3D vs 2D qualitative and semiquantitative evaluation of the glaucomatous optic disc atrophy using computer-assisted stereophotography

Abstract

Background and purpose Real colour documentation of the optic nerve head (ONH) is one of the most important methods to identify the early progression of glaucomatous optic nerve damage. This study compares the qualitative and semiquantitative evaluation of ONH photographs, using a 3D time-multiplexing system and conventional 2D photography, visualised on a computer monitor. Patients and methods Stereophotographs of the ONH were converted by special software in a 3D file. The same images were shown in 2D and 3D to 22 subjects with different training grades (residents and ophthalmologists). The evaluation based on a standardised questionnaire, containing semiquantitative parameters of the ONH. A weighted score for quality of ONH assessment counted the correct answers of the observers to compare their evaluation in 2D to the one made in 3D. Results All of the observers achieved a significant better evaluation of the ONH with 3D than with 2D images. No significant differences were observed between both groups. Classification errors with respect to the 'gold standard' were lower for 3D measurements as compared with 2D measurements (P ¼ 0.007). No significant differences were observed between the gold standard and residents or ophthalmologists for the ONH size, but for the c/d ratio the stereoscopic images lead to better results. Conclusion This study showed a better evaluation of parameters associated with the glaucomatous ONH atrophy with 3D images

3D retinal imaging and measurement using light field technology

“… 11 In particular, the 3D imaging of the optic nerve head and the quantitative analysis of the excavation can be applied in glaucoma diagnostics. 3 , 4 One strong risk factor for glaucoma is a suspicious optic nerve head appearance with abnormal cupping or an increase in the cup-to-disc ratio. 12 , 13 With demographic changes in industrialized countries, the incidence of glaucoma is increasing.…”

Software-Assisted Depth Analysis of Optic Nerve Stereoscopic Images in Telemedicine

“…Vessani et al demonstrated that stereoscopic images of several cameras have better diagnostic performance than subjective assessment of ONH by general ophthalmologists [ 13 ]. Other studies have also demonstrated the improved detection of at-risk eyes between stereoscopic imaging and nonstereoscopic imaging with higher CDR in all regions of the ONH and even increased interobserver agreement using stereoscopic imaging compared with monoscopic assessments [ 3 , 14 , 15 ]. These studies suggest that stereoscopic imaging and depth software analysis could supplement the clinical exam in glaucoma detection during remote screenings and telemedicine efforts.…”

“…For example, the three-dimensional aspect of CDR is poorly appreciated from two-dimensional images obtained with nonmydriatic cameras. Three-dimensional evaluation of the ONH has been shown significantly more accurate in comparison to traditional two-dimensional pictures [ 3 ]. In addition, discrepancies in observer training and experience evaluating the ONH can lead to significant variability in patient referral patterns [ 4 ].…”