Swept-source OCT reduces the risk of axial length measurement errors in eyes with cataract and epiretinal membranes

Aims To compare the biometric data from partial coherence interferometry (PCI) and swept-source OCT (SS-OCT) in patients with age-related cataract and epiretinal membrane (ERM): ERM, ERM with foveoschisis and macular pseudohole. Methods 49 eyes of 49 subjects including 36 ERM, 9 ERM foveoschisis and 4 macular pseudohole were analysed to evaluate the axial length (AL) measurements and the presence of AL measurement errors, defined basing on the shape of the biometric output graphs and on the concordance of AL values between instruments. Eyes with ERM were divided in four stages according to OCT features (i.e. presence/absence of the foveal pit, presence of ectopic inner foveal layers, disrupted retinal layers). Results The devices provided similar mean AL measurements in all subgroups, with differences <0.1 mm in 41/49 cases (83.6%). AL measurement errors were observed in ERM stages 3 and 4, characterized by ectopic inner foveal layers, and were significantly more frequent with the PCI (8/17, 47%) as compared with the SS-OCT device (2/17, 12%), p = 0.02. The refractive prediction error in cases with AL measurement errors was significantly greater using the PCI compared to the SS-OCT device (p<0.05). Conclusion Both devices provide reliable biometric data in the majority of patients and can be used in the preoperative assessment of patients with age-related cataract and ERM. In eyes with ectopic inner foveal layers, attention should be paid as AL measurement and refractive prediction errors may occur, more frequently with the PCI device.

Macular Pseudohole: Pathophysiology, Classification, Clinical Findings, Diagnosis, and Treatment

Macular pseudohole is characterized by a specific appearance of epiretinal membranes (ERM) that spares the foveal center resembling a macular hole in the ophthalmoscopic examination. The foveal center is displaced by the contraction of ERM. The differential diagnosis of pseudoholes from full-thickness and lamellar macular holes may not be easy. The natural history of macular pseudoholes is good but vision may decrease if the distortion in foveal center increases. The outcome of early surgical treatment of full-thickness macular holes is good and several methods and tests have been used for the differential diagnosis of full-thickness macular holes and pseudoholes. The diagnosis, determination of pathogenetic mechanisms, and subgroups of macular pseudoholes have become relatively easy after the availability of optical coherence tomography in ophthalmological practice. The macular pseudoholes may be classified as a subgroup of ERM’s and the treatment is either observation or vitreoretinal surgery with a good outcome in cases with decreased visual acuity.