ObjectiveTo observe the clinical characteristics of patients with familial vitreous amyloidosis (FVA) and the efficacy of vitrectomy (PPV) and the occurrence of complications. MethodsA retrospective clinical study. From June 2009 to March 2020, 32 eyes of 18 patients from 3 FVA families who were diagnosed and treated by PPV at Department of Ophthalmology of Jiaxing TCM Hospital were included in the study. Among them, there were 12 males with 22 eyes and 6 females with 10 eyes. The average age of onset was 42.28±3.25 years; the average duration of disease was 3.75±3.93 years. All the affected eyes underwent best corrected visual acuity (BCVA) and B-mode ultrasound examination. A logarithmic visual acuity chart was used in the BCVA examination, which was converted to the logarithmic minimum angle of resolution (logMAR) visual acuity when recorded. The average logMAR BCVA of the affected eye was 1.72±0.53; the intraocular pressure was less than 21 mm Hg (1 mm Hg=0.133 kPa). The vitreous body of the affected eye was obviously cloudy. All the affected eyes underwent standard three-channel PPV through the flat part of the ciliary body, and vitreous specimens were collected for pathological examination during the operation. Peripheral venous blood of probands from 3 families was collected, and the whole exome gene sequencing was performed. The follow-up time after surgery was ≥6 months. The patient's clinical characteristics, fundus lesions in PPV, changes in BCVA after surgery, and complications was observed. One-way analysis of variance or t test was performed for measurement data comparison; χ2 test was performed for count data comparison. ResultsThe vitreous body of the affected eye showed gray-white dense and thick flocculent changes, and the posterior capsule attached to the lens showed "foot disc-like" turbidity; later the lens was mainly cystic opacity. Pathological examination of the vitreous body showed positive staining of Congo red; under a polarized light microscope, it showed apple green dots and sheet-like birefringence. The genetic test results showed that there was a c.307G>C (p.Gly103Arg) missense mutation in the TTR gene of the proband in Family 2. Peripheral retinal hemorrhages in 4 eyes (12.5%, 4/32), retinal tears in 5 eyes (15.6%, 5/32), retinal degeneration in 4 eyes (12.5%, 4/32), retinal detachment were found in PPV 3 eyes (9.4%, 3/32). The vitreous body was filled with C3F8 and silicone oil respectively for 2, 1 eye. Six months after the operation, the logMAR BCVA of the affected eye was 0.39±0.32, which was significantly higher than that before the operation, and the difference was statistically significant (t=15.131, P=0.000). After the operation, high intraocular pressure occurred in 2 eyes (6.3%, 2/32), secondary glaucoma in 1 eye (3.1%, 1/32), retinal detachment in 2 eyes (6.3%, 2/32), neovascular glaucoma (NVG) in 2 eyes (6.3%, 2/32), cataract in 10 eyes (31.3%, 10/32). ConclusionThe vitreous body of FVA eyes are gray-white dense, thick and flocculent, attached to the posterior lens capsule, showing "foot disc-like" turbidity; PPV treatment can effectively improve the BCVA of the FVA eyes; secondary glaucoma, secondary retinal detachment, NVG can occur after surgery.