Simultaneous tectonic Descemet stripping endothelial keratoplasty and tectonic Bowman layer transplant for the management of corneal perforation

AIM

To report the outcomes of three cases of corneal perforation managed with simultaneous tectonic Descemet stripping endothelial keratoplasty (t-DSEK) and tectonic Bowman layer transplant (t-BLT) as an alternative to tectonic penetrating keratoplasty (t-PKP).

METHODS

Three eyes of three patients receiving simultaneous t-DSEK and t-BLT for corneal perforation were included. The technique for DSEK was modified depending on individual requirements. The t-BLT technique was standardised using an 8 mm graft and fixated with a running suture. Success was measured by the ability of this procedure to close a corneal perforation.

RESULTS

All three cases achieved tectonic eye globe restoration and remained stable during the minimum 3-month observation period. Reinterventions were relatively common: 2 cases required amniotic membrane transplant for persistent epithelial defects. One case required DSEK rebubbling. One case developed angle closure glaucoma requiring surgical peripheral iridectomy.

CONCLUSION

Simultaneous t-DSEK and t-BLT may be a useful strategy for the management of corneal perforation as an alternative management to t-PKP for selected cases.

A three-dimensional morpho-volumetric similarity study of Down syndrome keratopathy vs. keratoconus

BACKGROUND

To compare and contrast morpho-volumetric features between Down syndrome (DS) cornea and non-DS keratoconic cornea by three-dimensional (3D) modelling.

METHODS

Forty-three subjects (43 eyes) with DS and 99 patients matching their age and sex (99 eyes) with keratoconus (KC) were included in this single-center cross-sectional study. Main outcome measures were high-order aberrations (HOA), central corneal thickness (CCT), spherical equivalent refraction, and morpho-volumetric parameters established using a 3D corneal model, such as deviation of anterior and posterior corneal apices (D_apexant/D_apexpost) and minimum thickness points (D_mctant/D_mctpost) from corneal vertex, areas of the anterior and posterior surfaces (A_ant/A_post), sagittal area passing through the anterior and posterior corneal apices (A_apexant/A_apexpost) and minimum thickness point (A_mctpost) and corneal volume of the complete cornea (V_total).

RESULTS

Age, gender, spherical equivalent refraction, CCT and V_total were similar between the net on-DS KC and DS groups (P > 0.05), while non-DS KC group had higher HOA than the DS group (P < 0.05). D_apexant, A_ant, A_post and A_apexant showed higher values in the DS group than in the non-DS KC group, whereas D_apexpost showed a reduction in the DS group when compared with the non-DS KC group (P < 0.05).

CONCLUSIONS

This study demonstrated that anterior and posterior corneal apex dynamics were specifically different in DS subjects, as the anterior apex tends to displace more prominently when compared to that from the non-DS KC group, while the posterior apex appears to be more stable than that in non-DS KC, which also support the theory that DS patients suffer from a specific keratopathy, distinctively different to KC but strongly related to it, and probably showing a diversity of corneal phenotypes in all cases of DS.

Patients’ dissatisfaction with multifocal intraocular lenses managed by exchange with other multifocal lenses of different optical profiles

Background

The aim of the study was to evaluate the outcomes of dissatisfied patients reporting poor visual quality following implantation of multifocal intraocular lenses (MF-IOLs), managed by IOL exchange with another multifocal optical profile.

Methods

This is a retrospective series of cases. MF-IOL exchange was done in 15 dissatisfied patients (30 eyes) with the perception of poor visual quality for far distance affected by neuroadaptation failure. Patients underwent a bilateral exchange of a MF-IOL with another MF-IOL of a different optical profile. Visual outcomes and complications were analyzed. Questionnaires including Quality of Vision (QoV), Visual Function Index-14 (VF-14) and its Rasch-revised version (VF-8R) and a satisfaction questionnaire were also used for outcome evaluation.

Results

The mean elapsed time from implantation to explantation-reimplantation was 11.8 months. The QoV scores improved significantly across all the three subscales. Visual function improved with a change in VF-14 score from 60.41 ± 24.81 to 90.16 ± 10.91 (P < 0.001). The VF-8R score improved as well. The uncorrected distance visual acuity improved from 0.24 to 0.12 logMAR after exchange (P < 0.001) and corrected distance visual acuity improved from 0.15 to 0.04 logMAR (P < 0.001). Safety and efficacy indexes reached 1.46 and 1.16, respectively. Concerning patients’ satisfaction following MF-IOL exchange, 80% of the patients reported they would have the MF-IOL reimplantation procedure again.

Conclusions

Patient dissatisfaction with neuroadaptation failure following MF-IOL implantation can be managed in 80% of our cases by MF-IOL exchange with a different MF-IOL optical profile.

Evidence of a Down Syndrome Keratopathy: A Three-Dimensional (3-D) Morphogeometric and Volumetric Analysis

The aim of this study was to investigate whether a different and abnormal corneal profile is present in Down syndrome (DS) by personalized three-dimensional (3D) modelling. This single-centre cross-sectional study included 43 patients with DS (43 eyes) and 58 age-sex-matched control subjects (58 eyes) with normal karyotype and topography. Refraction, central corneal thickness (CCT), aberrations (high-order, coma and spherical), asphericity and morphogeometric/volumetric parameters based on a 3D corneal model that was generated from raw topographical data were evaluated. Deviation of anterior/posterior apex (D_apexant/D_apexpost) and thinnest point (D_mctant/D_mctpost) from corneal vertex, anterior/posterior surface area (A_ant/A_post), sagittal area passing through the anterior/posterior apex (A_apexant/A_apexpost) and thinnest point (A_mctpost), total corneal volume (V_total) and volumetric progression for each 0.05 mm step of the radius value centred to the thinnest point (VOL_MCT) and anterior/posterior apex (VOL_AAP/VOL_PAP) comprised the morphogeometric/volumetric parameters. In the DS group, 58.1% of the eyes presented abnormal topography. High-order and coma aberrations, asphericity, D_apexant, A_ant, A_post and A_apexant were significantly higher, whereas CCT, A_apexpost, A_mctpost, V_total, VOL_AAP, VOL_PAP and VOL_MCT were lower in the DS group than in the control group (p < 0.05). D_apexpost did not differ between the groups (p > 0.05). This study demonstrates that corneas of the subjects with DS are different and more aberrated than those of normal age- and sex-matched non-DS controls. Anterior corneal apex appears to be displaced in DS even with normal topography, while posterior apex seems stable although topography is abnormal. These findings may help to modify our approach in the diagnosis of keratopathy in subjects with DS.

Subclinical keratoconus detection with three-dimensional (3-D) morphogeometric and volumetric analysis

PURPOSE

To assess the efficacy of morphogeometric and volumetric characterization of the cornea based on three-dimensional (3-D) modelling in diagnosis of subclinical keratoconus (KC).

METHODS

Cross-sectional study. Ninety-three eyes with subclinical KC with a best spectacle-corrected distance visual acuity ≥20/20 (grade zero KC according to the RETICS classification) and 109 control eyes were included. Computer-based 3-D corneal morphogeometric model was generated using raw topographic data. Distance-, area- and volume-based parameters were used for statistical analysis. Distance parameters included deviation of anterior (D_apexant )/posterior (D_apexpost ) apices and minimum thickness points (D_mctant , D_mctpost ) from corneal vertex, and D_apexant -D_apexpost difference. Areal variables were derived from anterior (A_ant ) and posterior (A_post ) corneal surfaces, sagittal plane passing through corneal apices (A_apexant , A_apexpost ) and thinnest point (A_mctant , A_mctpost ). Total corneal volume (V_total ) and volumetric distribution (with 0.1mm steps) centred to thinnest corneal point (VOL_mct ) and anterior (VOL_aap )/posterior (VOL_pap ) apices comprised the volume-based parameters.

RESULTS

In the subclinical KC group, all D values, D_apexant -D_apexpost difference, A_ant , A_post and A_apexant values were higher (p < 0.001), while A_apexpost , A_mctpost , V_total , VOL_mct , VOL_aap and VOL_pap values were lower when compared to the control group (p < 0.001). Regression analysis-based formula correctly classified 96.8% of the eyes with subclinical KC and 94.5% of the normal ones (p < 0.0001).

CONCLUSIONS

Eyes with subclinical KC seem to represent asymmetrically displaced anterior and posterior corneal apex, corneal thinning and volume loss. 3-D morphogeometric and volumetric parameters and differentiation formula can be incorporated into topography software to detect subclinical KC with high sensitivity and specificity in clinical practice.