Flap motility sign helps determine extent of anterior capsular tear
Surgeons can decide which steps to take based on the sign, reducing complications and resulting in better outcomes.
Flap motility sign helps to ascertain the extent of anterior capsular tear and determines the endpoint of safe phacoemulsification. In this month’s column, I would like to invite Drs. Rohit Om Parkash, Shruti Mahajan and Tushya Om Parkash to explain this new sign that they have discovered.
Amar Agarwal, MS, FRCS, FRCOphthOSN Complications Consult Editor
Anterior capsular tear extension to the periphery occurs primarily while performing capsulorrhexis. However, it can occur during ophthalmic viscosurgical device injection, hydro procedure, phacoemulsification, cortical cleanup, secondhand instrument maneuvering and IOL implantation. There is a propensity for capsulorrhexis runaway in cases with intumescent and pediatric cataracts, cataracts with weak zonules, shallow anterior chambers, compromised red reflex and increased vitreous pressure.
If the anterior capsular tear remains pre-equatorial, phacoemulsification can be completed successfully. The majority of anterior capsular tears remain pre-equatorial and do not extend beyond the equator because of the barrier created by the relatively thickened anterior capsule in the mid-periphery and the zonular attachment on the peripheral anterior capsule.
However, the tear can extend beyond the equator to the posterior capsule, resulting in posterior capsule rupture. The classical signs of posterior capsule rupture are sudden deepening of the anterior chamber, pupil snap sign, increased fundal glow, reduced followability, nucleus tilt and nucleus drop. The shortcomings of these signs are that they do not appear instantaneously, and there is a window period for these signs to appear subsequent to the posterior extension of the peripherally extended anterior capsular tears. Moreover, depending on the expertise, the surgeon may take time to appreciate the signs of posterior capsule rupture. Therefore, the shortcomings in early appreciation of the posterior extension of the tear predispose to complications such as nucleus drop and associated sequelae. Furthermore, there is no definite intraoperative sign to appreciate the extent of anterior capsular tear. Subsequently, there is always a surgical dilemma of whether to continue with phacoemulsification or to convert to extracapsular cataract extraction or manual small-incision cataract surgery.
Flap motility sign
Flap motility sign (FMS), a new sign of posterior capsule rupture in peripherally extended anterior capsular tears, helps the surgeon to determine the extent of the anterior capsular tear. In the FMS, pre-equatorial tears have everted fluttering flaps, (Figure 1), while post-equatorial wraparound tears are non-fluttering, inverted and lie flat on the nuclear contents (Figure 2).
In the FMS, the pre-equatorial flap is fluttering, motile and everted. The short arm of the flap moves around the pivot formed at the endpoint of the capsular tear in response to pressure gradient dynamics of the anterior chamber (Figure 3). The fluttering and everted nature of the flap reassures the surgeon of the pre-equatorial extent of the runaway tear. Phacoemulsification can be carried out with conviction using a safe phaco technique.
While doing phacoemulsification, a close watch is kept on the motility of the flap. The surgeon who is accustomed to surgical gaze on the nuclear pieces while performing phacoemulsification needs to add monitoring of the flap of the capsular tear in his surgical protocol by widening his visual gaze (Figure 4). When the anterior capsular tear extends beyond the equator, the flap has a different characteristic. It is inverted and lies flat on the nucleus. It is nonresponsive to the fluid dynamics and is non-fluttering.
The non-fluttering and inverted nature of the flap can be described with this explanation: During phacoemulsification of the nucleus, there is a highly pressurized anterior segment and the relatively lesser pressurized posterior segment. With the runaway tear extending to the posterior capsule, the barrier between the two compartments is broken. The contents of the bag move posteriorly because of higher IOP in the anterior segment, lenticular content weight with increased capsular bag volume and negative pressure of the posterior segment (Figure 5). The posteriorly displaced wraparound tear moves the corresponding anterior part of the tear posteriorly. The posterior pull results in a flat and inverted taut flap that ceases to be responsive to anterior chamber fluidics and stops fluttering.
FMS is a conclusive sign to ascertain the endpoint of safe phacoemulsification. While carrying out a safe phacoemulsification technique in pre-equatorial tears, the moment the flap stops fluttering and becomes flat, we immediately realize the post-equatorial extension of the tear. This happens before the appearance of classical signs of posterior capsule rupture. The phacoemulsification is immediately stopped. The anterior chamber at this point should not be allowed to collapse, as that can further extend the wraparound tear. The anterior chamber is filled with a viscodispersive OVD before removing the phaco handpiece. The conversion to extracapsular cataract extraction or manual small-incision cataract surgery is undertaken. The early conversion, much before the appearance of the classical signs of posterior capsule rupture, helps minimize complications associated with posterior capsule rupture.
The flap motility sign helps to decide the site of IOL implantation. The fluttering and everted nature of the flap helps in deciding in-the-bag IOL implantation. With the wraparound post-equatorial tear, IOL implantation in-the-bag is avoided.
Flap motility sign is a landmark sign in phacoemulsification surgery in the presence of anterior capsular tears. FMS, a boon for surgeons with differing degrees of expertise, ushers in decisive surgical steps, and the complications associated with anterior capsular tears are reduced, resulting in better patient outcomes.
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- Amar Agarwal, MS, FRCS, FRCOphth, is director of Dr. Agarwal’s Eye Hospital and Eye Research Centre. Agarwal is the author of several books published by SLACK Incorporated, publisher of Ocular Surgery News, including Phaco Nightmares: Conquering Cataract Catastrophes, Bimanual Phaco: Mastering the Phakonit/MICS Technique, Dry Eye: A Practical Guide to Ocular Surface Disorders and Stem Cell Surgery and Presbyopia: A Surgical Textbook. He can be reached at 19 Cathedral Road, Chennai 600 086, India; email: email@example.com; website: www.dragarwal.com.
- Rohit Om Parkash, MBBS, MS, Shruti Mahajan, MBBS, MS, and Tushya Om Parkash, MBBS, MS, can be reached at Dr. Om Parkash Eye Institute, 117-A, The Mall, Amritsar-143001, Punjab, India; email: firstname.lastname@example.org.
Disclosures: Agarwal, Parkash, Mahajan and Parkash report no relevant financial disclosures.