Coloboma

Coloboma is a problem which occurs in the back of the eye. It is a lack of the fusion of the elements of the optic nerve, the retina or anteriorly into the iris and the lens. It can be in the front of the eye which means we can get a coloboma in the iris from the lack of fusion. 

A typical iris coloboma is in the inpharaoh nestled quadrant. The abnormally developed sphincter extends to the base of the iris and hence results in an ectopic pupil. A collabo mattes lens is due to defective or absent segments of zhonya's resulting in a notch in the lens. It is a misnomer in that there is no actual lenticular substance missing intact, so news are often seen in this area. It may occur along with the ciliary body coloboma.

Cataract often develops at a younger age in coloba matis lenses. The extent of the ocular structures affected by the coloboma should be determined preoperatively. The degree of posterior segment involvement should be confirmed by B scan preoperative IOL power assessment is difficult in eyes with coloboma extending to the macula and optic disc due to high variability in axial length measurements because of irregularities in the posterior globe shape small changes in the orientation of the ultrasound probe may result in different measurements surgery is done using a capsular tension ring using which forms the capsular fomix. The CTR protects against capsular fornix aspiration consecutive zone ela dialysis irrigation fluid flowing behind the capsule vitreous herniating into the anterior chamber. IOL D centration and capsular phimosis when Sonia lured essence is large and extend capsular bag shrinkage resulting in IO LD centration and pseudo fake Adonis's may occur even after a successful surgery with capsular ring modified versions of an endo capsular ring incorporate fixation elements that allow the surgeon to suture the ring to the steel wall to the ciliary sulcus without violating the capsular bag. The hook is kept in the area of dialysis and is pulled peripherally using a transdermal fixation suture to counteract capsular bag descent raishin and tilt.

In severe cases two such rings or two hooked model can be used. Giant retinal tears also occur with isolated lens coloboma a large optic IOL is advisable for better visualization of the posterior segment which is at greater risk of retinal detachment aberration free or aspheric IO ELLs may also be preferable in these eyes to decrease the effect of lens descent raishin on vision. Glaucoma may sometimes be associated and here a normal trabeculectomy with fake-o emulsification and IOL implantation is carried out. 

Congenital coloboma is often associated with Mycroft Almia and nystagmus phacoemulsification and these microf tonic eyes is often a challenge considering the relatively large size even small gauge instruments assume in these tiny eyes. An extra extra capsule catarct extraction is is therefore off from the best option. Post-operative IOL edge glass syndrome and monocular diplopia are potential complications. Eyes with congenital coloboma and cataract are at greater risk for surgical complications given the abnormal development of the scanner UVA and zhong use the structural integrity of the globe may be compromised increasing the risk of vitreous loss during cataract extraction. 

Using a vanna's scissors two small cuts are made to the inferior I distinct on either side to peripheral corneal stab incisions are made on either side of the coloboma. A straight needle on a 10-0 prolene suture is passed through the para synthesis and then edges of the central iris leaflets exiting to the distal incision it is then tied with a modified zipser sliding knot technique Irish tissue peripheral and central to the first knot is also closed in a similar technique to get around. Satisfactory pupil a cosmetic contact lens is another alternative for monocular diplopia iris colobomas may also be acquired and a coloboma shield may be used to handle the defect post tramatic large defects in the iris or extensive pseudo colobomas can be handled by placing an IRA dia rings two rings are placed so that the interspaces of one are covered by the shield's of the other. Coloboma with Mycroft almaas may also be associated with multi system developmental defects. The charge syndrome may sometimes be associated with coloboma.

Retinal choroidal colobomas may be small and peripheral or large involving the optic disc and macula eyes with retinal colloidal colobomas are at increased risk of reg meta genus retinal detachment surgery is based on performing a pass Glenna vitrectomy followed by isolating the coloboma from the rest of the retina by retina pixie around the collar boma margin and internal tamponade with silicone oil. The Morning Glory disc may be associated with congenital forebrain anomalies other craniofacial associations include cleft lip and palate agenesis of the corpus callosum defects in the sella turcica and endocrine dysfunction the eyelids may also develop a color Burma which present as a quadrilateral or triangular gap broadest at the lid margin upper lid colobomas are common and these can occur as part of the Goldenhar syndrome and lead colobomas are often associated with the Treacher Collins syndrome these occur most frequently at the junction of the middle and lateral thirds lids can be repaired by a pentagonal lit defect suturing or if more extensive may require lateral canthal Isis tencel's flap or other lid reconstruction techniques.