Intraretinal Degenerations


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1. Retinal dialysis

2. Peripheral cystoid degeneration

3. Retinal detachment

4. Retinal drusen

5. Full-thickness tear

6. Paving-stone degeneration

7. Lattice degeneration

8. Bullous retinoschisis

9. Flat retinoschisis

10. White-without-pressure

11. Retinal tuft

12. Snail-track degeneration

13. Pearl degeneration

14. Flap tear

15. Grouped congenital hypertrophy of the retinal pigment epithelium (“bear tracks”)

16. Snowflake degeneration

17. Unifocal hypertrophy of the retinal pigment epithelium

18. Atrophic retinal hole

19. Haemorrhage

20. Preretinal fibrosis

21. Honeycomb degeneration

22. Operculated retinal tear

23. Dark-without-pressure

24. Unifocal atrophy of the retinal pigment epithelium


Degenerative retinoschisis is highlighted in yellow: sector 8 – bullous retinoschisis; sector 9 – flat retinoschisis



There is currently no universally accepted classification of retinoschisis. Astakhov et al. (2004) proposed the classification of the SR based on the following features [4]:


  1. 1.


    Presence of retinal tears: in the inner, outer, or both layers, and without tears

     

  2. 2.


    Disease progression: non-progressive with retinal scarring, progressive without demarcation, complicated (vitreous haemorrhage, intracystic hemorrhage, and retinal detachment)

     

  3. 3.


    Development: primary or secondary

     

  4. 4.


    Location: central, peripheral, or combined

     

  5. 5.


    Type: flat or bullous

     

  6. 6.


    Affected side: unilateral or bilateral

     

SR may be associated with retinal detachment. According to various authors, SR is found in rhegmatogenous retinal detachment in 2.5–10.5 % of cases [4, 6], but may be considered the primary cause in only 0.05–2.5 % of cases [11, 14].

At the present moment there is no consensus on the best treatment of senile retinoschisis [15]. The majority of authors consider that retinoschisis should be treated in case of symptomatic, progressive retinal detachment threatening the macula [11, 14]. The lateral and central barring or treatment of the margins of an outer retinal break should be avoided [16]. Some experts strongly advocate individual approach in treating retinoschisis [17].

There are several studies claiming that high resolution OCT may be successfully used for the timely diagnosis of retinoschisis, differentiating it from retinal detachment and identifying breaks in its layers [1820].

Case 1. Flat Two-Layer Retinoschisis

A 54-year-old male patient was referred for decreased visual acuity in his left eye. During examination, moderate hyperopia and flat retinoschisis in his left eye were diagnosed.


Ophthalmoscopic Findings (Fig. 4.1a, b)


A slightly elevated whitish retinal area with blurred borders is observed in the peripheral temporal quadrant (2–4 o’clock) of the left eye.

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Fig. 4.1
(a) Flat retinoschisis. (b) Scanning (yellow line) of the elevated area in the temporal peripheral retina, left eye. (c, d) OCT-scanning line corresponding to the elevated area


OCT Scan Description (Fig. 4.1c, d)


The retinal profile is irregular. Intraretinal hyporeflective cavities split the neurosensory retina into two layers: the inner layer and the outer layer. Presumably, elongated Müller cells are seen in the cavity. Pigment epithelium is destroyed and thickened. The vitreous has irregular density and is detached from the retina. There is no vitreoretinal traction.


OCT Scan Details (Fig. 4.1c, d)






  • A420797_2_En_4_Figb_HTML.gifLayers of moderate reflectivity (increased density) in the vitreous over the split retina


  • A420797_2_En_4_Figc_HTML.gifElevated inner layers of the neurosensory retina


  • A420797_2_En_4_Figd_HTML.gifIntraretinal hyporeflective cavities separating the inner and outer layers of the neurosensory retina


  • A420797_2_En_4_Fige_HTML.gifAreas of thickening and redistribution of the pigment epithelium


  • A420797_2_En_4_Figf_HTML.gifIrregular and jagged layer in the outer layers of the neurosensory retina

Case 2. Flat Retinoschisis with Snowflake Degeneration

A 37-year-old female patient with bilateral moderate hyperopia and incomplete posterior vitreous detachment presented with the main complaint of floaters affecting her both eyes.


Ophthalmoscopic Findings (Fig. 4.2a, b)


An elevated grayish retinal area with blurred borders is observed in the inferior quadrant of the mid-peripheral retina of the right eye. Multiple white deposits are scattered over the degenerated surface and look like “snowflakes”.

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Fig. 4.2
(a) Flat retinoschisis with snowflake degeneration. (b) Lines indicate OCT-scanning direction. (c) OCT-scanning results according to the lines direction in (b)


OCT Scan Description (Fig. 4.2c)



Scan 1

The retinal surface is smooth and thickened. Multiple hyporeflective cylindrical cavities splitting the retina into two layers are seen in the center of the scan.


Scan 2

The retinal surface is smooth, the elevated area enlarged. There are multiple intraretinal hyporeflective cylindrical cavities between the inner and outer layers of the neurosensory retina. Multiple hyperreflective deposits in the outer plexiform layer are present. Destructive changes are seen in the vitreous, and there is no vitreoretinal traction.


OCT Scan Details (Fig. 4.2c)






  • A420797_2_En_4_Figb_HTML.gifLayers of increased density in the vitreous


  • A420797_2_En_4_Figc_HTML.gifElevated inner layers of the neurosensory retina


  • A420797_2_En_4_Figf_HTML.gifIrregular and jagged surface of the outer layers of the neurosensory retina


  • A420797_2_En_4_Figd_HTML.gifIntraretinal hyporeflective cavities separating the inner and outer layers of the neurosensory retina


  • A420797_2_En_4_Figg_HTML.gifDense outer plexiform layer with hyperreflective spot-like deposits

Case 3. Flat Three-Layer Retinoschisis

A 56-year-old female patient was referred for low vision in her right eye. Ocular examination revealed mild hyperopia, early-stage cortical cataract, and bilateral retinoschisis.


Ophthalmoscopic Findings (Fig. 4.3a, b)


A grayish line of a slightly elevated retina is observed in the far peripheral temporal retina of the right eye.

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Fig. 4.3
(a) Flat retinoschisis. (b) Lines indicate OCT-scanning direction. (c) OCT-scanning results according to the lines direction in (b)


OCT Scan Description (Fig. 4.3c)



Scan 1

The OCT scan shows retinoschisis secondary to cystoid degeneration. The retina is slightly elevated because of multiple hyporeflective cylindrical cavities in the inner plexiform layer of the neurosensory retina, that pass into splitting (schisis) of the retina into two layers: the inner and outer layers of the neurosensory retina. Vitreoretinal traction is not seen.


Scan 2

Three-layer retinoschisis. The retina is elevated because of three-layer splitting: multiple intraretinal cavities in the inner and outer nuclear layers separated by the dense outer plexiform layer.


OCT Scan Details (Fig. 4.3c)






  • A420797_2_En_4_Figc_HTML.gifDense inner layers of the neurosensory retina


  • A420797_2_En_4_Figd_HTML.gifIntraretinal hyporeflective cavities separating the inner and outer layers of the neurosensory retina


  • A420797_2_En_4_Figg_HTML.gifDense outer plexiform layer separated from other layers of the neurosensory retina by hyporeflective cavities


  • A420797_2_En_4_Figh_HTML.gifPhotoreceptor layer destruction. As intraretinal cavities grow in size, this destruction becomes more distinct

Case 4. Bullous Retinoschisis

A 35-year-old male patient with moderate hyperopia and incomplete posterior vitreous detachment presented with complaints about mild floaters affecting his both eyes.


Ophthalmoscopic Findings (Fig. 4.4a, b)


A clearly outlined, elevated cystoid area darker than the adjacent retina is seen in the temporal quadrant of the left eye. The retinal vessels are seen over the surface of the bullous formation.

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Fig. 4.4
(a) Bullous retinoschisis. (b) Line indicates OCT-scanning direction. (c, d) OCT-scanning results according to the line direction in (b)


OCT Scan Description (Fig. 4.4c, d)


The retinal surface is slightly elevated by multiple cylindrical cavities with hyporeflective content in the neurosensory retina. There is a clearly seen flat splitting into inner and outer layers of the neurosensory retina. This splitting progresses into a large cavity with hyperreflective content separated from the underlying tissues by what supposedly is the dense outer plexiform layer.

Multiple dense and slightly elevated pigment epithelium areas are seen at the borders of degeneration. The ellipsoid zone is destructed. No vitreoretinal traction is seen.


OCT Scan Details (Fig. 4.4c, d)






  • A420797_2_En_4_Figc_HTML.gifElevated inner layers of the neurosensory retina


  • A420797_2_En_4_Figi_HTML.gifLarge hyporeflective cavity between the inner and outer layers of the neurosensory retina


  • A420797_2_En_4_Figh_HTML.gifPhotoreceptor layer destruction in the area of the hyporeflective cavity


  • A420797_2_En_4_Figd_HTML.gifIntraretinal hyporeflective cavities splitting the inner and outer layers of the neurosensory retina


  • A420797_2_En_4_Figg_HTML.gifDense outer plexiform layer separated from other neurosensory retinal layers by hyporeflective cavities


  • A420797_2_En_4_Fige_HTML.gifAreas of increased density and slight elevation of the pigment epithelium

Case 5. Flat Retinoschisis with Subclinical Retinal Detachment

A 49-year-old male patient complained of central vision loss in his right eye. During examination, moderate myopia, early-stage cortical cataract, and far peripheral retinoschisis with subclinical retinal detachment were diagnosed.


Ophthalmoscopic Findings (Fig. 4.5a, b)


A slightly elevated grayish area with blurred borders is observed in the far peripheral retina of the inferotemporal quadrant of the right eye. Laterally, there is a clearly outlined red area imitating a giant retinal tear.

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Fig. 4.5
(a) Flat retinoschisis with subclinical detachment of the neurosensory epithelium. (b) Lines indicate OCT-scanning direction. (c) OCT-scanning results according to the line direction in (b)


OCT Scan Description (Fig. 4.5c)



Scan 1

The outer retinal layers are irregular. Two cavities separated by a thin layer of neurosensory retina are observed. The cavity on the right developed from the splitting of the neurosensory retina, whereas the one on the left resulted from the complete detachment of the neurosensory epithelium layer from the pigment epithelium.


Scan 2

The transition of retinoschisis to retinal detachment (left part of the scan) is shown, the detached retina is dense. There are no signs of vitreoretinal tractions and adhesions. Local area of destructive changes in the pigment epithelium and hyperreflective choroid in the area of retinoschisis are observed.


OCT Scan Details (Fig. 4.5c)






  • A420797_2_En_4_Figi_HTML.gifLarge hyporeflective cavity between the inner and outer layers of the neurosensory retina


  • A420797_2_En_4_Figf_HTML.gifThe outer layers of the neurosensory retina with irregular, jagged surface


  • A420797_2_En_4_Figh_HTML.gifDestroyed photoreceptor layer next to retinoschisis border


  • A420797_2_En_4_Figj_HTML.gifHyporeflective outer retinal layers, pigment epithelium, and choroid, at the level of presumably retinal vessels and dense parts in the inner retinal layers


  • A420797_2_En_4_Figd_HTML.gifIntraretinal hyporeflective cavities splitting the inner and outer layers of the neurosensory retina


  • A420797_2_En_4_Figg_HTML.gifDetached and dense neurosensory retina


  • A420797_2_En_4_Fige_HTML.gifAreas of dense and slightly elevated pigment epithelium


  • A420797_2_En_4_Figc_HTML.gifElevated and dense inner layers of the neurosensory retina separated from the outer layers by a hyporeflective cavity

Case 6. Bullous Retinoschisis Progressing into a Retinal Detachment with Fibrosis

A 67-year-old female patient presented with complaints about floaters and occasional flashes of light affecting her right eye for 2 days. During examination, pseudophakia was diagnosed, OD: VA, sc 20/20.


Ophthalmoscopic Findings (Fig. 4.6a, b)


An elevated area of the split retina extending to the mid- and far peripheral retina is observed at the equator and inferotemporal quadrant of the right eye. The medial border of the retinal split is white-gray and clearly outlined with the area of grayish and loose retina seen at its periphery.

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Fig. 4.6
(a) Bullous retinoschisis progressing into a retinal detachment. (b) Lines indicate OCT-scanning direction. (c) OCT-scanning results according to the lines direction in (b)


OCT Scan Description (Fig. 4.6c)



Scan 1

The retinal surface is raised up. Medially, there are multiple cylindrical elongated cavities at the neurosensory retina level and a schisis of the outer and inner layers progressing into a large hyporeflective cavity.


Scan 2

There is a tear of the outer layer of the neuroepithelium in the area of retinoschisis. The retina is detached.


OCT Scan Details (Fig. 4.6c)






  • A420797_2_En_4_Figc_HTML.gifElevated inner layers of the neurosensory retina


  • A420797_2_En_4_Figi_HTML.gifLarge hyporeflective cavity between the inner and outer layers of the neurosensory retina


  • A420797_2_En_4_Figf_HTML.gifInner layers of the neurosensory retina with irregular, jagged surface


  • A420797_2_En_4_Figh_HTML.gifPigment epithelium destruction at the retinoschisis border


  • A420797_2_En_4_Figd_HTML.gifIntraretinal hyporeflective cavities splitting the inner and outer layers of the neurosensory retina


  • A420797_2_En_4_Figg_HTML.gifDetached and dense neurosensory retina


  • A420797_2_En_4_Fige_HTML.gifThe tear of the outer layers of the neurosensory retina



White-Without-Pressure Degeneration


White-without-pressure degeneration (Table 4.2) is an optical phenomenon in retinal periphery characterized by the fundus color change from orange-red to translucent white without a mechanical stimulus [21]. This degeneration is commonly found in the post equatorial area at the base of the vitreous and ora serrata, and may be focal or affect the entire segment of the peripheral retina [22].


Table 4.2
Diagram of peripheral retinal degenerations























































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1. Retinal dialysis

2. Peripheral cystoid degeneration

3. Retinal detachment

4. Retinal drusen

5. Full-thickness tear

6. Paving-stone degeneration

7. Lattice degeneration

8. Bullous retinoschisis

9. Flat retinoschisis

10. White-without-pressure

11. Retinal tuft

12. Snail-track degeneration

13. Pearl degeneration

14. Flap tear

15. Grouped congenital hypertrophy of the retinal pigment epithelium (“bear tracks”)

16. Snowflake degeneration

17. Unifocal hypertrophy of the retinal pigment epithelium

18. Atrophic retinal hole

19. Haemorrhage

20. Preretinal fibrosis

21. Honeycomb degeneration

22. Operculated retinal tear

23. Dark-without-pressure

24. Unifocal atrophy of the retinal pigment epithelium


White-without-pressure degeneration in sector 10 is highlighted in yellow

Different sources give different data on the prevalence of white-without-pressure degeneration. Some authors report that this degeneration is found in up to 30 % of normal eyes and is usually bilateral [10]. Other authors claim that white-without-pressure is more frequently diagnosed in young individuals (less than 19 years of age – 36 %, 20–39 years of age – 35 %) and there is a definite correlation with the axial length: there were no cases of degeneration in eyes with the shortest axial length of 21 mm and a 54 % incidence in eyes with axial length of >33 mm [22].

This degeneration is widespread, its occurrence in the peripheral retina was first described by Rutnin and Schepens (1967) and Nagpal (1976), however, the clinicopathologic interrelations in this group still remain unclear [2325]. According to some authors the changes of retina color from orange-red to translucent white or gray-white are due to vitreous traction, and appear more often in African-Americans [1, 26], whereas other authors explain the retina whitening by increased density of collagen fibrils at the inner retinal surface [10].

There are reports of a circumferential dark-red band around the area of degeneration that may give a false impression of linear retinal tear [21].

Currently there is no universally accepted classification of white-without-pressure. This degeneration is considered by some authors to be benign [27], with no risk of rhegmatogenous retinal detachment [21]. Other experts consider it a trophic-tractional phenomenon [28], or vitreoretinal degeneration [29] with the risk of linear and giant retinal tears along the posterior margin of the lesion [3].

OCT imaging plays an important role in studying white-without-pressure degeneration. OCT-scanning results have shown that the whitish areas in equatorial and peripheral retina correspond to hyperreflective outer retinal layers and ellipsoid zone with no signs of vitreous traction [25, 30].

It is therefore ascertained that white-without-pressure is not associated with vitreoretinal traction and increased risk of retinal detachment, so this degeneration is not considered an indication for prophylactic laser photocoagulation [10, 21, 31]. The patient should be routinely examined every 1–2 years, informed about the symptoms of a retinal tear or detachment and asked to have his retina examined if these symptoms occur [21].

Case 7. White-Without-Pressure

An asymptomatic 25-year-old female patient with mild myopia. Degeneration was diagnosed during routine examination.


Ophthalmoscopic Findings (Fig. 4.7a, b)


A wide, white retinal band without a clear border is seen in the mid-peripheral retina of the superotemporal quadrant of the right eye. The retinal vessels are not changed in terms of direction, caliber, and color.

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Fig. 4.7
(a) White-without-pressure. (b) Line indicates OCT-scanning direction. (c, d) OCT-scanning results according to the position of the line in (b)


OCT Scan Description (Fig. 4.7c, d)


The retinal surface is smooth. A hyperreflective ellipsoid zone is in the left part of the scan corresponding to the white-without-pressure lesion. A hyporeflective ellipsoid zone is in the right part of the scan corresponding to the normal retina. In the center of the scan, there is a border where the hyperreflective layer changes into hyporeflective. No vitreoretinal tractions or adhesions are seen.

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Jun 27, 2017 | Posted by in OPHTHALMOLOGY | Comments Off on Intraretinal Degenerations
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