Long-term safety of in-the-bag implantation of a supplementary intraocular pinhole

Managing Post Keratoplasty Astigmatism

Corneal transplantation, when used in the correct setting, can significantly improve visual acuity and therefore quality of life. One of the barriers to good vision following keratoplasty is residual post operative surgical astigmatism. Following a thorough literature search, we present the different options available to readers, with regards to how post-operative astigmatism can be approached and managed in order to improve vision. We present available data from the literature, which in some areas are scarce, with a view to collating all of this information in one place, allowing comparison between different modalities of treatment.

Refractive surgical correction and treatment of keratoconus

Keratoconus is an ectatic corneal disorder that causes severe vision loss. Surgical options allow us to correct, partially or totally, the induced refractive error. Intracorneal ring segments (ICRS) implantation represents a minimally invasive surgical option that improves visual acuity, with a high success rate and a low overall complication rate. Corneal allogenic ICRS consists of ring segments derived from allogenic eye bank-processed donor corneas. Selective topography-guided transepithelial photorefractive or phototherapeutic keratectomy combined with CXL is another way in selected cases to improve spectacles corrected distance visual acuity. The microphotoablative remodeling of the central corneal profile is generally planned by optimizing the optical zones and minimizing tissue consumption. Phakic intraocular lens (PIOL) implant is considered in patients with stable disease and acceptable anatomical requirements. The two types of pIOLs, depending on their implantation inside the eye, are anterior chamber-pIOLs, which fixate to the anterior surface of the iris by using a polymethomethacrolate claw at the two haptics, and posterior chamber-pIOLs. In patients with both cataracts and keratoconus, the correct IOL power is difficult to obtain due to the irregular corneal shape and K values. Toric IOL is recommended, but carefully judging the topography and the possible need of subsequent keratoplasties.

Review of surgical devices using small aperture optics

Small aperture optics work by blocking unfocused peripheral light rays while allowing central light rays to focus on the retina. This pinhole effect creates an extended depth of focus and has been used in presbyopia correction, improving intermediate and near vision without markedly affecting distance vision. Another beneficial effect of small aperture optics is reducing aberrations caused by irregular corneas or irregular pupils. The first small aperture surgical device was the Kamra corneal inlay used on the nondominant eyes of presbyopic emmetropes. The pinhole concept was also adapted into the IC-8 intraocular lens (IOL) for presbyopia correction during cataract surgery and by the XtraFocus piggyback device to lessen unwanted aberrations in eyes with irregular corneas or pupils. The IC-8 IOL can be placed monocularly or binocularly with mini-monovision for further near vision improvement. The XtraFocus piggyback device can be placed either in the sulcus or capsular bag. The aim of this literature review is to synthesize evidence on the efficacy, safety, and patient-reported outcomes on surgical devices utilizing small aperture optics. A comprehensive search on PubMed was conducted with the keywords “small aperture optics,” “small aperture corneal inlay,” “small aperture IOL,” “Kamra corneal inlay,” “IC-8 IOL,” and “XtraFocus.” In this review, we describe the progression of small aperture surgical devices, patient criteria, visual outcomes, complications, satisfaction, and recommendations for surgical success.

Bilateral implantation of a supplementary intraocular pinhole

PURPOSE

To evaluate the safety and efficacy of bilateral implantation of a supplementary small-aperture device to treat irregular corneal astigmatism.

SETTING

Private practice.

DESIGN

Retrospective consecutive case series.

METHODS

Patients with bilateral irregular corneal astigmatism secondary to multiple causes and consented for implantation of the XtraFocus intraocular pinhole (IOPH) were enrolled. The mean follow-up was 27 months (range 5 to 66 months). Patients were assessed in their scheduled follow-up visits and monocular and binocular uncorrected and corrected distance and near visual acuities were recorded. Assessment of darkening vision complaints was also performed after implantation in the first eye and repeated after second-eye surgery.

RESULTS

Thirty-two eyes of 16 patients were analyzed. The mean monocular and binocular uncorrected distance visual acuities improved from logMAR 1.091 ± 0.208 and 1.078 ± 0.259 preoperatively to 0.342 ± 0.091 (P < .001) and 0.342 ± 0.147 (P = .001) 1 year postoperatively. Three patients were excluded because of darkening vision complaints after surgery in the first eye. No major complications were noted after implantation of the IOPH.

CONCLUSIONS

Bilateral implantation of the XtraFocus IOPH is a safe technique in a selected group of patients. There was improvement in visual acuity sustained over the analyzed period. Postoperative darkening vision complaints vary between individuals and can limit the application of this approach in certain patients.

One-year visual outcome of secondary piggyback pinhole device implantation in pseudophakic eyes with irregular corneal astigmatism and iris trauma

PURPOSE

Retrospective case series evaluating the efficacy and safety of implanting XtraFocus^™ pinhole device in pseudophakic patients with irregular corneal astigmatism with concurrent or standalone iris defect.

METHODS

Electronic case records were searched for: uncorrected distance visual acuities (UDVA) and corrected distance visual acuities (CDVA), automatic or manifest refraction and spherical equivalent (SE). All main outcomes were evaluated preoperatively and postoperatively at 1, 3, 6, 9 and 12 months, along with patients' satisfactory outcome and complications.

RESULTS

Eleven pseudophakic eyes of 11 patients with a mean age of 54 (range 27-81) years were included. Median UDVA improved significantly from logMAR 0.7 (range 0.1-1.22) pre-operatively to 0.4 (range 0-1.3) at 1-month (p = 0.002); median CDVA remained unchanged at logMAR 0.4 (range 0-0.1) pre-operatively and 0.4 (range 0-0.8) at 1-month (p = 0.36). There were no significant statistical differences in both UDVA and CDVA between the post-operative periods. Ten patients (90.9%) had initial UDVA improvement at 1-month post op. Eight (72.7%) patients expressed satisfaction with improved vision or reduction of glare/halos. Three (27.3%) patients had unsatisfactory visual outcome resulting in 2 requested for implant explantation due to worsening of glare and distressing floaters.

CONCLUSIONS

XtraFocus^™ is effective in improving vision or reducing glare in pseudophakic patients with irregular corneal astigmatism or intragenic iris trauma, with over 70% expressed satisfactory outcome. Disturbing floaters and glare preclude its use in some resulting in implant explantation.

Handling regular and irregular astigmatism during cataract surgery

PURPOSE OF REVIEW

There are several different approaches to handling regular and irregular astigmatism during cataract surgery, but still much debate on which solutions are most effective given unique patient circumstances. In this review, we examine recent literature and studies to highlight some of the most effective ways to plan preoperatively, manage regular and irregular astigmatism during cataract surgery, as well as managing postoperative complications.

RECENT FINDINGS

Recent developments in technology have provided increased courses of action for astigmatism management during cataract surgery. Additional options of toric IOLs with presbyopic platforms, light adjustable lenses, intraocular pinhole lenses, online technological tools and platforms, wavefront or topographic laser technology, and phototherapeutic keratectomy are all effective solutions to managing regular and irregular astigmatism. In this review, we will explore optimal approaches for unique situations.

SUMMARY

With increased technology, research, and methods, correcting regular and irregular astigmatism during cataract surgery is achievable in most patients. With in-depth preoperative planning, analysis of patient-specific factors, and a tailored approach, surgeons can obtain excellent uncorrected vision for patients.

Toric intraocular lens combined with a supplementary pinhole implant to treat irregular corneal astigmatism

A case of refractive lens exchange with the implantation of a supplementary intraocular pinhole (IOPH) to treat a challenging case of keratoconus is presented. Four months after the initial procedure, an intraocular lens (IOL) exchange (under the IOPH) was performed to a toric implant to correct the residual manifest astigmatism. This significantly improved both distance and near acuities and demonstrates how a toric IOL and astigmatism correction in combination with a pinhole device could be used to treat selected cases of keratoconus.