Selective Laser Trabeculoplasty Versus Eye Drops for the First-Line Treatment of Ocular Hypertension and Glaucoma (LiGHT): A Multicentre Randomised Controlled Trial
Gazzard G, Konstantakopoulou E, Garway-Heath D, et al; LiGHT Trial Study Group1
ABSTRACT SUMMARY
Investigators recruited treatment-naïve patients with open-angle glaucoma (OAG) or ocular hypertension (OHT) and no ocular comorbidity from six sites in the United Kingdom and randomly assigned these patients to receive initial selective laser trabeculoplasty (SLT; laser-first, n = 356) or glaucoma medical therapy (medicine-first, n = 362). An objective target IOP was determined based on severity of disease. The primary outcome was health-related quality of life (HRQL) at 3 years (EuroQol EQ-5D). Secondary outcomes were cost and cost-effectiveness, disease-specific HRQL, clinical effectiveness, and safety.
At 36 months, 652 patients (91%) returned the primary outcome questionnaire, and no significant difference in EQ-5D was found between the two groups (difference, 0.012; 95% confidence interval [CI], -0.007 to 0.031; P = .23). Compared with the medicine-first group, more visits in the laser-first arm were within target IOP (93.0% vs 91.3%), and fewer individuals required subsequent glaucoma surgery (0 vs 11 patients). There was a 97% probability of greater cost-effectiveness over 36 months for laser-first compared with medicine-first if the willingness to pay for every quality-adjusted life year was £20,000 per quality-adjusted life year gained.
DISCUSSION
What are the clinical benefits of offering SLT as a first-line treatment?
Glaucoma progressed in a lower proportion of patients in the laser-first versus the medicine-first arm (3.8% vs 5.8%). Over the course of 36 months, IOP control was also better in the laser-first arm, with more visits at target IOP compared with the medicine-first arm, a lower number of glaucoma medications, and no glaucoma surgeries. Patient noncompliance with topical glaucoma therapy may partially explain this difference between the treatment arms. In addition, SLT may provide better diurnal IOP stability compared with the episodic administration of glaucoma medication.
At 36 months, 74.2% of patients in the laser-first arm were free of medications, a substantially higher figure than reported in previous studies in which SLT was used as either a primary or an adjunctive treatment. It is possible that treatment-naïve patients respond better to SLT because prior treatment and more severe disease may reduce the efficacy of SLT in lowering the IOP. There was a low rate of SLT-related adverse events in this study, with an IOP spike after only one out of 776 SLT applications, which is much lower than the rates of up to 28.8% reported in other studies. Treatment at an earlier stage of the disease may help reduce the incidence of SLT-related complications. The rate of cataract surgery was also lower in the laser-first arm, supporting evidence that glaucoma eye drops are associated with a greater incidence of nuclear cataract.2
Patients in the LiGHT study were predominantly white, so the clinical efficacy of SLT reported in the study may not be generalizable to patients of other ethnicities.
What are the economic benefits of SLT as a first-line treatment?
The laser-first approach resulted in overall cost savings of £451 per patient for the National Health Service in England and Wales, with a significant reduction in the cost of surgery and glaucoma medications. For every patient treated with primary SLT rather than primary medication, the amount of money saved exceeded the cost of SLT procedures for two additional patients or was equivalent to the cost of five additional ophthalmology outpatient appointments.
The results of this study indicate that SLT is cost-effective over a 3-year period in a National Health Service setting, but these findings may not be applicable to other health care settings. That said, cost savings have also been predicted for the Canadian health care system at 6 years when SLT was compared with topical glaucoma therapy with a single agent or multiple drugs and allowing for repetition of SLT within 2 to 3 years.3
Was there a difference in HRQL between first-line SLT and first-line medical therapy?
The primary outcome of HRQL using the EQ-5D questionnaire was a requirement of the UK National Institute for Health and Care Excellence cost-utility analyses required by the study’s funder, and there was no significant difference between the treatment arms. That said, the EQ-5D has a low sensitivity for ophthalmology, particularly for glaucoma, which can be asymptomatic, even when the disease is severe enough to make driving unsafe.4
The Glaucoma Utility Index and the Glaucoma Qualify of Life-15 (GQL-15) are glaucoma-specific HRQL instruments that capture differences in glaucoma severity more effectively than treatment side effects, so it was not surprising that the Glaucoma Utility Index and GQL-15 scores were similar between the two treatment arms. The Glaucoma Symptom Scale (GSS) incorporates measures related to the side effects of treatment, and repeated measures analysis showed worse GSS scores for the medicine-first arm at five of six time points over 36 months. Better GSS scores for the laser-first arm might have been a consequence of glaucoma eye drop use, but they may also reflect differences in baseline scores between the two arms.
1. Gazzard G, Konstantakopoulou E, Garway-Heath D, et al; LiGHT Trial Study Group. Selective laser trabeculoplasty versus eye drops for the first-line treatment of ocular hypertension and glaucoma (LiGHT): a multicentre randomised controlled trial [published online ahead of print March 8, 2019]. Lancet. doi: 10.1016/S0140-6736(18)32213-X.
2. Heijl A, Leske MC, Bengtsson B, et al. Reduction of intraocular pressure and glaucoma progression: results from the Early Manifest Glaucoma Trial. Arch Ophthalmol. 2002;120:1268-1279.
3. Lee R, Hutnik CM. Projected cost comparison of selective laser trabeculoplasty versus glaucoma medication in the Ontario Health Insurance Plan. Can J Ophthalmol. 2008;41:449-456.
4. Saunders LJ, Russell RA, Crabb DP. Practical landmarks for visual field disability in glaucoma. Br J Ophthalmol. 2012;96(9):1185-1189.
European Multicenter Trial of the Prevention of Cystoid Macular Edema After Cataract Surgery in Nondiabetics: ESCRS PREMED Study Report 1
Wielders LHP, Schouten JSAG, Winkens B, et al; ESCRS PREMED Study Group1
ABSTRACT SUMMARY
Despite various advances in the techniques of cataract surgery, cystoid macular edema (CME) remains a postoperative complication of phacoemulsification that can affect the visual acuity of the operated eye.2-5 This randomized clinical trial compared the efficacy of a topical NSAID, a topical corticosteroid, and a combination of both regimens for the prevention of CME after phacoemulsification in nondiabetic patients at 6 and 12 weeks postoperatively.1 This study enrolled 914 nondiabetic patients who had undergone phacoemulsification cataract surgery. They were randomly assigned to receive topical bromfenac 0.09% twice daily for 2 weeks; topical dexamethasone 0.1% four times daily, decreased by one drop per day every subsequent week; or a combination of both regimens.
Central subfield mean macular thickness was 288.3, 296.0, and 284.5 µm, respectively, in the bromfenac, dexamethasone, and combination-treatment groups. The incidence of CME within 12 weeks after surgery in these groups, respectively, was 3.6%, 5.1%, and 1.5%.
The investigators reported that patients treated with a combination of a topical NSAID and corticosteroid had a lower risk of developing CME after cataract surgery than patients treated with either drug alone.
DISCUSSION
CME after cataract surgery, also known as Irvine-Gass syndrome, was reported by Irvine in 1953 and by Gass and Norton in 1969.6,7 Since then, several investigators have attempted to identify the optimal regimen for preventing this postoperative complication. Although researchers have investigated the use of topical corticosteroids and/or NSAIDs for CME prevention, there remains a lack of clinically significant data to develop an effective treatment regimen.
In this trial, the ESCRS PREMED Study Group demonstrated the efficacy of a combination of topical drops on the operated eye, the visual acuity outcomes of the patients, and the reduced incidence of CME.1 The central subfield mean macular thickness was lowest in patients treated with the combined regimen; this metric was 9.6 µm higher in the dexamethasone group and 2.7 µm higher in the bromfenac group compared to the combination group. Moreover, the incidence of CME was lowest in the combination group compared to either group of patients treated with one of the individual drugs. With its excellent design and large cohort, this study offered conclusive data that the best strategy for preventing CME after cataract surgery is to administer a combination of steroid and NSAID eye drops. Future studies should evaluate the cost-efficiency of administering these topical agents after cataract surgery. Other research should aim to develop an agent that combines the efficacy of a steroid and an NSAID in order to reduce the number of eye drops, frequency of administration, and overall cost of treatment.
1. Wielders LHP, Schouten JSAG, Winkens B, et al; ESCRS PREMED Study Group. European multicenter trial of the prevention of cystoid macular edema after cataract surgery in nondiabetics: ESCRS PREMED Study Report 1. J Cataract Refract Surg. 2018;44(4):429-439.
2. Yonekawa Y, Kim IK. Pseudophakic cystoid macular edema. Curr Opin Ophthalmol. 2012;23(1):26-32.
3. Zur D, Loewenstein A. Postsurgical cystoid macular edema. Dev Ophthalmol. 2017;58:178-190.
4. Henderson BA, Kim JY, Ament CS, et al. Clinical pseudophakic cystoid macular edema. Risk factors for development and duration after treatment. J Cataract Refract Surg. 2007;33(9):1550-1558.
5. Wielders LHP, Schouten JSAG, Nuijts RMMA. Prevention of macular edema after cataract surgery. Curr Opin Ophthalmol. 2018;29(1):48-53.
6. Irvine SR. A newly defined vitreous syndrome following cataract surgery. Am J Ophthalmol. 1953;36(5):599-619.
7. Gass JD, Norton EW. Follow-up study of cystoid macular edema following cataract extraction. Trans Am Acad Ophthalmol Otolaryngol. 1969;73(4):665-682.
