a 55-year - old male with megalocornea in isolation developed fluctuating visual loss in his right eye , exacerbated by head movements . his best - corrected visual acuity ranged from 20/40 to 20/70 depending upon the head position . a slit - lamp examination of the anterior segment demonstrated clear , compact corneas , with no scarring or deformity of descemet 's membrane . the corneas demonstrated increased horizontal and vertical diameters of 16 and 14 mm , respectively , with keratometry readings of k1 : 40.52  169 , k2 : 41.93  79 . an abnormality of the posterior chamber intraocular lens ( pciol ) capsular bag complex was noted ( fig . an uneventful iol ( sn60wf 17.0d ; alcon laboratories , inc . , fort worth , tex . , usa ) and capsular bag explantation was performed , and the patient was left aphakic . a custom - manufactured aphakic contact lens was used for visual rehabilitation of the patient . after 6 months , the patient developed severe contact lens intolerance , and a surgical option was sought . accordingly , the patient was enrolled in an fda - monitored clinical trial ( nct01547429 ) for the artisan aphakia lens for the correction of aphakia ( secondary ) in adults ( ophtec usa inc . , a 15.0 d lens was chosen based on iol calculations utilizing the holladay 2 formula . the artisan anterior chamber iris claw lens ( acicl ) was implanted as follows : a biplanar 6.5 mm corneoscleral incision was performed . the pupil was constricted with acetylcholine chloride intraocular solution 1:100 to a diameter of approx - imately 3 mm , and the anterior chamber was filled with viscoelastic . the acicl was in - troduced through the incision , oriented in the horizontal plane , grasped with the inserter forceps ( artisan enclavation forceps , do2 - 40 , ophtec usa inc . ) , and enclavated to the iris using an enclavation needle ( artisan enclavation needle , od125 , ophtec usa inc . ) . the viscoelastic was irri - gated from the eye and the incision was closed using 10 - 0 nylon sutures . the postoperative course was complicated by a wound leak and hypotony due to a pathologically thin corneosclera . the patient was brought back to the operating room for a successful surgical wound revision . at 10 months after surgery , the anterior chamber and artisan lens remain in stable condition , without any evidence of intraocular inflammation . manifest refraction , utilizing + 0.75 1.00  165 , yielded a best - corrected visual acuity of 20/30 . megalocornea in isolation is a rare , congenital , bilateral condition that manifests itself via corneal enlargement of greater than 13 mm in diameter , with a normal histology and thickness . males are more commonly affected as the hereditary patterns observed are either x - linked or autosomal recessive . megalocornea has been reported to coexist with other anterior segment abnormalities such as stromal mosaic dystrophy , arcus lipoides , iris anomalies including atrophy of the stroma , miosis , and microcoria ( sometimes referred to as  anterior megalophthalmos ) [ 1 , 2 ] . it has also been associated with systemic diseases such as congenital marfan syndrome , albinism , and neuhauser syndrome . the enlarged corneas are accompanied by an increase in the depth of the anterior segment and posteriorly positioned iris - lens diaphragm , resulting in a relatively shortened vitreous cavity . the anomalous anatomy of the anterior chamber structures , predisposes patients to both crystalline lens subluxation   as well as to dislocate of the iol within a pathologically large capsular bag . traditional methods of treating aphakia in patients with megalocornea involves fitting for aphakic spectacles , aphakic contact lens correction and alternate methods of iol fixation . iol calculations with first - generation lens formulas in these patients can be challenging as predicting the effective lens position may be difficult . the use of newer - generation formulas such as holladay 2   is therefore preferable to take into account , not only for the anterior chamber depth measurement , but also for the white - to - white measurements [ 1 , 5 ] . surgical options for correcting aphakia in these patients , utilizing currently available fda - approved iols , is limited . standard one - piece anterior chamber use is precluded in eyes with enlarged anterior segments as the haptic - to - haptic length of the largest model is 14.5 mm , which would preclude secure anterior chamber angle fixation . patients with megalocornea are also not ideal candidates for the placement of a scleral fixated iol since posterior chamber lenses are limited to 14.5 mm in their overall length   ( 14.0 mm in the united states ) . both sutured as well as nonsutured externalized / intrascleral haptic techniques (  fibrin glued iol ) have been successfully reported for the scleral fixation of a posterior chamber lens within the posterior chamber . both of these techniques are very challenging in eyes with megalocornea due to the enlarged sulcus diameter . many of the available 14.0-mm iols have flexible haptics that can be stretched further than 14.0 mm to potentially fill in the enlarged ciliary sulcus . however , there are concerns regarding the long - term stability of the haptics , as fixating the haptics when stretched beyond their intended dimension puts increased mechanical stress on the fixating sutures or fibrin glue . the stress on the sutures may induce early suture erosion or iol displacement , thus causing lens instability and the possibility of haptic damage , with the late dislocation of the iol . furthermore , the iols haptics were designed to withstand compression within the capsular bag , and not stretching , which may cause biomechanical weakening of the haptics especially at the optic / haptic juncture compromising iol stability . posterior iris fixation of the iol is theoretically also a viable surgical option in the treatment of aphakia in these patients . however , there are significant technical challenges to the use of the mccannel suture technique due to the enlarged anterior segment , small poorly dilating pupils   and 9 - 0 or 10 - 0 prolene sutures with needles of limited length . fixation of an iol to the anterior surface of the iris has significant advantages in these patients . has proposed suturing of a conventional three - piece iol directly to the anterior surface of the iris . anterior fixation of the iol does not require an intervention behind the pupil , thus reducing the risk of a dropped iol especially in vitrectomized eyes . this anterior iris approach of fixating the iol allows for ease of an iol exchange ( in case it should be necessary ) . this approach is not without technical challenges as the limitations of needle length on the appropriate sutures exist . acicl allows the implantation in the absence of capsular support as its fixation does not depend on contact with the anterior chamber angle , ciliary sulcus , or sclera . the implantation within the anterior chamber and the enclavation to the iris stroma eliminates the need for any posterior or anterior suturing , making the procedure very efficient . in the event of a refractive surprise , which , as a result of the abnormal anatomic proportions in eyes with megalocornea , makes the exchange of the acicl easy this is in sharp contrast to performing an iol exchange in a patient with either posterior iris or scleral fixation , where a removal can be at least as difficult if not more difficult than the primary procedure . complications of iol exchange carry the risk of iris damage or iol luxation into the vitreous cavity . the long - term complications of artisan lens implantation include pupil ovalization , disenclavation , and subluxation . our case illustrates that the use of the artisan aphakia iol is well suited for the treatment of aphakia in patients with megalocornea . informed consent has been obtained from the subject and the study protocol has been approved by the institute 's committee on human research . he received noncash equivalents ( e.g. devices at no cost ) from ophtec usa inc .
megalocornea in isolation is a rare congenital enlargement of the cornea greater than 13 mm in diameter . 
 patients with megalocornea are prone to cataract formation , crystalline lens subluxation , zonular deficiencies and dislocation of the posterior chamber intraocular lens ( pciol ) within the capsular bag . a 55-year - old male with megalocornea in isolation developed subluxation of the capsular bag and pciol . 
 the pciol and capsular bag were explanted , and the patient was subsequently implanted with an anterior chamber iris claw lens . 
 an anterior chamber iris claw lens is an effective option for the correction of aphakia in patients with megalocornea .