The Role of Optical Coherence Tomography Signal Strength in the Diagnosis and Follow-up of Patients with Posterior Capsular Opacification Treated with Nd:YAG Laser Capsulotomy

Study of the relationship between the severity of posterior capsular opacification detected by objective detection techniques and visual acuity

PURPOSE

To explore the severity of posterior capsule opacification (PCO) using objective detection techniques and its relationship with visual acuity.

SETTING

The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.

DESIGN

Prospective cohort study.

METHODS

All patients underwent slitlamp examination, intraocular pressure (IOP) measurement, and corrected distance visual acuity (CDVA) testing before Nd:YAG laser capsulotomy, and examination, after fully dilated, with: IOLMaster 700, optical coherence tomography (OCT), Sirius Topographer (CSO) anterior segment analysis, and color fundus photography (CFP). CDVA and IOP were taken post treatment. Thickness and density of the posterior capsule, CFP quality (CFPQ) and OCT signal strength (OCTSS) were recorded. Analysis used Spearman correlation, heatmaps, and receiver operating characteristic curves.

RESULTS

83 eyes in 78 patients were included in this study. Spearman correlation analysis revealed correlations between pretreatment CDVA and IOLMaster 700 PCO thickness (MT), IOLMaster 700 cumulative effect (MCE), Sirius PCO thickness (ST), Sirius maximum density (SMD), Sirius cumulative effect (SCE), OCTSS, and CFPQ (correlation coefficients were 0.500, 0.484, 0.465, -0.256, 0.317, -0.442, -0.412, all P < .05). The improvement of vision acuity (ImpVA) showed correlations with MT, MCE, ST, SCE, OCTSS, and CFPQ (correlation coefficients were -0.452, -0.471, -0.346, -0.278, 0.320, 0.381, all P < .05). For ImpVA, the predictive ability of IOLMaster 700 was superior to Sirius, and the joint model was significantly better than single factors.

CONCLUSIONS

Posterior capsule thickness and cumulative effect were reliable indicators for evaluating PCO. Compared with Sirius, the IOLMaster 700 demonstrated superior predictive ability and higher correlation.

The influence of mild posterior capsular opacification on spectral domain optical coherence tomography retinal nerve fiber layer thickness

PURPOSE

Τo investigate whether Yag laser capsulotomy, in addition to restoring ocular media transparency, may also significantly alter retinal nerve fiber layer (RNFL) thickness analysis and spectral domain optical coherence tomography (SD OCT) indices and quality parameters, such as signal strength (SS), in patients with mild, diffuse posterior capsular opacification (PCO).

METHODS

Prospective interventional case series study which enrolled 28 patients with mild PCO and good baseline best-corrected visual acuity (BCVA). All patients underwent a complete ophthalmologic examination, including SD OCT RNFL thickness measurement prior to Yag laser capsulotomy. Following laser intervention, all patients repeated the same complete ophthalmic examination and results were recorded and analysed.

RESULTS

Mean RNFL thickness showed a significant postoperative increase from 89.6 to 94.1 μm (p = 0.01), which was also confirmed for superior (p = 0.041), nasal (p = 0.011) and inferior quadrants (p = 0.032). SS and BCVA were also significantly increased after laser treatment (p < 0.01). A significant positive correlation was observed between SS and mean RNFL thickness postoperatively (p = 0.043) but not preoperatively (p = 0.059). Similarly, a significant relationship was found between BCVA and average RNFL thickness after (p = 0.017) but not before (p = 0.457) laser intervention.

CONCLUSIONS

Our study suggests that the presence of even mild PCO may alter the sensitivity of SD-OCT acquisition and lead to inadvertent RNFL thickness underestimation. Clinicians should be alerted to this contingency and take it into consideration when evaluating various optic neuropathies with SD OCT, in pseudophakic eyes.