Rates of glaucomatous visual field change before and after transscleral cyclophotocoagulation: a retrospective case series

Abstract

BackgroundThe primary goal of glaucoma treatment is to lower and control intraocular pressure (IOP) and thereby prevent functional deterioration. For glaucomas that are refractory to medical and incisional surgical therapies, transscleral diode cyclophotocoagulation (TCP) is a well-established procedure to effectively decrease IOP. This study investigated rates of visual field (VF) change in patients with glaucoma before and after TCP.MethodsThis retrospective case series investigated rates of VF changes in glaucoma patients before and after they underwent TCP. At least four VF examinations were required, two before and two after surgery. VF examinations were performed using standard automated perimetry and rates of change were calculated by linear regression analysis of mean deviation (MD) values measured over time.ResultsA total of 46 eyes of 43 patients were included and followed on average 3.6 years before and 2.1 years after TCP. 67 % of the eyes showed further progression of glaucoma following surgery. Mean preoperative MD change was −0.21 dB/year (SE = 0.08, 95 % CI [−0.06, −0.37]). Postoperatively the mean change was −0.26 dB/year (SE = 0.22 95 % CI [0.38, −0.48]) which results in a difference between pre- and postoperative MD rate of 0.05 dB/year (p = 0.824). The mean MD value was worse after surgery and dropped by 1.73 dB (SE = 0.58, 95 % CI [−0.59, −2.87], p = 0.003). Intraocular pressure (IOP) decreased from 23.2 mmHg (SD = 4.67) before TCP to 14.3 mmHg (SD = 3.17) after TCP (p < 0.001). For each 1 mmHg of IOP reduction after surgery, postoperative rate of VF loss decreased by 0.15 dB/year.ConclusionRates of glaucomatous visual field loss did not significantly change after TCP and the majority of the eyes showed further progression of glaucoma after surgery. Mean MD value was considerably lower after TCP.

An update on continuous‐wave cyclophotocoagulation (CW‐CPC) and micropulse transscleral laser treatment (MP‐TLT) for adult and paediatric refractory glaucoma

“…Eyes not experiencing an IOP spike during the first 3 hr postsurgery show a greater IOP lowering at 3 months (Uppal et al 2015). Despite these potential IOP spikes, the rates of glaucomatous visual field loss do not significantly change after CW‐TSCPC, even in case of severe end‐stage glaucoma (Bleisch et al 2015). A possible bias could be that the central corneal thickness (CCT) measured with the Orbscan increases during the 10 days after CW‐TSCPC and returns to its prelaser level at 1 month, which could be due to inflammation and transient endothelial dysfunction induced by cyclophotocoagulation (Arikan et al 2008).…”

Outcome of Transscleral Cyclophotocoagulation in Refractory Glaucoma at a Tertiary Eye Hospital in India

“…[10] Contrary to this, Bleisch found that the visual fields continued to worsen after cyclophotocoagulation and Hasan reported cyclophotocoagulation is less effective that trabeculectomy in POAG. [ 21,22] Abdull found TSCPC to be safe and effective in cases of primary glaucoma where regular follow-up is not critical. [12] Stanca described a 'slow-burn' technique which can be used in eyes with better vision.…”

Observational report

“…TSCPC has proved to be a successful surgical method to lower IOP [ 3 – 5 ] while not increasing visual field loss. [ 6 ] However, many ophthalmologists hesitate to perform this procedure due to its painful nature and high risk of complications such as hypotony and phthisis bulbi. [ 7 , 8 ] Trabeculectomy has often been considered the most effective method in controlling glaucoma, but the number of trabeculectomies performed worldwide is steadily decreasing.…”