Sir,

Posterior polar cataract is associated with deficiency of the posterior capsule in 11–26% cases1 leading to high incidence of capsule rupture and potential vitreous loss.2 Identification of the posterior capsule defect (PCD) preoperatively is an obvious advantage that aids in surgical planning.

Case report

A 23-year-old man presented with bilateral progressive diminution of vision for 3 months. On examination his BCVA was 20/200 OU. Slit-lamp examination revealed a posterior polar cataract in both eyes with central conical projection into the vitreous more prominent in the left eye (Figure 1a and b). Scheimpflug imaging (Pentacam 70700: Oculus, Wetzlar, Germany)3 (Figure 2a and b) in the left eye revealed a posterior lenticonus simulation with dehiscence in the posterior capsule giving a ‘tear drop’ or ‘hanging drop’ appearance (Figure 2b). The corresponding lens spike in the left eye is broader and irregular than in the right eye. The patient underwent phacoemulsification in the left eye and a central PCD was noted as highlighted on Scheimpflug photography. The vitreous face was intact. A three-piece Tecnis Z9000 (AMO Inc., Santa Anna, CA, USA) IOL was implanted in the bag. The right eye underwent uncomplicated phacoemulsification and no PCD was noted.

Figure 1
figure 1

(a and b) Slit lamp photographs. [Upper panel, right eye] The posterior polar plate can be seen with intact posterior capsule [Lower panel, left eye]. The bulging posterior polar cataract due to deficient posterior capsule producing a posterior lenticonus simulation.

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Figure 2
figure 2

(a and b) Scheimpflug imaging with densitometry readings of both eyes. [Upper panel, right eye] Single scan image showing a posterior polar plaque with a densitometry reading of approximately 30 units. The posterior capsule beneath is well imaged and is intact. [Lower panel, left eye] Single scan image showing the posterior polar cataract bulging through the deficient posterior capsule appearing as ‘Hanging-drop’ or ‘Tear-drop’ sign. Note the corresponding lenticular spike of 60 units is broader and irregular as compared to right eye.

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Posterior polar cataracts may be associated with remnants of the hyaloid system or the tunica vasculosa lentis.4 An important feature of posterior polar cataract is a significant incidence of extreme capsule weakness or perhaps even absence in the area of polar opacity, which is difficult to identify in the presence of dense polar cataracts.1, 4, 5 Scheimpflug photography identified the preexistent PCD, in our case evident as protrusion through the PCD producing a broader, irregular spike of 60 U on densitometry scale. This ‘hanging drop’ or ‘tear drop’ sign on Scheimpflug photography is probably created by preexisting PCD with herniation of dense posterior plaque through it.

Comment

This simulated posterior lenticonus producing hanging drop/tear drop sign should be taken as diagnostic of PCD in posterior polar cataracts. To our knowledge, this is the first report of PCD with coexistent posterior polar cataract being characterized on Scheimpflug imaging.

Conflict of interest

The authors declare no conflict of interest.