From Gimbel Eye Centre (MA-U, HVG, GDC), Calgary, Alberta, Canada; and Loma Linda University (HVG), Loma Linda, California.
Presented as a poster at the annual meeting of the American Society of Cataract and Refractive Surgeons, April 25–29, 2011, San Diego, California.
The authors have no financial or proprietary interest in the materials presented herein.
Address correspondence to Howard V. Gimbel, MD, MPH, Gimbel Eye Centre, 450, 4935–40 Avenue NW, Calgary, Alberta T3A 2N1, Canada. E-mail: firstname.lastname@example.org
Peripheral iris stromal cysts are located near the junction of the iris and ciliary body. In most cases, even with maximum pupil dilation, direct iris cyst visualization is not usually possible with routine slit-lamp examination. Ultrasound biomicroscopy (UBM) provides a higher resolution and more complete visualization of the anterior segment, allowing for better delineation of the ciliary sulcus anatomy and better surgical planning. We describe a patient who presented for refractive surgery assessment. No peripheral iris cysts were visible in either eye on dilated eye examination, but were detected in both eyes during standard UBM sulcus-to-sulcus preoperative measurements. The patient subsequently underwent successful bilateral toric implantable collamer lens (TICL) implantation. We report on the result of the surgical procedure that, to our knowledge, is the first such report to date.
A 34-year-old man with high myopia and astigmatism presented to our clinic for refractive surgery assessment. His manifest refraction was −11.25 −1.00 × 015 in the right eye and −13.25 2.00 × 150 in the left eye, bringing him to 20/15−2 and 20/20+2 visual acuity, respectively. Anterior and posterior segment examination did not reveal any significant pathology in either eye. The patient was not a candidate for laser refractive surgery due to thin corneal pachymetries and was offered phakic posterior chamber intraocular lenses.
During routine UBM sulcus-to-sulcus measurements, peripheral iris cysts were observed in the right eye at the 9:00-o’clock position measuring 1.03 × 1.03 mm and in the left eye at the 2:30-o’clock position measuring 1.22 × 1.54 mm (Fig. 1). A diagnosis of peripheral iris stromal cysts was made based on their thin wall and internal echolucency as seen on UBM. Two peripheral iridotomies were performed in each eye preoperatively with the Nd:YAG laser, as per our protocol. An attempt was made to collapse the larger cyst in the left eye with the laser through an additional peripheral iridotomy at the 2:30-o’clock position. However, the cyst was too peripheral and not amenable to such treatment (Fig. 2). TICL implantation surgery was subsequently performed in both eyes, 1 day apart. The first surgery was performed in the right eye and a Visian TICL TICM125V4, −16.50 diopters, +1.00 cylinder at 105 degrees, 12.5 mm length (STAAR Surgical, Monrovia, CA), was implanted through the temporal clear corneal incision. The next day, the patient had similar surgery in the left eye and a Visian TICL T1CM125V4, −19.00 diopters, +1.50 cylinder at 60 degrees, 12.5 mm length, was implanted. The patient had postoperative follow-up visits at 1 day, 7 weeks, 7 months, and 15 months (Table). The final uncorrected distance visual acuity was 20/15−1 in the right eye and 20/20−2 in the left eye at 15 months. Stability of the TICL position was also confirmed in both eyes at 15 months (Figs. 3 and 4).
Figure 1. Preoperative ultrasound biomicroscopy photographs of temporal iris cysts (c) in both eyes. OD = right eye; OS = left eye.
Figure 2. Ultrasound biomicroscopy photograph after attempted collapse of temporal cyst (c) in the left eye through a peripheral iridotomy (pi) with Nd:YAG laser.
Table: Preoperative and Postoperative Results
Figure 3. Ultrasound biomicroscopy photographs demonstrate stability of toric implantable collamer lens (TICL) placement in both eyes after 15 months. OS 1: TICL in cross section with measurement (0.72 mm) from the left eye anterior lens capsule. OS 2: TICL temporal haptic (v) pushing against the left eye iris cyst. OD 1: TICL in cross-section with measurement (0.74 mm) from the right eye anterior lens capsule. OD 2: TICL temporal haptic (v) seen above the right eye iris cyst in the ciliary sulcus.
Figure 4. Slit-lamp photographs after toric implantable collamer lens (TICL) in both eyes. OS 1: Undilated left eye with peripheral laser iridotomies at 12:00, 13:00, and 14:30 clock hours. OS 2: Dilated left eye with centrally positioned TICL. OD 1: Undilated right eye with peripheral laser iridotomies at 11:00 and 12:30 clock hours. OD 2: Dilated right eye with centrally positioned TICL.
Peripheral iris cysts located at the junction of the iris and ciliary body are reported to be the most common.1 These are more common in women and are typically diagnosed at approximately 20 to 30 years of age. Peripheral iris cysts are usually solitary, temporal, and located between either the 2:00- and 5:00-o’clock or the 7:00-and 10:00-o’clock meridians. They are typically thin walled with rounded reflective walls and somnolucent, fluid-filled interiors. In our patient, these solitary, temporal cysts could only be detected by UBM, located at the 9:00-o’clock position in the right eye and the 2:30-o’clock position in the left eye. In some cases, peripheral iris cysts may be seen on slit-lamp examination as a subtle anterior displacement of the iris stroma at or just below the horizontal meridian, especially when using a thin, vertical slit beam. With maximum pupil dilation, peripheral cysts can often be directly visualized. Our patient had no such appearance on slit-lamp examination due to the peripheral location of both cysts. We found UBM particularly useful in the diagnosis and surgical planning of this case.
UBM systems are suitable for examining virtually all anterior segment anatomy and pathology. The examination is non-invasive, localizing, and, for the anterior segment, far superior in resolution to that of the conventional B-scan ultrasound. The resolution of anterior segment lesions is increased to 20 to 50 μm with tissue penetration of up to 4 mm with UBM, compared to 300 to 400 μm with conventional 10-MHz ultrasonography.2
Visian TICL implantation is currently the preferred refractive procedure for young patients with moderate to high myopia and astigmatism.3 Many studies have proven the long-term stability of TICL implantation,4–7 but, to our knowledge, no study has described the long-term results of a TICL implant in eyes with peripheral iris cysts. In this case of a patient with bilateral peripheral iris cysts, TICL implantation was uneventful and the lenses were rotated into position without any difficulty. Postoperatively, the TICL haptics were properly positioned except for the temporal haptic in the left eye, which remained slightly posterior to the ciliary sulcus and pressed into the cyst (Fig. 3). At 15 months of follow-up, this had not caused any problems with the vault of the lens or any shift in the TICL axis. The postoperative vault of the TICL in both eyes is described as the comparative vault to the central TICL thickness (Table). Although the patient initially had problems with near vision in both eyes during the first 6 weeks postoperatively, this difficulty gradually disappeared. Similar transient accommodation impairment in the early postoperative period with gradual recovery has been described by Kamiya et al.8 The presence of iris cysts in our case did not have any long-term effect on accommodation.
This case demonstrates the feasibility of TICL implantation in the presence of peripheral iris cysts, with TICL stability in terms of axis and vault at a follow-up of 15 months. Further studies are required to better assess the long-term stability of TICLs in eyes with peripheral iris cysts. UBM is an effective diagnostic tool in detecting these peripheral iris cysts. While doing horizontal sulcus-to-sulcus UBM measurements, the other regions of the sulcus should also be examined for any such structural abnormalities.
- Shields JA, Primary cysts of the iris. Trans Am Ophthalmol. 1981;79:771–809.
- Pavlin CJ, McWhae JA, McGowan HD, Foster FS. Ultrasound biomicroscopy of anterior segment tumors. Ophthalmology. 1992;99;1220–1228.
- Guell JL, Morral M, Kook D, Kohnen T. Phakic intraocular lenses: Part 1. Historical overview, current models, selection criteria, and surgical techniques. J Cataract Refract Surg. 2010;36:1976–1993.
- Alfonso JF, Baamonde B, Fernandez-Vega L, et al. Posterior chamber collagen copolymer phakic intraocular lenses to correct myopia: five-year follow-up. J Cataract Refract Surg. 2011;37:873–880. doi:10.1016/j.jcrs.2010.11.040 [CrossRef]
- Kamiya K, Shimizu K, Igarashi A, Hikita F, Komatsu M. Four-year follow-up of posterior chamber phakic intraocular lens implantation for moderate to high myopia. Arch Ophthalmol. 2009;127:845–850. doi:10.1001/archophthalmol.2009.67 [CrossRef]
- Tsiklis NS, Kymionis GD, Karp CL, Naoumidi T, Pallikaris AI. Nine-year follow-up of a posterior chamber phakic IOL in one eye and LASIK in the follow eye of the same patient. J Refract Surg. 2007;23:935–937.
- Pesando PM, Ghiringhello MP, Di Meglio G, Fanton G. Posterior chamber phakic intraocular lens (ICL) for hyperopia: ten-year follow-up. J Cataract Refract Surg. 2007;33:1579–1584. doi:10.1016/j.jcrs.2007.05.030 [CrossRef]
- Kamiya K, Shimizu K, Aizawa D, Ishikawa H. Time course of accommodation after implantable collamer lens implantation. Am J Ophthalmol. 2008;146:674–678. doi:10.1016/j.ajo.2008.05.049 [CrossRef]
Preoperative and Postoperative Results
|Follow-up||Laterality||UCVA||Manifest Refraction||TICL Vault||IOP (mm Hg)|
| Day 0||OD||CF @ 4 ft||−11.25 −1.00 × 015||N/A||10|
|OS||CF @ 3 ft||−13.25 −2.00 × 150||N/A||12|
| Day 1||OD||20/20+1||+0.75 −0.25 × 157||3.5||16|
|OS||20/25+1||0.00 −0.50 × 114||2||12|
| Week 7||OD||20/15−2||+0.75 0.00 × 000||3–4||12|
|OS||20/20−1||+0.25 −0.50 × 025||2–3||12|
| Month 7||OD||20/15−1||+0.25 0.00 × 000||3||18|
|OS||20/25+2||−0.25 −0.50 × 032||3||15|
| Month 15||OD||20/15−1||+0.25 −0.25 × 067||2.5||18|
|OS||20/20−2||−0.50 −0.25 × 030||2.5||18|