A literature search of articles published before 31 December 2022 was conducted on PubMed using the following keywords: "
diabetic retinopathy," "rhegmatogenous
retinal detachment," "idiopathic
epiretinal membrane," "idiopathic
macular hole," "
vitrectomy," "optical coherence tomography," "optical coherence tomography angiography," "microstructure," "microstructural," "hemodynamic," "hemodynamics," and "microcirculation." Additional studies were identified by hand-searching references for relevant studies. Articles were screened for language, repetition, and relevance to the direction of study. Studies with a sample size ≥ 7 and the final follow-up time ≥ 4 weeks after
vitrectomy were included in this review. Only articles published in English were included. Articles not related to our topic were excluded. Reviews and single case reports were excluded. We structured this review by disease category. The thickness of the retina and choroid, the area of the foveal avascular zone, the vessel density of the
retinal and choroidal capillary plexus, and the potential association of related parameters with postoperative visual outcomes are the main outcome measures of studies included in this review.
RESULTS: A total of 48 studies were included in this review. There were contradictory results regarding the association between postoperative microcirculatory parameters and visual acuity in patients with diabetic
macular edema, with some studies concluding that improvement in perimacular microcirculation may be an important factor that affects visual acuity, and others concluded that postoperative improvement in visual acuity was not related to changes in macular blood flow. The results of studies on the relationship between postoperative microstructural and microcirculatory parameters and visual acuity in rhegmatogenous
retinal detachment, idiopathic
epiretinal membrane, and idiopathic
macular hole eyes have been inconsistent. In gas tamponade macula-off rhegmatogenous
retinal detachment eyes, postoperative best-corrected visual acuity has been reported to correlate positively with vessel density of deep capillary plexus and negatively with foveal avascular zone area of superficial capillary plexus and deep capillary plexus. In
silicone oil tamponade macula-off rhegmatogenous
retinal detachment eyes, best-corrected visual acuity has been reported to be positively correlated with the
retinal thickness of the parafoveal 3 mm temporal quadrant and positively correlated with the vessel density of the superficial capillary plexus in the foveal, parafoveal, and perifoveal area. In addition, best-corrected visual acuity was worse and associated with reduced thickness of the inner retina,
ganglion cell layer, outer plexiform layer, and outer nuclear layer in
silicone oil tamponade rhegmatogenous
retinal detachment eyes compared to gas tamponade. Postoperative best-corrected visual acuity in idiopathic
epiretinal membrane eyes was positively correlated with the foveal avascular zone area but negatively correlated with full
retinal thickness and inner
retinal thickness in the foveal and parafoveal areas. Improvement in postoperative best-corrected visual acuity in idiopathic
macular hole eyes was associated with reduced inner
retinal thickness and reduced foveal avascular zone area.
CONCLUSIONS: Microstructural and hemodynamic changes are involved in the recovery process after PPV for different vitreoretinal diseases. The thickness of each
retinal layer in different regions of the macula, foveal avascular zone area, and vessel density of different
retinal capillary plexuses in different macular regions may be potential prognostic factors for postoperative visual recovery. However, the results of the existing literature are inconsistent and require further study.