Chorioretinal 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


Paving-stone degeneration in sector 6 and unifocal atrophy of the retinal pigment epithelium in sector 24 are highlighted in yellow



Paving-stone changes can be congenital and are not considered degenerative by some experts [5]. Paving-stone degeneration is present in 4.4–28.4 % of general population [2, 4, 6].

Although this degeneration can resemble retinal holes, this is an outer retina defect; the inner neurosensory layers are intact, and retinal breaks do not occur [5]. Majority of clinicians consider this degeneration benign with low risk of retinal detachment. Paving-stone degeneration has been reported to have a protective effect against the progression of rhegmatogenous retinal detachment [1].

Many authors consider chorioretinal atrophy of the pigment epithelium as bearing no risk of retinal detachment and not indicated for prophylactic laser treatment [57]. However, some authors report 11.1 % frequency of retinal breaks associated with marked stages of chorioretinal degeneration [3].

Case 62.  Paving-Stone Degeneration

A 56-year-old female patient with mild myopia and no symptomatic complains was referred for fundus examination because of arterial hypertension.


Ophthalmoscopic Findings (Fig. 6.62a, b)


Multiple atrophic lesions in the pigment epithelium of various forms and sizes are seen in the far-periphery of the inferior quadrant of the right eye. Some lesions merge, others are isolated. Pigment clumps of various forms and intensity are located within and between the chorioretinal atrophy lesions. There is a clearly seen choroidal pattern in the atrophic areas.

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Fig. 6.62
(a) Paving-stone degeneration. (b) Line indicates OCT-scanning direction. (c, d) OCT-scanning results according to the line direction in (b)


OCT Scan Description (Fig. 6.62c, d)


The retinal surface is irregular and wavy. Multiple areas of pigment epithelium destruction are observed. The reflectivity in the neurosensory retina layers is increased. Neurosensory retina is thinned at the level of the pigment epithelium destruction, and hyperreflective shadows are observed at the choroidal level because of increased retinal echogenicity and light permeability. The ellipsoid zone is not seen. Choroid hyperreflectivity correlates with the areas of pigment epithelium destruction. Multiple hyperreflective deposits are present in the vitreous, there is no evidence of vitreous traction.


OCT Scan Details (Fig. 6.62c, d)






  • A420797_2_En_6_Figb_HTML.gif Pre-retinal consolidation of the vitreous with multiple hyperreflective deposits


  • A420797_2_En_6_Figc_HTML.gif Areas of dense pigment epithelium


  • A420797_2_En_6_Figd_HTML.gif Areas of pigment epithelium and photoreceptor layer destruction


  • A420797_2_En_6_Fige_HTML.gif Increased choroidal reflectivity at the level of the areas of pigment epithelium destruction


  • A420797_2_En_6_Figf_HTML.gif Decreased choroidal reflectivity at the level of the areas of dense pigment epithelium

Case 63. Focal Pigment Epithelium Atrophy

An asymptomatic 40-year-old female patient with mild myopia came to have distance glasses prescribed. Fundus examination revealed an atrophic lesion with sharp borders in the inferotemporal quadrant of her left eye. No signs of traction were noted.


Ophthalmoscopic Findings (Fig. 6.63a, b)


A round-shaped area of atrophic pigment epithelium with clearly outlined borders is seen at the 7 o’clock position in the mid-periphery of the inferonasal quadrant of the left eye. Pigment clumps are observed around the borders.

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Fig. 6.63
(a) Focal pigment epithelium atrophy. (b) Line indicates OCT-scanning direction. (c, d) OCT-scanning results according to the line direction in (b)


OCT Scan Description (Fig. 6.63c, d)


The retinal profile is deformed, the structure of all layers is altered. Neurosensory retina is thinned, neuroepithelial surface is slopy on one side of the lesion and excavated on the other side. The pigment epithelium is hyporeflective and atrophic. The ellipsoid zone is not distinguishable. Choroidal reflectivity and light transmittance in the atrophic area is considerably increased.


OCT Scan Details (Fig. 6.63c, d)






  • A420797_2_En_6_Figc_HTML.gif Neurosensory retina thinning


  • A420797_2_En_6_Figd_HTML.gif Pigment epithelium and photoreceptor layer destruction


  • A420797_2_En_6_Fige_HTML.gif Increased choroidal reflectivity at the level of the pigment epithelium destruction



Congenital Hypertrophy of the Retinal Pigment Epithelium


Congenital hypertrophy of the retinal pigment epithelium (CHRPE) is a common benign retinal condition [6]. According to some authors, CHRPE is characterized by pigment deposits found along the ora serrata, which may extend as far as equator. In early stages pigment spots and clumps reach 1/8 PD, and in advanced stages the lesion occupies 1/4–1.0 PD [3]. Other authors claim that CHRPE can be unifocal or multifocal (Table 6.2). Unifocal CHRPE is a round or oval flat lesion, 1–2 PD in size, with well-defined borders, that can be deep gray or black. The lesion can be surrounded by a hypopigmented halo. Multifocal CHRPE appears as grouped pigmented deep gray or black spots of various sizes, that resemble animal tracks (“bear tracks”) [5].


Table 6.2
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


Multifocal hypertrophy of the retinal pigment epithelium (bear tracks) in sector 15 and unifocal hypertrophy of the retinal pigment epithelium in sector 17 are highlighted in yellow

Histological studies have established CHRPE to be a result of pigment redistribution [2, 3]. Patients with multifocal CHRPE (bear tracks) should be evaluated for familial adenomatous polyposis of colon and rectum, which may lead to colorectal cancer after 50 years of age [5, 6].

As reported by many authors, CHRPE is not usually associated with vitreous traction, changes in the vitreoretinal interface, or risk of retinal detachment. However, there have been reports of retinal tears in 11.9 % of cases of advanced CHRPE [3]. Nonetheless, prophylactic laser treatment for this condition is not indicated [5].

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