Impact of Ophthalmic Viscosurgical Devices in Cataract Surgery

Author: Malvankar-Mehta MS, Fu A, Subramanian Y, Hutnik C.

Geographical coverage: North America, Europe, and Asia

Sector: Cataract surgery

Sub-sector: Impact

Equity focus: Not reported

Study population: Patients with cataract

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background:

Ophthalmic viscoelastic devices (OVDs) are indispensable in small-incision cataract surgery: they protect intra-ocular tissues, maintain anterior-chamber depth and facilitate precise manoeuvres. Their rheological properties vary, influencing post-operative outcomes. A principal concern is transient intra-ocular pressure (IOP) elevation when retained OVD obstructs aqueous outflow—particularly hazardous for patients with glaucoma. Previous studies disagree on which products carry the greatest IOP risk and at what point after surgery, making a clear synthesis essential for safe practice.

Objective:

To analyse and quantify the effects of different OVDs on post-operative IOP and best-corrected visual acuity (BCVA).

Main findings:

The review included 36 studies (3893 subjects) for qualitative synthesis and 28 studies (2613 subjects) for quantitative synthesis. The included studies varied in methodological quality. The findings showed that several OVDs, such as:

Immediate IOP spikes (day 1): Healon, Viscoat, Provisc and Soft-Shell techniques produced significant rises (standardised mean difference [SMD] 0.29 – 0.58). By contrast, Healon GV, Healon5, 2 % HPMC and OcuCoat showed non-significant increases, while the Viscoat + Provisc combination showed a slight non-significant reduction.

• Early hours (1–6 h): Pronounced IOP elevations were noted for Healon GV, Healon5 and Viscoat (SMD 0.44 – 1.46).
• Longer term: At one week or later, most OVDs were associated with stable or reduced IOP; by six months the pooled estimate indicated a significant fall (SMD –0.72).
• Visual outcomes: BCVA improved significantly as early as day 1 (SMD –0.85) and continued to improve up to six months regardless of OVD type, underscoring their overall benefit despite short-term IOP concerns.

Methodology:

Searches of MEDLINE, Embase, BIOSIS Previews, CINAHL, HEED, Web of Science, the Cochrane Library and grey literature were conducted to December 2018. Only English-language randomised controlled trials involving adults (≥ 19 years) were eligible. Two reviewers independently screened, extracted data and appraised quality using the modified Downs & Black checklist, resolving disagreements by consensus or third-reviewer arbitration. Fixed- or random-effects models were applied according to heterogeneity (I², χ², Z-test). Publication bias was examined with funnel plots, and subgroup analyses explored the influence of OVD type on IOP and BCVA.

Applicability / external validity:

Heterogeneity in study design, populations and OVD formulations—and the English-only restriction—limit generalisability. Although variations were acknowledged, the review did not formally assess how these factors affect applicability to wider clinical contexts or high-risk groups such as glaucomatous eyes.

Geographic focus:

Studies originated from North America, Europe and Asia; no geographical limits were imposed.

Summary of quality assessment:

The eligibility criteria were clear, and dual-reviewer methods were robust. Study characteristics were thoroughly documented and heterogeneity addressed. Nonetheless, the absence of an excluded-studies list, English-language restriction, and unreported reviewer numbers for data extraction reduce overall confidence in the conclusions to low.