1. Comparison of anterior and posterior polar cataracts with novel Scheimpflug images
Shafi Balal MBBS, Anant Sharma MD, Nisha Nesartanam MBBS, Jonathan Than MBBS Moorfields Eye Hospital, Bedford, United Kingdom
PURPOSE
Posterior polar cataracts (PPC) can be difficult to diagnose and are often over-diagnosed; if >4mm they have a higher risk of posterior capsular rupture (PCR). Anterior polar cataracts (APCs) may be easier to diagnose but can affect visual development if they progress in childhood. Scheimpflug imaging allows precise measurement and progression of these cataracts to aid surgical decision making. It also is useful for less experienced clinicians to help diagnose between other types of cataracts such as posterior subcapsular or posterior cortical cataract.
Figure 2. APC in Left eye with signal intensity
RESULTS
Images obtained show the similarity between anterior and posterior polar cataract in their anterior and posterior protrusion from the capsular plane. Scheimpflug also allows the precise localisation of each cataract.
Figure 4. PPC in Left eye with signal intensity
CONCLUSION
The authors believe this is the first time anterior polar cataract has been imaged with Scheimpflug imaging. APC shows similarities to PPC in anterior and posterior protrusion, perhaps reflecting their common similarity of lens fibre disarray and capsule thinning. Accurate diagnosis, documentation and progression is best measured with Scheimpflug imaging and helps in the surgical planning of these rare cataracts.
Figure 1. Slit lamp images of our patient with APC
Figure 3. APC in Right eye with signal intensity
METHODS
We used Pentacam Scheimpflug (Oculus, Wetzlar, Germany) imaging in the diagnosis, documentation and surgical planning of anterior and posterior polar cataract in two separate patients. The APCs are in a 45 year old female patient and PPCs in a 50 year old female. Images obtained were analysed using ImageJ software. Volume and intensity signal of anterior polar cataract was measured to aid surgical planning and progression.
DISCUSSION
PPCs are associated with deficiency of the posterior capsule in 11–26% cases. High incidence of capsule rupture and potential vitreous loss. Scheimpflug photography identifies the pre-existent posterior capsule deficiency and provides a standardised grading system. Size of the polar opacity has a significant impact on the risk of PCR. Excessive adherence of the opacity to the posterior capsule and unusual thinness of the capsule predisposes these eyes to posterior capsular rupture. In modern healthcare settings, the patient is often examined by a different ophthalmologist at each visit and thus an objective method of measuring is advantageous..
Figure 5. PPC in Right eye with signal intensity
References: Vasavada, A.R., Raj, S.M., Vasavada, V. and Shrivastav, S., Surgical approaches to posterior polar cataract: a review. Eye, 26(6), pp Arora, R., Mehta, S., Goyal, J.L., Jain, S. and Gupta, D., Tear-drop sign of posterior capsule dehiscence on Scheimpflug imaging. Eye, 24(4), pp Kumar, S., Ram, J., Sukhija, J. and Severia, S., Phacoemulsification in posterior polar cataract: does size of lens opacity affect surgical outcome?. Clinical & experimental ophthalmology, 38(9), pp