The present protocol describes how a 10-0 polypropylene suture crosses the anterior surface of the iris, forming a pentagram to prevent both iris and pupil from moving toward the cornea. This can be combined with subsequent keratoplasty to cure bullous keratopathy with extensive anterior synechia of the iris.
Extensive anterior synechia of the iris can result in the gradual disappearance of the anterior chamber. It is one of the most common outcomes of both oculopathy and complicated post anterior segment surgery. This can impact visual function and lead to bullous keratopathy, making it one of the most complex clinical problems. Conventional anterior chamber plasty will partially create the anterior chamber, but the anterior chamber disappears again in some cases. The main reasons are: (1) the iris lens diaphragm is loose with atrophied and tension-free iris so that the aqueous humor circulation will push and squeeze the iris forward; (2) the effect of “roller” formed in the process of inflammation or restoration will change the iris structure from peripheral anterior synechia (PAS) to extensive anterior synechia again; (3) the fibration will result in synechia from iris to the cornea. In such cases, corneal endothelium deficiency can’t stop the aqueous humor from entering the cornea. This results in persistent corneal edema post-conventional anterior chamber plasty, resulting in progressive rubbing and lachrymation. Therefore, anterior chamber plasty is not the first choice for patients without surgical indications of Descemet’s stripping automated endothelial keratoplasty (DSAEK). However, this can be performed in patients with surgical indications who plan to receive DSAEK. A unique method of iris fixation via external pentagram suturing anterior chamber plasty (PSACP) is described here. The present technique is also compared with the conventional anterior chamber plasty. PSACP and DSAEK might be an effective way to cure the bullous keratopathy with extensive anterior synechia of the iris and disappeared anterior chamber.
Extensive anterior synechia is usually observed in the eyes of patients with malignant glaucoma or primary angle-closure glaucoma after laser peripheral iridotomy or iridoplasty and after anterior segment surgery1,2,3,4,5,6. This can cause gradual reduction of the anterior chamber leading to visual dysfunction. Once extensive anterior synechia forms, the aqueous humor can enter the cornea due to endothelium decompensation, leading to bullous keratopathy7. Although a well-controlled intraocular pressure (IOP) has been obtained after lens extraction and anterior vitrectomy, the iris lens diaphragm is still soft due to atrophied and tension-free iris8. Therefore, conventional anterior chamber plasty can only temporarily form the anterior chamber9. In cases where anterior synechia is extensive, the anterior chamber disappears again and adds difficulty to the subsequent keratoplasty surgery.
Keratoplasty with iris-diaphragm intraocular lens (IOL) implantation was reported as an effective way to cure the bullous keratopathy with aniridia10,11,12,13,14. Therefore, it may be helpful to treat eyes with bullous keratopathy and extensive anterior synechia after removing the atrophied and tension-free iris. However, this idea is possibly bringing significant iatrogenic injury now and not feasible in China due to unaffordable price of such IOL.
A recent study suggested that retention or barrier sutures could prevent silicone oil from moving into the anterior chamber in aphakic eyes with iris loss15,16,17,18. Sutures enhance the surface tension of silicone oil in such situations. Therefore, the current study was conducted to investigate whether these retention or barrier sutures could improve atrophy's stress and make the iris tension-free by preventing the iris and iris lens diaphragm from approaching the cornea. The presented study was performed to explore an effective way of doing anterior chamber plasty before keratoplasty to cure the bullous keratopathy with extensive anterior synechia of the iris. The current surgery method was named "Pentagram Suturing Anterior Chamber Plasty" (PSACP) with a core process of iris fixation via external pentagram suturing.
Malignant glaucoma patients with bullous keratopathy and extensive anterior synechia who already underwent lens extraction, anterior vitrectomy, IOL implantation, and had a well-controlled IOP were included for the current study. Willingness to receive further keratoplasty to cure bullous keratopathy was also considered an inclusion criterion. Exclusion criteria include (1) eyes with no light perception, (2) IOP ≥ 35 mmHg under anti-glaucoma medications, (3) eyes with infection, acute inflammation,aniridia or chronic uveitis, (4) eyes with retinal detachment, choroidal detachment, or ciliary detachment, (5) patients with uncontrolled hypertension, cardiovascular disease, cerebrovascular disease, or diabetes mellitus, (6) patients with a severe hemorrhagic tendency or mental disorders.
Bullous keratopathy with extensive anterior synechia has been considered one of the most challenging clinical problems. Although well-controlled IOP with successful lens extraction and anterior vitrectomy surgery was performed, the iris lens diaphragm was still flabby with the existence of an atrophied and tension-free iris. Case 1 showed that even when PKP was completed, conventional anterior chamber plasty with synechia separation would only partially and temporarily form in the anterior chamber. The main reasons are: (1) the aqueous humor circulation would continuously push and squeeze the atrophied and tension-free iris forward; (2) the effect of "roller" formed in the process of inflammation or restoration would make the iris from PAS to extensive anterior synechia again; (3) the fibration would result in synechia from iris to the cornea.
Keratoplasty with iris-diaphragm IOL implantation was a valuable method to cure the bullous keratopathy with aniridia10,11,12,13,14. To solve such extensive anterior synechia of the iris, iris-diaphragm IOL implantation after removing the iris might work15. However, total iridectomy was a surgery with significant iatrogenic injury, and iris-diaphragm IOL comes at an unaffordable price in China. A new method of forming a stable anterior chamber without recurrent extensive anterior synechia was needed to be explored.
Gentile et al.16 first reported the "# pattern" retention sutures across the anterior chamber to simulate an iris diaphragm. They made the sutures act as a barrier between the silicone oil and aqueous, preventing silicone oil-corneal contact, and this has been effective over 3-6 months. To deal with an atrophied and tension-free iris, there must be enough line segments and points of crossing to prevent the peripheral iris or pupil from moving forward to the cornea. The "# pattern" retention sutures could work well theoretically. But it was a complicated operation with 20 suture segments and 16 points of crossing times of sclerocentesis, which prolonged the operation time and increased the risk of infection. Similarly, this problem was even more severe in the report of Kemal et al.17 with "Chessboard pattern" barrier sutures.
Syed et al.18 and Du et al.19 suggested that improved "Z pattern" retention sutures could prevent silicone oil from moving to the anterior chamber in aphakic eyes with iris loss for 3-6 months. However, the points of crossing within the improved "Z pattern" sutures were not enough to prevent anterior synechia of the iris. Moreover, theoretically, triangle or quadrilateral sutures would be even worse than the improved "Z pattern" sutures.
In the current study, PSACP was invented because pentagram was a magical pattern with 15 line segments and 10 points of crossing, especially drawing with one stroke. Therefore, PSACP could not only use one 10-0 prolene suture alone across the anterior surface of the iris, forming a barrier in front of the iris by the 15 suture segments from the pentagram but also prevent the pupil from moving forward to the cornea by the central five points of crossing and fix the suture to the surface or superficial sclera by the peripheral five points of crossing. With the help of PSACP, the anterior chamber was stable with iris fixation and almost without recurrency of anterior synechia for at least 12 weeks in Case 2. Finally, Case 2 received DSAEK, and the bullous keratopathy was cured.
To our knowledge, DSAEK was one of the best surgeries to cure bullous keratopathy with minimally invasive, time-saving, and fast recovery7,20,21. The operative procedure needed adequate space basis in the anterior chamber. In Case 3, some recurrent anterior synechia resulted in an unstable anterior chamber in 24 weeks post-PSACP, suggesting that the timing of DSAEK was recommended from 4-12 weeks post-PSACP. Furthermore, Case 3 had received DSAEK jet and had also been performed with conventional anterior chamber plasty several times. If DSAEK was performed again, it might bring in more severe inflammation, restoration or fibration, and uncontrolled IOP. Therefore, PKP was finally performed. However, retention sutures were broken accidentally in PKP, and PAS was formed rapidly in 1-week post PKP, implying that PSACP prevented the iris from moving toward the cornea in such a complicated case only to some extent. Care needs to be taken of these sutures during the PKP procedure.
The limitation of this study was that it was a pilot study with only three cases with stringent inclusion and exclusion criteria. The success and benefits of PSACP with subsequent DSAEK or PKP were shown in two instances from only one hospital. Further studies in multi-center with a bigger sample size might be helpful to improve the flow chart.
In summary, iris fixation via PSACP might provide an adequate space basis for DSAEK to help cure the bullous keratopathy caused by a vanished anterior chamber or extensive anterior synechia to some extent. PSACP and DSAEK or PKP might be an effective way to cure the bullous keratopathy with extensive anterior synechia of the iris.
The authors have nothing to disclose.
The authors have no one to acknowledge.
1% crystal violet solution | HEBEI JINZHONG PHARMACEUTIAL CO., LTD. Hebei, PRC | 200709 | |
10-0 prolene sutures on an STC-6 needle | Alcon Laboratories, Inc.,Sinking Spring, PA | 13M4AT | |
2% lidocaine hydrochloride injection | TIANSHENG PHARMACEUTIAL GROUP CO., LTD. Hubei, PRC | 42021839 | |
29-gauge syringe | Becton, Dickinson and Company, NE 68949 | 160404 | |
Anterior segment optical coherence tomography | Carl Zeiss Meditec, Inc., Dublin, CA | 1000-1238 | |
Balanced salt solution | Alcon Laboratories,Inc., Fort Worth,TX | 7950191 | |
Cohesive viscoelastic | Bausch+Lomb Inc., Shandong, CN | 6.92409E+12 | |
Color slit lamp photography | HAAG-STREIT AG, Gartenstadtstrasse 10, 3098 Koeniz, Switzerland | 6543-2012 | |
Rebound tonometer (iCare, Type TA01i) | Tiolat Oy, Finland | 44 | |
Sterile irrigator for single use | SHANDONG WEIGAO GROUP MEDICAL POLYMER CO., LIMITED | (01)06932992101486 | |
Ultrasound biomicroscopy | Paradigm Medical Industries, Salt Lake City, UT | 5290-2012 |