Posterior dislocation of lens material can occur after trauma, surgeries or in certain conditions like Marfans syndrome where the lens is subluxated in view of zonular dehiscence or weakness. History and clinical examination usually reveal the causative pathology.
In case of trauma, coexisting damage to the different structures of the eye must be assessed before making the treatment decisions. Similarly, in post operative cases, the condition of cornea, intraocular pressure(IOP) and presence of intraocular inflammation is noted. Any incidental findings like vitreous haemorrhage or retinal detachment is also noted. In case of pre existing pathologies like Marfan’s syndrome, homocystinaemia and Weil-Marchesani syndrome a thorough systematic evaluation is essential before making the decision to operate.
Procedure:
After ensuring that the patient is systemically stable, a decision to operate is made after ensuring that the cornea is clear enough for visibility and the IOP is under control. Surgery usually involves vitrectomy to ensure that the lens matter which is dislocated is free from any form of vitreous adhesions followed by removal of the lens material. The procedure is usually accompanied by the placement of a secondary intra ocular lens either on the remnant capsular support or a sclera fixated intraocular lens in the absence of adequate capsular support.
Intraocular Lens dislocation (IOL dislocation): Posterior dislocation of IOL can occur during placement of IOL during surgery or after surgery either due to trauma or due to weakening of zonules as in case of pseudoexfoliation. In case of trauma or weakening of zonules, the patient notices a decrease in vision in the concerned eye. Examination reveals aphakia with a posteriorly dislocated IOL. The nature of IOL (fodable/ rigid, Single piece or 3 piece) is noted. The doctor also looks of r the presence of associated findings like vitreous haemorrhage, incarceration of IOL in vitreous or retina, retinal detachment.
Procedure:
Operation is done after ensuring a good visibility. The IOL is first cleared of any associated vitreous traction by vitrectomy. A sclera tunnel of adequate size is created in order to explants the IOL. The IOL is slowly lifted from the vitreous cavity after the surgeon is satisfied that there is no remnant vitreous traction. The IOL is slowly eased into the anterior chamber and then delivered out through the scleral tunnel. In case of a 3 piece IOL, the same lens can be used as a secondary IOL in presence of capsular support. In the absence of capsular support, a sclera fixated IOL is placed.