Title: IOL scaffold in phacoemulsification to prevent posterior capsule tear.

1 Dr. Ashraful Huq Ridoy, 2 Dr. Niaz Abdur Rahman 3 Dr. Mahziba Rahman Chowdhury, 4 Dr. Syeed Mehbub Ul Kadir, 5 Dr. Mahbubur Rahman Chowdhury

Purpose – To prevent posterior capsule tear and evaluate the post-operative outcomes of phacoemulsification with IOL scaffold technique.

Design – Single-center, prospective, interventional, non-comparative, consecutive case series.

Materials and Methods – A total of 17 eyes of 17 patients with morgagnian (04 eyes) and hard (nuclear sclerosis grade – IV of 13 eyes) who had undergone phacoemulsification with IOL scaffold technique to prevent posterior capsule tear in a tertiary clinic. All surgeries were performed by a single surgeon. 6.0 mm optic, acrylic, foldable IOL was implanted in all eyes. The pre- operative and post-operative parameters evaluated were uncorrected distance visual acuity, corrected distance visual acuity, cornea status, intraocular pressure and anterior segment inflammation.

Results – Posterior capsule tear were prevented in all eyes. At 1-month follow- up, a significant improvement was noted in uncorrected distance visual acuity post-operatively (P-value <0.0001) and 6/6 visual acuity achieved in 71% eyes. Corrected visual acuity 6/6 achieved in 18% eyes. Mean post-operative IOP at 1-day and 1-month follow-up without any medication were 12.79 mmHg and 13.06 mmHg respectively. Immediate post-operative grade-2 anterior segment reaction (02 eyes) and minimal corneal edema (03 eyes) noted which were resolved by 1-month.

Conclusion - IOL scaffold provides a safe and effective way to prevent posterior capsule tear in phacoemulsification of morgagnian and hard , with a good visual outcome.

Keywords – IOL scaffold, posterior capsule tear, visual acuity.

1 Consultant Phaco Surgeon, Bangladesh Eye Hospital 2 Vitreo-Retina Consultant, Bangladesh Eye Hospital 3 Consultant Phaco Surgeon, Bangladesh Eye Hospital 4 Consultant, Bangladesh Eye Hospital 5 Consultant Phaco Surgeon, Bangladesh Eye Hospital

Introduction

Phacoemulsification of a morgagnian cataract is associated with a high incidence of posterior capsular rupture and remains a challenge for surgeons regardless of their surgical expertise. The difficulty results from the presence of morphologic changes such fibrous and rigid anterior capsule, lack of cortical support, zonular weakness and a hard nucleus. The high machine parameters used in emulsifying the hard nucleus which predispose the rupture of the floppy posterior capsule. IOL scaffold technique has been used when posterior capsular tear occurs, a 3-piece foldable IOL scaffolds or barriers used to prevent vitreous prolapse and remaining nucleus drop.

A surgical technique that uses an IOL as a scaffold to prevent posterior capsule rupture over the intact, yet lax and floppy posterior capsule before complete or partial emulsification of nucleus is a safe surgery. We aim to evaluate the post- operative outcomes of patients with morgagnian or hard cataract who underwent IOL scaffold technique without posterior capsular tear in phacoemulsification.

Materials and Methods

This is a prospective, interventional, non-comparative, consecutive case series study held in Bangladesh Eye Trust Hospital, Dhaka from August 2017 to November 2017. A total of 17 eyes of 17 patients were selected with morgagnian (04 eyes) and hard (nuclear sclerosis grade – IV of 13 eyes) cataract who had undergone phacoemulsification with IOL scaffold technique to prevent posterior capsule tear. The pre-operative uncorrected distance visual acuity, corrected distance visual acuity, cornea status, intraocular pressure and anterior segment inflammation were recorded. All surgeries were performed by a single surgeon. Peribulbar anesthesia was used. 6.0 mm optic, acrylic, foldable IOL was implanted in all eyes. Shrunken, hard nucleus of the morgagnian cataract 04 eyes, 50% unemulsified nucleus in 02 eyes, 25% unemulsified nucleus or last piece in 09 eyes and some epi-nucleus in 02 eyes were remaining when the scaffold IOL was implanted to prevent posterior capsule rupture. OVD was injected into the anterior chamber and over the nucleus to prevent damage to the corneal endothelium, also under the nucleus and over the posterior capsule before implanting IOL (Figure-1). IOL was implanted in the capsular bag under the remaining nuclear fragments to serve as a scaffold or barrier to prevent posterior capsule tear (Figure-2). Nuclear emulsification is then done in iris plane. The power and vacuum parameters were maintained at low to prevent endothelial damage. The surgery was completed with an intact posterior capsule and in-the-bag IOL in all eyes.

Figure-01: OVD fill-up before implanting IOL.

Figure-2: IOL implanted under the remaining nucleus fragment.

The post-operative uncorrected distance visual acuity on 1-day, 1-month with corrected distance visual acuity on 1-month were recorded and analyzed. Cornea status, intraocular pressure by goldmann applanation tonometer and anterior segment inflammation were recorded in every visit.

Results

With the use of IOL scaffold technique, posterior capsule tear was prevented in all eyes. At 1-month follow-up, a significant improvement was noted in uncorrected distance visual acuity (UDVA) post-operatively (P-value is <0.0001) and 6/6 visual acuity achieved in 71% (12 eyes) (Table-01). Corrected visual acuity 6/6 achieved in 18% (03 eyes). Mean pre-operative IOP were 13.76 mmHg and post-operative IOP at 1-day and 1-month follow-up without any medication were 12.79 mmHg and 13.06 mmHg respectively. Immediate post-operative grade-2 anterior segment reaction (02 eyes) and minimal corneal edema (03 eyes) noted which were resolved by 1-month.

Table-01 (n=17) UDVA Pre-op (eyes) POD day-1 POD month-1 (eyes) (eyes) 6/6 00 07 12 6/9 – 6/12 00 06 04 6/18 – 6/36 01 04 01 < 6/36 16 00 00

Discussions

A Morgagnian cataract is a hypermature lens in which the lens fibers degenerate, creating large accumulations of liquefied lens protein. The liquefied cortex has a floating dense hard nucleus that sinks inferiorly in the capsular bag4,5. And also in hard cataract (nuclear sclerosis, grade IV), hardness of the nucleus warrants the use of higher machine settings during phacoemulsification. Holding the thickened or shrunken nucleus is challenging in an empty capsular bag. Additionally, the vitreous syneresis makes the bag floppy. These factors predispose the patient to posterior capsule tear. The challenge of fear of posterior capsule tear that a surgeon faces during phacoemulsification in Morgagnian and hard cataract can be overcome by IOL scaffold technique. The IOL is also used to protect the posterior capsule in positive vitreous pressure and an unstable chamber.

The technique called “IOL scaffold” to prevent nucleus drop without extending the original corneal incision and use of 3-piece foldable IOL as a scaffold for preventing the nucleus drop after posterior capsular rupture by et al in 20061. There are various techniques to prevent posterior capsule tear in Morgagnian cataracts, described by many authors. Rohit Om Parkash et al described an effective lens scaffold technique technique to prevent posterior capsule rupture in cases of Morgagnian cataract3. We followed same techniques per-operatively. We could not measure specular microscopy anytime.

Conclusions

IOL scaffold provides a safe and effective way to prevent posterior capsule tear in phacoemulsification of Morgagnian and hard cataracts. The technique helps the surgeons to perform phacoemulsification with less complications and with a good visual outcome.

References

1. Kumar DA, Agarwal A, Prakash G, Jacob S, Agarwal A, Sivagnanam S. IOL Scaffold technique for posterior capsular rupture. J Refract Surg 2012; 28:314-315. 2. Luo L, Lin H, Chen W, Qu B, Zhang X, Lin Z, Chen J, Liu Y. -shell technique: adjustment of the surgical procedure leads to greater safety when treating dense nuclear cataracts. PLoS One 2014; 9:e112663. 3. Parkash RO, Mahajan S, Parkash TO, Nayak V. Intraocular lens scaffold technique to prevent posterior capsule rupture in casa of Morgagnian cataract. J Cataract Refract Surg 2017 Jan;43(1):8-11. 4. Spencer TS, Mamalis N, The pathology of cataractsIn: Steinert RF, ed, Cataract Surgery, 3rd ed. Philadelphia, PA, Saunders, 2010; 3-8. 5. Webb L, Gupta M, Mechanism of cataract formation. In:Albert DM, Miller JW, eds, Albert & Jakobiec’s Principles and Practice of , 3rd ed. Philadelphia, PA, Saunders, 2008, 1375-1378.