surgical intervention or a parental decision to decline surgery. Thirty of 61 operated eyes (49.2%) had an intraocular lens implanted and 31 (50.8%) were left aphakic. Of those patients receiving an intraocular lens, 3/30 (10%) received an anterior chamber lens and 27/30 (90%) received a posterior chamber lens (in the ciliary sulcus or within the capsular bag).All patients underwent aggressive amblyopia therapy (after contact lens fitting or spectacle correction in the aphakic group) following surgery. The authors reported that 9/60 (15%) operated and evaluated eyes (6 of these 9 eyes were pseudophakic) as opposed to only 2/27 (7.4%) nonoperated eyes, achieved 6/15 or better vision. Vision of 6/60 or better was obtained by 22.2% of the operated eyes and 25% of the nonoperated eyes. The authors indicated that a selection bias of including more eyes with residual potential for vision in the nonoperated group may account for the higher proportion of eyes achieving 6/60 or better vision. Further analysis of the patients who underwent intraocular lens implantation showed that, 20% of eyes achieved 6/15 or better vision and 33.3% achieved 6/60 or better vision in this group. Among the aphakic eyes, only 18.77% of the eyes obtained 6/60 or better vision. No light perception vision was the final result in 26/87 eyes (36.7%) (10/27 nonoperated and 16/60 operated eyes). Interestingly, within the operated group of eyes that had no light perception, there were four times the number of aphakic eyes compared to pseudophakic eyes (43.3 vs. 10%). The anterior and posterior PFV were associated with higher rates of useful vision of 6/60 or better than the combined type (13 of 29–44.8%, 7 of 28–25%, and 1 of 30–3.3% in the posterior, anterior and combined types respectively). Poor cosmesis defined by the investigators as extreme microphthalmia or buphthalmos, and/or decompensation of the cornea with extensive calcific deposits, was noticed more in the aphakic (12/31– 38.7%) and the nonoperated patients (10/28–35.7%) than the patients who were pseudophakic (5/30–16.7%). In this series, overall 15.3% of patients developed glaucoma (aphakia 22.6%, nonoperated 11.8%, and pseudophakia 8.3%). The authors concluded that surgical intervention along with intraocular lens implantation may help in the surgical rehabilitation of patients with PFV without significantly increasing the risk for glaucoma and poor cosmesis. The possibility of selection bias in determining which eyes underwent intraocular lens implantation should also be considered when interpreting these results.

8.4  Practical Surgical Issues

In general, the complexity of the disease determines the prognosis. Surgery is most successful at treating isolated problems in either the anterior or posterior segments. Indeed quite good outcomes result from selected cases of posterior disease in which both lens clarity and macular function may be obtained. Eyes with significant combined anterior and posterior disease are less likely to end with favorable outcomes. For example, eyes with retrolental masses that involve significant RD are very difficult to repair, and they often require a combination of lensectomy, vitrectomy, and membranectomy. Eyes with severe microphthalmia and disorganized internal structures remain inoperable. Ultimately surgery alone cannot provide success and must be combined with aggressive amblyopia therapy. Amblyopia remains a major cause of blindness in PFV.

Beyond the details of cataract or RD repair, surgical success and failure often turns on the detailed appreciation of the pathoanatomy of PFV. Surgery must accommodate and treat the small pupil from persistent pupillary membrane, anteriorly displaced ora serrata, and abnormal vitreous base. Furthermore, the posterior lens capsule may be weakened or ruptured near the stalk, and the retina may be connected to this stalk anywhere along its path. The stalk’s path may be deviated by strong connections to peripheral retina.

In preparation for treatment, we recommend examination under anesthesia in order to define anatomic relations. Although indirect ophthalmoscopy is the gold standard for the examination of the peripheral retina, the relationships are distorted in a nonlinear manner as one looks obliquely through the condensing lens. Therefore, we suggest use of ultrasound and UMB technology, even in cases in which a satisfactory view may be available.

We begin all our surgical cases with consideration of pupillary dilation. The pupillary dilation determines the exposure of the surgical target, and if the standard drops are inadequate we place a cotton pledget soaked with 2.5% neosynephrine, 1% tropicamide, and 1% cyclopentolate. We discuss the blood pressure with the anesthesiologist prior to placing the pledget as it may occasionally induces blood pressure elevation. We never use 10% phenylephrine. In cases in which the pupil does not respond to maximal dilation we usually find synechiae. We then perform a mechanical

synechiolysis. Using a 12 o’clock paracentesis made with a “superblade,” we gently inflate the anterior chamber with a viscoelastic. Tissue is then separated with a cyclodialysis spatula freeing the iris from the lens surface. In many cases, the release of the pupillary membrane with mechanical lysis of the pupil results in adequate dilation. However, if the dilation is less than 7 mm, we consider using iris retraction hooks. Four hooks widely dilate the pupil. The internal aspect of the corneal wound is placed near the limbus to allow maximal iris retraction. Finally, the viscoelastic utilized for the pupillary maneuvers pushes the lens posterior, which may be helpful for cataract surgery. However, if retina surgery without lensectomy is planned, the viscoelastic in the anterior chamber may be removed, narrowing the anterior chamber in order to move the lens forward. Using this technique one can sharply enter the pars plicata without lacerating the lens.

Both the limbal and pars plicata approaches may be used successfully for removal of the lens. Each has advantages and disadvantages, and the surgeon must decide as a function of case or comfort. One of the disadvantages of the limbal approach is the creation of corneal edema near the keratotomy. This approach also accelerates diffuse corneal edema throughout the case and limits the duration of surgery. The limbal approach is often associated with significant iris manipulation and post-op fibrin formation. On the other hand, the limbal approach does not endanger the retina even in the event it is dragged anteriorly beyond the ora serrata.

Both vitrectomy instrumentation and the irrigation– aspiration tip from standard cataract surgery can be used initially on the lens. Our experience using the vitrectomy probe to aspirate clear lenses has been positive. Using the limbal approach one may irrigate with a 20 gauge bent needle or cannula with one hand and remove the lens with the vitrectomy probe in the second hand. The beveled point of the bent needle may also function as a pick knife to cut the capsular bag to begin the removal of the anterior capsule and carry out synechiolysis. Using the vitrectomy probe with emphasis on aspiration rather than constant cutting allows more complete removal of the lens from the equator. For example, the lens can be engaged and once the port is fully occluded the suction can be increased as high as needed to aspirate the lens (even to 300 mmHg). Once the lens material is aspirated into the probe it can

be peeled from the capsule. Using high aspiration vacuuming, one must be both patient and alert. One must be patient to allow for the soft lens material to slowly aspirate. One must also remain alert because in the event that the vitrectomy probe finishes aspirating the lens and one does not immediately release the pedal, the low viscosity fluid will be very rapidly aspirated and the eye will collapse. Rapid collapse of the eye may cause a miosis, as well as Descemet’s folds and loss of control during surgery. Occasionally, during lens aspiration, a cast of soft lens material will clog the probe; using the cut mode intermittently will prevent this occlusion. Because of the potential for damage, it is important to emphasize that when the lens is not fully engaged in the vitrector port, very high aspiration pressure must be avoided. Finally, if the cast of soft lens material cannot be dislodged in the cut mode, then it can be flushed out using a syringe.

Scleral depression is a critical part of lens removal in children. It is difficult to perform scleral depression using the bimanual technique described above, because it requires three instruments. One solution is to hand off the irrigation to an assistant. Alternatively, one may exchange the needle for a self retaining anterior chamber maintainer. The scleral depressor is centered approximately 9 mm posterior to the limbus and slowly brought forward to reveal the ora seratta, the pars plana, and finally the pars plicata. The peripheral lens material is removed with the vitrectomy probe. Using the microscope, we prefer a small diameter light in order to reduce the amount of reflection and glare off the eye surface. Scleral depression with a cotton tip applicator is effective for many anterior cases, however, its large volume may prevent its posterior positioning in the conjunctiva fornix. Smaller profile depressors allow more posterior positioning in areas of intact conjunctiva. A conjunctival incision may help with depression. Although in an adult we grasp the capsule with forceps and pull it out of the eye, the elasticity and strength of the connection of the infantile zonule may prevent the rupture of the zonule. As a result, the ciliary body and retina may tear with traction on the capsule. Therefore, sharp removal of the peripheral capsule is preferred and scleral depression optimizes this removal. Leaving a ring of capsule and lens material invites fibrosis, inflammation, and cyclitic membrane, which frequently leads to hypotony.

During the removal of the lens material, the “hyperplastic” fibrous tissue needs to be treated. Intraoperative