Sutureless Scleral-Fixated Intraocular Lens Implantation for Refractive Rehabilitation in Eyes With Spherophakia

Abstract

Purpose:

Spherophakia is a rare, debilitating congenital ocular disorder.

Methods:

This institution-based, retrospective, interventional study evaluated medical records of 16 patients with spherophakia with a median age of 19.5 years. Twenty-six eyes underwent scleral-fixated intraocular lens implantation. The technique involved 2 parallel-to-limbus scleral tunnels fashioned using a microincision vitrectomy blade, followed by lensectomy, core vitrectomy, externalization of haptics through 2 separate diametrically opposite sclerotomies, and tucking in of the haptics into the tunnels. Anterior and posterior segment examination, visual acuity, and intraocular pressure (IOP) were noted at baseline and final follow-up.

Results:

Baseline best-corrected visual acuity (BCVA) of all eyes was 0.49 ± 0.51 logarithm of the minimum angle of resolution (logMAR) (Snellen equivalent, 6/18). BCVA of more than 6/60 was present in 28 of 32 (87.5%) eyes, and 13 of 26 (50%) eyes that were operated on had a baseline BCVA of more than 6/18. Postoperative BCVA in 26 eyes improved from 0.43 ± 0.32 logMAR to 0.19 ± 0.21 logMAR (Snellen equivalent, 6/9) (P = .002). Postoperative BCVA was more than 6/18 in 20 of 26 (76.9%) operated-on eyes (P = .046), and all eyes had a final BCVA of more than 6/60. In 20 of 26 (76.9%) eyes, BCVA improved from preoperative status. Postoperatively, spherical equivalent improved from –9.55 ± 5.17 diopters to –0.29 ± 1.45 diopters (P < .001). Apart from 2 patients with Marfan syndrome, 1 with Weill-Marchesani syndrome, and 1 with homocystinuria, the remaining patients had isolated spherophakia. Six eyes presented with an IOP greater than 21 mm Hg, and 50% of these eyes had a final IOP that decreased to less than 15 mm Hg after lensectomy.

Conclusions:

Lensectomy with pars plana vitrectomy and scleral-fixated intraocular lens is an effective method of refractive rehabilitation for patients with spherophakia presenting with visual disability.

Introduction

Spherophakia is a rare, congenital, bilateral disease of the crystalline lens that presents with a smaller, spherical crystalline lens, weak zonules, increased anteroposterior thickness, and high lenticular myopia. ¹ The presence of weak zonules and sometimes the absence of posterior zonule attachment at the lens equator may render the lens a spherical shape and cause instability, making it prone to possible subluxation or dislocation from the patellar fossa. The lens may subluxate anteriorly, inferiorly, or posteriorly, leading to complications like pupillary block glaucoma, inverse glaucoma, and corneal edema. ² Several patients with spherophakia may have additional familial and systemic diseases such as homocysteinemia, Weill-Marchesani syndrome, Marfan syndrome, Alport syndrome, hyperlysinemia, megalocornea-spherophakia-secondary glaucoma, and arrhythmogenic right ventricular dysplasia type 1. ³ Patients with spherophakia may seek treatment because of high lenticular myopia, subluxation of the lens and defective vision, and secondary glaucoma, and lensectomy has been shown to be therapeutic in most cases. ⁴

The most common time of presentation of spherophakia in patients is in early adulthood or adolescence. However, in patients with systemic associations, the disease may present earlier in life. A clinical triad of angle-closure glaucoma, shallow anterior chamber (AC), and high myopia is indicative of spherophakia. Patients may have developed bilateral amblyopia because of uncorrected lenticular myopia since childhood. Although high myopia associated with spherophakia is amenable to correction with glasses or contact lenses, anterior subluxation of the lens, causing pupillary block glaucoma or mechanical angle closure and “inverse glaucoma,” needs immediate attention. ^2,5 Trabecular meshwork crowding if left untreated may lead to chronic pupillary block by formation of peripheral anterior synechiae (PAS). ⁶ If the lens stays in the patellar fossa and intermittently moves into the AC and falls back, repeated vitreous traction may eventually lead to a retinal detachment (RD). ⁶ Spontaneous and posttraumatic dislocation of the spherical lens have been described. In all of these circumstances, lensectomy seems to be an effective all-encompassing surgery.

Additional medical management may be required for eyes with secondary glaucoma. Many of these eyes may have end-stage glaucoma at presentation, and the decision for surgery needs to be individualized, keeping in mind the actual benefit for each patient.

Several methods of refractive rehabilitation of such aphakic eyes have been described for spherophakia eyes, including glasses, contact lenses, AC intraocular lenses (IOLs), iris-fixated IOLs, and scleral-fixated IOLs (SFIOLs). ^{7 -10} To the best of our knowledge, limited data of only a few eyes exist on postoperative outcomes of SFIOL implantation in spherophakia eyes. ^4,10 In this study, we present management and postoperative outcomes of 26 spherophakia eyes with lensectomy and SFIOL implantation.

Methods

This retrospective study was conducted in a tertiary care hospital in South India. We searched the medical records of patients with spherophakia who presented to our center with different clinical requirements and underwent SFIOL implantation and noted their postoperative outcomes. Sixteen patients were included from December 2014 to February 2019. Clinical data collected included their demographic characteristics, family history, chief concerns, physical and ocular examination results, type of surgery performed, and final outcome. Any complications that occurred intraoperatively or postoperatively as well as the chosen management were also recorded. A general physician evaluated the systemic status of each patient.

All participants underwent comprehensive ocular examination including visual acuity (VA) (best-corrected visual acuity [BCVA]) using a Snellen chart at 6 m, intraocular pressure (IOP) using a noncontact applanation tonometer (Topcon Corp), slit-lamp biomicroscopy for anterior segment, dilated fundus examination, dynamic retinoscopy for refractive status, AC depth, and white-to-white measurement using the IOLMaster (Carl Zeiss Meditec). Patients with poor glow or corneal edema underwent a B-scan ultrasonography. Biochemical tests were performed to diagnose homocystinuria whenever clinical suspicion was present. Postoperative examination for BCVA, IOP, refractive status, anterior segment, and fundus was performed regularly until the final follow-up.

Protocol for Pars Plana Vitrectomy, Lensectomy, and SFIOL Implantation

Eyes underwent 23-gauge (G) pars plana vitrectomies (PPVs) along with lensectomy and SFIOL implantation. Strict asepsis was maintained for all surgical procedures and all operating surgeons followed a uniform surgical technique. Conjunctival peritomy of superior 270 degrees was performed and 2 partial-thickness scleral pockets were created, 180 degrees apart, at a distance of 1.5 to 2 mm away from the limbus with the help of a 23-G microvitreoretinal blade. These pockets were made parallel to the limbus to contain the IOL haptics. After performing the lensectomy and core vitrectomy, a 3-piece nonfoldable IOL (Aurolab) was placed into the AC through the tunnel. The leading haptic tip was clasped with the 23-G end of a grasping forceps (Alcon Laboratories), pulled out through the sclerotomy, and tucked into the scleral pocket. The second haptic was then similarly grasped, pulled out through the second sclerostomy, and tucked into the scleral pocket. Lens centration was checked by adjusting the amount of haptic in each pocket. The procedure is demonstrated in Figure 1.

Figure 1.

(A and B) Two partial-thickness scleral pockets created 180 degrees apart and 1.5 to 2 mm away from the limbus with the help of a 23-gauge microvitreoretinal blade. (C and D) Tucking in of haptics into scleral tunnels.

At the end of all surgical procedures, ofloxacin 0.3% eye ointment was put in the conjunctival cul-de-sac. All patients were routinely prescribed a topical combination therapy of antibiotics (ofloxacin 0.3%) and steroid (prednisolone acetate suspension 1%) for 6 weeks. Postoperatively, slit-lamp examination was performed at each follow-up to assess corneal clarity, AC integrity, and status of the IOL. IOP was measured using a noncontact applanation tonometer, and the refractive status of patients was also checked by retinoscopy. Any postoperative complications seen in any of the eyes were treated accordingly.

Results

Demographics and Clinical Presentation

This study evaluated 16 patients with spherophakia, and the age at presentation ranged from 9 to 49 years (median, 19.5 years). Nine patients were younger than 20 years, and none of them were younger than 10 years. Eight were male and 8 were female. Patients presented with complaints of diminution in vision (n = 14) and pain (n = 2). All patients had bilateral disease at presentation, and 12 eyes had some form of subluxation of the crystalline lens present. None of the lenses were cataractous. Anterior dislocation into the AC was seen in 2 eyes, and a shallow AC was present in 12 eyes. Iridodonesis was seen in 13 eyes, with frank phacodonesis in 8 eyes. VA in all 32 eyes was documented.

Baseline BCVA of all eyes was 0.49 ± 0.51 logarithm of the minimum angle of resolution (logMAR) (Snellen equivalent, 6/18). Uncorrected VA of less than 6/60 was present in 27 (84.4%) eyes, with the mean spherical equivalent at presentation being –9.55 ± 5.17 diopter sphere. A BCVA of more than 6/60 was present in 28 of 32 (87.5%) eyes; however, only 17 of 32 (53.1%) eyes had a BCVA better than 6/18. One eye presented with severe corneal edema secondary to inverse glaucoma due to anterior dislocation of the lens into the AC and had a BCVA of only 6/180. Light perception BCVA was present in 1 eye that had end-stage glaucomatous optic atrophy with a relative afferent pupillary defect.

The average axial length of the eyes was 22.95 ± 2.51 mm with an average white-to-white diameter of 12.59 ± 0.5 mm. Four eyes had an axial length of more than 24 mm, and 2 of these eyes were in a patient with Marfan syndrome.

Family History and Systemic Associations

Three patients had a history of similar illness in the family. One patient’s elder sister had a history of bilateral lensectomy performed at age 8 years, and the same patient was also diagnosed with homocystinuria by a pediatrician and started on systemic pyridoxine therapy. Two patients had a history of a seizure disorder since childhood and were on medications. Marfan syndrome was diagnosed in 2 patients (after cardiac evaluation) and Weill- Marchesani syndrome in 1 patient. The remaining patients had isolated spherophakia without any familial associations. The patients with Marfan syndrome also had axial myopia apart from lenticular myopia.

Surgical Outcomes

Twenty-six eyes underwent crystalline lens extraction followed by SFIOL implantation. None of the eyes remained aphakic after surgery. Of the eyes that underwent operation, baseline BCVA was 0.43 ± 0.32 logMAR. Thirteen of 26 (50%) eyes had a baseline BCVA of more than 6/18. Postoperative BCVA improved to 0.19 ± 0.21 logMAR (Snellen equivalent, 6/9) (P = .002). Postoperative BCVA was more than 6/18 in 20 of 26 (76.9%) eyes, which was significantly different from baseline (P = .046). Moreover, all eyes had final BCVA of more than 6/60. In 20 of 26 (76.9%) eyes, the BCVA improved from the preoperative status. Postoperative spherical equivalent was –0.29 ± 1.45 diopter sphere (P < .001).

The average follow-up duration of the cases was 17.0 ± 11.3 months (median, 13.5 months; range, 10-48 months). In patients undergoing bilateral surgery, the fellow eye surgery was performed after a gap of at least 1 month after the first eye. Six eyes underwent no surgical procedure; however, 4 of these eyes underwent peripheral iridotomy with Nd:YAG laser.

Complications of Surgery

No intraoperative complication occurred in any of the cases. One eye developed IOL decentration 1 week postoperatively, for which a minor adjustment of haptics was performed in the operation room. The same eye developed cystoid macular edema that was intractable to anti-inflammatory medications and had to undergo intravitreal injection of an antivascular endothelial growth factor drug.

Glaucoma Management

A diagnosis of secondary glaucoma was made in 15 eyes (Table 1). Eyes that underwent lensectomy had final IOPs lowered to less than 15 mm Hg. Antiglaucoma medication was started for eyes presenting with a raised baseline IOP, and 4 eyes received 3 or more antiglaucoma drugs. In total, 20 eyes received a peripheral iridotomy, including the fellow eyes in cases in which 1 eye received surgical intervention later. One eye with secondary glaucoma presented with near total optic nerve head cupping with pressures controlled by maximum topical antiglaucoma medication along with systemic acetazolamide. A combined lensectomy with SFIOL and tube shunt implantation procedure was performed in this eye, and IOP was postoperatively controlled at final follow-up without any medications.

Table 1.

Clinical Presentation With Glaucoma in the Series.

	No.
Total eyes with glaucoma	15
Presenting intraocular pressure > 21 mm Hg	6
Eyes receiving > 3 antiglaucoma drops	4
Lensectomy performed	3
Advanced glaucomatous optic nerve cupping at presentation	10

Discussion

Refractive rehabilitation of postlensectomy aphakic eyes has been a point of discussion recently. Primarily the type of IOL depends solely on the surgeon’s choice and expertise, and different modalities have been described in the literature. Angle-supported AC intraocular lenses (ACIOLs) and iris-enclavated lenses have commonly been used. ⁷ Historically, corneal endothelial cell loss, PAS formation, and secondary glaucoma due to chronic AC irritation associated with angle-supported ACIOLs have led surgeons to be skeptical of their widespread use. ¹¹ However, Khokhar et al have documented the safe implantation of modern ACIOLs and presented long-term follow-up outcomes in spherophakic eyes. ⁴

Recently iris-supported ACIOLs have been used in pediatric patients with aphakia with good visual outcome and no significant effect on the endothelium; however, concerns remain regarding chronic uveitis leading to PAS and glaucoma, iris chaffing, and pupillary constriction. ^8,9,12 Placing a posterior chamber IOL in the capsular bag is controversial because the zonules in spherophakic eyes are developmentally weak, and there is a possibility of the bag-lens complex dropping into the vitreous. ¹³ A dual-support technique with a capsular tension ring and segment has been described in a case of spherophakic eyes to overcome zonular weakness. ¹⁴

SFIOLs eliminate angle-related problems and have been considered an effective option for treatment of such aphakic eyes. Several scleral-fixation techniques have been described over the years. Sutured SFIOLs may suffer from various complications like suture breakage, decentration of the IOL, exposure of the haptic by conjunctival erosion, RD, suprachoroidal hemorrhage, and endophthalmitis. ^15,16 McAllister and Hirst in a long-term study on SFIOLs reported ocular hypertension in 30.5% eyes, suture breakage in 6%, RD in 4.9%, cystoid macular edema in 7.3%, and suture erosion in 1.2%. ¹¹ Major causes of suture-related problems are suboptimal placement and/or usage of less-durable suture materials. To avoid the direct contact of conjunctiva and sutures, scleral flaps were described that would cover the knots. Scleral pocket creation was first described by Hoffman and colleagues. ¹⁷ A sutureless technique of haptic burial by fashioning 2 diametrically opposite scleral tunnels with a 24-G cannula was described by Scharioth et al. ^18,19 Agarwal and colleagues used fibrin glue in the bed of a scleral flap to close the flap over the haptic, forming a tight seal. ²⁰

In our series mean postoperative VA after SFIOL improved significantly in all operated eyes (P = .002), and the final BCVA was more than 6/18 in 76.9% compared with 50% at baseline. This apparent improvement in BCVA may be due to the minification factor present in patients because of usage of thick meniscus lenses for correction of high myopia. Moreover, the SFIOL after placement may be closer to the nodal point of the eye, reducing spherical aberrations, thereby enhancing the BCVA. Lensectomy also seemed to lower the IOP in eyes with increased IOP and can be considered as synergistic to glaucoma management in these eyes, as has been previously described. ⁴

Although the retrospective design of this study comes because of its own limitations of heterogeneity of data recording with variability in periods of follow-up, the study is unique in that, to the best of our knowledge, this is the largest series of spherophakic eyes managed with SFIOL to date. We have a clinical presentation of 32 spherophakia eyes and managed 26 eyes by PPV and SFIOL implantation with good outcome. Because spherophakia is a rare ocular disease, designing prospective studies is difficult. Moreover, because of variability in the clinical presentations of such patients, it is difficult to uniformly recruit patients with similar inclusion criteria in a small period of time for a longitudinal study. In this regard, retrospective studies like ours may provide valuable data regarding management outcomes.

Conclusions

In summary, apart from providing effective and safe refractive rehabilitation in spherophakia eyes, the sutureless SFIOL technique we describe may help reduce surgical costs and time, although it may be associated with a learning curve.

• Spherophakia is a rare, debilitating congenital disease and leads to vision loss due to myopia, lens dislocation, and glaucoma complications.

• Treatment may be targeted toward lens complications or glaucoma with optimum results; however, there is no consensus regarding the perfect choice for preferred type of IOL.

• To the best of our knowledge, this is the largest cohort of spherophakia eyes operated on for PPV, lensectomy, and SFIOL implantation, with optimum surgical results and minimal complications.

• SFIOL eliminates angle-related complications due to AC lenses and risk of pigment dispersion in iris-fixated lenses and seems to be an appropriate posterior chamber lens choice in patients without adequate capsular support.