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Case Report and Clinical Features of Elschnig Pearls

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Title: Case Report and Clinical Features of Elschnig Pearls

Authors: Marissa Larochelle, MD; Wyatt Corbin, BS

Date: 9/22/2023

Keywords/Main Subjects: Elschnig pearl, cataract surgery, PCO, posterior capsular opacification

Diagnosis: Elschnig Pearls

Images or video:

Image 1. Slit-lamp exam of the patient’s left eye’s anterior surface. Cloudy material consisting of Elschnig pearls is protruding from the superonasal and inferotemporal quadrants and obscuring the visual axis. Some of the material may also be seen extruding anteriorly from behind the inferotemporal iris at the 5 o’clock position. The iris is poorly dilated and moderate iris bombe is also present.

Image 1. Slit-lamp exam of the patient’s left eye’s anterior surface. Cloudy material consisting of Elschnig pearls is protruding from the superonasal and inferotemporal quadrants and obscuring the visual axis. Some of the material may also be seen extruding anteriorly from behind the inferotemporal iris at the 5 o’clock position. The iris is poorly dilated and moderate iris bombe is also present.

 

Image 2. Magnified image of a large amount of round, individually translucent yet collectively opaque Elschnig pearls protruding from the superonasal and inferotemporal quadrants and obscuring the visual axis; PCIOL is present and appears centered. Individual Elschnig pearls may be visualized in this image.

Image 2. Magnified image of a large amount of round, individually translucent yet collectively opaque Elschnig pearls protruding from the superonasal and inferotemporal quadrants and obscuring the visual axis; PCIOL is present and appears centered. Individual Elschnig pearls may be visualized in this image.

 

Image 3. Slit-lamp exam of the patient’s left eye’s anterior surface after surgical peeling and aspiration of the Elschnig pearls. Unlike the comparative preoperative photo, no Elschnig pearls are seen in this image and the visual axis appears clear.

Image 3. Slit-lamp exam of the patient’s left eye’s anterior surface after surgical peeling and aspiration of the Elschnig pearls. Unlike the comparative preoperative photo, no Elschnig pearls are seen in this image and the visual axis appears clear.

 

Case Report

Patient medical history:
A 67-year-old female was referred for the surgical treatment of Elschnig pearls. A uveitis colleague noted decreased visual acuity due to Elschnig pearls on slit lamp exam one month prior. The patient described having “filmy vision” in her left eye with light sensitivity. The visual acuity in the left eye was 20/40 with no improvement with pinhole testing, a decrease from her baseline vision of 20/20 documented 3 months prior. Ultrasound biomicroscopy confirmed the presence of material on the anterior surface of the IOL optic consistent with our clinical diagnosis.

The patient has an ocular history of pseudophakia of both eyes, non-granulomatous anterior uveitis in both eyes, and intermediate uveitis in her left eye. Cataract surgery was performed nearly 17 years prior in the left (affected eye). For her ocular inflammatory conditions, she was taking Prednisolone BID OU, methotrexate 25mg weekly, and folic acid 1mg daily. The patient also has a history of type 2 diabetes mellitus, hypothyroidism, hypertension, chronic sinusitis, cervicalgia, and headache.

Examination:
The patient presented with a visual acuity of 20/20 in the right eye and a visual acuity of 20/40 with no improvement with pinhole testing in the left eye. At the current visit, she had a normal eye pressure reading of 10 in the left eye. The patient did not have any afferent pupillary defects, although the left eye had minimal reactivity to light. All extraocular movements were intact.

The left eye presented with extensive inferotemporal and superonasal Elschnig pearls anterior and posterior to the PCIOL and obscuring the visual axis (see Images 1 and 2). The Elschnig pearls were also seen extruding anteriorly from behind the inferotemporal iris at the 5 o’clock position (see Image 1). The left eye also had old pigmented keratic precipitates inferiorly, a quiet anterior chamber and a centered posterior chamber intraocular lens. Otherwise, the external and fundus exams were normal.

Management:
Due to the extensive amount of Elschnig pearls in the visual axis, the patient was managed with anterior chamber washout via surgical peeling and aspiration (see Image 3). This was done in the operating room with bimanual irrigation and aspiration. She was treated prophylactically with Prednisolone acetate 1% drops four times daily starting 1 week before the surgery to prevent a uveitis flare in the peri-operative period.

After a successful surgery, the patient’s visual axis became clear. However, her visual acuity did not improve. We suspect that the patient’s lack of visual improvement post-operatively may be due to their long-standing history of uveitis.

 

Clinical Features of Elschnig Pearls

Definition and Background Information: Elschnig pearls are cystic, giant cell-like structures that are thought to be a manifestation of regenerative posterior capsular opacification (PCO) caused by residual equatorial lens epithelial cell (LEC) migration and proliferation between the posterior capsule and the intraocular lens (IOL) after cataract surgery.1 The exact morphology and histology of Elschnig pearls are yet to be fully elucidated, but they have been described as containing a nucleus and few cell organelles.1,2 Elschnig pearls are also thought to be products of the ballooning of cytoplasm emerging from the cell membrane of degenerating lens fibers.1,3 Interestingly, another case report of Elschnig pearls in a patient with chronic uveitis was published, suggesting a possible mechanism of development associated with intraocular inflammation.4 However, one study reported that individual variability may have a greater effect on their formation than the degree of inflammation.4,5

The epidemiology of Elschnig pearls is unknown because they have a variable presentation and thus are difficult to distinguish from other forms of PCO.4 For example, our patient presented with debris, which was revealed to be Elschnig pearls, posterior and anterior to the IOL optic, rather than the more common clinical presentation of PCO posterior to IOL optics. Also, although they were once considered rare, they are now regarded as a relatively common post-operation complication of cataract surgery.4,6 It is not known exactly why they are regarded as a more common complication now. However, it may be due to enhanced diagnostic techniques including ultrasound biomicroscopy increasing their detection rate, or another factor related to the current population or modern cataract surgery practices resulting in increased Elschnig pearl formation. More research would be needed to elucidate why their prevalence has seemed to increase.

Diagnosis: Like other forms of PCO, Elschnig pearls are diagnosed in clinical settings via slit-lamp microscopy. They appear as cloudy clusters of pearls, most commonly posterior to PCIOLs and anterior to the posterior lens capsule. However, they may also present anterior to PCIOLs yet mostly contained within the posterior chamber such as in our patient.

Symptoms: Like other forms of PCO, Elschnig pearls do not always cause symptoms, but they can lead to a decrease in visual acuity and contrast sensitivity due to light scattering. It is proposed that the cellular material inside the Elschnig pearls has a higher refractive index which results in this light scattering.1,4,7-9

Prognosis: The presence of Elschnig pearls generally does not resolve spontaneously, although there are case reports of rare spontaneous regression.10,11 In part, spontaneous regression is rare because when visual symptoms occur the pearls are often treated immediately by neodymium yttrium garnet (Nd:YAG) laser capsulotomy. Like other forms of PCO, however, Elschnig pearls may continually progress or remain stable over time.1,4,12 Regression, with or without the assistance of laser or surgical intervention, generally occurs through pearls falling through a capsulotomy posteriorly into the vitreous, phagocytosis of the pearls by macrophages, or apoptotic cell death.6,12 Although the presence of Elschnig pearls in a patient is generally persistent for months to years, one study demonstrated that individual pearls may appear and disappear within days, most likely via different mechanisms as stated earlier.1 The progression and regression of individual pearls were observed to be influenced by the size, shape, and solidity of the pearls, as well as variability between patients.1,4,5

Management: Similar to other forms of PCO, Elschnig pearls may only need to be treated if visual symptoms occur, thus patient monitoring with patient reports, functional vision testing, and slit-lamp examination is a part of management. For example, although one case report presented a patient with Elschnig pearls obstructing his central visual axis, his vision was still 20/15, so no treatment was performed.10 When symptomatic, the primary treatment option for the pearl or regeneratory form of PCO is Nd:YAG laser capsulotomy due to the convenience of the procedure and decreased risks associated with surgical treatment. Additionally, an anterior chamber washout by surgical peeling, irrigation, and aspiration may be performed.13 Notably, the fibrous form of PCO is only treated by Nd:YAG laser capsulotomy.13 Patients with other complications secondary or unrelated to the Elschnig pearls, prior cataract surgery, or potential underlying causes of inflammation, such as uveitides causing synechiae, must also be managed via the appropriate surgical or medical interventions. Chronic medically induced pupil dilation to allow for a greater visual window and bimanual anterior vitrectomy may also be considered as treatment options for patients with Elschnig pearls.

One study compared Nd:YAG laser capsulotomy with surgical peeling and aspiration and showed that both techniques are comparable with regard to visual outcomes.13 However, Nd:YAG laser capsulotomy was associated with a higher incidence of spikes in intraocular pressure (IOP) and retinal detachment whereas treatment with surgical peeling and aspiration was associated with a higher incidence of pearl recurrence. Thus, caution must be exercised when considering Nd:YAG laser capsulotomy in patients with previous retinal disease and pathologic myopia.13

After Nd:YAG laser capsulotomy or surgical peeling, irrigation, and aspiration, the patient must be monitored to diagnose and treat any post-operative inflammation or spikes in IOP. Repeat treatment may also be necessary to treat recurring Elschnig pearls by utilizing any of the aforementioned methods based on clinical judgment.

Summary of the Case:
We present a case and two images of Elschnig pearls in a 67-year-old female patient with a history of pseudophakia in her ipsilateral eye and anterior segment uveitis. Given this patient’s clinical background and the extent of growth of Elschnig pearls, an anterior chamber washout with surgical peeling, irrigation, and aspiration was performed successfully.
Elschnig pearls are a relatively common regenerative form of PCO after cataract surgery and are currently thought to be cystic, cell-like structures that are products of lens fiber cells that degenerate after cataract surgery. The most common risk factor for Elschnig pearls is previous cataract surgery, although chronic inflammation and other patient-specific factors may present varying risks for pearl formation. Patients with Elschnig pearls may experience visual disturbances such as photopsias which are commonly persistent. They are primarily treated with Nd:YAG laser capsulotomy. Although if clinically appropriate, they may also be treated surgically with an anterior chamber washout via irrigation and aspiration. Each treatment modality is accompanied by risks and benefits that must be weighed by each clinician when considering the safest and most optimal treatment for specific patients.

Format: Case Report and Clinical Features

References:

    1. Findl O, Neumayer T, Hirnschall N, Buehl W. Natural Course of Elschnig Pearl Formation and Disappearance. Investigative Opthalmology & Visual Science. 2010;51(3):1547. doi:10.1167/iovs.09-3989
    2. COWAN A, FRY. SECONDARY CATARACT. Archives of Ophthalmology. 1937;18(1):12. doi:10.1001/archopht.1937.00850070024002
    3. Jongebloed WL, Kalicharan D, Los LI, van der Veen G, Worst JG. A combined scanning and transmission electronmicroscopic investigation of human (secondary) cataract material. Doc Ophthalmol. 1991;78(3-4):325-334. doi:10.1007/BF00165696
    4. K Foutch B, A Garcia C, S Ferguson A. Pearls of Elschnig. J Ophthalmic Vis Res. 2019;14(4):525-527. doi:10.18502/jovr.v14i4.5469
    5. Neumayer T, Buehl W, Findl O. Effect of topical prednisolone and diclofenac on the short-term change in morphology of posterior capsular opacification. Am J Ophthalmol. 2006;142(4):550-556. doi:10.1016/j.ajo.2006.04.047
    6. Caballero A, Salinas M, Marin JM. Spontaneous disappearance of Elschnig pearls after neodymium:YAG laser posterior capsulotomy. J Cataract Refract Surg. 1997;23(10):1590-1594. doi:10.1016/s0886-3350(97)80035-1
    7. Brown N. Visibility of transparent objects in the eye by retroillumination. Br J Ophthalmol. 1971;55(8):517-524. doi:10.1136/bjo.55.8.517
    8. Buehl W, Sacu S, Findl O. Association between intensity of posterior capsule opacification and contrast sensitivity. Am J Ophthalmol. 2005;140(5):927-930. doi:10.1016/j.ajo.2005.05.022
    9. Jose RMJ, Bender LE, Boyce JF, Heatley C. Correlation between the measurement of posterior capsule opacification severity and visual function testing. J Cataract Refract Surg. 2005;31(3):534-542. doi:10.1016/j.jcrs.2004.07.022
    10. Nakashima Y, Yoshitomi F, Oshika T. Regression of Elschnig pearls on the posterior capsule in a pseudophakic eye. Arch Ophthalmol. 2002;120(3):397-398.
    11. Caballero A, Marín JM, Salinas M. Spontaneous regression of Elschnig pearl posterior capsule opacification. J Cataract Refract Surg. 2000;26(5):779-780. doi:10.1016/s0886-3350(00)00412-0
    12. Kurosaka D, Kato K, Kurosaka H, Yoshino M, Nakamura K, Negishi K. Elschnig pearl formation along the neodymium:YAG laser posterior capsulotomy margin. Long-term follow-up. J Cataract Refract Surg. 2002;28(10):1809-1813. doi:10.1016/s0886-3350(02)01222-1
    13. Bhargava R, Kumar P, Sharma SK, Kaur A. A randomized controlled trial of peeling and aspiration of Elschnig pearls and neodymium: yttrium-aluminium-garnet laser capsulotomy. Int J Ophthalmol. 2015;8(3):590-596. doi:10.3980/j.issn.2222-3959.2015.03.28

     

    Faculty Approval by: Austin Nakatsuka, MD

    Copyright statement: Marissa Larochelle and Wyatt Corbin ©2023. For further information regarding the rights to this collection, please visit: http://morancore.utah.edu/terms-of-use/