Peripheral Retinal Degenerations: Clinical Guidelines

List of Abbreviations

DD – optic disc diameter

ONH – optic nerve head

PVD – posterior vitreous detachment

LP – laser photocoagulation

ICD-10 – International Classification of Diseases 10th Revision

MF – meridional folds

OCT – optical coherence tomography

PRD – peripheral retinal degenerations

AL – axial length (of the eye)

LD – lattice degeneration

RPE – retinal pigment epithelium

vitreous body

Terms and Definitions

A retinal tear is any defect involving the full thickness of the neurosensory retina. The clinical significance of tears is that fluid from the vitreous cavity can enter the space between the sensory retina and the retinal pigment epithelium (RPE), thereby causing a rhegmatogenous retinal detachment.

Retinal holes are breaks caused by atrophy of the inner retinal layers.

Tractional retinal tear is a tear caused by vitreoretinal traction.

Symptomatic tear is a tear where the patient presents with specific complaints of "lightning", "flashes", sudden onset of "floaters", etc., in front of the affected eye.

Asymptomatic tear is a tear where the patient has no specific complaints indicating the presence of retinal tractions and is generally an incidental finding.

Rhegmatogenous retinal detachment is the separation of the neurosensory retina from the retinal pigment epithelium associated with retinal breaks through which fluid from the vitreous body (VB) penetrates into the subretinal space.

Vitreous destruction – is an alteration in the structure of the vitreous body resulting from multiple causes: involutional changes, increase in the axial length (AL) of the eye in high myopia, after surgical interventions, intraocular inflammation, and eye trauma. It develops due to altered bonding forces between hyaluronic acid and collagen fibers, leading to liquefaction of the VB – synchisis, as well as fiber condensation – syneresis.

Posterior vitreous detachment (PVD) – is the separation of the vitreous body cortex from the retina and optic nerve. If PVD extends to the ora serrata, it can be considered complete.

Symptomatic posterior vitreous detachment is a detachment accompanied by patient complaints of floating opacities, "floaters", "flashes", transient visual field "blurring", photopsias, and metamorphopsias. However, symptoms are often so subtle that many patients do not pay attention to them and therefore do not report them spontaneously. Consequently, it is necessary to thoroughly question the patient about all (even the most minor) visual changes.

Vitreoretinal adhesion is the connection or "gluing" of the extracellular matrix that anchors the cortical collagen fibrils to the inner limiting membrane and the Müller cell endfeet.

Lattice degeneration is characterized by whitish, intersecting bands forming a lattice pattern in the peripheral retina, between which reddish areas of retinal thinning, cysts, and pigmentation may occur. Histological features include varying degrees of atrophy, irregularity of the inner retinal layers, a pocket of liquefied VB overlying the affected area, and VB adhesion to the margins of the lesion.

Snail-track degeneration is a degeneration similar to lattice degeneration, but lacking obliterated retinal vessels and pigmentation in the affected area.

Peripheral retinal tufts are small peripheral focal areas of elevated glial hyperplasia associated with vitreous or zonular attachment and traction.

Meridional folds are retinal folds typically located in the superonasal sector, their appearance associated with the tractional effect of the vitreous body on the retina.

"White-with-pressure" is an optical phenomenon where the fundus color changes from its usual orange-red color to a translucent white or grayish-white color when examined with scleral depression. "White-without-pressure" has the same appearance but is detected without applying pressure to the sclera, which, however, allows for clearer visualization of the whitish lesion and better delineation of its boundaries. The detection of these optical phenomena is associated with the tractional effect of the VB on the retina at the sites of observed whitening.

Pavingstone degeneration (or cobblestone degeneration) – peripheral, discrete areas of atrophy of the outer retinal layers, pigment epithelium, and choriocapillaries of various sizes.

Peripheral cystoid degeneration – is a degeneration characterized by the presence of microcysts in the extreme retinal periphery along the ora serrata. It occurs in virtually all adults over the age of 20.

Ora serrata pearls are bright, white, shiny rounded granules located near the dentate processes.

Retinal drusen are white or yellowish, round, elevated areas deep in the retina, representing areas of RPE atrophy and hyperplasia. They vary in shape and size, but are usually small and round.

Frost-like degeneration consists of punctate, whitish foci with clear boundaries within the retinal thickness.

Retinal pigment epithelial hypertrophy («bear tracks», «animal tracks») is located in the equatorial region as oval or round, flat formations (foci) measuring 1–2 disc diameters, with distinct black borders. Marginal hypopigmentation is possible. Vitreous traction is absent.

Retinal pigment hyperplasia is a consequence of proliferation due to chronic traction caused by trauma, inflammation, or traction.

Non-rhegmatogenous degenerations are degenerations that do not lead to retinal detachment.

Rhegmatogenous degenerations are degenerations that increase the risk of retinal detachment.

1. Brief information on the disease or condition

Based on current literature data, conducted studies, and personal experience, these clinical guidelines contain information on the diagnosis and management of patients with peripheral retinal degenerations.

1.1 Definition of the disease or condition

• Peripheral retinal degenerations encompass all degenerative and dystrophic changes of the fundus tissues located in the equatorial and post-equatorial zones.

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

The etiology of peripheral retinal degenerations has not been fully determined.

One of the causes of non-rhegmatogenous degeneration, such as pavingstone degeneration, is considered to be an increase in the axial length of the eye in high myopia, leading to morphological changes in the sclera, choroid, and, consequently, the pigment epithelium and outer retinal layers. The development of peripheral drusen is defined as a manifestation of age-related retinal changes.

A leading role in the development of rhegmatogenous forms of peripheral degenerations is attributed to alterations in the vitreous body. The vitreous body is most firmly attached to the retina in the region known as the vitreous base – a peripheral zone encompassing the ora serrata, extending approximately 2 mm anteriorly and 4 mm posteriorly from the ora serrata. VB collagen fibers in the base region can be so firmly attached to the retina and the epithelium of the pars plana that the VB cannot be detached from these structures without forming tractions and even a retinal tear. The VB is also firmly attached to the margins of the optic disc, in the macular region, and along major blood vessels. There is tight VB attachment at the margins of lattice and other rhegmatogenous degenerations.

Most retinal tears occur as a result of traction caused by spontaneous or traumatic posterior vitreous detachment. A contributing factor is VB collapse. There is growing evidence that age-related PVD progresses slowly over many years. It typically begins with a small VB detachment in the perifoveal area. Liquid VB penetrates through a tear in the posterior cortical layers and detaches them in the macular area, causing a partial PVD. In the early stage, the course is usually asymptomatic. In most eyes, progressive PVD remains subclinical for years until VB detachment occurs at the margins of the optic disc. This phenomenon is accompanied by symptoms associated with the appearance of Weiss's ring in the patient's visual field. Meanwhile, the VB remains attached at the vitreous base. Vitreoretinal traction on the retina in this area can lead to a retinal tear. The prevalence of PVD increases with age. Conditions such as aphakia and pseudophakia with posterior capsule defects, inflammatory diseases, trauma, vitreous hemorrhage, and axial myopia are accompanied by vitreous liquefaction and PVD.

1.3 Epidemiology of the Disease or Condition

Epidemiological data are very sparse and pertain primarily to the prevalence of PVD and other predictors of peripheral retinal rhegmatogenous degenerations and tears.

The results of clinical studies indicate a low prevalence of PVD among patients under 50 years of age. An analysis of autopsy material revealed the presence of PVD in less than 10% of eyes in patients younger than 50 years and in 63% of eyes in patients older than 70 years [1].

Important predictors of new retinal tears are vitreous hemorrhage at the initial examination and an increase in the number of floaters during follow-up. Overall, 7% to 18% of all patients with acute PVD have retinal tears. In the presence of vitreous hemorrhage, retinal tears are present in 50% to 70% of cases compared to 7% to 12% without hemorrhage. Patients with acute PVD complicated by a retinal tear are 7 times more likely to exhibit vitreous pigment granules compared to patients without a retinal tear [1].

Lattice degeneration (LD) – a pathology of the vitreoretinal interface occurring in 6% to 10% of the general population, is bilateral in 1/3 to 1/2 of cases. It is more frequently (though not exclusively) diagnosed in myopic eyes, and a genetic predisposition may exist. LD is found in approximately 20% to 30% of all eyes with rhegmatogenous retinal detachment [2, 3].

Meridional folds (MF) occur in 26% of the population, are bilateral in 55% of cases, and are therefore present in 20% of all eyes. They are more commonly found in male patients. The number of meridional folds in a single eye ranges from 1 to 10. Some data indicate that no more than one MF is found per eye, whereas other information suggests the presence of multiple closely spaced MFs. One study described the occurrence of multiple MFs in 27% of cases [4].

Vitreoretinal tufts – occur in 75% of the adult population, are bilateral in half of the cases, and are thus present in 59% of adult eyes [5].

“White-with-pressure” or “white-without-pressure” are found to varying degrees in more than 30% of normal eyes, with a strong tendency toward bilateral involvement. In individuals under 20 years of age, the incidence is 5%, whereas in individuals over 70 years, this figure is approximately 66%. Across all age groups, this condition is more frequently detected in myopes (22.8%). The frequency of these changes increases with the elongation of the anteroposterior axis of the eye, reaching 54% when the eye length exceeds 33 mm [6].

Ora serrata pearls. Ora serrata pearls occur in any quadrant of the fundus, in approximately 20% of 700 autopsy eyes. Examination of both eyes shows a tendency toward a symmetrical arrangement of ora serrata pearls. The causes of their appearance are unknown [6].

1.4 Features of Coding the Disease or Condition

H35.4 Peripheral retinal degenerations

H33.3 Retinal breaks

H43.8 Other disorders of vitreous body

1.5 Classification of the disease or condition

Peripheral Retinal Degenerations:

I. Conditions predisposing to retinal detachment (rhegmatogenous degenerations):

1.1. Lattice degeneration;

1.2. Snail-track degeneration;

1.3. Vitreoretinal tufts:

1.3.1. Non-cystic retinal tufts;

1.3.2. Cystic retinal tufts;

1.3.3. Retinal tufts with zonular traction;

1.4. Meridional folds, isolated ora serrata bays, and peripheral retinal excavations.

II. Conditions not predisposing to retinal detachment (non-rhegmatogenous):

2.1. Paving-stone (cobblestone) degeneration;

2.2. RPE hyperplasia;

2.3. RPE hypertrophy;

2.4. Peripheral cystoid degeneration;

2.5. Ora serrata pearls;

2.6. Retinal drusen;

2.7. Frost-like degeneration;

2.8. “White-with-pressure” and “white-without-pressure” degeneration.

III. Retinal breaks:

3.1. Valvular or horseshoe tear;

3.2. Giant tear;

3.3. Operculated tear;

3.4. Dialysis;

3.5. Atrophic (hole) retinal break.

1.6 Clinical presentation of the disease or condition

I. Conditions predisposing to retinal detachment.

1.1. Lattice degeneration is a predisposing factor for retinal tears and detachment. In most cases, it is asymptomatic and causes no patient complaints; in the presence of pronounced traction, complaints of “lightning flashes” may occur, typically upon movement of the eyeball. Ophthalmoscopy reveals whitish, interlacing bands forming a lattice pattern, with reddish areas of retinal thinning, cysts, and pigmentation potentially occurring between the interlacing strands. Histological features include varying degrees of atrophy, irregularity of the inner retinal layers, a pocket of liquefied vitreous overlying this zone, and adhesion of the vitreous to the edges of the lesion. A tractional tear may develop at the lateral or posterior edge of the LD or, more rarely, atrophic holes within the LD zone, which predispose to the development of retinal detachment. Retinal detachment more frequently develops in young patients in myopic eyes without acute symptoms of PVD. There are limited data in the literature regarding the risk of retinal detachment associated with this type of degeneration. A prospective study referenced by the majority of the ophthalmological community showed that over 11 years of follow-up in patients with untreated lattice degeneration and asymptomatic breaks, retinal detachment developed in only 1% of cases [6]. Thus, the presence of lattice degeneration with or without atrophic holes usually does not require prophylactic treatment in the absence of other risk factors or symptoms. If a patient with lattice degeneration has risk factors such as retinal detachment in the fellow eye, valvular tears, aphakia, or pseudophakia, prophylactic treatment should be considered. In patients with retinal detachment, the risk of developing a detachment in the fellow eye is approximately 10% in phakic eyes and 20%–30% in aphakic and pseudophakic eyes [6].

1.2. Snail-track degeneration

In most cases, this degeneration is asymptomatic and causes no patient complaints; in the presence of pronounced traction, complaints of “lightning flashes” may occur, typically upon movement of the eyeball. Snail-track degeneration appears as a white, shiny area on the retina, named for its resemblance to the slime trail left by a mollusk. The shape of these defects can vary from an elongated oval or spindle to a band spanning an entire quadrant. The appearance of the degeneration consists of spots ranging from white to shiny silver-white or glazed whitish. During scleral depression, the area of snail-track degeneration appears even whiter, allowing a better assessment of the extent of retinal involvement. The zones of degeneration are typically found between the equator and the ora serrata, with 80% of changes detected 2 optic disc diameters anterior to the equator [6]. These defects are most commonly found in the temporal half of the fundus. Up to 15 lesions may be present in a single eye. There is an opinion that snail-track degeneration is an early stage of lattice degeneration, preceding the appearance of obliterated retinal vessels and pigment epithelial hyperplasia. At the same time, it is suggested that despite the similar location of the lesions, snail-track degeneration does not progress to typical lattice degeneration and is classified as an independent type of degeneration. Furthermore, snail-track degeneration is no less common than lattice degeneration. It has been found that the ultrastructure of snail-track degeneration differs from that of lattice degeneration and therefore should not be considered a variant of the latter. However, the probability of retinal breaks and retinal detachment developing with this form of degeneration is no different from that of LD.

1.3. Vitreoretinal tufts.

Peripheral retinal tufts are small peripheral focal areas of elevated glial hyperplasia associated with vitreous or zonular attachment and traction. Tractional tufts are classified according to anatomical, pathogenetic, and clinical differences into the following groups:

- non-cystic retinal tufts;

- cystic retinal tufts;

- retinal tufts with zonular traction.

Tufts may be surrounded by retinal pigment epithelial hyperplasia. Cystic tufts with zonular traction, as well as those with dense vitreoretinal adhesions and the appearance of pigmentary hyperplasia, may predispose to the development of retinal tears and detachment. In most cases, they are asymptomatic and cause no patient complaints; in the presence of pronounced traction, complaints of “lightning flashes” may occur, typically upon movement of the eyeball.

1.4. Meridional folds, isolated ora serrata bays, and peripheral retinal excavations.

Meridional folds are retinal folds typically located in the superonasal sector. They are usually associated with dentate processes, but may also extend posteriorly from the bays of the ora serrata. Occasionally, tears resulting from PVD occur at the very edge of the posterior part of the folds. Retinal tears also occur at or near the posterior edges of isolated bays of the ora serrata, which are oval islands of pars plana epithelium posterior to the ora serrata, completely or almost completely surrounded by the peripheral retina. Less commonly, tears occur in the area of peripheral retinal excavations. Excavations may have strong vitreoretinal adhesions and are found at the ora serrata or posterior to it at a distance of up to four disc diameters, often in combination with meridional folds. 

II. Conditions not predisposing to retinal detachment.

2.1. Paving-stone (cobblestone) degeneration – is characterized by peripheral, discrete areas of varying size of outer retinal, retinal pigment epithelium, and choriocapillaris atrophy. It is detected in 22% of individuals over 20 years of age. Atrophic areas may be single or arranged in groups, and are sometimes confluent. Histologically, cobblestone degeneration is characterized by atrophy of the retinal pigment epithelium and outer retinal layers, rarefaction or absence of the choriocapillaris network, and adhesions between the residual neuroepithelium and Bruch's membrane. These defects are most often located in the inferior quadrants, anterior to the equator; ophthalmoscopically they are yellowish-white, sometimes surrounded by a ring of hypertrophied RPE, with underlying large choroidal vessels visible in the area of the lesions due to RPE atrophy. The clinical course is generally asymptomatic.

2.2. RPE hyperplasia.

RPE cells begin to proliferate, undergoing mild chronic traction. Diffuse RPE hyperplasia extends along the ora serrata in the area of attachment of the vitreous base, or is located focally on the pars plana and fundus periphery, particularly in areas of focal traction (vitreoretinal tufts, retinal defects), as well as in post-traumatic and post-inflammatory areas. It does not lead to retinal detachment if the traction has resolved.  The clinical course is asymptomatic.

2.3. RPE hypertrophy.

Acquired RPE hypertrophy is an age-related degenerative change most commonly observed in the fundus periphery and presenting with a reticular pattern. Histologically, it is characterized by the presence of large cells with large melanin granules. Similar histological changes are observed in congenital hypertrophy of the RPE (e.g., grouped pigmentation of the retina or "bear tracks"). Tractional changes over these zones are absent. The clinical course is asymptomatic.

2.4. Peripheral cystoid degeneration.

Typical peripheral cystoid degeneration is represented by zones of microcysts in the extreme fundus periphery and occurs in almost all adults over 20 years of age. Although retinal holes may form in these areas, they extremely rarely lead to retinal detachment. Reticular peripheral cystoid degeneration is almost always located posterior to typical peripheral cystoid degeneration. It is localized in the inner retinal layers and presents as a linear or reticular pattern along the retinal vessels. This form occurs in 20% of adults and may in some cases lead to the development of reticular degenerative retinoschisis. The clinical course is asymptomatic.

2.5. Ora serrata pearls – bright, white, shiny rounded granules located near the dentate processes. They are usually solitary and located between the base and apex of the dentate process. At an early stage of development, they appear near the tooth of the ora serrata as dark brown formations due to the overlying retinal pigment epithelium (RPE). Later, as the layer thins or the RPE overlying the pearls atrophies, they become more prominent and white. The clinical course is asymptomatic.

2.6. Retinal drusen – are white or yellowish, round, elevated areas deep within the retina. They vary in shape and size, but are usually small and round. Drusen are characterized by a glistening crystalline consistency, from which they get their name, which translates from German as "stone knot". Equatorial drusen refer to those located in the mid-periphery of the fundus. Equatorial drusen are more likely to cause hyperpigmented clusters; they are called drusen surrounded by a pigment ring. Drusen appear white when they become calcified. Drusen may coalesce to form larger, irregular drusenoid lesions. Literally thousands of drusen can be found in the eyes of elderly patients. During ophthalmoscopy, indirect illumination of drusen causes a brighter glow effect compared to the surrounding retina, as they are covered by a thinner layer of pigment epithelium. The clinical course is asymptomatic.

2.7. Frost-like degeneration – changes are generally symmetrical in both eyes. The thinning zones appear as fragments of a yellowish-white frost pattern, protrude into the vitreous body, and progress slowly. The clinical course is asymptomatic.

2.8. "White-with-pressure" and "white-without-pressure" retinopathy.

The clinical course is generally asymptomatic. "White-with-pressure" is an optical phenomenon in which the color of the fundus changes from its usual orange-red color to a translucent white or grayish-white color upon scleral depression. "White-without-pressure" has the same appearance, but is detected without applying pressure to the sclera, which, however, allows better visualization of the whitish lesion and better demarcation of the lesion boundaries.

This type of degeneration may be localized to a small isolated area or present as a band along the entire retinal periphery. The band may have smooth or scalloped edges. Completely white-without-pressure is visualized during wide-field ophthalmoscopy and takes various shapes. Areas of white-with-pressure or white-without-pressure can migrate, causing their shape to change upon subsequent examinations. The posterior edge tends to be pointed, while the anterior edge gradually fades toward the retinal periphery. Quite unusually, immediately posterior to the area of white-without-pressure lies a dark red retinal patch that can be mistaken for a linear retinal tear. It is hypothesized that the etiology of this dark zone is similar to the origin of white-without-pressure. This area is often found approximately 3 optic disc diameters posterior to the ora serrata, sometimes closer to the temporal vascular arcades. White-with-pressure and white-without-pressure are optical phenomena associated with the vitreoretinal interface. Prolonged mild vitreoretinal traction is believed to be responsible for altering the transparency of the vitreoretinal interface. These areas of vitreoretinal adhesion may represent more peripherally located parts of the vitreous body. The whitish coloration may be related to collagen fibers in the peripheral retina or to the reflection of the ophthalmoscope light from tangential bundles of dense vitreous collagen. The literature contains reports of retinal degenerations with impaired retinal transparency in areas of white-without-pressure. These findings may be the result of the chronicity of the process. Loss of transparency in the early stages may be subtle and detected only with scleral depression. Vitreous changes associated with white-with-pressure or white-without-pressure are characterized by posterior vitreous detachment with collapse or intense liquefaction in its middle and posterior sections. In either case, tractional forces are exerted on the peripheral retina, leading to subsequent degeneration. Typically, these conditions require periodic examination for horseshoe tears and giant tears at the posterior margin of the degeneration, as well as patient vigilance. These tears appear to occur more frequently if the posterior margin of the degeneration is uneven and jagged, or if vitreous traction and destruction are observed in the area of degeneration. Since white-without-pressure is extremely rarely the cause of a retinal tear or detachment, the prognosis is favorable. 

III. Retinal tears

The term "retinal tear" refers to any defect affecting the entire thickness of the neurosensory retina. The clinical significance of tears is that fluid from the vitreous cavity can penetrate into the space between the sensory retina and the RPE, thereby causing rhegmatogenous retinal detachment. Some tears are caused by atrophy of the inner retinal layers (holes); others occur due to vitreoretinal traction (tears). Retinal tears can be classified as follows:

• Flap, or horseshoe, tear;

• Giant tear;

• Operculated tear;

• Dialysis (avulsion);

• Atrophic (hole) tear. 

3.1. Flap tear

A flap tear occurs when a part of the retina is pulled anteriorly due to vitreoretinal traction, often during posterior vitreous detachment or trauma. The tear clinically manifests when the patient complains of photopsia and/or floaters.

3.2. Giant tear

A giant tear extends for 90° or more of the circumference of the eyeball and is usually located along the posterior margin of the vitreous base.

3.3. Operculated tear

An operculated tear occurs when the traction forces are sufficient to completely detach a section of the retina from the adjacent retinal surface.

3.4. Dialysis (avulsion)

Dialysis is a circumferential linear tear along the ora serrata with the vitreous attached to the posterior edge of the tear; it is usually the consequence of blunt trauma.

3.5. Atrophic (hole) tear

An atrophic hole is generally not associated with vitreoretinal traction and does not carry a high risk of developing retinal detachment. 

Symptomatic tears. Overall, at the time of the initial examination, 1 or more tractional tears are detected in 7% to 18% of eyes with symptomatic posterior vitreous detachment. Numerous clinical studies have shown that acute symptomatic tears lead to retinal detachment more often than others, especially in the presence of vitreous hemorrhage. Consequently, acute symptomatic flap tears are usually treated prophylactically.

In acute operculated tears, the probability of developing retinal detachment is lower since there is no residual traction on the adjacent retina, and they are usually not treated. However, prophylactic treatment should be considered if biomicroscopy of the fundus or examination of the fundus periphery using a Goldmann three-mirror lens reveals vitreous traction at the edge of the tear, if the tear is large and located superiorly, or if there is a vitreous hemorrhage.

Atrophic holes are usually "incidental findings" in patients with acute posterior vitreous detachment. Treatment is generally not indicated in such cases.

Asymptomatic breaks. Asymptomatic valve breaks lead to retinal detachment in approximately 5% of cases. Due to this low risk, treatment is generally not performed in emmetropic, phakic eyes. However, the risk of retinal detachment is high in the case of asymptomatic valve breaks combined with lattice degeneration, myopia, subclinical detachment, aphakia, pseudophakia, or a history of retinal detachment in the fellow eye; therapy must be considered in such cases. Asymptomatic operculated breaks and atrophic holes rarely lead to retinal detachment and, for this reason, treatment is typically not performed.

Risk factors for retinal detachment:

1. Symptomatic posterior vitreous detachment;

2. Eyeball trauma;

3. Hemophthalmos;

4. Cataract extraction with posterior capsule rupture;

5. Aphakia and pseudophakia following laser capsulotomy for secondary cataract;

6. Retinal detachment in the fellow eye;

7. Family history of retinal detachment;

8. Signs of Stickler syndrome;

9. Myopia.

2. Diagnostics, medical indications and contraindications for diagnostic methods

Diagnosis of peripheral retinal degenerations should be primarily aimed at identifying rhegmatogenous forms, taking into account the availability of effective methods in modern ophthalmology to prevent the onset of retinal detachment.

Table 1. Main diagnostic criteria for establishing peripheral retinal degenerations

2.1 Complaints and Anamnesis

Comments: for all forms of degeneration and retinal breaks, many patients report no complaints. In the event of PVD or the presence of vitreoretinal tractions, characteristic phenomena may appear, such as photopsias (flashing lights, lightning, sparks, etc.), numerous floaters, and the appearance of a "curtain" or "cloud" in the visual field. The occurrence of photopsias is associated with physical traction exerted by the vitreous body on the retina. Floaters are opaque structures, such as blood, glial cells detached from the optic disc, or collagen fiber clumps capable of casting a shadow on the retina. Vitreous hemorrhage can occur from superficial retinal or peripapillary vessels or from retinal vessels in the area of a retinal break. When taking the medical history, it is necessary to clarify whether there have been previous retinal problems in one or both eyes, whether there were injuries and inflammation in the eye (uveitis), whether the patient suffers from Stickler syndrome or any other systemic diseases, and whether there have been cases of retinal detachment in close relatives.

2.2 Physical Examination

Comments: it is necessary to refer patients with concomitant systemic diseases that could cause ocular inflammation for consultation with relevant specialists [7]. The choice of specialist profile is determined depending on the presence of a concomitant systemic disease and the risk factor for systemic complications in the patient.

2.3 Laboratory Diagnostics

Diagnostic criteria for peripheral retinal degenerations based on clinical laboratory test data do not exist.

Comments: the choice of laboratory tests is determined by the presence of concomitant systemic disease and risk factors for systemic complications in the patient.

Comments: the examination is performed on the basis of voluntary informed consent (Sanitary and Epidemiological Rules SP 3.1.5.2826-10 "Prevention of HIV Infection"). The choice of laboratory tests is determined based on the presence of a concomitant systemic disease and risk factors for systemic complications in the patient [9].

2.4 Instrumental Diagnostics

Comments: if necessary, examination of the peripheral fundus can be performed with scleral depression. Upon completion of the examination, it is recommended to document the identified changes in the medical history and/or sketch them on a fundus diagram, as shown in the attached figure (diagram 1 presented in Appendix A3).

2.5 Other Procedures

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

3.1 Conservative Treatment

3.2 Laser Treatment

Comments: the goal of prophylactic laser treatment for retinal tears and rhegmatogenous degenerations is to create chorioretinal adhesion around each tear or degeneration zone to prevent fluid entry into the subretinal space by performing focal laser photocoagulation of the fundus that surrounds the pathological area on all sides [7, 10, 11]. It is important to note that treatment does not reduce the risk of developing new tears. Upcoming refractive surgery and labor are not additional risk factors that broaden the indications for prophylactic focal laser photocoagulation of the fundus [15-20]. Furthermore, after laser photocoagulation and barrier formation of the tear up to 35-37 weeks of gestation, the physician may issue a clearance regardless of clinical refraction, stating that no contraindications to spontaneous vaginal delivery were identified at the time of the examination. If photocoagulation cannot be performed and if tears or retinal degenerations requiring treatment are identified at 35-37 weeks of gestation or later, the physician should issue a statement regarding the high risk of retinal detachment during spontaneous vaginal delivery [15].

Indications for emergency focal laser photocoagulation of the fundus: acute symptomatic dialysis, acute symptomatic horseshoe (flap) tear, acute symptomatic operculated tear, asymptomatic horseshoe tear (with subretinal fluid no greater than two disc diameters in size), traumatic tears.

Indications for elective focal laser photocoagulation of the fundus: symptomatic and lattice degeneration, and snail track degeneration with or without tears and holes (without subretinal fluid, asymptomatic flap tear and dialysis without subclinical detachment and without signs of self-limitation in the presence of risk factors.

Indications for elective focal laser photocoagulation of the fundus or observation: for asymptomatic round holes, asymptomatic flap tears without subclinical retinal detachment, for asymptomatic dialyses, asymptomatic lattice degeneration and snail-track degeneration, with or without holes, even in the presence of risk factors.

Contraindications for focal laser photocoagulation of the fundus: symptomatic posterior cortical detachment without rhegmatogenous retinal detachment; frost-like peripheral degeneration, pavingstone degeneration, peripheral drusen, cystoid peripheral degeneration; "white without pressure" and "white with pressure" without tears.

Preparation for surgery. Treatment is performed under the maximum possible drug-induced mydriasis. (using anticholinergics and sympathomimetics, excluding antiglaucoma drugs, including fixed combinations), instilled 20–30 minutes before the procedure.

Anesthesia. Treatment is performed under topical epibulbar anesthesia. In special cases, with severe nystagmus, tremor, or in pediatric ophthalmology practice when local anesthesia cannot be performed, other types of anesthesia may be used.

Treatment is performed using a Goldmann three-mirror lens or other surgical and diagnostic ophthalmic lenses (e.g., a wide-angle panfundus lens). Before placing the lens on the eyeball, 2–3 drops of contact medium are applied to prevent corneal damage by the lens.

Technique of focal laser photocoagulation of the fundus (barrier): spot diameter 200–500 µm, power is selected individually to obtain grade 2–3 burns, applied in 3–5 rows as closely spaced as possible, with the first row as close as possible to the edge of the tear or degeneration, mandatory on all sides of the pathological zone [1, 7].

Following focal laser photocoagulation of the fundus (retinal tears and dialyses), monitoring is required every 1–2 weeks for 2 months; if detachment occurs, immediate referral for vitreoretinal surgery. If no detachment is present, the next follow-up is in 6 months. No further monitoring is required thereafter. Examination is indicated if characteristic symptoms appear.

Following the coagulation of rhegmatogenous degenerations, monitoring is required in 1–2 weeks. Follow-up examinations upon the appearance (or worsening) of symptoms and routine preventive examinations once every 6 months for 1 year, after which no further monitoring is required.

3.3 Surgical Treatment

Surgical treatment for patients with peripheral retinal degenerations is indicated only for symptomatic flap tears when laser treatment cannot be performed (partial hemophthalmia, inability to achieve mydriasis, inability to perform coagulation on all sides of the tear, etc.) or when it is ineffective. This type of treatment is described in clinical guidelines for the management of retinal detachments.

3.4 Dietary Therapy

4. Medical Rehabilitation and Sanatorium-Resort Treatment

5. Prevention and Dispensary Observation

Comments: the frequency of examinations is determined by the ophthalmologist depending on the severity of the pathological process, the treatment option, and the presence of concomitant systemic diseases and risk factors in the patient.

6. Organization of Medical Care

Primary specialized health care is provided by an ophthalmologist in the outpatient department of a medical organization.

Treatment (laser interventions) is performed by an ophthalmologist in an outpatient setting, a day hospital, or an inpatient setting.

Indication for planned hospitalization in a medical organization:

• the need for elective laser treatment when it cannot be performed in an outpatient setting.

Indication for emergency hospitalization in a medical organization:

• a flap tear or retinal dialysis when laser treatment cannot be performed in an outpatient setting, or the need for multi-stage laser photocoagulation over several days, e.g., due to partial hemophthalmia combined with the need for bed rest with eyeball immobilization for faster blood resorption.

Indications for discharging a patient from a medical organization:

• completion of treatment or one of the stages of specialized medical care in an inpatient or day hospital setting, provided there are no treatment complications requiring drug correction and/or medical interventions in an inpatient setting;

• refusal of the patient or their legal representative from specialized medical care in an inpatient or day hospital setting, established by a medical board of the medical organization;

• the need to transfer the patient to another medical organization.

7. Additional Information

Even after timely and high-quality treatment, any patient retains a risk of disease progression (formation of new degeneration zones, tears, retinal detachment). Fundus monitoring under drug-induced mydriasis (see treatment table) and upon the appearance of characteristic symptoms is required. Examination of the peripheral retina of the fellow eye in case of retinal detachment is mandatory.

Patient counseling is necessary:

1. Explain to patients the causes of possible complications of peripheral degenerations and the characteristic symptoms that the patient should pay attention to and consult a doctor;

2. Explain to patients that the appearance of complaints of "sparks" or "flashes" before the eye requires limiting physical activity and consulting an ophthalmologist in the coming days;

3. Explain to patients that the appearance of complaints of a "curtain" before the eye, or a sharp restriction of the visual field requires limiting physical activity and urgent consultation with an ophthalmologist;

4. Warn patients with retinal detachment in one eye about the need for self-monitoring of the vision quality of the fellow eye and immediate consultation with an ophthalmologist if changes in vision quality occur, especially with the appearance of characteristic symptoms.

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

1. Budzinskaya M.V., Head of the Group, Doctor of Medical Sciences, Professor at the Department of Ophthalmology of the FSBSI «M.M. Krasnov Research Institute of Eye Diseases», member of the «Society of Ophthalmologists of Russia».

2. Gatsu M.V., Doctor of Medical Sciences, Deputy Director for Organizational and Clinical Work at the St. Petersburg Branch of the S.N. Fyodorov Eye Microsurgery Federal State Institution of the Russian Ministry of Health, Associate Professor at the Department of the North-Western State Medical University named after I.I. Mechnikov of the Russian Ministry of Health, member of the «Society of Ophthalmologists of Russia».

3. Shadrichev F.E., Candidate of Medical Sciences, Head of the Ophthalmological Consultative and Diagnostic Department of the Regional Endocrinological Center of the City Consultative and Diagnostic Center No. 1, Assistant at the Department of Ophthalmology with the Clinic named after Professor Yu.S. Astakhov of the Pavlov First Saint Petersburg State Medical University, member of the «Association of Ophthalmologists».

4. Shklyarov E.B., Candidate of Medical Sciences, Ophthalmologist at the Ophthalmological Consultative and Diagnostic Department of the Regional Endocrinological Center of the City Consultative and Diagnostic Center No. 1, member of the «Association of Ophthalmologists».

Conflict of interest none.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience for these clinical guidelines:

• Ophthalmologists

• General practitioners (family physicians)

Methods used for evidence collection/selection: search in electronic databases; analysis of modern scientific developments regarding peripheral retinal degenerations and retinal tears in Russia and abroad; synthesis of practical experience of Russian and foreign specialists. Description of methods used for evidence collection/selection: the evidence base for the guidelines includes publications from the Cochrane Library, EMBASE and MEDLINE databases, as well as monographs and articles in leading specialized peer-reviewed domestic medical journals on this topic. Methods used for quality and strength of evidence assessment: expert consensus, significance rating according to the rating scheme.

Table 1. Scale for assessing levels of evidence (LE) for diagnostic methods (diagnostic interventions)

Table 2. Scale for assessing the levels of evidence (LE) for prevention, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, therapeutic, and rehabilitation interventions)

Table 3. Scale for assessing the grades of recommendation (GR) for prevention, diagnostic, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, diagnostic, therapeutic, and rehabilitation interventions)

Procedure for updating clinical guidelines.

The clinical guidelines update mechanism provides for their systematic revision—at least once every three years, as well as upon the emergence of new evidence-based data regarding the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or the presence of justified additions/comments to previously approved clinical guidelines, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

1. Current package leaflets for the drugs mentioned in these clinical guidelines can be found on the website http://grls.rosminzdrav.ru

2. International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10). World Health Organization.

3. Nomenclature of Medical Services. Order of the Ministry of Health of the Russian Federation No. 804n dated October 13, 2017 «On Approval of the Nomenclature of Medical Services». Order of the Ministry of Health of the Russian Federation No. 205n dated May 2, 2023 «On Approval of the Nomenclature of Positions of Medical Workers and Pharmaceutical Workers».

4. Federal Law No. 323-FZ dated November 21, 2011 «On the Fundamentals of Protecting the Health of Citizens in the Russian Federation».

5. Order of the Russian Ministry of Health No. 633n dated October 24, 2025 «On Approval of the Procedure for Providing Medical Care to the Adult Population in the Profile "Ophthalmology"».

6. Order of the Russian Ministry of Health No. 614n dated October 9, 2025 «On Approval of the Procedure for Providing Medical Care to Children in the Profile "Ophthalmology"».

7. Decree of the Government of the Russian Federation No. 2406-r dated October 12, 2019, "On Approval of the List of Vital and Essential Drugs, as well as Lists of Medicinal Products for Medical Use and the Minimum Assortment of Medicinal Products Required for the Provision of Medical Care."

8. Decree of the Government of the Russian Federation No. 2188 dated December 29, 2025 «On the Program of State Guarantees of Free Medical Care to Citizens for 2026 and for the Planning Period of 2027 and 2028».

9. Sanitary and Epidemiological Rules and Regulations SP 2.1.3678-20 «Sanitary and Epidemiological Requirements for the Operation of Premises, Buildings, Structures, Equipment, and Vehicles, as well as Working Conditions for Business Entities Engaged in the Sale of Goods, Performance of Work, or Provision of Services» (Decree of the Chief State Sanitary Doctor of the Russian Federation No. 44 dated December 24, 2020).

10. Sanitary-epidemiological rules and regulations SanPiN 3.3686-21 "Sanitary and epidemiological requirements for the prevention of infectious diseases" (Resolution of the Chief State Sanitary Doctor of the Russian Federation No. 4 dated January 28, 2021).

11. "Management of planned hospitalization in a multidisciplinary hospital. Methodological Recommendations No. 2001/144" (approved by the Ministry of Health of the Russian Federation on November 9, 2001).

12. "MR 3.1.5.0076/1-13. 3.1.5. Epidemiology. Prevention of infectious diseases. HIV infection. Pre- and post-test counseling as prevention of HIV transmission."

13. Order of the Russian Ministry of Health No. 1129n dated October 20, 2020, "On Approval of the Rules for Conducting Mandatory Medical Examination to Detect the Human Immunodeficiency Virus (HIV Infection)."

Figure 1. Possible scheme for recording fundus changes in peripheral retinal degenerations

1. lattice degeneration

2. lattice degeneration with a tear

3. snail track degeneration without a tear

4. snail track degeneration with a tear

5. pigmented vitreoretinal tuft

6. white-without-pressure degeneration

7. flap retinal tear

8. operculated retinal tear

9. atrophic retinal tear

10. peripheral retinal tuft

11. frost-like degeneration

12. paving stone degeneration

13. peripheral drusen

14. ora serrata pearl

15. hypertrophy and hyperplasia of the retinal pigment epithelium

16. hyperplasia of the retinal pigment epithelium with vitreous traction

Appendix B. Physician Action Algorithms

Algorithm 1. Examination and treatment protocol for patients with various forms of retinal degenerations and tears

Appendix C. Patient Information

The onset of symptoms such as "flashes" or "lightning streaks" before the eye requires limiting physical activity and consulting an ophthalmologist within the next few days.

The onset of symptoms such as a "curtain" or "veil" before the eye, or a sharp restriction of the visual field requires limiting physical activity and immediate medical attention from an ophthalmologist.

If there is a history of retinal detachment in one eye, it is necessary to self-monitor the visual function of the fellow eye and immediately visit an ophthalmologist if any changes in visual quality occur, especially with characteristic symptoms.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

No.