Morphology and incidence of drusen-like deposits in peripheral retina of eyes with high myopia

Abstract

Purpose

To determine the morphology and incidence of peripheral drusen-like deposits (DLDs) in eyes with pathological myopia (PM) using ultra-widefield (UWF) fundus photographs and UWF optical coherence tomographic (OCT) images.

Design

Retrospective, observational case series study.

Method

We reviewed the medical records of 676 patients (1352 eyes) with high myopia (HM) who were examined in the Advanced Clinical Centre for Myopia between 2017 and 2021. The main outcome measures were the incidence and morphological characteristics of the DLDs in the peripheral retina detected by ultra-widefield (UWF) imaging devices.

Results

Sixty-six of the 1352 (4.9%) eyes had peripheral DLDs. In 5 eyes, the DLDs were found at the staphyloma edge. The mean age of the patients was 70.0 ± 13.0 (range, 46.0–92.0) years, and the mean axial length was 29.8 ± 2.4 mm. Myopic macular neovascularization (MNV) was found in 41 of the 66 eyes with DLDs (62.1%). Patients with drusen in Zone 2 were significantly older than those in Zone 3 (80 ± 13 vs 64 ± 13 years; P < 0.001).

Conclusions

Ultra-widefield images showed that peripheral DLDs were present in 4.9% of highly myopic eyes. The findings in eyes with DLDs may provide a basis for the evaluations of the natural progression of peripheral retinal changes in eyes with PM.

Introduction

Pathologic myopia (PM) is a major cause of blindness [1], and a lot of attention has been paid to the macular and optic nerve lesions of highly myopic eyes [2]. However, there are only a few reports on the retinal changes in the periphery of these eyes. With the advances of ultra-widefield (UWF) imaging devices, it has become possible for clinicians to examine the peripheral retina in greater detail.

The most prevalent peripheral retinal changes in highly myopic Asian eyes are white without pressure (WWOP) and lattice degeneration (LD) [3]. Abnormal fluorescein angiography (FA) findings in high myopia, such as abnormal bending of retinal vessels, capillary microaneurysms, and capillary telangiectasias, correspond to OCT-determined paravascular abnormalities [4]. Areas of nonperfusion are also common [5]. Additionally, peripheral lacquer cracks have been reported as an early finding in pathological myopia [6].

Further research is necessary to study peripheral changes and their progression in pathological myopia, as these changes could play a role in understanding the pathogenesis of various macular and optic nerve lesions. This knowledge could aid in the early diagnosis and prognosis of pathological myopia.

Until recently, documenting these peripheral retinal changes was challenging. However, the advent of ultrawide-field imaging with the Optos 200 T device (Optos, Dunfermline, Scotland) has enabled reproducible imaging of the retinal periphery. The Optos system utilizes scanning laser ophthalmoscopy with an ellipsoidal mirror, allowing for simultaneous visualization from the central pole to the periphery of up to 200 degrees of the retina, with or without mydriasis. Fundus autofluorescence (FAF) can also be obtained using the green 532 nm laser for excitation and an emission filter (570–780 nm) to detect autofluorescence [7]. Ultra Widefield Optical Coherence Tomography (UWF-OCT) has been utilized to examine and characterize aspects of high myopia, such as posterior staphylomas, dome-shaped macula (DSM), and choroidal thickness. This has offered valuable insights into the classification and pathophysiology of these conditions. Peripheral retinal degenerations are conditions that may exhibit the greatest benefits from UWF-OCT. UWF-OCT can clearly characterize and document these peripheral pathologies, including lattice degeneration, retinal tufts, retinal tears, retinal holes, and paving-stone degeneration [8].

In the Advanced Clinical Centre for Myopia of the Tokyo Medical and Dental University, we have noted the presence of drusen-like lesions (DLD) in eyes of PM patients. Drusen are considered the main pathognomonic finding of AMD, and they are not limited to the posterior pole but are also reported to be present in both the mid and far periphery in most AMD eyes [9]. Peripheral drusen are occasionally present in eyes without drusen in the macula area [9].

However, as best we know, no studies have reported on the peripheral DLDs in patients with pathologic myopia. Thus, the incidence and morphological characteristics of these lesions in eyes with pathologic myopia have not been determined.

Thus, the purpose of this study was to determine the incidence and morphological characteristics of the DLDs located in the peripheral retina of eyes with HM.

Methods

Study design

This was a retrospective, observational case series study. The procedures used conformed to the tenets of the Declaration of Helsinki and were approved by the Ethics Committee of Tokyo Medical and Dental University. An informed consent was obtained from all participants for all examinations and the use of all data in future studies and publications.

We reviewed the medical records of 676 patients who were diagnosed with high myopia in the Advanced Clinical Centre for Myopia of the Tokyo Medical and Dental University between 2017 and 2021. The presence of yellowish DLDs in the peripheral retina was determined by a thorough examination of the images obtained by different imaging devices especially the ultra-widefield (UWF) fundus imaging devices. The UWF pseudo colour, UWF fundus autofluorescence (FAF; Optos Daytona, Optos, PLC, Dunfermline, Scotland, UK) images and the UWF OCT images obtained with a swept-source UWF-OCT instrument (prototype and Xephilio S-1, Canon Corp, Tokyo, Japan) were also helpful in studying the peripheral DLDs.

Fundus images were assessed in Zone 1, Zone 2, and Zone 3 as reported [9–11]. Zone 1 was defined as the area within a 5.4 mm diameter centred on the fovea within the vascular arcade. Zone 2 was defined as the area within a 16.2 mm circle which is equivalent to 9-disc diameters (DDs) and it overlapped the vortex veins. Zone 3 was defined as the peripheral retina beyond Zone 2, (see Supplemental Digital Content Figure which illustrates of Zones 1, 2, and 3 on the fovea-centred image.) and was sub-divided into the superior nasal, superior temporal, inferior nasal, and inferior temporal quadrants. Because the DLDs in Zone 1 were difficult to detect due to co-existing myopic maculopathy, only Zones 2 and 3 were examined for the presence of DLDs.

The inclusion criteria were high myopia with a refractive error > −6 dioptres (D) or axial length ≥26.5 mm, and the presence of yellowish DLDs in the peripheral retina. The exclusion criteria were patients who had prior vitreoretinal surgery or laser photocoagulation, and patients whose images were of low quality. In the end, we studied 1352 eyes of 676 patients.

Evaluations of clinical findings and images

All participants underwent a comprehensive ocular examination, and their age, sex, the best-corrected visual acuity (BCVA) measured by a Landolt C chart, and axial length measured by IOL Master (Carl Zeiss Meditec AG, Jena, Germany), were collected from the medical records. Conventional 50° colour fundus photographs centred on the macula were also recorded with a fundus camera (TRC-50DX, Topcon, Tokyo, Japan). For the OCT images, 12 radial scans that were centred on the fovea were recorded in most cases with a swept-source OCT (DRI-OCT, Topcon Co., Tokyo, Japan) device. UWF pseudo colour and fundus autofluorescence (FAF) images were obtained with the Optos 200Tx scanning laser ophthalmoscope (Optos PLC, Dunfermline, Scotland, United Kingdom). The UWF OCT images were obtained with a swept-source UWF-OCT instrument (prototype and Xephilio S-1, Canon Corp, Tokyo, Japan). The length of the scanned line was 23 mm horizontally and 20 mm vertically, and the scan depth was 5 mm. Cross-sectional radial scans centred on the fovea were also recorded.

Diagnostic criteria

The peripheral extracellular DLDs were analysed by examining the pseudocolour fundus and FAF images, and the UWF-OCT images according to the criteria presented earlier [9–11]. The DLDs appeared as isolated or scattered yellowish-white deposits in the fundus images [9]. In the OCT images, DLD were categorized according to the classification system introduced by Khanifar et al. This system distinguishes the RPE elevation shape (convex, concave, or saw-toothed), reflectivity levels (low, medium, or high), homogeneity of reflectivity (homogeneous, non-homogeneous) of the drusen content [12].

Not all drusen-like deposits (DLD) are referred to as drusen due to differences in their characteristics and clinical implications. Drusen are specific deposits located between the RPE and Bruch’s membrane, frequently associated with age-related macular degeneration (AMD). They are typically found in the macula area, and sometimes in both the macula and peripheral retina. Drusen can also be a normal part of aging or occur in younger individuals due to inherited disorders and systemic conditions. While they are typically found external to the retinal pigment epithelium (RPE), some deposits internal to this layer, known as pseudodrusen or subretinal drusenoid deposits, have a drusen-like appearance [13].

Some earlier studies used the term ‘DLD’ for deposits found in diseases other than AMD. Several inherited disorders with macular dystrophy describe deposits in the macula as drusen-like deposits, such as in Sorsby fundus dystrophy, Malattia Leventinese, North Carolina macular dystrophy, and late-onset retinal degeneration [13–16]. Additionally, several systemic conditions might present with drusen-like deposits, such as in young adults diagnosed with systemic lupus erythematosus, with or without glomerulonephritis [17], membranoproliferative glomerulonephritis (MPGN), chronic inflammatory conditions like hepatitis B and C, immunoglobulinemias, Alport syndrome, vitamin A deficiency, pseudoxanthoma elasticum, Sjogren-Larsson syndrome, Kjellin syndrome, familial partial lipodystrophy, and in patients with multiple myeloma [13, 18, 19].

The clinical implications of drusen-like deposits (DLD) may differ from those of typical drusen. While drusen are closely associated with age-related macular degeneration (AMD), DLD may be found in other retinal conditions or represent different stages or types of retinal degeneration [13]. In our study, large DLD lesions located in the mid-peripheral area and at the edge of the staphyloma were examined using Optical Coherence Tomography (OCT). The OCT images of DLD showed irregularities and elevations of the retinal pigment epithelium (RPE) filled with hyperreflective materials. Some lesions were present above the RPE and sometimes exhibited a saw-tooth appearance.

Hyper-AF and hypo-AF changes were also recorded. The diagnosis of peripheral DLDs were made by two of the authors (SK, KO-M) independently. There was a high level of agreement between the two independent graders regarding the diagnosis of peripheral DLDs, identified by the presence of multiple small yellow lesions in fundus photography, and the corresponding characteristics of these lesions on FAF and UWF-OCT scans.

The background myopic maculopathy was classified based on the classification of the META-analysis for Pathologic Myopia (META-PM) Study Group [20].

Statistical analyses

Descriptive parameters are presented as the means ± standard deviations. Nominal P-values for comparisons of age, axial length, refractive error, BCVA, incidence of MNV, and comparisons between different zones were made by either Kruskal-Wallis tests or Pearson’s chi-square tests. No corrections were made for multiple testing. All statistical analyses were performed with the SPSS software (version 22.0, IBM-SPSS, Chicago, IL).

Results

Demographic data

The Optos images of 1352 eyes of 676 patients with high myopia that were recorded between 2017 and 2021 were examined for peripheral DLDs. DLDs were found in 66 eyes (4.9%) of 39 (5.8%) patients (Fig. 1). The baseline demographics of these 66 eyes are shown in (Supplemental Digital Content Table 1. which shows Baseline characteristics of highly myopic eyes with drusen-like deposits.)The mean age of the patients was 70.0 ± 13.0 (range; 46.0–92.0) years. The median refractive error (spherical equivalent) was −13.8 ± 6.6 dioptres (D; 27 eyes with IOL implantation excluded), and the mean axial length was 29.8 ± 2.4 mm. There were 27 cases (69.2%) with DLDs in both eyes. A posterior staphyloma was detected in 45 of the 66 eyes (68.2%).

Fig. 1. Peripheral and mid peripheral drusen like deposits (DLDs) in eyes with pathologic myopia (PM).

A Photograph of right fundus of an 83-year-old woman with an axial length of 28.6 mm showing yellowish DLDs at the staphyloma edges (Zone 2, arrowheads). Scarred macular neovascularization can also be seen in the macular area. B Photograph of right fundus of a 69-year-old woman with an axial length of 26.5 mm showing multiple yellowish DLDs in the temporal fundus (Zone 2). Pigmentation (arrowhead) is also seen among the DLDs. C Fundus photograph of the left eye of a 69-year-old woman with an axial length of 29.5 mm showing multiple DLDs in the far temporal quadrant of Zone 3 (arrowhead). Similar findings are observed at the nasal peripheral fundus (Zone 3, arrowhead). D Left fundus of a 69-year-old woman with an axial length of 28.1 mm shows soft and confluent DLDs at the midperiphery with pigmentary changes in Zone 2 (arrowhead). E Fundus photograph of the right eye of a 78-year-old woman with an axial length of 27.6 mm showing many small hard DLDs at the far nasal peripheral area of Zone 3 (arrowhead). F Fundus photograph of the right eye of a 69-year-old woman with an axial length of 31.0 mm showing many soft and confluent DLDs at the far nasal peripheral area of Zone 2 (arrowhead).

Among the 66 eyes with DLDs, 18 eyes (27.3%) had macular atrophy, 28 eyes (42.4%) had patchy atrophy, 16 eyes (24.2%) had diffuse atrophy, and 4 eyes (6.1%) had only tessellated fundus. Myopic macular neovascularization (MNV) was found in 41 eyes (62.1%). Thus, about 95% of our patients with DLDs were diagnosed with pathologic myopia (PM).

A comparison of the findings in the high myopic eyes with and without peripheral drusen-like deposits lesions is shown in Table 1.

Table 1.

Clinical characteristics of high myopic eyes with or without DLD.

	DLD eyes	Non-DLD eyes	P value**
Number of eyes	66 (4.9%)	1286 (95.1%)	–
Age (years)	70.0 ± 13.0	63.8 ± 14.1	0.0012*
Sex (female/male)	50/16	992/294	0.794†
Axial length (mm)	29.8 ± 2.4	29.8 ± 2.3	0.864*
Refractive error (spherical equivalent (dioptre))	−13.8 ± 6.6	−11.8 ± 6.6	0.019*
BCVA (logMAR (Snellen))	0.7 ± 0.4 (20/100 ± 20/50)	0.7 ± 0.5 (20/40 ± 20/50)	0.683*
MNV	41 (62.1%)	503(39.1%)	0.0002†
Post staphyloma	45(68.2%)	526(40.1%)	1.208†
Macular atrophy	18(27.3%)	169(13.45%)	0.001†
Patchy atrophy	28(42.4%)	464(36.1%)	0.296†
Diffuse atrophy	16(24.2%)	513(39.9%)	0.011†
Tessellated	4(6.1%)	140(10.9%)	0.215†

DLD drusen-like deposits, BCVA best-corrected visual acuity, logMAR minimum angle of resolution, MNV macular neovascularization.

*Student’s t test, †Pearson’s chi-squared test. **Nominal p values not corrected for multiple testing.

The refractive errors of 441 eyes with an IOL implantation were excluded.

A comparison of the patients with and without DLD showed that the DLD patients were significantly older and more highly myopic than those without DLD (70.0 ± 13.0 vs 63.8 ± 14 years-old, P = 0.001) (−13.8 ± 6.6.vs −11.8 ± 6.6 dioptre, P = 0.019) The differences in the sex, axial length, best corrected visual acuity and post staphyloma between the two groups were not significant.

The proportion of MNV and macular atrophy among DLD patients was significantly higher than those without DLD (62.1%) (41 eyes) vs 39.1% (503 eyes), P < 0.001 and (27.3%) (18 eyes) vs 13.45% (169 eyes), P = 0.001. Conversely, the proportion of diffuse atrophy among non-DLD patients was significantly higher than those with DLD (39.9%) (513 eyes) vs 24.2%(16 eyes), P = 0.011 (Table 1).

Evaluations of fundus images

Among the 66 eyes, DLDs were observed only in Zone 2 in 18 eyes (27.3%), only in Zone 3 in 37 eyes (56.1%), and in both Zone 2 and Zone 3 in 11 eyes (16.7%; Fig. 1). In 5 eyes, DLDs were found at the staphyloma edge (Figs. 2A, 3A). Hyperpigmentation in the area with DLDs was found in 30 eyes (45.5%; Fig. 1B–D).

Fig. 2. Drusen-like deposits (DLDs) along staphyloma edge.

A Photograph of the fundus of the left eye of an 83-year-old woman with an axial length of 27.9 mm showing many yellow DLDs at the staphyloma edge (Zone 2). B Fundus autofluorescence (FAF) image shows hyper-AF corresponding to the DLDs. Chorioretinal folds can be seen to emanate from the staphyloma edge. Arrow indicates the scan line of OCT image in (C). C Vertical OCT scan across the fovea with an ultra-widefield OCT device. White box indicates the magnified part shown as image (D). D Magnified image of C shows irregularities and the elevation of the RPE filled with hyperreflective materials.

Fig. 3. Drusen-like deposits (DLDs) along staphyloma edge.

A Photograph of the right fundus of an 83-year-old woman with an axial length of 28.6 mm showing multiple, yellowish DLDs at the staphyloma edges (Zone 2). Scarred MNV can be seen in the macular area. Scattered retinal haemorrhages due to branch retinal vein occlusion are seen in the lower fundus. B Fundus autofluorescence (FAF) image showing hyper-AF corresponding to some of the DLDs. Arrow indicates the OCT scan line for image (C). C Vertical UWF-OCT image cross the fovea. White box indicates the magnified part in image (D). D Magnified image of the image (C) shows undulations of the RPE with drusenoid PED with hyperreflective materials.

The peripheral DLDs were hyper-AF in 53 eyes (80.3%; Figs. 2B, 3B), hypo-AF in 4 eyes (6.1%; Fig. 4B), and iso-AF in 9 eyes (13.6%). The ocular characteristics of participants are shown in (Supplemental Digital Content Table 2. Which demonstrates the ocular characteristics of participants.)

Fig. 4. Peripheral drusen-like deposits (DLDs) located away from posterior staphyloma.

A Fundus photograph of the left eye of a 69-year-old woman with an axial length of 28.1 mm showing confluent DLDs in the peripheral fundus away from the staphyloma edges. Some pigmentary changes are also seen in the areas of the confluent DLDs especially in the nasal quadrant (Zone 2). B Fundus autofluorescence (FAF) image showing hypo-AF corresponding to some of the DLDs. Arrow indicates the OCT scan line of image (C). C Image of an oblique UWF-OCT scan cross the fovea. The staphyloma edges can be seen (arrowheads). Macular retinoschisis is also present. White box indicates the magnified part in image (D). D Magnified image of image (C) shows irregularity of the RPE with drusenoid PED with hyperreflective materials.

The UWF-OCT images with DLDs showed that the retinal pigment epithelium (RPE) in these regions was irregular and wavy with hyperreflective material (Figs. 2C, D, 3C, D, 4C, D).

Statistical comparisons showed that the patients with DLDs in Zone 2 were significantly older than those in Zone 3 (80 ± 13 vs 64 ± 13 years; P < 0.001). (see Supplemental Digital Content Table 3. which compares the data in the different zones).

Discussion

Analyses of UWF fundus images showed that peripheral DLDs were present in 66 of 1352 highly myopic eyes (4.9%). Because of the co-existing myopic choroidal atrophy, it was difficult to detect DLDs in Zone 1, the macular area.

Earlier studies have shown that peripheral DLDs can be detected in the colour and FAF images of AMD patients, and the most common type of peripheral lesions was the DLDs [11, 21]. Earlier studies also showed that peripheral DLDs can be seen in healthy eyes. Thus, Tan et al. [11] found that the incidence of peripheral drusen was 18% in normal eyes, 61% in eyes with non-neovascular AMD, and 55% in neovascular AMD [11]. Patients with normal eyes were significantly younger than those with either non-neovascular or neovascular AMD, with a mean age of 68.8 years compared to 80.3 years for both AMD groups [11]. In a meta-analysis of 12 studies, Forshaw et al. [22] reported that peripheral DLDs were found in 82.7% of eyes with AMD,with mean age 76.9 years and 33.3% of healthy eyes with mean age 64.4 years [22]. Lengyel et al. [23] reported that in subjects without specific retinal pathology, drusen and pigmentary changes are the most common findings in the peripheral retina. This observation aligns with cross-sectional studies indicating that 10.1% of the general population over the age of 62 exhibit AMD-like abnormalities in the peripheral retina [23]. These findings indicate that peripheral DLDs are somewhat prevalent regardless of the refractive error.

The occurrence and progression of AMD are less likely in individuals with myopia [24]. As, decrease scleral rigidity and diffusion of oxygen and nutrients with minimized the risk for AMD [25]. However, Corbelli et al. [26] reported that older patients with HM were at a significantly higher risk of the dry and the neovascular forms of AMD. They reported that the rate of AMD in HM patients over 55-years-of-age was 11.9% [26]. However, they only analysed the macular area. In addition, the mean axial length of their HM patients was 27.57 ± 2.04 mm which is much shorter than the mean axial length of 29.8 ± 2.4 mm in our patients. It is also possible that their study did not include many patients with PM while 95% of our patients had PM. Thus, the incidence of peripheral DLDs in patients with high myopia and pathologic myopia has not been definitively determined.

The present study also showed that DLDs are not rare among eyes with pathologic myopia. Additionally, some studies have reported peripheral DLDs in patients with macular lesions other than AMD, such as epiretinal membrane (ERM), central serous chorioretinopathy (CSCR), inherited macular dystrophy, as well as in those with extensive macular dystrophy [27, 28].

Our study also reported that the proportion of MNV and macular atrophy among DLD patients was significantly higher than those without DLD (62.1%) (41 eyes) vs 39.1% (503 eyes), P < 0.001 and (27.3%) (18 eyes) vs 13.45% (169 eyes), P = 0.001. These findings suggest that peripheral DLDs may be associated with complications of pathologic myopia.

The eyes with DLDs have 86.4% of FAF abnormalities which is a higher incidence than FAF abnormalities reported in studies of peripheral drusen in AMD cases [9, 10]. The mean incidence of DLDs in these studies was 68.4% [11, 22].

Domalpally et al. [9] reported that peripheral drusen were located in the midperiphery and 78% in the far periphery in eyes with AMD. Küçükiba et al. [10] reported that 29.6% of the peripheral drusen were in Zone 2, 54.2% in the superior quadrant, and 40.9% were in the inferior quadrant of Zone 3 in the AMD group. In our cohort, peripheral DLDs were observed only in Zone 2 in 18 eyes (27.3%), only in Zone 3 in 37 eyes (56.1%), and both in Zone 2 and Zone 3 in 11 eyes (16.7%). Thus, the peripheral DLDs in HM or PM eyes are mostly seen in Zone 3 which is similar to that in other types of eyes.

Patients with peripheral DLDs in Zone 3 were significantly younger than those with DLDs in Zone 2 (64 ± 13 vs 80 ± 13 years respectively, P < 0.001).

It is well-known that various lesions occur in the macula in eyes with pathologic myopia, including myopic maculopathy and myopic traction maculopathy. Following the development of posterior staphyloma, the posterior fundus tends to be most affected, leading to a primary focus on macular lesions in these cases.

However, our study has clarified that the peripheral fundus also undergoes degenerative changes in eyes with pathologic myopia. This finding provides new insights into the management of pathologic myopia. Physicians must now examine both the peripheral and posterior fundus. This highlights that pathologic myopia affects the entire fundus, not just the posterior segment.

The presence of drusen-like deposits in the peripheral fundus and at the staphyloma edge in eyes affected by pathological myopia suggests changes in the retinal pigment epithelium (RPE) and chronic damage typically associated with this condition.

Previous studies indicated that in eyes with high myopia (HM), the equatorial region undergoes marked stretching, resulting in a decrease in both RPE density and retina thickness [29, 30]. Kaneko et al.‘s was supported this stretching of the peripheral retina by findings of peripheral non-perfusion in eyes with pathologic myopia [5]. This study supports the finding of peripheral RPE changes and the development of DLD.

The incidence of staphylomas in Zone 2 was slightly higher at 66.7% than in Zone 3 at 62.2%. Interestingly, five eyes had DLDs precisely along the staphyloma edges (Figs. 2A, 3A). Previous studies reported different kinds of changes along the staphyloma edge. Thus, Ishida et al. [10] showed linear tracts extending from the staphyloma edge. The retinal pigment epithelium (RPE) was damaged at the staphyloma edge, and the spread of the subretinal fluid was related to the progression of the radial tracts [31].

The atrophy of the retinal pigment epithelium (RPE) at the staphyloma’s edge may play a role in the development of focal serous retinal detachment (SRD), polypoidal choroidal vasculopathy (PCV), and choroidal neovascularization (CNV) in these eyes as reported in Nakanishi et al. [32].

Although different degrees of changes at the staphyloma edge have been reported, previous studies have not reported the presence of DLDs along the staphyloma edge. We suggest that mechanical tension on the RPE at the staphyloma edge results in chronic RPE damage and drusen deposition.

Describing peripheral retinal changes using ultra-widefield imaging (UWFI) in high myopia in literature is relatively limited [2]. A few studies have reported alterations in the peripheral retinal vasculature, such as retinal capillary telangiectasia and retinal capillary microaneurysms, through the use of ultra-widefield images [5].

We found that 95% of our patients with DLDs had PM. These findings suggest that peripheral DLDs may play a role in the pathogenesis of pathologic myopia.

There are several limitations in this study. First, all of the participants were from a tertiary referral centre so the findings may not be representative of highly myopic eyes in the general population. Second, because the DLDs in Zone 1 were difficult to detect due to co-existing myopic maculopathy, we cannot be sure if these peripheral changes are related to the pathological changes. Third, this study was not able to determine a longitudinal progression of the peripheral changes because no follow-up data were examined. Finally, all UWF-OCT scans were restricted to the mid peripheral area and not the far peripheral area. Further research is required to determine if the peripheral drusen changes occur before the posterior changes because this information could lead to earlier diagnosis and better treatment and prognosis for eyes with PM.

In conclusion, the results indicate that HM especially PM is a retinochoroidal disorder that affects the entire fundus. Mechanical tension due to an elongation of peripheral fundus and staphyloma formation may be causative factors for the peripheral DLDs. These morphological findings may provide a base for further evaluations on the natural progression of peripheral retinal changes as part of PM.

The existence and the distribution of peripheral DLDs may reflect where of the eyeball is stretched. Although only lesions occurring in the posterior fundus are paid attention to in eyes with pathologic myopia, these findings showed that pathologic myopia is a pathology affecting the entire eye.

Summary

What was known before

• The morphology and incidence of DLDs provide a basis for further evaluations of the natural pathogenesis of peripheral retinal changes in eyes with pathological myopia.

What this study adds

• Peripheral drusen-like deposits (DLDs) were observed in 4.9% of 1352 highly myopic eyes.

Author contributions

All authors were involved in writing, reviewing, and editing the manuscript.

Data availability

All data are available from the corresponding author upon a reasonable request.

Competing interests

The authors declare no competing interests.

Supplementary information

The online version contains supplementary material available at 10.1038/s41433-024-03438-x.