GRAND ROUND CASE Year : 2023  |  Volume : 69  |  Issue : 1  |  Page : 41-42

Lunar lenses – Acquired lens colobomas

S Choudhary, D Katoch, SS Pandav, S Kaushik
Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India

Date of Submission10-Dec-2021Date of Decision20-Feb-2022Date of Acceptance24-Feb-2022Date of Web Publication07-Jun-2022

Correspondence Address:
Prof. S Kaushik
Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jpgm.jpgm_1145_21

Acquired lens colobomas secondary to ocular surgeries are scarcely described in the literature. We describe two cases of acquired lens coloboma in two infants with glaucoma who underwent ocular surgery. The coloboma in the first case was likely because of direct trauma to the lens zonules during an optical iridectomy with a vitrectomy cutter, resulting in localized loss of zonules and consequently localized lens coloboma. The coloboma in the second case was noticed during examination under anesthesia after scleral buckling and cryopexy for retinal detachment. The cause for coloboma development in this case could be disruption of the lens zonules because of stretching of the globe after scleral buckle surgery or because of injury to zonules during scleral buckling and the cryopexy procedure.

Keywords: Acquired lens coloboma, cryopexy, optical iridectomy

How to cite this article:
Choudhary S, Katoch D, Pandav S S, Kaushik S. Lunar lenses – Acquired lens colobomas. J Postgrad Med 2023;69:41-2
 :: Introduction 

A coloboma is a term used to describe a localized absence of any ocular structure, which may be a developmental malformation or have an acquired cause. An “acquired lens coloboma” appears as a notch or flattening of the lens margin because of the localized zonular absence. It is technically a misnomer because there is no actual absence of the lenticular substance. The localized loss of tension on the lens capsule results in retraction of the unsupported lens portion, giving the appearance of a lens defect. Careful clinical examination reveals the absence of zonules in the area of the coloboma.[1] Isolated developmental lens colobomas are uncommon, and they usually occur in association with a ciliary body, iris, or choroidal coloboma.[2]

Acquired zonular disruption could occur secondary to an abnormally stretched eye, as seen in buphthalmos. We have previously reported a developed lens coloboma in a child with neglected congenital glaucoma.[1] It has also been reported as a consequence of disruption of the weak zonules in Marfan's syndrome with axial elongation of the globe.[3],[4]

 :: Grand Round Cases 

We describe two cases of acquired lens coloboma in two infants with glaucoma who underwent ocular surgery. One was likely because of direct trauma during an optical iridectomy, and the other was noticed on the examination after scleral buckling for retinal detachment.

Case 1

A 1-year-old boy diagnosed with newborn glaucoma had a residual central corneal opacity after glaucoma surgery, obscuring the visual axis [Figure 1]a. He underwent an inferonasal optical iridectomy in the left eye with a vitreous cutter. On follow-up, the lens looked like a bitten apple [Figure 1]b. There was a coloboma with broken zonules in the area of the deformity.

Figure 1: (a) Pre-operative anterior segment photograph of the eye showing central corneal opacity obscuring the visual axis. (b)Three-month post-operative picture of the eye showing localized concavity in the lens contour (yellow arrow) and pupillary margins post optical iridectomy (white arrows)

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Case 2

An 8-month-old baby (born at a gestational age of 28 weeks) was diagnosed with right eye buphthalmos 5 months following a scleral buckle surgery. He had previously presented at 3 months of age with rhegmatogenous retinal detachment in the right eye, for which he underwent a scleral buckle with inferotemporal cryopexy. No lens abnormality was noted during surgery [Figure 2]a. We suspected Stickler's syndrome, but the systemic evaluation showed no abnormality, and the caregivers did not consent for genetic testing. Five months following surgery, the baby presented with a cloudy cornea and buphthalmos in the operated eye [Figure 2]b. The child had already undergone a scleral buckle explant 2 months prior to this for the suspicion of developing buphthalmos. We noted a localized lens coloboma in the inferotemporal quadrant during examination under anesthesia (EUA) [[Figure 2]c, white arrow]. This was also the area of the primary break and cryopexy [Figure 2]d. Focal lenticular opacities were also noted [[Figure 2]c – yellow arrow].

Figure 2: (a) Anterior segment photograph of the right eye during the scleral buckle surgery showing no evidence of the lens coloboma. Note the gray retinal detachment visible behind the lens. (b) Right eye buphthalmos and corneal haze noticed 5 months after scleral buckling surgery. (c) Surgeon's view of the right eye during EUA showing the area of the zonular absence and the flattened lens margin (white arrow) in the inferotemporal quadrant of the right eye and focal lens opacity (yellow arrow). (d) Fundus photograph of the right eye showing the scar of cryopexy in the inferotemporal quadrant (green arrow) and the attached retina

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 :: How to Identify? 

Subtle acquired lens colobomas are likely to be missed on examination as they may not get noticed under the peripheral iris, and zonular injuries during ocular surgeries may be missed. A thorough ophthalmic examination with a dilated pupil is necessary in the post-operative period.

 :: Mechanism of Development of Acquired Lens Colobomas and How to Prevent it? 

In the first case, the coloboma most likely occurred because of accidental zonular injury at the time of the optical iridectomy. Abnormally stretched zonules may also have been an underlying pre-disposition. Care while doing an iridectomy with the liberal use of a cohesive visco-elastic substance between the iris and lens may help avoid this complication. In the second baby, the coloboma may have arisen secondary to an accidental zonular injury during retinal detachment surgery and the cryopexy procedure. The other possible reason could be the development of coloboma because of zonular stretching secondary to buphthalmos development after scleral buckling as reported by Dhingra et al.[1] Under conditions of extreme stretching such as buphthalmos, lens zonules may eventually rupture and leave the lens edge un-taut. Such lens edges then shrink and develop a localized concavity or acquired lens coloboma. An acquired lens coloboma in secondary buphthalmos is not hitherto reported, but it is important to keep this possibility in mind while planning the follow-up schedule for buphthalmic eyes.

Declaration of patient consent

The authors certify that appropriate patient consent was obtained.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 

 :: References 
1.Dhingra D, Tekchandani U, Pandav SS, Kaushik S. Neglected congenital glaucoma with lens coloboma. J Glaucoma 2019;28:e140-2.  
    2.Duke-Elder S. Anomalies of the lens: Congenital Deformities, Normal and Abnormal Development System of Ophthalmology. Vol 3. Henry Kimpton; 1964, 706-8.  
    3.Gupta G, Goyal P, Malhotra C, Jain AK. Bilateral lens coloboma associated with Marfan syndrome. Indian J Ophthalmol 2018;66:1192.  
[PUBMED]  [Full text]  4.Thapa BB, Singh R, Ram J, Kumar A. Lens coloboma in one eye and ectopia lentis in the other eye of a patient with Marfan syndrome. BMJ Case Rep 2014:bcr2014207112.  
    
  [Figure 1], [Figure 2]