Degradation of Contrast Sensitivity Function Following Posterior Vitreous Detachment

• Published in: American journal of ophthalmology 2016-12, Vol.172, p.7-12
• Main Authors: Garcia, Giancarlo A, Khoshnevis, Matin, Yee, Kenneth M.P, Nguyen-Cuu, Jeannie, Nguyen, Justin H, Sebag, J
• Format: Article
• Language: English
• Subjects: Adult; Age; Aged; Contrast Sensitivity - physiology; Female; Follow-Up Studies; Funding; Humans; Independent sample; Light emitting diodes; Male; Middle Aged; Ophthalmology; Prospective Studies; Studies; Surgery; Time Factors; Tomography, Optical Coherence; Visual Acuity; Vitrectomy - methods; Vitreous Body - diagnostic imaging; Vitreous Detachment - diagnosis; Vitreous Detachment - physiopathology; Vitreous Detachment - surgery
• ISSN: 0002-9394; 1879-1891
• DOI: 10.1016/j.ajo.2016.09.005

Purpose To evaluate the effect of posterior vitreous detachment (PVD) on contrast sensitivity function (CSF) in previously normal eyes, with the hypothesis that PVD reduces CSF. Design Prospective observational case series. Methods At a single clinical practice 28 eyes were evaluated: 8 eyes of 8 adults (mean age=54.4 ± 10.1 years; range=39 to 68) with normal CSF documented by Freiburg Acuity Contrast Testing (Weber index: %W) who subsequently experienced PVD, as confirmed by ultrasonography and OCT; 8 fellow eyes without PVD; and 12 control eyes: 9 eyes with PVD in patients who chose observation and 3 fellow eyes without PVD. Results At study entry there was no significant difference in CSF of fellow eye controls (mean=1.44 ± 0.27 %W; range=1.06 to 2.00 %W) and eyes that subsequently developed PVD (1.81 ± 0.61 %W; P=0.146; range=1.01 to 2.69 %W). Following PVD there was a 52.5% reduction in CSF (2.76 ± 0.30 %W; P=0.001; range=2.25 to 3.14 %W). CSF in the patients who chose limited vitrectomy (2.51 ± 0.46 %W; range=2.03 to 3.06 %W) was 41.8% worse than in the eyes with PVD of patients who chose observation (1.46 ± 0.21 %W; P = 0.001; range=1.08 to 1.87 %W). After vitrectomy, CSF improved by an average of 43.2%, normalizing in each case at 1 month (CSF=1.51 ± 0.28 %W; P=0.001; range=1.14 to 2.00 %W), 3 months (1.38 ± 0.10 %W; P=0.0002; range=1.28 to 1.51 %W), and 12 months (1.34 ± 0.34 %W; P=0.0001; range=1.01 to 1.89 %W, n=5) post-op, attaining the same CSF as the control fellow eyes (1.34 ± 0.20 %W; range=1.06 to 1.56 %W). Conclusion PVD is associated with significant reduction in CSF of previously normal eyes. This quantifiable negative impact on visual function can distinguish patients who are not signifcantly bothered by vitreous floaters from those with clinically significant symptoms.