Central mfERG amplitude ratio as a predictor for visual outcome of macular hole surgery

[Multimodal topographically oriented approach to the study of full-thickness macular holes]

PURPOSE

This article studies the relationship between structural changes according to the findings of optical coherence tomography (OCT) and OCT angiography (OCTA), microperimetry (MP), multifocal electroretinography (mfERG) parameters in topographically corresponding areas of the macular region in idiopathic full-thickness macular holes (FTMH).

MATERIAL AND METHODS

OCT, OCTA, MP and mfERG were performed in 14 eyes with FTMH stages I-IV according to Gass. In 13 points at a distance of 0-2.5°, 2.5-5.0°, and 5.0-10.0° from the fixation point, the light sensitivity (LS), amplitude and latency of the P1 component were compared with the size of the hole, the area of cystic changes (CC) at the level of the inner nuclear layer (INL) and the outer plexiform layer and Henle fiber layer complex (OPL+HFL), vessel density in the superficial and deep capillary plexus (SCP and DCP).

RESULTS

LS and P1 component amplitude were significantly reduced at a distance of up to 5.0° from the fixation point. LS correlates with the apical and basal diameter of the hole (R> -0.53), the area of CC in the INL (R> -0.62) and the OPL+HFL complex (R> -0.55), the density of vessels in the SCP at a distance of up to 2.5° from the fixation point (R>0.51) and in the DCP at a distance of up to 5° from the fixation point (R>0.49). The P1 amplitude correlates with the basal diameter of the hole (R= -0.38), the area of CC in the INL and the OPL+HFL complex (R> -0.33) and vessel density in the SCP (R=0.37) at a distance of up to 2.5° from the fixation point, as well as vessel density in the DCP at a distance of up to 5° from the fixation point (R=0.47). Vessel density in the DCP is significantly lower in the presence of CC in the retina (p<0.001).

CONCLUSION

In FTMH, there is a relationship between bioelectrical activity and LS, and structural disorders, capillary perfusion in different layers of the retina. A multimodal topographically oriented approach allows studying the relationship between structural and functional parameters in individual points of the retina and can be used in monitoring of FTMH after surgical treatment.

Morphological and Functional Features in Patients with Idiopathic Macular Hole Treatment

Purpose

To evaluate the multifocal electroretinogram (mfERG) and optical coherence tomography (OCT) angiography features in patients with idiopathic macular hole (IMH) before and after vitrectomy.

Patients and Methods

This prospective study was conducted at Shanxi Eye Hospital from January 2019 to December 2021. Twenty-five eyes of 25 patients with unilateral IMH, the unaffected fellow eyes, and 30 eyes of healthy patients were investigated. All unilateral IMH eyes underwent vitrectomy.

Results

The IMH eyes had significantly delayed latency (rings 2-5) of mfERG compared with the healthy control eyes, and the amplitude density of all rings of mfERG was reduced (P < 0.05). When comparing the mfERG components before surgery and at the follow-up, the amplitude density of IMH eyes (ring 1, 3, 4 and 5) was increased significantly (P < 0.05). The delayed implicit times of the second and fifth ring were significantly shortened compared with those of preoperative eyes (P < 0.05). The mean delayed implicit time of mfERG in six months after surgery was negatively correlated with visual acuity (r = -0.890, P = 0.043). Significant differences of superficial retinal blood flow density (SRBFD, P < 0.001) and choroidal blood flow density (CBFD) (P < 0.05) got via OCTA were found between IMH before surgery and healthy control eyes. SRBFD of the fellow eyes were significantly different with the healthy control eyes (P = 0.038). Statistically significance of SRBFD and CBFD changes in IMH eyes were found before and after surgery (P < 0.05).

Conclusion

IMH eyes had a decreased amplitude density and a delayed implicit time in some regions. Additionally, SRBFD and CBFD were both increased after vitrectomy, which suggests that the blood supply of the retina and choroid is partially restored after vitrectomy.