Iatrogenic Posterior Polar Cataract with Capsular Cystic Formation Following Lens Touch During Intravitreal Injection: A Case Report and Literature Review

Abstract

This case report describes a unique ocular finding in a 64-year-old male with a history of central serous chorioretinopathy with choroidal neovascular membrane, treated with intravitreal injections of Aflibercept. The patient was found to have an iatrogenic retro-lenticular non-pigmented cystic formation in the left eye, an anomaly not previously documented in the literature. Comprehensive imaging included ultrasound biomicroscopy and anterior segment optical coherence tomography. This report emphasises a rare ocular finding and the significance of recognising iatrogenic cataracts following intravitreal injections. It also highlights the necessity of individualised patient management and preoperative evaluations to prevent surgical complications.

1. Introduction

Intravitreal injections have become one of the most commonly performed ophthalmic procedures worldwide for the treatment of retinal diseases such as age-related macular degeneration (AMD), diabetic macular edema (DME), and retinal vein occlusions through the use of anti-vascular endothelial growth factor (anti-VEGF) agents and corticosteroids. They are generally considered low-risk procedures, and serious complications are rare. However, complications such as endophthalmitis, retinal detachment, and raised intraocular pressure have been reported. Less common, yet no less clinically significant, is the increased risk of posterior capsular rupture (PCR) [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17]. PCR refers to an unintended breach in the integrity of the posterior capsule or adjacent zonular fibres, resulting in communication with the vitreous cavity. This complication significantly increases the risk of postoperative sequelae, including endophthalmitis, retinal detachment, and cystoid macular edema, potentially compromising visual outcomes following cataract surgery [16].

We present a unique case of iatrogenic posterior polar cataract associated with capsular cystic changes, likely resulting from lens touch during intravitreal injection. To our knowledge, this is one of the first reports describing cystic capsular formation secondary to such trauma, with implications for diagnosis, surgical planning, and patient counselling.

2. Case Report

In March 2024, a 64-year-old Caucasian male presented to our Cataract Service referred from the Medical Retina Service for evaluation of an unusual lens finding in his left eye. His past medical history included mild anxiety, with no current medications.

His ocular history included left eye central serous chorioretinopathy (CSCR) since 1999, unresponsive to spironolactone, and treated with focal argon laser treatment in 2016.

In December 2021, due to a choroidal neovascular membrane (CNVM) in the left eye, the patient commenced treatment with Aflibercept intravitreal injections.

The treatment regimen consisted of an initial loading phase of three-monthly injections, followed by a pro re nata (PRN) approach.

All intravitreal injections were performed under standard aseptic conditions, delivering 2 mg (0.05 mL of a 40 mg/mL solution) of Aflibercept via a 30-gauge needle in the inferotemporal quadrant, 4 mm posterior to the limbus. No intraoperative complications were reported.

On examination, the right Corrected Distance Visual Acuity was 0 LogMAR and the left was 0.48 LogMAR. The intraocular pressure was 19 mmHg in the right eye and 18 mmHg in the left eye. The right eye’s clinical examination showed a mild nuclear cataract, with no other discernible abnormalities.

In contrast, the clinical examination of the left eye revealed a retro-lenticular, non-pigmented cystic formation located paracentrally and inferiorly on the lens. This was associated with early nuclear and localised posterior subcapsular lens opacities [Figure 1]. Only an early nuclear cataract in the left eye was documented before the last injection. The patient reported that his left eye vision had not been optimal for several years, particularly after developing CNVM, but noted that it had remained relatively stable, with no recent exacerbations.

Ultrasound biomicroscopy (UBM) of the left eye confirmed a small cluster of cysts with hyperechoic walls adherent to a disarrayed posterior lens capsule surface.

The maximum transverse base was 0.81 mm (+/− 1.8 mm), maximum longitudinal base was 0.84 mm (+/− 1.8 mm), and maximum elevation was 0.37 mm [Figure 2].

Anterior segment optical coherence tomography revealed a retro-lenticular lobulated cystic formation with hyper-reflective walls surrounding a hypo-reflective interior and capsular disruption [Figure 3].

Optical coherence tomography (OCT) imaging of the left macula further revealed the presence of a fibrovascular pigment epithelial detachment with minimal subretinal fluid.

Based on the findings, we suspected a post-needle lens touch posterior polar cataract associated with a unique retro-lenticular cystic formation. Given the patient’s asymptomatic presentation and the early stage of the cataract, we adopted a conservative approach with observation and postponed cataract surgery for the time being.

3. Discussion

Intravitreal injections are generally considered safe procedures. However, an incidence range of 0–0.07% for iatrogenic cataracts and an increased risk of intraoperative PCR following intravitreal injections have been reported in the literature [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17]. Although the incidence appears low, it becomes clinically significant given the high volume of procedures: over 20 million intravitreal injections are performed globally each year [18], with more than 8 million annually in the United States alone—a number expected to rise to 10 million by 2025 [19]. Even a small complication rate under these circumstances may translate into thousands of cases, highlighting the need for greater awareness and preventive strategies against iatrogenic injury.

Several studies have explored the association between intravitreal injections and PCR.

Bjerager et al. conducted a meta-analysis, finding a significant association between previous intravitreal injections and PCR. They determined that any prior intravitreal injection increased the PCR odds ratio (OR) by 2.30 times. This risk outweighed other known factors like a longer axial length (OR 1.47), small pupil size (OR 1.45), or the patient using doxazosin (OR 1.51). However, it was lower than factors such as surgeon experience (OR 2.83 for surgeons training year 1–2) or certain types of cataracts (OR 2.99 for brunescent or white cataracts) [1]. They also observed a 4% increase in the PCR risk per additional injection, suggesting heightened concern with a history of multiple injections, particularly ten or more [1].

Shalchi et al. similarly found increased risk (OR 1.66), although they noted that the number of injections did not correlate with increased risk [3].

Miller et al. also reported an incidence of PCR of 2.6% during surgery in eyes that had previously received intravitreal injections, compared to 0.5% in eyes that had not [6]. A recent retrospective study by Daradkeh et al. analysed over 2700 eyes and found that patients who had received three or more intravitreal bevacizumab injections within one year had a significantly higher rate of PCR during cataract surgery (5.2%, p < 0.01), compared to non-injected diabetic (1.6%) and non-diabetic controls (1.4%). These findings suggest a possible dose-dependent relationship [20]. Notably, a recent population-based cohort study by Falb et al. challenged the assumption that intravitreal injections are an independent risk factor for posterior capsular rupture. In a univariate analysis, a history of intravitreal injection was associated with a higher risk of PCR (OR 1.27, p = 0.008), but this association lost statistical significance in multivariate models adjusted for confounders such as pseudoexfoliation, surgical technique (extracapsular extraction vs. phacoemulsification), and combined procedures (OR 1.04, p = 0.664). The authors concluded that the observed increase in risk may be explained by coexisting ocular pathologies or surgical complexity, rather than by intravitreal injection exposure alone. These findings contrast with earlier reports, including meta-analyses and large retrospective cohorts, which identified a statistically significant and often dose-dependent relationship between intravitreal injection history and PCR risk. The discrepancy may reflect differences in study design, statistical models, population characteristics, or unmeasured confounding variables. Nevertheless, the totality of evidence suggests that while intravitreal injections may not be an independent risk factor in all contexts, it remains a relevant consideration, particularly in patients with additional predisposing factors such as diabetes, pseudoexfoliation, or multiple prior injections [21].

The mechanisms behind this heightened risk are not fully understood. Potential factors include direct trauma from the needle, accelerated cataract formation, iatrogenic zonulopathy (especially after repeated intravitreal injections) or delayed surgery in patients receiving intravitreal treatments for retinal issues. However, changes in lens mechanical properties due to exposure to anti-vascular endothelial growth factor or corticosteroids have been reported. This exposure may weaken the capsule and place it at a higher risk of PCR [1,6,22].

Daradkeh et al. further suggested that long-standing diabetes may predispose patients to increased capsular fragility through biochemical alterations of the lens capsule [20].

In our case, we report an iatrogenic posterior polar cataract with cystic lesion development behind the posterior capsule of the lens following intravitreal injections. There is a small body of literature on iatrogenic capsular cysts and to the best of our knowledge, we did not find any similar findings reported.

Although the primary mechanism of injury in this case appears to be mechanical trauma due to direct lens touch, the possibility that the injected agent, Aflibercept, contributed to the cystic alteration of the posterior capsule cannot be entirely ruled out. While Aflibercept is generally considered safe when used intravitreally, its direct exposure to the lens is uncommon and not well studied. Therefore, it is plausible that in this scenario, the combination of mechanical trauma and inadvertent chemical exposure may have synergistically contributed to the capsular changes.

Salisbury et al. described the first case of lens capsular cyst development following penetrating ocular injury, assuming the cyst wall consisted of a dislodged lens capsule [5].

In our case, the nature of cystic development remains unclear but we hypothesised that, after trauma to the posterior lens capsule, lens epithelial cells migrated and formed a cyst-like structure analogous to Elschnig’s pearls [23,24].

As the lens changes did not significantly affect the patient’s vision, an observational approach was chosen, emphasising the importance of individualised patient management and the need to balance the risks and benefits of surgical intervention.

Preoperative evaluation, which includes a comprehensive slit lamp examination and imaging modalities like ultrasound and anterior segment OCT, is essential for assessing lens status, zonular stability, and identifying any defects in the posterior capsule [1,2,25,26].

Preoperative clues suggesting the presence of a ruptured posterior capsule include visible needle track through the lens, loss of posterior capsule convexity, and posterior capsule rupture on B-scan ultrasonography [2]. The results of Daradkeh et al. include careful evaluation of the anterior vitreous for signs of inflammation or condensation and checking for phacodonesis and pupillary dilation before surgery [20].

The recommended approach to cataract surgery in eyes with a pre-existing posterior capsule tear following intravitreal injections requires a meticulous surgical strategy to minimise complications. In these cases, the lens may resemble a posterior polar cataract. Refs. [2,4,27] and a posterior capsule tear can potentially enlarge at various stages of the procedure, including hydrodissection, phacoemulsification, nucleus extraction, cortical removal, or vacuuming of the posterior capsule. Careful intraoperative techniques are essential to prevent further extension of the rupture and ensure surgical success [28].

Hydrodissection should be avoided to prevent extension of the capsular tear or pushing back of lens material. However, a quiescent posterior capsule tear may not be discovered until hydrodissection is performed during cataract surgery [29].

Gentle hydrodelineation with small waves of fluid is recommended to reduce the risk of lens matter dislocating into the posterior segment. Some authors also recommend using a low bottle height, low flow rate and vacuum, and using a balanced salt solution ophthalmic viscosurgical device exchange technique when withdrawing instruments to maintain the anterior chamber stability during the procedure [2,4].

Vajpayee et al. suggested that in any cataract with posterior capsular rent, nuclear rotation should be avoided and advised performing nuclear emulsification through a chopping technique, and viscodissection to mobilise the epinucleus and cortex. They also recommended preserving a posterior layer of the lens cortex over the posterior rent region until the emulsification procedure’s conclusion to minimise the risk of lens material loss into the vitreous cavity through the capsular defect [27]. Finally, they suggested removing the posterior cortical layer adherent to the posterior capsule at the end of the procedure using a bimanual irrigation–aspiration cannula to minimise turbulence in the anterior chamber and the anterior hyaloid face after opening the posterior capsular defect [27].

In summary, the surgical approach to posterior polar cataracts and any posterior capsular rent aims to perform gentle manoeuvres to avoid excessive stress on the posterior capsule, avoid hydrodissection, use low fluidics during lens removal, maintain the anterior chamber stability, and minimise fluctuations to prevent the vitreous from bulging forward and the potential enlargement of the posterior capsular tear over time [4].

If any vitreous is detected in the anterior chamber, a bimanual anterior vitrectomy should be performed with triamcinolone to stain the vitreous.

4. Conclusions

In conclusion, our case report highlighted distinctive ocular findings that, to the best of our knowledge, have not been previously described in the literature.

In addition, it underscores the importance of recognising and managing rare complications such as iatrogenic cataracts following intravitreal injections. As the number of patients undergoing repeated anti-VEGF injections continues to rise, even rare complications may have a growing cumulative impact. To mitigate these risks, comprehensive preoperative assessment, including anterior segment imaging and evaluation of lens and zonular integrity, is crucial. When surgery is indicated, adopting tailored surgical strategies, such as avoiding hydrodissection and using low-fluidics phacoemulsification techniques, can significantly improve outcomes. Ultimately, this case reinforces the importance of interdisciplinary collaboration between retinal and anterior segment specialists and calls for further prospective studies to clarify the mechanisms of lens capsule vulnerability and guide preventive approaches in the management of patients undergoing both intravitreal therapy and cataract surgery.