History
JH, a 69-year-old Caucasian female and patient of long-standing, presented with the chief complaint of decreased acuity in the left eye. JH has been a patient with us since 2007 and initially presented with a refraction as follows:
R: +2.00/-0.25 x 180 (6/6)
L: +2.25/-0.75 x 177 (6/6)
Add +2.50 (N5)
In 2008, she underwent bilateral clear lens extraction which left her with a residual refraction as follows:
R: +0.75 (6/6)
L: +0.50/-1.00 x 65 (6/7.5)
Presentation
On her most recent visit her refraction was now:
R: +1.25/-2.00 x 85 (6/9)
L: +1.50/-0.75 x 80 (6/9)
Ultrawide field retinal scanning with the Optos Daytona (figure 1) and swept source OCT assessment with the Topcon Triton suggested hazy media, but a normal arrangement of the macula, retina and retinal nerve fibre layer (RNFL). We suspected posterior capsular opacification (PCO).
Figure 1: Daytona retinal scan
JH was dilated and slit lamp examination, using diffuse illumination showed anterior capsular thickening (figure 2).
Figure 2: Anterior view suggesting anterior capsular thickening
A narrow bright beam was then used and there was no PCO. What we saw instead was a clear narrow band, with a thicker yellowish band behind it. We then did an anterior segment OCT to try to get better visualisation (figures 3 and 4).
Figure 3: Anterior OCT scan for the right eye
Capsular bag distension
Between myself and colleagues (combining over 60 years in clinical practice), we had not seen this presentation before and decided that it required referral, but were curious about what it could be.
Figure 4: Anterior segment OCT scan for left eye
After getting patient permission and anonymising the images, I used some private web forums to try to determine what we had been looking at.
I posted at 11:37, had a reply by 11:50 and by 12:00 had a potential diagnosis of capsular bag distension syndrome.
Discussion
First described by Davison,1 capsular bag distension syndrome (CBDS) is a rare complication after cataract when the continuous curvilinear capsulorrhexis (CCC) is blocked by the intraocular lens (IOL). Liquified material then builds up between the IOL causing distension of the capsular bag.
This may also lead to anterior displacement of the IOL, an unexpected myopic shift and increased IOP.1-3,5,6 The term ‘liquified after cataract’ (LAC) has also been used and is increasingly accepted as the term to describe this condition. Miyake et al4 felt this was a separate entity to CBDS, but Bhattacharjee et al7 felt that it may be on the spectrum of CBDS, though without shallowing of the anterior chamber.
Differential diagnosis of LAC should rule out the following:4
- Delayed endophthalmitis – inflammatory response due to bacterial invasion
- Phaco-anaphylactic uveitis – a severe inflammatory response due to residual lens cortex remaining post-operatively
Kim and Shin2 developed a classification as follows:
- Non-cellular – one day after surgery presenting with shallow anterior chamber and an inferiorly placed IOL
- Inflammatory – presenting several days after surgery with a distended capsular bag and an inflammatory reaction
- Fibrotic – late post-operative period with development of circumferentially anterior capsule fibrosis and PCO
A mechanism of action has been speculated suggesting the condition is due to residual cells within the capsular bag proliferating4,6 or movement of the ring of Soemmering (due to saccadic movement) which then breaks down.7 Either of these actions might lead to an osmotic gradient and aqueous humour being drawn into the capsular bag. This potentially could lead to anterior movement of the IOL, but it may be held in place if there is significant fibrosis of the anterior capsule.5
Anterior movement of the IOL can cause a myopic shift in prescription due to a change in the focal point of the IOL and a narrowing of the anterior chamber depth. This in turn could lead to an increase in intraocular pressure secondary to a narrowing of the anterior chamber angle.
The aim of treatment for CBDS is to reduce the fluid that has accumulated between the capsule and the lens. This can be achieved by Nd:Yag capsulotomy2,3,6,7 or surgically.2,4-6
Using a Nd:Yag laser to pierce the capsule can allow the fluid to drain into either the anterior or posterior chamber. There is some concern of potential Propionbacterium acnes bacteria being released from the capsule and leading to endophthalmitis.4,7
Dr Keyur Patel is a therapeutic optometrist based at the New England College of Optometry, Northampton.
References
1 Davison, James A. 1990. ‘Capsular Bag Distension after Endophacoemulsification and Posterior Chamber Intraocular Lens Implantation’. Journal of Cataract & Refractive Surgery 16 (1):99–108. https://doi.org/10.1016/S0886-3350(13)80883-8.
2 Kim, Hong Kyun, and Jae Pil Shin. 2008. ‘Capsular Block Syndrome after Cataract Surgery: Clinical Analysis and Classification’. Journal of Cataract & Refractive Surgery 34 (3):357–63. https://doi.org/10.1016/j.jcrs.2007.11.026.
3 Koh, Joong Sik, Young Bin Song, Won Ryang Wee, and Young Keun Han. 2016. ‘Recurrent Late-Onset Fibrotic Capsular Block Syndrome after Neodymium-Yttrium-Aluminum-Garnet Laser Anterior Capsulotomy: A Case Report’. BMC Ophthalmology 16 (1). https://doi.org/10.1186/s12886-016-0261-x.
4 Miyake, Kensaku, Ichiro Ota, Sampei Miyake, and Masayuki Horiguchi. 1998. ‘Liquefied Aftercataract: A Complication of Continuous Curvilinear Capsulorhexis and Intraocular Lens Implantation in the Lens Capsule’. American Journal of Ophthalmology 125 (4):429–35. https://doi.org/10.1016/S0002-9394(99)80182-2.
5 Yang, Min Kyu, Won Ryang Wee, Ji-Won Kwon, and Young Keun Han. 2015. ‘Anterior Chamber Depth and Refractive Change in Late Postoperative Capsular Bag Distension Syndrome: A Retrospective Analysis’. Edited by Demetrios Vavvas. PLOS ONE 10 (4):e0125895. https://doi.org/10.1371/journal.pone.0125895.
6 Zafeiropoulos, Paraskevas, Andreas Katsanos, Konstantina Gorgoli, Ioannis Asproudis, and Miltiadis Aspiotis. 2014. ‘Late-onset capsular bag distension syndrome: a report of two cases’. Acta Medica (Hradec Kralove, Czech Republic) 57 (4):165–67. https://doi.org/10.14712/18059694.2015.83.
7 Bhattacharjee, Harsha, Kasturi Bhattacharjee, Pankaj Bhattacharjee, Dipankar Das, Krishna Gogoi, and Diyali Arati. 2014. ‘Liquefied after Cataract and Its Surgical Treatment’. Indian Journal of Ophthalmology 62 (5):580. https://doi.org/10.4103/0301-4738.129771.