Subjects
We reviewed twenty-eight patients (28 eyes) who were diagnosed as refractory glaucoma in our outpatient department from June 2018 to February 2019, of whom 14 cases (14 eyes) underwent UCP and 14 cases (14 eyes) TSCP. Preoperative information was collected, including gender, age, best-corrected visual acuity (BCVA), IOP, the number of anti-glaucoma agents used, and type of primary disease. The indications for both procedures were similar, including (1) IOP was persistently higher than 21mmHg (using applanation tonometer, 1mmHg=0.133kPa) after the maximum usage of anti-glaucoma agents; (2) Patients voluntarily signed informed consent. Contra-indications were: (1) aged < 18 years; (2) evidence that the sclera was significantly thinned; (3) intraocular tumour or infection; (4) normal-tension glaucoma; and (5) choroidal hematoma. This study was approved by the ethics committee of the first affiliated Hospital of Nanjing Medical University (No. 2019-MD-168), and patients and their families were fully informed and signed informed consent.
Treatment
Focused ultrasound cycloplasty
All treatments in both groups were performed in the operating room by the same experienced surgeon. The affected eyes were routinely disinfected. Retrobulbar anaesthesia was performed with ropivacaine, and topical anaesthetic was applied in the conjunctival sac. The machine (EyeOP1, Eye Tech Care, France) was prepared, the patient's information was input to the system, and an appropriate size of probe (11mm, 12 mm and 13 mm) was selected according to pre-treatment Ultrasound Biomicroscopy (UBM). The positioning cone was aligned and fixed on the ocular surface, and negative pressure was secured. The probe was put into the positioning cone, which was then filled with saline solution, then the treatment was activated by the surgeon. Patients with IOP of 21~35mmHg were treated with 6 sectors; patients with IOP of 36~45mmHg were treated with 8 sectors, and those with IOP of >45mmHg were treated with 10 sectors. At the end of the procedure, Tobramycin and Dexamethasone Eye Ointment were applied. Postoperatively, Tobramycin Dexamethasone Eye Drops were used to prevent inflammation and infection. All anti-glaucoma medications were continued, but the dose was titrated according to the follow-up IOP. If necessary, analgesics were orally administrated after pain assessment.
Transscleral cyclophotocoagulation
After a similar disinfection and anaesthesia procedure, an eyelid speculum was placed on the affected eye. Oculight Slx semiconductor laser (IRIDEX, Mountain View, USA) with a wavelength of 810nm was prepared. The fibre probe was placed 1.0–1.2 mm posterior to the limbus, which was directly over the ciliary processes. The pulse time was set to 2000ms. The energy was set to 1200mW initially, which was gradually increased until a significant blasting sound ("pop") could be heard, then it was reduced by 100mW to start treatment. The range of photocoagulation was adjusted according to the IOP, avoiding "3 and 9 o'clock" position. Specifically, for patients with IOP of 21~35mmHg were treated with 20 laser shots, IOP of 36~45mmHg were treated with 25 shots, and those with IOP>45mmHg were treated with 30 shots. Postoperative management was similar to the UCP group according to the conditions of the patients.
Follow-up
Patients were regularly followed up in clinics after the operation at 1-day, 7-day, 1-month, 3-month, 6-month and 12-month. At every visit, routine ophthalmology examination was performed, IOP was measured by applanation tonometry, visual acuity was determined with the standardized chart (Snellen chart). For those who failed to see, "count finger", "hand motion", "light perception" and "no light perception" were noted accordingly. Anti-glaucoma agents were prescribed by doctors according to patients' IOPs at each visit. IOP, the number of anti-glaucoma agents used, BCVA and complications were recorded each time. The pain was scored on the first day after surgery using a digital pain grading method, in which a 0-10 scale indicates from no pain to the most severe pain. A number was circled by patient himself/herself to show the subjective feeling of pain (0 refers to 0 grade: no pain, 1~4 refers to grade 1: mild pain, 5~9 refers to grade 2: moderate pain, 10 refers to grade 3: severe pain).
Statistical analysis
Data were presented as mean ± standard deviation. Quantitative data were analyzed by t-test, count data were analyzed by chi-square test, and repeated measurement data were analyzed by analysis of variance of repeated measurement. A difference with P<0.05 was considered statistically significant. Statistical analyses were performed using IBM SPSS 25 software (https://www.ibm.com/analytics/spss-statistics-software, IBM, USA).