can arguably stand an argument on their own. Applications of dropless protocols in high-volume, resource-limited settings may prove to be one of the more practical contributions the surgical community can make toward closing the cataract coverage gap.

Cataract blindness is avoidable and perhaps one of the highest yield quality of life issues that can be solved en masse. The tools, it seems, are increasingly available.

References

(1).  World Health Organization. Blindness and visual impairment. February 2024. (2).  IAPB Vision Atlas. Cataract surgical coverage. 2024.

(3).  Riaz Y, de Silva SR, Evans JR. Manual small incision cataract surgery (MSICS) with posterior chamber intraocular lens versus phacoemulsification with posterior chamber intraocular lens for age-related cataract. Cochrane Database Syst Rev. 2013;(10):CD008813.

(4).  Venkatesh R, Tan CS, Sengupta S, Ravindran RD, Krishnan KT, Chang DF. Phacoemulsification versus manual small-incision cataract surgery for white cataract. J Cataract Refract Surg. 2010 Nov;36(11):1849-54. doi: 10.1016/j.jcrs.2010.05.025. PMID: 21029891.

(5).  Priyanka, Khan K, Kishnani M, Dube M (2022) To compare postoperative astigmatism and visual outcome following phacoemulsification versus Manual Small Incision Cataract Surgery (MSICS) seen at tertiary care center. J Clin Res Ophthalmol. 2022; 9(1): 001-004. Available from: 10.17352/2455-1414.000094

(6).  Massa S, Smits DJ, Nguyen AT, Patil SA, Chen EM, Shorstein NH, Friedman S, Parikh R. Cost analysis of dropless cataract surgery prophylaxis with intracameral antibiotics and subconjunctival steroids. J Cataract Refract Surg. 2024 Dec 1;50(12):1215-1223. doi: 10.1097/j.jcrs.0000000000001526. PMID: 39025664; PMCID: PMC11556800.

(7).  Shorstein NH, Myers WG. Drop-free approaches for cataract surgery. Curr Opin Ophthalmol. 2020 Jan;31(1):67-73. doi: 10.1097/ICU.0000000000000625. PMID: 31688226; PMCID: PMC7362995.

(8).  Das T. Intracameral antibiotic in cataract surgery. Indian J Ophthalmol. 2024 Sep 1;72(9):1375. doi: 10.4103/IJO.IJO_1588_23. Epub 2024 Aug 23. PMID: 39185836; PMCID: PMC11552808.

(9).  Barry P, Seal DV, Gettinby G, Lees F, Peterson M, Revie CW; ESCRS Endophthalmitis Study Group. ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery: Preliminary report of principal results from a European multicenter study. J Cataract Refract Surg. 2006 Mar;32(3):407-10. doi: 10.1016/j.jcrs.2006.02.021. Erratum in: J Cataract Refract Surg. 2006 May;32(5):709. PMID: 16631047.