Intumescent cataract is a condition in which the lens cortex liquefies and swells as cataracts progress, causing the entire lens to become swollen. In the severity classification of cataracts, it progresses in the order: incipient stage → immature stage → intumescent stage → mature stage → hypermature (Morgagni) stage.
In the United States, most cataracts are surgically treated during the immature stage. On the other hand, in areas with limited access to healthcare, patients often present after the condition has progressed. Therefore, extraction of intumescent cataracts tends to be more difficult.
The prevalence of age-related cataracts is approximately 45% in people in their 50s, 75% in their 60s, 85% in their 70s, and nearly 100% in those aged 80 and older. Among these, cases with delayed treatment progress to intumescent cataracts.
They are different concepts. Mature cataract refers to a state where the entire lens is opaque. Intumescent cataract is a condition where the lens swells due to liquefaction of the cortex, leading to increased intralenticular pressure. Although mature cataracts may be accompanied by intumescent changes, not all mature cataracts exhibit swelling.
Intumescent cataract is an advanced cataract that presents with the following symptoms.
The first finding on slit-lamp examination is the formation of vacuoles and cortical spokes.
The essence of intumescent cataract is the progression of untreated cataract.
The main causes and risk factors are as follows:
Diagnosis of intumescent cataract is made by slit-lamp microscopy. Since the fundus cannot be visualized, preoperative evaluation of the posterior segment by ultrasound is essential.
White opacity, swelling of the lens, and fluid accumulation under the anterior capsule are observed. The Emery-Little classification is used to estimate nuclear hardness.
| Grade | Color | Nuclear hardness |
|---|---|---|
| Grade 1–2 | Clear to yellowish-white | Soft to moderately soft |
| Grade 3–4 | Yellow to ocher | Moderate to hard |
| Grade 5 | Brown | Extremely hard |
In intumescent cataract, the fundus is not visible, so B-scan ultrasound is necessary to rule out posterior segment diseases such as retinal detachment and vitreous hemorrhage 1).
Nayak et al. (2024) identified two high-reflectivity spikes (reflectance 80–90%) corresponding to the posterior capsule and posterior nuclear surface on A-scan overlay of B-scan, and named it the “double-peak sign” 1). The hypoechoic area between the two spikes corresponds to liquefied cortex. A positive sign suggests the presence of liquefied cortex posteriorly and high intralenticular pressure.
When the double-peak sign is present, the risk of complications during anterior capsulotomy is high. The surgeon must take all precautions 1). Conversely, if only one spike is present, posterior cortical liquefaction is minimal and the risk of complications is low 1).
It is useful for quantitative assessment of anterior chamber depth and lens intumescence. Swept-source OCT (SS-OCT) can detect cortical liquefaction from multiple echoes within the lens, but device cost remains a barrier to widespread use 1).
If the double-peak sign is negative, the posterior intralenticular pressure is low, and the risk of anterior capsulotomy is relatively small1). However, anterior cortical liquefaction may still exist, so standard preoperative preparation is necessary.
Treatment for intumescent cataract is surgical lens extraction. Phacoemulsification (PEA) and intraocular lens (IOL) implantation are standard procedures, but intumescent cataracts require more intraoperative measures compared to routine cataract surgery2).
In mature or intumescent cataracts, retroillumination from the fundus is not possible, so anterior capsule staining is essential. Use trypan blue or brilliant blue G (BBG) to visualize the anterior capsule.
Care must be taken because excessive injection of staining solution can cause it to flow into the vitreous, reducing intraoperative visibility.
Decompression of the intralenticular pressure is an essential procedure for safe anterior capsulotomy.
Attach a 27-gauge needle to a 1 mL syringe, puncture the anterior capsule, and aspirate the liquefied cortex. Perform this while applying downward pressure on the lens with an ophthalmic viscosurgical device.
According to Nayak et al. (2024), if liquefied cortex corresponding to the double-peak sign remains posteriorly after aspirating the anterior liquefied cortex, the intralenticular pressure is not sufficiently reduced, and the risk of radial extension of the anterior capsulotomy persists 1).
Continuous curvilinear capsulorhexis (CCC) is recommended. The recommended diameter is 5 to 5.5 mm. Can-opener capsulotomy should be avoided due to high complication risk.
The technique for continuous curvilinear capsulorhexis used in intumescent cataract is as follows.
Two-Stage Continuous Curvilinear Capsulorhexis
Procedure Overview: First, a small continuous circular anterior capsulotomy is created, and the lens material is removed to decompress. Then, the small opening is enlarged into a larger continuous circular anterior capsulotomy.
Advantages: The initial small opening ensures a continuous edge and prevents radial tears.
Phaco Capsulotomy
Procedure Overview: The anterior capsule is punctured with an ultrasound tip, and liquefied cortex and nuclear material are simultaneously removed while decompressing.
Advantages: The capsulotomy can eliminate outward tearing forces during the procedure.
Continuous curvilinear capsulorhexis with a femtosecond laser can be performed with the anterior chamber closed, potentially reducing the risk of radial tears in intumescent cataract 3). In white cataract, adjusting the capsulotomy distance (shortening the pre-capsular distance and lengthening the post-capsular distance) is considered useful 3). Laser nuclear fragmentation reduces the amount of ultrasound energy used.
The choice of nuclear fragmentation technique is also important. The divide-and-conquer method requires significant rotation of the lens, increasing the risk of zonular rupture. Techniques that minimize rotation and ultrasound energy, such as phaco-chop, are recommended.
If the nuclear hardness is extremely high, planned extracapsular cataract extraction may be selected.
For intumescent cataracts, a three-piece intraocular lens may be preferred. The three-piece haptics exert strong tension on the equatorial capsule, enhancing zonular stability. It can also be fixated in the ciliary sulcus, providing flexibility during surgery.
Advanced cataracts are often accompanied by zonular instability2). Preparation of capsule tension rings, capsule retractors, Ahmed segments, etc., is necessary2). For more severe zonular instability, scleral-sutured capsule tension rings or intrascleral fixation may be chosen2).
Surgery for intumescent cataract requires higher skill than standard cataract surgery. It is important to have an experienced surgeon perform the operation. Preoperative ultrasound examination should be used for risk assessment, and surgery should be performed with adequate preparation.
The pathology of intumescent cataract is based on dysfunction of lens epithelial cells.
The trigger is dysfunction of lens epithelial cells. This causes changes at the gene and protein level in the Na-K pump of epithelial cells. Impaired pump function creates an osmotic gradient into the lens, leading to epithelial swelling.
This osmotic change is the critical difference between intumescent cataract and nuclear cataract. In nuclear cataract, protein aggregation and insolubilization mainly progress, whereas in intumescent cataract, water influx due to Na-K pump dysfunction in the epithelium is the main pathology.
Increased intralenticular pressure results from impairment of the iron pump and metabolic barrier3). Breakdown of the barrier function allows fluid to flow into the lens nucleus, causing cortical hydration. Consequently, the lens swells and intracapsular pressure rises.
Histologically, the following features are observed.
Intumescent Cataract
Main pathology: Water influx and cortical liquefaction due to Na-K pump dysfunction
Tissue changes: Vacuole formation present, no apoptosis, extensive debris
Intralenticular pressure: Elevated (surgical risk factor)
Nuclear Cataract
Main pathology: Protein oxidation, aggregation, and insolubilization
Tissue changes: Nuclear sclerosis and yellow-brown discoloration progress
Intralenticular pressure: Usually not elevated
Nayak et al. (2024) reported that the double-peak sign on A-scan overlay on B-scan is a predictive marker for posterior cortical liquefaction and high intraocular lens pressure 1). Cases with a positive double-peak sign have a high risk of anterior capsule extension, while negative cases completed surgery without issues. Preoperative routine screening is expected to prevent complications.
This is a new capsulotomy device consisting of a console and a disposable handpiece. It is inserted into the anterior chamber to deliver energy to the anterior capsule, creating a circular capsulotomy instantly. Because the capsulotomy is completed immediately, the risk of radial extension in intumescent cataracts is low. Its usefulness in difficult cases has been reported.
Swept-source optical coherence tomography can detect multiple echoes within the lens and noninvasively assess the degree of cortical liquefaction 1). It is attracting attention as a preoperative evaluation method that complements conventional ultrasound, but equipment cost remains a challenge.
