Damian Lake

Outcomes of pseudophakic toric intraocular lens implantation in Keratoconic eyes with cataract.

PURPOSE To evaluate the outcomes of pseudophakic toric intraocular lens (IOL) implantation in eyes with stable keratoconus and cataract. METHODS Retrospective, noncomparative, case series of 12 eyes from 9 patients (mean age: 63.4±3.5 years) with stable mild to moderate keratoconus and cataract who underwent pseudophakic toric IOL implantation (AT TORBI 709M, AcriTec). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, keratometric findings, adverse events, and postoperative complications were recorded for all eyes. RESULTS Mean postoperative follow-up was 9.0+8.8 months. At last postoperative follow-up, UDVA was 20/40 or better in 75% and CDVA was 20/40 or better in 83.3% of eyes. Postoperative mean refractive sphere (pre- vs postoperative: -4.80±5.60 vs 0.30±0.50 diopters [D]) and cylinder (pre- vs postoperative: 3.00+1.00 D vs 0.70+0.80 D) were significantly better (P<.01 for both). No intra- or postoperative complications occurred. No eyes had progression of keratoconus or significant IOL rotation at postoperative follow-up. CONCLUSIONS Pseudophakic toric IOLs are an effective option and provide good vision in eyes with stable mild to moderate keratoconus and cataract.

Corneal collagen cross linking (CXL): a review.

Treatments for conditions affecting the biomechanical strength of the cornea, until now, have been limited to treatment of the consequences of progressive weakness of the cornea such as inserts (Intacs or Ferrara rings) and corneal grafting (Deep anterior Lamellar or Penetrating Keratoplasty). Neither addresses the basic defect within the cornea. Corneal collagen crosslinking (CXL) is a treatment designed to increase the rigidity and structural integrity of the cornea, preventing progression to end-stage disease. Keratoconus is a common condition, affecting 1 in 2000 of the population. It typically affects the young, presenting in adolescence with distorted vision. It is a noninflammatory, degenerative disorder of the cornea, characterized by stromal thinning and conical ectasia, resulting in irregular astigmatism and associated visual loss. It is usually an isolated condition; however, commonly recognized associations include Down syndrome, Leber congenital amaurosis, and connective tissue disorders. Atopy, eye rubbing, and hard contact lenses have also been reported to be highly associated with this disorder, and 6% to 8% of reported cases have a positive family history or show evidence of familial transmission. Recent biochemical assays and immunohistological studies of corneas with keratoconus suggest that the loss of corneal stroma after digestion by proteolytic enzymes could be caused by increased levels of proteases (matrix metalloproteinase) and

Management of angle-supported intraocular lens and iridectomy in Descemet-stripping endothelial keratoplasty.

PROBLEM Effective tamponade of a Descemet-stripping endothelial keratoplasty graft with a gas bubble requires that there is no route for the bubble to escape into the posterior chamber. SOLUTION Exchange the angle-supported anterior-chamber intraocular lens (IOL) for an iris-enclaved Artisan IOL and position the IOL haptics over the peripheral iridectomy to occlude it to the extent that no gas can pass.

Sterile keratitis after combined riboflavin-UVA corneal collagen cross-linking for keratoconus

PurposeTo investigate patient risk factors and to look for potential causes of sterile infiltrates following an unexpected cluster of sterile keratitis after a routine collagen cross-linking (CXL) list.MethodsThe records of all 148 cases of CXL were reviewed retrospectively. The equipment and solutions used and our clinic’s standard operating procedure for CXL were reviewed. An in-vitro experiment to explore the variation in ultraviolet A (UVA) irradiance from fluctuations in the working distance of the UVA lamp was conducted.ResultsThe four patients who developed sterile infiltrates had steeper maximum corneal curvatures (68.0±7.3 D) and thinner pachymetry (389.9±49.0 μm) than the 144 who did not (57.0±8.2 D, P=0.05; 454.6±45.4 μm, P=0.08). A corneal curvature of >60 Dand a pachymetry of <425 μm were significant risk factors. All four affected cases obtained a complete resolution with topical antibiotics and steroids. The unaided VA and the maximum K improved from their pre-operative levels in three out of four patients. A 2-mm reduction in distance of the VEGA C.B.M. X-Linker from a treated surface increased irradiance to 3.5–3.7 mW/cm2, which is above the threshold for endothelial toxicity.ConclusionPatients with thinner and steeper corneas are at an increased risk of developing sterile keratitis. The visual outcomes despite this complication are good.

Blink Lagophthalmos and Dry Eye Keratopathy in Patients with Non-facial Palsy: Clinical Features and Management with Upper Eyelid Loading

PURPOSE To evaluate the outcome of using upper eyelid gold weight implantation for patients with non-paralytic lagophthalmos on blink (LOB) only. We highlight the features of incomplete blink and reduced blink rate in patients with non-facial palsy as an exacerbating factor in dry eye keratopathy. DESIGN Retrospective, noncomparative case series. PARTICIPANTS Twelve patients (21 procedures) who underwent upper eyelid gold weight implantation for non-paralytic LOB only. METHODS Retrospective case note review of patients who underwent upper eyelid loading for non-paralytic LOB only over a 5-year period at a single institution. MAIN OUTCOME MEASURES Improvement in LOB, gentle and forced closure, increased frequency of blinking (FOB), degree of corneal staining, incidence of epithelial defects or corneal ulcer, improvement in vision, and subjective improvement in ocular discomfort. RESULTS Twenty-one procedures in 12 patients. Nine patients underwent bilateral surgery. Mean age was 56 (range, 8-80) years. Median postoperative follow-up was 15 months, and mean follow-up was 20.38 ± 16.61 (6-58) months. Eleven of 12 patients had an improvement in LOB and increased FOB, resulting in improvement of keratopathy and reduced ocular discomfort. One patient developed superior corneal thinning and descemetocele, requiring removal of the gold weight; 1 patient required ptosis surgery; and 1 patient developed a gold allergy and underwent platinum chain exchange. CONCLUSIONS We highlight the need to consider incomplete blink and reduced FOB as exacerbating factors for corneal-related disorders, including dry eye. Upper eyelid loading with gold weight implantation is a useful and predictive method of improving exposure-related keratopathy due to LOB in the absence of facial palsy.

Intraocular pressure control and corneal graft survival after implantation of Ahmed valve device in high-risk penetrating keratoplasty.

Purpose: To analyze the control of intraocular pressure (IOP) and corneal graft survival after implantation of Ahmed glaucoma device (AGD) in eyes that had high-risk penetrating keratoplasty (PK). Methods: This is a retrospective noncomparative case series of 59 eyes that had high-risk PK and underwent AGD insertion. The primary outcome measures are the control of IOP between 6 and 21 mm Hg and corneal graft survival. The secondary outcome measures are risk factors associated with IOP control and corneal graft survival. Results: The mean IOP reduced significantly after the AGD procedure (26.45 ± 6.8 mm Hg preoperatively vs. 16.85 ± 7.4 mm Hg, 16.95 ± 4.6 mm Hg, 17.97 ± 5.7 mm Hg, 15.78 ± 5.2 mm Hg, and 15.59 ± 5.5 mm Hg, at 1 month, 6 months, 1 year, 2 years, and at the last follow-up postoperatively; P < 0.0001). Over a median follow-up of 78 months (range, 9–175 months) after AGD insertion, IOP control was successful in 44 eyes (75.8%). IOP control was successful in 96% of the eyes at 1 year, 87% at 2 years, 83% at 3 years, and 83% at 5 years. The percentage of clear corneal grafts after 1, 2, 3, and 5 years following the AGD insertion were 87%, 77%, 65%, and 47%, respectively. Further surgery after AGD insertion was associated with 1.79 times greater risk of failure of IOP control. Conclusions: AGD was effective in controlling the IOP associated with high-risk PK over a 5-year period. Postvalve surgery doubles the risk of failure of IOP control.

Posteriorly enclavated iris claw intraocular lens for aphakia: long-term corneal endothelial safety study.

Purpose To report 2 years follow-up experience, corneal endothelial cell loss results, and A constant used in retroiridis-fixated iris-claw aphakic intraocular lens (IOL) secondary implantation to correct aphakia in eyes without adequate capsule support. Methods In this prospective, interventional, clinical case series, 16 consecutive eyes of 14 patients (13 adults and 1 child) underwent retroiridis implantation of Artisan iris-claw aphakic IOL (Ophtec BV, Groningen, the Netherlands). Outcome measures included spherical equivalent (SE) of refractive error, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA) expressed as the logarithm of the minimum angle of resolution (logMAR), endothelial cell density (ECD), and complications, including raised intraocular pressure (IOP) and pigment dispersion. Results All eyes were followed up for 2 years postoperatively. Postoperative SE of refractive error was between −1.25 and +1.63 D in all eyes at last follow-up. The mean CDVA was 0.27 ± 0.30 logMAR preoperatively and 0.13 ± 0.21 logMAR at 2 years postoperatively (p = 0.0188). Postoperative UDVA mean was 0.31 ± 0.26 logMAR at last follow-up. Preoperative manual ECD mean of 2269 ± 611 cells/mm2 decreased postoperatively to 2002 ± 532 cells/mm2 at 2 years (p = 0.0005) (mean endothelial cell loss of 11.9 ± 2.0%). No intraoperative complications occurred. There was no significant postoperative IOP increase throughout the follow-up. Iris pigment precipitates on the IOLs occurred in 1 eye (6.3%). No other serious complications occurred. Conclusions Two-year results show that retroiridis-fixated iris-claw aphakic IOL implantation is an effective and safe method with regards to corneal endothelial cell loss, and a new A constant is suggested.

Corneal collagen crosslinking for keratoconus or corneal ectasia without epithelial debridement

PurposeCorneal collagen crosslinking (CXL) is a relatively new technique to reduce the progression of keratoconus. The technique can be performed with or without complete debridement of the corneal epithelium. We describe a novel intermediate technique involving mechanical disruption of the epithelium, and evaluate its safety and efficacy.MethodsThe case notes of 128 eyes with progressive keratoconus or iatrogenic corneal ectasia who had undergone CXL using the epithelial disruption technique were retrospectively reviewed. Thin corneas were treated with hypotonic riboflavin. All others were treated with an isotonic solution. Note was made of preoperative and postoperative parameters, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, endothelial cell count, and corneal tomography. Occurrence of procedure-related complications was recorded. Statistical analyses were performed using the paired sample t-test and Wilcoxon signed-rank test, with a level of P<0.05 being accepted as statistically significant.ResultsAt 12 months, 41.8% of patients treated with isotonic riboflavin had improved UCVA and 29.7% had improved BSCVA. Only 13.4% lost lines of UCVA and 14.9% lost BSCVA. Of the patients treated with hypotonic riboflavin, at 12 months, 75% demonstrated stability of BSCVA and 25% had stable Kmax. In addition, 25% showed improved visual acuity at 12 months, and 58.3% showed regression of their Kmax. Our rate of short-term complications was comparable to studies using complete epithelial removal.ConclusionsCXL with epithelial disruption is a safe and effective treatment for keratoconus or iatrogenic corneal ectasia, and may be better tolerated by patients than the epithelium-off technique.

Deep anterior lamellar keratoplasty over penetrating keratoplasty for host rim thinning and ectasia.

Purposes: To describe the technique and evaluate the outcomes of patients who had deep anterior lamellar keratoplasty (DALK) for ectasia within or outside the graft-host interface in a previous penetrating keratoplasty (PK). Design: Retrospective review of interventional case series. Patients: Seven eyes that underwent DALK for corneal ectasia after previous PK. Intervention: DALK encompassing the area of ectasia and the previous PK. Main outcome measures: Uncorrected visual acuity, best spectacle-corrected visual acuity, keratometry and topography, and complications. Results: Seven eyes had DALK, 4 developed Descemet membrane tears, and 2 eyes had deep graft-host dehiscence from the previous PK intraoperatively. At 12 months, mean uncorrected visual acuity (logarithm of the minimum angle of resolution) improved from 1.157 to 0.74. Mean best spectacle-corrected visual acuity improved from 0.82 to 0.37 at 12 months. Conclusions: DALK can be successfully performed over a previous PK. Intraoperative Descemet tears or dehiscence of Descemet at the previous graft-host interface can complicate surgery, but if successfully managed can produce a significant improvement in visual acuity.

Comparison of equivalent keratometric indices on Scheimpflug tomography with Placido-based topography system at different optical zones

Aim To compare Holladay equivalent keratometric indices on Scheimpflug tomographer and keratometry on Placido topographer at different optical zones. Methods In this observational study, 50 right eyes of 50 patients were recruited. All patients were scanned on both machines. Data on K1, K2, mean keratometry (Km) and meridian of steepest keratometry (MoSK) were collected for central 3 mm and 5 mm optical zones from Holladay Equivalent keratometry report on Scheimpflug tomographer and keratometric data from Placido topographer. Difference (Diff(S-P)) in Km and MoSK were calculated by subtracting corresponding values of Placido from Scheimpflug scans. Concordance was evaluated using paired t tests, the Pearson correlation and Bland-Altman analyses. Results Comparing 3 mm vs 5 mm optical zones on each machine, there was no significant difference in Km and MoSK values but Km showed good correlation unlike MoSK. Comparing Scheimpflug versus Placido, Km showed good correlation at all scan sizes, unlike MoSK. 95% limits of agreement between the machines for Km was −1.20D to 1.08D(3 mm) and −1.46D to 1.23D(5 mm); whereas, for MoSK it was −83.05 to 85.82°s(3 mm) and −107.9 to 77.48°s(5 mm) respectively. The Diff(S-P) for Km at 3 mm (−0.45±0.79) was significantly less than that at 5 mm (−0.10±0.70) (p<0.01) whereas Diff(S-P) for MoSK were not significantly different at both optical zones. Conclusions Mean keratometry correlated well between Scheimpflug and Placido scans. Axes showed poor correlation between optical zones on same machine and between the machines with same optical zone. Scheimpflug showed flatter keratometry at smaller optical zone. These machines cannot be used interchangeably in refractive surgery.