Peripheral Retinal Degenerations as a Risk Factor for Rhegmatogenous Retinal Detachment



Fig. 3.1
OCT of peripheral retinal tears: (a) Flap tear; (b) Operculated tear



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Fig. 3.2
Schematic image of peripheral retinal tears in PVD: (a) Flap tear; (b) Operculated tear


The RRD develops when liquefied vitreous humor accelerated by rotary eye movements passes through the retinal tear or retinal holes (Fig. 3.3a) into the subretinal space and detaches (Fig. 3.3b) the neurosensory retina from the underlying pigment epithelium (Figs. 3.4, 3.5, and 3.6) [6, 10]. The most common risk factors for RRD include vitreous liquefaction, posterior vitreous detachment, retinal tears (flap tears, dialysis), lattice degeneration, cystic retinal tufts, degenerative retinoschisis, myopia, aphakia, pseudophakia, Nd:YAG laser posterior capsulotomy, RRD of the fellow eye, family history of RRD, systemic diseases, and peripheral vitreochorioretinal degenerations [1, 10].

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Fig. 3.3
Schematic image of RRD: (a) Local detachment; (b) Detachment progresses to the central retina


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Fig. 3.4
Color fundus images: (а) Subtotal retinal detachment with a giant flap tear; (b) Local retinal detachment with a flap tear and a demarcation line


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Fig. 3.5
(a) Color fundus image of the superior retinal detachment with a flap tear; (b) Scanning direction; (c) OCT images Scan 1 Central retina. The detachment of para- and perifoveal neurosensory retina (red circle); multiple folds observed on the external retinal surface (green arrow); Scan 2 Detached retina with an overhanging flap tear (blue arrow). Tear margins represented by the neurosensory retina (green arrow) with intraretinal cavities (red cross); retinal detachment cavity (red circle) and marked vitreoretinal adhesion with traction at the tear margins (red asterisks)


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Fig. 3.6
(a) Color fundus image of retinal detachment with macula involved; lattice degeneration with multiple tears seen in the inferonasal retina; (b) Scanning direction; (c) OCT images Scan 1 Neurosensory retina detached (green arrow) from the retinal pigment epithelium up to the macula, with a large cavity (red circle) between the layers. Multiple hyporeflective irregular cavities in the neuroepithelium (red cross). Dense retinal pigment epithelium at the fovea (red arrow). Scan 2 Detached neuroepithelium corresponding to the lattice degeneration with tears (red crescent), intraretinal cavities in neurosensory retina (red cross), and marked vitreoretinal traction (red asterisk)

The main causes for vitreous liquefaction (synchysis) are advanced age, myopia, eye injuries, and chronic inflammation [12]. Several studies claim that synchysis is associated with the depolymerization of hyaluronic acid leading to structural changes of the vitreous [13, 14]. Posterior vitreous detachment usually manifests with photopsias (flashing lights), floaters or blurry vision. Photopsias arise from the mechanical stimulation of vitreoretinal traction on the retina, and floaters are shadows on the retina cast by vitreous opacities: blood, glial cells, aggregated collagen fibers.

Peripheral retinal degenerations with vitreoretinal adhesions and tractions are associated with the highest risk of rhegmatogenous retinal detachment [8, 9, 15]. We can recognize these high-risk forms of degenerations if we perform a careful OCT study of their morphology and progression, thus preventing retinal detachment [1620].

In this atlas we explore the interrelations between vitreous and retina in most common peripheral retinal degenerations by means of OCT imaging and reveal the most severe degenerations with increased risk of RRD.


Classifications of Peripheral Retinal Degenerations


The first classifications of peripheral retinal degenerations were proposed by Halpern [21] and Duke-Elder et al. [22]. These classifications were based on the histological studies of peripheral degenerations in asymptomatic patients published by Okun (1960, 1961) and Rutnin (1967) [2326].

There is currently no universally accepted classification system of peripheral retinal degenerations.

Upon careful consideration of various published classifications, we have chosen several major features they all have in common. These features include:


  1. 1.


    Location: equatorial, peripheral, and combined degenerations [1].

     

  2. 2.


    Pathomorphology: trophic, tractional, trophic-tractional degenerations [27]; atrophic, tractional, and combined degenerations [28].

     

  3. 3.


    Depth of retinal changes: intraretinal, vitreoretinal, chorioretinal [2, 29]; retinal, vitreoretinal, chorioretinal [30]

     

  4. 4.


    Risk of retinal detachment: lesions predisposing to retinal detachment, lesions not predisposing to retinal detachment [11, 31, 32]; conditions that affect the outer retina (low risk of detachment) and conditions that affect the inner retina (high risk of detachment) [15].

     

  5. 5.


    Prognosis: progressive and stationary (non-progressive) [1].

     

  6. 6.
Jun 27, 2017 | Posted by in OPHTHALMOLOGY | Comments Off on Peripheral Retinal Degenerations as a Risk Factor for Rhegmatogenous Retinal Detachment
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