Patients and Samples
20 patients with PSS, who suffered from recurrences and poor IOP controlled by drugs between April 2018 to January 2019 at the Affiliated Eye Hospital of Nanjing Medical University, were recruited in this study. The inclusion criteria in PSS group were (1) unilateral, (2) recurrent episodes of mild, non-granulomatous cyclitis, (3) symptoms of mild discomfort, halos, and slight blurring of vision, (4) findings of elevated IOP, open angles, hoar and suet-shaped KP, no or minimal cells and flare, and mydriasis in the affected eye, (5) IOP > 21 mm Hg after the treatment of drugs, (6) more than one recurrence. All the inspections and diagnosis of these patients were done by the same glaucoma specialist. The exclusion criteria were (1) with retinal disease, non-glaucoma optic neuropathy, anterior uveitis or corneal abnormalities, (2) suspected chronic glaucoma, (3) angle-closure glaucoma excluded by gonioscopy examination, (4) received antiviral treatment (5) best-corrected vision < 20/50, absolute spherical lens value ≥ 5 D, absolute column lens value ≥ 3 D.
20 age-matched patients with POAG at the corresponding period were selected as control group in this study. The homolateral eyes of PSS patients in control group were set as control eyes. The inclusion criteria in control group were (1) open anterior segment angles; (2) reproducible glaucomatous visual field loss on reliable tests; (3) IOP > 21 mm Hg. The exclusion criteria were (1) with identifiable secondary cause for optic nerve diseases, (2) best-corrected vision < 20/50, absolute spherical lens value ≥ 5 D, absolute column lens value ≥ 3 D.
All participants underwent a series of ophthalmologic examinations, including vision measurement, best-corrected vision measurement, specular microscopy, refraction test, IOP measurement (Goldmann applanation tonometry, Haag-Streit, Koeniz, Switzerland), slit-lamp biomicroscopy (Haag-Streit, Koeniz, Switzerland) and gonioscopy (Haag-Streit, Koeniz, Switzerland).
Methods
1. How to perform anterior chamber puncture
All operations were performed by the use of microscope in operating rooms. The whole surgical procedure was sterile. Post-operative eyes were rinsed with sterile saline before puncture. We performed puncture in corneal limbus with a 15º stab knife. 100 µl of aqueous humor was extracted with a rinse needle. All operations were performed by the same person. After operation, all patients received levofloxacin eyedrops three times a day.
2. DNA extraction and amplification
DNA extraction of aqueous humor was done by the use of EZ1 Advanced XL automatic nucleic acid purification system (Qiagen, Hilden, Germany). The aqueous humor specimen was taken from the affected eyes of 20 PSS patients and homolateral eyes of 20 POAG patients. A pair of primers was designed according to the gene sequence of the tested virus. Quantitative PCR (qPCR) of CMV, HSV and VZV was performed within 24 hours after sample collection. All the qPCR detection was performed according to the manufacturer’s instructions. All samples were sent to Beijing GiantMed Diagnostics Inspection Office for quantitative detection.
3. RNA extraction and amplification
RNA extraction of aqueous humor was done by the use of TRI reagent (Sigma, St. Louis, USA). This step must be performed immediately. The cDNA synthesis was carried out in the thermocycler. qPCR was performed by use of cDNA samples for amplification of studied gene RV. All the qPCR detection was performed according to the manufacturer’s instructions. All samples were sent to Beijing GiantMed Diagnostics Inspection Office for quantitative detection.
This study was carried out in accordance with the principles of Declaration of Helsinki. All participants were provided with written informed consent.
In this study, all PSS patients were divided into two groups. Patients with negative viral infection were set as the observation group while patients with positive viral infection were set as the treatment group. Patients in treatment group were given local and systemic antiviral treatment for 3 months and then the treatment was discontinued.
Data were analyzed by SPSS software (version 22.0, SPSS Inc., Chicago, IL). All demographic data were expressed as mean ± SD. The mean differences of different groups were analyzed by Student’s t test, Levene’s test, paired-samples T test and Chi-Square test. P value of less than 0.05 was considered as indicating significant statistical difference.