Deep Anterior Lamellar Keratoplasty followed by Toric Lens Implantation for the Treatment of Concomitant Anterior Stromal Diseases and Cataract

Deep Anterior Lamellar Keratoplasty: Current Status and Future Directions

ABSTRACT

Deep anterior lamellar keratoplasty (DALK) involves selective replacement of diseased corneal stroma while preserving normal healthy endothelium. Despite several well-recognized advantages, the uptake of DALK has remained sluggish with an adoption rate that has plateaued over the past decade. Misconceptions such as the rarity of complications of penetrating keratoplasty, lack of standardization of the DALK technique, and limited substantial benefit in visual and refractive outcomes are frequently cited as arguments against performing DALK. This brief review discusses the recent findings that refute these perceived barriers; describes contemporary techniques, tools, and modifications in the surgical approach; and evaluates the evidence regarding the clinical outcomes of DALK.

Outcomes of cataract surgery with toric intraocular lens implantation after keratoplasty

PURPOSE

To evaluate the efficacy and predictability of cataract extraction with toric intraocular lens (IOL) implantation after deep anterior lamellar keratoplasty (DALK) or mushroom penetrating keratoplasty (PK).

SETTING

Villa Igea Hospital, Forlì, Italy.

DESIGN

Prospective case series.

METHODS

Toric IOL implantation was offered to patients with cataract, corneal astigmatism >1.5 diopters (D) and regular central corneal topography after complete suture removal. Phacoemulsification was performed through a 2.4 mm scleral tunnel and an enVista monofocal toric MX60T or Eyecryl monofocal toric IOL was inserted in the capsular bag. Main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, total prediction error, and IOL misalignment.

RESULTS

37 consecutive patients who had previously undergone either DALK (n = 27, 73%) or 2-piece mushroom PK (n = 10, 27%) were included. All patients completed the 6-month follow-up. The mean toric IOL power was 5.3 ± 1.1 D. Both UDVA and CDVA significantly improved (from 1.02 ± 0.27 to 0.46 ± 0.31 logMAR and from 0.65 ± 0.27 to 0.11 ± 0.12 logMAR, respectively; P < .001). 20 eyes (54%) reached UDVA ≥20/40, whereas 35 eyes (95%) reached a CDVA ≥20/40. Final refractive astigmatism was 0.93 ± 0.87 D, with 35 eyes (95%) within 2 D. Prediction error was ≤1 D in 18 eyes (49%). Absolute IOL misalignment was 3.3 ± 3.5 degrees.

CONCLUSIONS

Toric IOL implantation in postkeratoplasty eyes allowed reduction of refractive astigmatism to predictably low levels with concomitant improved visual outcomes.

Customized Toric Intraocular Lens Implantation in Eyes with Cataract and Corneal Astigmatism after Deep Anterior Lamellar Keratoplasty: A Prospective Study

Purpose

To investigate the effectiveness of toric intraocular lenses (IOLs) for treating corneal astigmatism in patients with cataract and previous deep anterior lamellar keratoplasty (DALK).

Setting

San Giovanni-Addolorata Hospital, Rome, Italy.

Design

Prospective interventional case series.

Methods

Patients undergoing cataract surgery after DALK for keratoconus were enrolled. Total corneal astigmatism (TCA) was assessed by a rotating Scheimpflug camera combined with Placido-disk corneal topography (Sirius; CSO, Firenze, Italy). A customized toric IOL (FIL 611 T, Soleko, Rome, Italy) was implanted in all eyes. One year postoperatively, refraction was measured, the IOL position was recorded, and vectorial and nonvectorial analyses were performed to evaluate the correction of astigmatism.

Results

Ten eyes of 10 patients were analyzed. The mean preoperative TCA magnitude was 4.92 ± 1.99 diopters (D), and the mean cylinder of the IOL was 6.18 ± 2.44. After surgery, the difference between the planned axis of orientation of the IOL and the observed axis was ≤10° in all eyes. The mean surgically induced corneal astigmatism was 0.35 D at 20°. The mean postoperative refractive astigmatism power was 1.13 ± 0.94 D; with respect to preoperative TCA, the reduction was statistically significant (p < 0.0001). The mean change in astigmatism power was 3.80 ± 1.60 D, corresponding to a correction of 77% of preoperative TCA power. Nine eyes out of 10 had a postoperative refractive astigmatism power ≤ 2D.

Conclusions

Toric IOLs can effectively correct corneal astigmatism in eyes with previous DALK. The predictability of cylinder correction is partially lowered by the variability of the surgically induced changes of TCA. This trial is registered with NCT03398109.