Effect of posterior capsular opacification removal on scanning laser polarimetry measurements.
OBJECTIVE
To evaluate the effect of posterior capsular opacification (PCO) on retinal nerve fiber layer (RNFL) retardation measurements obtained during scanning laser polarimetry (SLP). We are unaware of previous studies undertaken in this sense.


METHODS
SLP was performed using GDx variable corneal compensation (VCC) on 28 eyes of 28 non-glaucomatous patients with clinically significant PCO, previous uneventful cataract surgery and no other ocular pathology, both before and after Nd:YAG capsulotomy. Best-corrected visual acuity (BCVA), intraocular pressure (IOP) and SLP examination parameters prior and following PCO removal were compared using the Student t-test and Wilcoxon's test. Spearman correlations between BCVA and SLP measurements before and after capsulotomy were also performed.


RESULTS
PCO removal was associated with an increase of BCVA (P<0.0001), nerve fiber indicator (NFI) (P<0.0001) and typical scan score (TSS) (P<0.0001). In parallel, significant decreases of all absolute parameters were observed after capsulotomy. IOP, symmetry, superior ratio, inferior ratio and temporal-superior-nasal-inferior-temporal (TSNIT) standard deviation (SD) revealed no changes. Before capsulotomy, marked correlation existed between the BCVA and some SLP measurements such as nasal average (r= -0.703; P<0.0001) or NFI (r= 0.564; P=0.0017). After PCO removal these correlations were no longer found.


CONCLUSIONS
PCO removal changes SLP measurements. Therefore, new measurements to serve as a baseline for future comparisons should be obtained after Nd:YAG capsulotomy. Furthermore, some SLP measurements were significantly associated with BCVA before capsulotomy, suggesting that this technology may be useful to quantify PCO degree in non-glaucomatous patients.
Ophthalmology Research Unit Santiago Grisolia Department of Ophthalmology, University Hospital Doctor Peset, Avenida Gaspar Aguilar, 90, 46017 Valencia, Spain. josegarciam@yahoo.com
José Javier
JJ
García-Medina
Manuel
M
García-Medina
Samuel González-Ocampo
SG
Dorta
María Dolores
MD
Pinazo-Durán
Roberto
R
Gallego-Pinazo
Vicente Calixto
VC
Zanón-Moreno
D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001718:Birefringence; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D007834:Lasers; D007903:Lens Capsule, Crystalline / Q000473:pathology / Q000601:surgery*; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000502:physiology*; D018918:Phacoemulsification; D011183:Postoperative Complications; D011446:Prospective Studies; D019591:Pseudophakia / Q000503:physiopathology*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D014792:Visual Acuity