This section describes safety outcomes from the published literature that the committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview.
5.1 Surgery was stopped in 5% (11/217) of patients because of complications such as posterior capsule rupture in 7 patients, choroidal effusion in 1 patient, choroidal haemorrhage in 2 patients and zonular dehiscence in 1 patient in a non-randomised comparative study of 217 patients.
5.2 Device explantation was reported in 6% (12/206) of patients in the non-randomised comparative study of 217 patients at 2‑year follow-up. Two were removed because of surgical trauma resulting in condensation inside the telescope, 2 were removed during corneal transplantation, and 8 were removed because of patient dissatisfaction. All devices were replaced with a conventional intraocular lens.
5.3 Corneal decompensation was reported in 1% (2/206) of patients in the non-randomised comparative study of 217 patients at 1‑year follow-up. Both needed device removal and corneal transplantation more than 1 year after the initial surgery.
5.4 Choroidal neovascularization after telescope implantation was reported in 2% (4/206) of patients in the non-randomised comparative study of 217 patients at 2‑year follow-up. One patient had successful treatment with focal laser photocoagulation through the telescope without complications. Details about management of the neovascularization in the other 3 patients were not reported.
5.5 Increased intraocular pressure (IOP) within 7 days needing treatment was reported in 28% (57/206) of patients in the non-randomised comparative study of 217 patients. Increased IOP beyond 7 days needing treatment was reported in 3% (6/206) of patients in the same study. No further details were reported.
5.6 Hypopyon (treated with topical steroids) was reported in11% (4/36) of patients in a case series of 40 patients (40 eyes). No further details were reported.
5.7 Posterior capsule opacification (treated successfully with a Nd-YAG laser capsulotomy) was reported in 30% (3/10) of patients in a case series of 10 patients (13 eyes).
5.8 Inflammatory deposits on the device were reported in 25% (51/206) of implanted eyes and pigment deposits on the device were reported in 11% (23/206) of implanted eyes in the non-randomised comparative study of 217 patients. No further details were reported.
5.9 Loss of 3 or more lines of best-corrected distance visual acuity (BCDVA) or best-corrected near visual acuity (BCNVA) occurred in less than 1% (1/173) of implanted eyes compared with 8% (13/174) of fellow control eyes (p=0.0013) in the non-randomised comparative study of 217 patients. No further details were given.
5.10 In the non-randomised comparative study of 217 patients with age-related macular degeneration, comparing an implanted telescope lens system with fellow eye controls, the loss of 2 or more lines in BCDVA was significantly less frequent in implanted eyes compared with fellow eyes (2% compared with 9%; p=0.005) at 1‑year follow-up. In the subgroup analysis for age, 3 patients (9%) in each group (65–75 years, and over 75 years) had lost more than 2 lines of BCDVA at 60‑month follow-up. Both groups had greater vision loss in the fellow eyes (65–75 years, 16% [n=5]; compared with 28% [n=9] in those over 75 years).
5.11 Ocular adverse events were reported in the non-randomised comparative study of 217 patients up to 60 months after the procedure, including: iris prolapse in 6% (12/206) of patients, iris incarceration in 1% (3/206), iris damage in 4% (9/206), iris transillumination defects lasting more than 21 days in 5% (11/206), iritis lasting more than 30 days in 6% (12/206), iris atrophy more than 7 days after surgery in 6% (12/206), guttata in 8% (16/206) and posterior synechiae in 7% (15/206). No further details were reported.
5.12 Endothelial cell density (ECD) was reduced by 20% below baseline at 3‑month follow-up and by 25% at 1 year, compared with fellow eye controls, in the non-randomised comparative study of 217 patients with age-related macular degeneration implanted with a telescope lens system. The mean cell loss from 1 year to 2 years was 2%. In the subgroup analysis for age, ECD loss was less in those aged between 65 and 75 years than in those over 75 years (35% compared with 40%) at 60‑month follow-up. The decrease in ECD was correlated with post-surgical oedema (p<0.0001), suggesting that endothelial damage occurred during surgery, rather than during the postoperative period.
5.13 Transient complications reported in a case series of 40 patients included corneal oedema in 25% (9/36) of patients, fibrin at the pupil in 33% (12/36), synechias in 19% (7/36), hyphema in 11% (4/36), conjunctivitis in 6% (2/36), uveitis in 8% (3/36) and cyclitic membrane in 3% (1/36). Persistent complications included pupillary cyclitic membrane in 1 eye, synechias in 2 eyes and posterior capsular opacification in 4 eyes.
5.14 Ocular pain due to mild corneal epithelial trauma was reported in 20% (2/10) of patients in a case series of 10 patients. This resolved with no complications.
5.15 Other complications reported in the non-randomised comparative study of 217 patients included corneal abrasion in 5% (11/206) of patients, foreign-body sensation in 3% (7/206), anterior chamber inflammation lasting beyond 30 days in 2% (actual numbers not reported), device dislocation in 1% (3/206), sub-retinal haemorrhage in 2% (5/206), vitreous haemorrhage more than 7 days after surgery in 2% (4/206), vitreous in the anterior chamber more than 7 days after surgery in 4% (8/206) and vitreous loss in 4% (9/206).
5.16 In addition to safety outcomes reported in the literature, specialist advisers are asked about anecdotal adverse events (events which they have heard about) and about theoretical adverse events (events which they think might possibly occur, even if they have never done so). For this procedure, specialist advisers reported no anecdotal adverse events. They considered that the following were theoretical adverse events: increase in falls due to the differences in magnification in each eye for devices that give larger magnification, and failure to improve vision for devices that have lower magnification.