The role of the optical coherence tomography in identifying shape and size of idiopathic epiretinal membranes

The RAP study, report 3: Discoloration of the macular region in patients with macular neovascularization type 3

BACKGROUND/AIMS

To explore whether the existence and pattern of distribution of macular haemorrhage or exudate can be valuable diagnostic markers for macular neovascularization type 3 (MNV3) in patients with neovascular age-related macular degeneration.

METHODS

Eighty-three eyes of 83 consecutive treatment naïve patients with stage 3 MNV3 were enrolled. The diagnosis was based on fluorescein angiography (FA) and optical coherence tomography (OCT). Subretinal and intraretinal haemorrhage and dense exudates were evaluated on colour fundus photography. Fluorescein angiography (FA) images and OCT scans were used to identify the axial location of the haemorrhage. 83 patients with MNV1 and 83 with MNV2 were included as two control groups.

RESULTS

In the MNV3 group, 62 (75%) eyes had intraretinal haemorrhage and 52 (63%) had dense exudates. 73 (88%) eyes had intraretinal haemorrhage and/or dense exudates. 41 (49%) had both pathologies. The intraretinal haemorrhage was flame shaped over the lesion and punctate or semi-punctate further away from it and directed to the fovea. No subretinal haemorrhage was noticed. In the MNV1 and MNV2 groups, 11 (13%) and 24 (29%) eyes had subretinal haemorrhage or dense exudates, respectively. No intraretinal haemorrhage was seen in the two control groups. The prevalence of exudates and haemorrhage (irrespective of its location) was greater in MNV3 than in MNV1 or 2 (p < 0.0001).

CONCLUSION

The existence and pattern of distribution of intraretinal haemorrhage is pathognomonic of MNV3. It makes (alone or with dense exudates) the diagnose MNV3 possible using fundoscopy or colour fundus photo and without further diagnostic expenditure.

[Study of vitreomacular interface in patients with pseudophakia by means of spectral optical coherence tomography]

AIM

to investigate the state of vitreomacular interface in pseudophakic patients by means of spectral optical coherence tomography (OCT).

MATERIAL AND METHODS

Spectral OCT of the macular region was performed in 58 pseudophakic eyes that underwent laser treatment for secondary cataract, 28 newly pseudophakic eyes (day 1 after cataract phacoemulsification with IOL implantation), and 40 eyes with early senile cataract.

RESULTS

A higher incidence of subclinical fibrosis of the internal limiting membrane was noted in pseudophakic patients after YAG laser surgery for secondary cataract as compared to cataract patients and those right after cataract phacoemulsification.

CONCLUSION

Fibrosis of the internal limiting membrane significantly more often develops in the late period after cataract extraction as compared to patients with early senile cataract and those who have just underwent phacoemulsification surgery. Fibrosis of the internal limiting membrane arising in the late period after cataract extraction cannot be unambiguously attributed to either primary or secondary. The resolution of spectral OCT is high enough to allow detection of preclinical ultrastructural changes in the vitreomacular interface.

[Idiopathic epiretinal membranes: visual function impairment, morphological and functional features of retinal involvement]

By affecting different retinal layers, an idiopathic epiretinal membrane (iERM) produces changes in macular architectonics and functioning. Morphological and functional assessment of these patients using modern visualization methods and electroretinography contributes to a better understanding of pathogenetic mechanisms of iERM.

Retinal Changes Induced by Epiretinal Tangential Forces

Two kinds of forces are active in vitreoretinal traction diseases: tangential and anterior-posterior forces. However, tangential forces are less characterized and classified in literature compared to the anterior-posterior ones. Tangential epiretinal forces are mainly due to anomalous posterior vitreous detachment (PVD), vitreoschisis, vitreopapillary adhesion (VPA), and epiretinal membranes (ERMs). Anomalous PVD plays a key role in the formation of the tangential vectorial forces on the retinal surface as consequence of gel liquefaction (synchysis) without sufficient and fast vitreous dehiscence at the vitreoretinal interface. The anomalous and persistent adherence of the posterior hyaloid to the retina can lead to vitreomacular/vitreopapillary adhesion or to a formation of avascular fibrocellular tissue (ERM) resulting from the proliferation and transdifferentiation of hyalocytes resident in the cortical vitreous remnants after vitreoschisis. The right interpretation of the forces involved in the epiretinal tangential tractions helps in a better definition of diagnosis, progression, prognosis, and surgical outcomes of vitreomacular interfaces.