|Year : 2014 | Volume
| Issue : 3 | Page : 150-152
Case of isolated bilateral coloboma of the lens
Vipul Bhandari, Ameya Ingawale, Jagadeesh Kumar Reddy
Department of Cornea, Sankara Eye Center, Coimbatore, Tamil Nadu, India
|Date of Submission||07-Sep-2013|
|Date of Acceptance||07-Sep-2013|
|Date of Web Publication||16-Aug-2014|
Dr. Vipul Bhandari
Sankara Eye Center, Sathy Road, Coimbatore, Tamil Nadu
Source of Support: None, Conflict of Interest: None
A 52-year-old male presented with gradually progressive painless diminution of vision in both eyes since two years. There was no history of trauma, and family history was non-contributory. Ocular examination revealed a vision of 6/60 in both eyes improving to 6/36 with pinhole and bilateral colobomata of the crystalline lens along with nuclear cataract in both eyes. The edges of the colobomata were irregular and notched. The fundus examination was normal. A lens extraction was done by a temporal section small incision cataract surgery and an iris claw lens implanted after an automated vitrectomy. The post-operative vision was 6/18 improving to 6/6 in both eyes.
Keywords: Cataract, iris claw, lens coloboma
|How to cite this article:|
Bhandari V, Ingawale A, Reddy JK. Case of isolated bilateral coloboma of the lens. J Clin Ophthalmol Res 2014;2:150-2
This is an unusual case of bilateral lens coloboma located inferiorly without any iris abnormality and no retinochoroidal coloboma. We present this rare case of isolated bilateral lens colobomata. Unlike most of the cases reported earlier, ,, our case is not associated with colobomata of other ocular structures, other ocular developmental anomalies, Marfan's syndrome or other systemic conditions. Moreover, this patient had no amblyopia. The purpose of this report was to report this rare presentation of bilateral lens colobomata and the good prognosis associated with appropriate management of the case.
| Case Report|| |
A 52-year-old male presented with gradually progressive painless diminution of vision in both eyes since two years. There was no history of trauma, and family history was non-contributory. The systemic examination was normal. Ocular examination revealed a vision of 6/60 in both eyes improving to 6/36 with pinhole and bilateral colobomata of the crystalline lens. The edges of the colobomata were irregular and notched; the lenses showed nuclear cataract grade two in both eyes [Figure 1] and [Figure 2]. The colobomata were present inferiorly. A few irregularly arranged zonules were seen attached to the coloboma areas. The iris was normal with no abnormality in its architecture, and gonioscopy showed normal architecture of the angle structures. The fundus examination was normal, except for a tessellated background. There were no colobomas seen in the posterior segment, which was examined with scleral indentation and indirect ophthalmoscopy with a 20D lens.
The arm span and height were within normal limits for age and ethnicity. The cardiovascular examination including echocardiography revealed no abnormalities. The blood and urine homocysteine levels were normal.
An automated keratometry and axial length measurement was done, and intra ocular lens (IOL) power calculation for an iris claw lens was done with an A constant of 117.5. A lens extraction was done in both eyes by a temporal section extra capsular small incision cataract surgery. An iris claw lens was implanted after an automated vitrectomy. The post-operative vision [Figure 3] was 6/18 improving to 6/6 and N6 with +2.5 D in both eyes. It is presumed that as the colobomata were away from the visual axis, being bilateral and no associated retinal or choroidal coloboma, the resultant lenticular astigmatism did not result in significant amblyopia leading to 6/6 vision post-operatively
| Discussion|| |
A lens coloboma is characterized by its notching at the equator.  Colobomas of the lens are divided into typical colobomas (those that occur at the site of the embryonic fissure) and atypical colobomas (not occurring at the site of embryonic fissure).  A lens coloboma represents an incomplete lens formation due to failure of the fetal fissure to close completely and is thus usually inferonasal.  A lens colobomas associated with a deficiency or absence of the zonules at that site. , A segmentally defective or absent development of the zonules results in a coloboma of the lens secondary to the flattening of the equator in the region of the zonular defect. There is no actual loss of lens substance. The lens assumes a more spherical shape in that region, which is thought to be the cause of high astigmatism. 
Lens coloboma is often a misnomer and might better be called coloboma of the zonules or of the ciliary body, as the process actually involves the segmental notching and contraction of the lens due to an absence of the zonules in that location.  The zonules fail to form in the anterior secondary vitreous or the marginal bundle of Druault during the 3 rd -4 th month of gestation, due either to the failure of condensation and differentiation of the vitreous substance or to the failure of the lens to induce such changes. 
Lensectomy with scleral fixation of the IOL is another option with fewer incidences of posterior capsule opacification, but late dislocation of sclera-fixated IOL has been reported after 7-14 years.  Price et al. reported prolene suture degradation and cracking.  Tilting of the sclera sutured IOL and erosion of the prolene suture are well-known complication of this technique.
The case report is unusual because of bilateral coloboma without iris abnormality and posterior segment colobomas. Unlike our case, previous cases reported were associated with Marfan's syndrome or other systemic association.
| References|| |
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[Figure 1], [Figure 2], [Figure 3]