Safety, Tolerability, and Short-Term Efficacy of Low-Level Light Therapy for Dry Age-Related Macular Degeneration.

INTRODUCTION: Photobiomodulation (PBM) has become a promising approach for slowing the progression of early and intermediate dry age-related macular degeneration (dAMD) to advanced AMD. This technique uses light to penetrate tissues and activate molecules that influence biochemical reactions and cellular metabolism. This preliminary analysis is aimed at assessing the safety, tolerability, and short-term effectiveness of the EYE-LIGHT®PBM treatment device in patients with dAMD. METHODS: The EYE-LIGHT® device employs two wavelengths, 590 nm (yellow) and 630 nm (red), in both continuous and pulsed modes. Patients over 50 years of age with a diagnosis of dAMD in any AREDS (Age-Related Eye Disease Study) category were randomly assigned to either the treatment group or the sham group. The treatment plan consisted of an initial cycle of two sessions per week for 4 weeks. Safety, tolerability, and compliance outcomes, along with functional and anatomical outcomes, were assessed at the end of the fourth month. RESULTS: This preliminary analysis included data from 76 patients (152 eyes). All patients were fully compliant with treatment sessions, and only one fifth of patients treated with PBM reported mild ocular adverse events, highlighting exceptional results in terms of tolerability and adherence. Changes in best-corrected visual acuity (BCVA) from baseline to month 4 differed significantly between the sham and PBM-treated groups, favoring the latter, with a higher proportion achieving a gain of five or more letters post-treatment (8.9% vs. 20.3%, respectively; p = 0.043). No significant differences in central subfield thickness (CST) were observed between the two groups over the 4-month period. The study also found a statistically significant disparity in mean drusen volume changes from baseline to month 4 between the groups in favor of patients treated with PBM (p = 0.013). CONCLUSION: These preliminary results indicate that PBM treatment using the EYE-LIGHT® system is safe and well tolerated among patients with dAMD. Furthermore, both functional and anatomical data support the treatment's short-term efficacy. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT06046118.

Surgical Strategies to Manage Stromal Interface Irregularity Following Deep Anterior Lamellar Keratoplasty.

PURPOSE: The purpose of this study was to describe the various surgical approaches to manage stromal interface irregularity following deep anterior lamellar keratoplasty (DALK). METHODS: This interventional case series included patients requiring repeat keratoplasty procedures for stromal interface opacity and/or irregularity following DALK. The following surgical techniques with the aim of restoring transparency and regularity of the central optical zone and improving visual acuity in eyes that underwent unsuccessful DALK were performed: 1) simple anterior lamellar graft exchange, 2) repeat DALK with pneumatic dissection, 3) repeat DALK with deepening of manual lamellar dissection, 4) small diameter stripping of the central stroma-endothelium-Descemet complex and its replacement with a new endothelial lamella, and 5) 2-piece microkeratome-assisted mushroom penetrating keratoplasty. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), slit-lamp examination, tonometry, and anterior corneal tomography were evaluated preoperatively, as well as 3, 6, and 12 months after surgery. Intraoperative and postoperative complications were recorded. RESULTS: Preoperative BCVA was less than 20/200 and improved to 20/40 or better in all cases, reaching 20/20 in 1 patient. Corneal clarity was restored in all eyes, and no recurrence of underlying disease was observed. No intraoperative or postoperative complications were reported. CONCLUSIONS: This case series describes several successful surgical approaches to improve the transparency and regularity of stromal interface obtained after a DALK procedure; the choice of the technique should be customized for the single eyes to still maintain the advantages of lamellar or minimally invasive grafts.

Accuracy of formulas for intraocular lens power for eyes undergoing descemet stripping automated endothelial keratoplasty and cataract surgery.

BACKGROUND: To compare accuracy in intraocular lens (IOL) power calculation in eyes undergoing combined cataract and Descemet stripping and automated endothelial keratoplasty (C-DSAEK) surgery of the following formulas: Barrett Universal II, EVO, Haigis, Hoffer Q, Holladay 2, Kane and SRK/T. METHODS: 72 eyes from 72 patients (38 males, (53%)) with a mean age 68.08 ± 8.69 years (from 44 to 88 years old) underwent combined C-DSAEK were included. The IOL powers to implant were calculated with Barrett Universal II formula targeting -1 D refraction. Preoperative and postoperative data were used to obtain the median of absolute prediction errors (MAE) targeting emmetropia with every tested formula. RESULTS: Means of MAE calculated were +1.45 D for Barrett Universal II, +1.37 D for EVO, +1.48 D for Haigis, +1.38 D for Hoffer Q, +1.37 D for Holladay 2, +1.39 D for Kane and +1.31 D for SRK/T. SRK/T MAE showed major significant (p < 0.01) differences compared to the other formulas. DISCUSSION: Even if tested formulas are not able to accurately target emmetropia, SRK/T seems to be able to provide closer results in eyes undergoing C-DSAEK.

Diffusion of curcumin in PLGA-based carriers for drug delivery: a molecular dynamics study.

CONTEXT: The rapid growth and diversification of drug delivery systems have been significantly supported by advancements in micro- and nano-technologies, alongside the adoption of biodegradable polymeric materials like poly(lactic-co-glycolic acid) (PLGA) as microcarriers. These developments aim to reduce toxicity and enhance target specificity in drug delivery. The use of in silico methods, particularly molecular dynamics (MD) simulations, has emerged as a pivotal tool for predicting the dynamics of species within these systems. This approach aids in investigating drug delivery mechanisms, thereby reducing the costs associated with design and prototyping. In this study, we focus on elucidating the diffusion mechanisms in curcumin-loaded PLGA particles, which are critical for optimizing drug release and efficacy in therapeutic applications. METHODS: We utilized MD to explore the diffusion behavior of curcumin in PLGA drug delivery systems. The simulations, executed with GROMACS, modeled curcumin molecules in a representative volume element of PLGA chains and water, referencing molecular structures from the Protein Data Bank and employing the CHARMM force field. We generated PLGA chains of varying lengths using the Polymer Modeler tool and arranged them in a bulk-like environment with Packmol. The simulation protocol included steps for energy minimization, T and p equilibration, and calculation of the isotropic diffusion coefficient from the mean square displacement. The Taguchi method was applied to assess the effects of hydration level, PLGA chain length, and density on diffusion. RESULTS: Our results provide insight into the influence of PLGA chain length, hydration level, and polymer density on the diffusion coefficient of curcumin, offering a mechanistic understanding for the design of efficient drug delivery systems. The sensitivity analysis obtained through the Taguchi method identified hydration level and PLGA density as the most significant input parameters affecting curcumin diffusion, while the effect of PLGA chain length was negligible within the simulated range. We provided a regression equation capable to accurately fit MD results. The regression equation suggests that increases in hydration level and PLGA density result in a decrease in the diffusion coefficient.

Ophthalmic Manifestations in Patients with Blood Malignancies.

Ocular complications can occur in up to 90% of patients with blood malignancies. Such complications range from direct infiltration to local hemostatic imbalance and treatment-related toxicity. This narrative review is based on a systematic computerized search of the literature conducted until January 2024 and examines the common ocular complications associated with blood cancers. Ocular complications from primary disease include mass effects from ocular adnexal lymphomas and intraocular lymphomas, with B-cell lymphomas accounting for 95% of primary ocular presentations. Secondary disease involvement from systemic hematological malignancies can lead to a wide range of ocular manifestations, such as leukemic retinopathy. Furthermore, toxicity from antineoplastic therapies and ocular graft versus host disease (oGVHD) after hematopoietic stem cell transplantation present additional risks to ocular health. In conclusion, ocular complications in blood cancer patients are an integral part of patient management, requiring regular ophthalmic evaluations and close collaboration between oncologists and ophthalmologists. Advances in therapy and an increased focus on early symptom recognition are essential for preserving vision and enhancing patient quality of life.

Phacoemulsification Under the Complex Dua Layer-Descemet-Endothelium for Combined Cataract Surgery and Penetrating Keratoplasty After Failed Deep Anterior Lamellar Keratoplasty.

PURPOSE: The aim of this study was to report the surgical management of an eye with a cataract and a failed deep anterior lamellar keratoplasty (DALK) graft. Given the null visualization of the anterior chamber, instead of performing penetrating keratoplasty (PK) combined with open-sky extracapsular extraction, the cleavage plane of the previous DALK was used to expose the transparent complex including Dua layer (DL)-Descemet membrane (DM)-endothelium and to perform phacoemulsification in a closed system; then, PK was completed after the surgical removal of the complex DL-DM-endothelium. METHODS: This study is a case report. RESULTS: A 45-year-old woman with corneal opacity due to Acanthamoeba keratitis underwent multiple (n = 2) DALK surgeries. The second DALK graft underwent failure, with the development of severe corneal edema; a dense opacity of the lens was also present. The patient was scheduled for combined PK and cataract surgery. Because the cornea was too opaque to allow closed-system cataract surgery, a partial trephination was performed with the purpose of reopening the old donor-host junction and finding the deep cleavage plane. This maneuver permitted the exposition of the complex DL-DM-endothelium that was completely transparent, thus allowing standard phacoemulsification using the phaco-chop technique. A full-thickness corneal graft was then positioned and sutured. CONCLUSIONS: This case confirms the toughness of the complex DL-DM-endothelium and reveals the transparency of this complex even in the presence of a failed endothelium, thus highlighting distinct advantages of our surgical approach over the conventional one involving PK combined with open-sky extracapsular extraction.

Impact of topographic localization of corneal ectasia on the outcomes of deep anterior lamellar keratoplasty employing large (9 mm) versus conventional diameter (8 mm) grafts.

OBJECTIVES: Visual and topographic outcomes of large (9.0 mm) versus conventional (8.0 mm) deep anterior lamellar keratoplasty (DALK) for the treatment of keratoconus (KC) were compared in relation to the different localization of the corneal ectasia (within or beyond the central 8.0 mm). METHODS: This is a retrospective, comparative case series. Preoperatively, the topographic extension of the conus was calculated by measuring the distance from the geometric center of the cornea and the outermost point of the corneal ectasia (ectasia <8.0 mm, group A; ectasia ≥8.0 mm, group B). DALK was performed using both small grafts (8.0 mm, group 1) and large grafts (9.0 mm, group 2). Best-corrected visual acuity and topographic astigmatism were evaluated preoperatively (T0) and postoperatively after complete suture removal (1 year, T1). RESULTS: Data from 224 eyes of 196 patients (mean age 37.6 ± 15.1 years) were evaluated. Topographic astigmatism improved from T0 to T1 (4.94 ± 2.92 diopters (D) [95% CI, 4.56-5.33] vs 4.19 ± 2.45 D [95% CI, 3.87-4.51], p = 0.001). There was no significant difference in postoperative topographic cylinder between group 1 and group 2 when considering eyes with corneal ectasia <8.0 mm (group 1 A, 4.15 ± 2.19 D [95% CI, 3.64-4.66] vs group 2 A, 3.65 ± 2.13 D [95% CI, 2.92-4.38], p = 0.14); conversely, the difference was significant considering eyes with corneal ectasia ≥8.0 mm (group 1B, 4.74 ± 2.90 D [95% CI, 4.09-5.38] vs group 2B, 3.68 ± 1.94 D [95% CI, 3.10-4.26], p = 0.02). CONCLUSIONS: Large 9.0-mm DALK provided better anatomical outcomes compared to conventional 8.0-mm DALK, particularly in eyes with corneal ectasia extending beyond the central 8.0 mm.

Outcomes of Conventional 8.0-mm Versus Large 9.0-mm Diameter Deep Anterior Lamellar Keratoplasty for Keratoconus.

PURPOSE: The purpose of the study was to compare the clinical outcomes of large 9.0-mm diameter and conventional 8.0-mm big-bubble deep anterior lamellar keratoplasty (DALK). METHODS: In this comparative, retrospective interventional case series, medical records of 124 cases of large 9.0-mm diameter DALK from January 2017 to December 2019 and 133 conventional 8.0-mm DALK from January 2014 to December 2016 performed by a single surgeon for the indication of keratoconus were reviewed. Main outcome measures were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism (RA), and postoperative complication rates. RESULTS: Postoperative logarithm of the minimum angle of resolution BSCVA did not significantly differ between 9.0-mm and 8.0-mm DALK at any time points. Although the cumulative percentage of eyes achieving Snellen BSCVA of 20/40 or better was comparable between groups (9.0-mm DALK: 93%, 8.0-mm DALK: 90%, P = 0.571), the cumulative percentage of eyes achieving 20/20 or better (9.0-mm DALK: 44%, 8.0-mm DALK: 26%, P = 0.01) and 20/25 or better (9.0-mm DALK: 74%, 8.0-mm DALK: 59%, P = 0.03) was significantly higher in the 9.0-mm DALK group. RA was significantly lower in the 9.0-mm DALK group compared with the 8.0-mm DALK group during all time points ( P < 0.001). The percentage of eyes with RA less than or equal to 4.0 D was significantly lower in the 9.0-mm DALK patients (90%) compared with in 8.0-mm DALK group (72%) ( P = 0.002). Postoperative complication rates were similar between groups. CONCLUSIONS: Compared with conventional 8.0-mm DALK, large 9.0-mm DALK can provide superior visual outcomes at higher levels of Snellen BSCVA and significantly lower degrees of astigmatism without an increased risk of immune rejection and graft failure.

Maternal serum eye drops to treat bilateral neurotrophic keratopathy in congenital corneal anesthesia: Case report and literature review.

PURPOSE: To report the feasibility and the successful outcomes of a pediatric neurotrophic keratopathy (NK) owing to congenital corneal anesthesia (CCA) treated with allogeneic serum eye drops obtained from the mother as the only therapy. OBSERVATIONS: A 18-month-old girl with generalized pain insensitivity presented with a large epithelial defect in the right eye (RE) and superficial punctate keratopathy (SPK) in the left eye (LE). Corneal sensitivity was completely absent in both eyes (BE). Peripheral serum eye drops obtained from the mother was prescribed and administered every 2 hours in BE. Two weeks after the beginning of treatment, compete healing of the epithelial defect in the RE was obtained, while the severity of the SPK in the LE markedly improved; in parallel, conjunctival hyperemia disappeared in BE. The treatment was continued over the course of 3 months with good tolerability and neither signs of recurrence of the epithelial defect nor other complications were noted. CONCLUSIONS AND IMPORTANCE: Allogeneic serum eye drops obtained from the mother are effective in treating pediatric NK owing to CCA. This treatment may represent a readily available and inexpensive option when topical nerve growth factor is unavailable or corneal neurotization is not feasible.

Corneal neovascularisation following deep anterior lamellar keratoplasty for corneal ectasia: incidence, timing and risk factors.

BACKGROUND: The purpose of this study was to evaluate the incidence, timing and risk factors of corneal neovascularisation (NV) after deep anterior lamellar keratoplasty (DALK) for corneal ectasia. METHODS: This study included 616 eyes who underwent DALK between 2012 and 2020 in two tertiary referral centres. In one centre topical corticosteroids were discontinued after complete suture removal 1 year after surgery, whereas in the other they were discontinued 3-4 months after surgery. The presence and severity of corneal NV was ascertained based on slit lamp photographs. Potential risk factors for corneal NV were evaluated using the Cox proportional hazards model. RESULTS: The cumulative incidence of corneal NV was 8.7% at 1 year after surgery and 13.2% at 5 years. Mean time interval from surgery to development of corneal NV was 12.8±16.2 months, with 68.9% of cases occurring before complete suture removal. Early discontinuation of topical steroids, older age and ocular allergy were associated with an increased risk of developing corneal NV (respectively, HR=2.625, HR=1.019, HR=3.726, all p<0.05). CONCLUSIONS: The risk of corneal NV is higher in the first year following DALK. Early discontinuation of topical steroids, ocular allergy and older age are significant predictors of corneal NV.

Automated digital analysis of intraoperative keratoscopy and its correlation with postoperative astigmatism after big-bubble deep anterior lamellar keratoplasty.

PURPOSE: To investigate the correlation between postoperative corneal astigmatism (PCA) and values of intraoperative keratoscopy analyzed with a newly developed automated technique in patients undergoing big-bubble (BB) deep anterior lamellar keratoplasty (DALK). METHODS: Photographs of keratoscope rings taken at the end of BB-DALK were analyzed using ImageJ for the calculation of "roundness" (R): values = 1 indicate a perfect circle. Pearson's correlation was used to evaluate the relationship between R and PCA that measured 1 week (V1), 3 months (V2), and 18 months (V3), postoperatively. The area under the curve (AUC) of receiver operating characteristic (ROC) curve was used to evaluate the accuracy of R for identifying patients with PCA < 3 diopters (D). The point on the ROC curve nearest to the coordinate (0,100) was used as a cutoff to determine sensitivity and specificity. RESULTS: Data from 121 patients were included. The mean value of R*was 0.93 ± 0.04 (range 0.76-0.99). R showed a significant correlation with PA at V3 (R = - 0.42, P < 0.01). The ROC curve had an AUC of 0.69 (95% CI 0.59-0.79). A cutoff value of R = 0.93 had a sensitivity of 70.3% and specificity of 61.0% for identifying patients with PA < 3D at V3. CONCLUSIONS: This new digital analysis of keratoscope rings allows to identify with reasonably good diagnostic accuracy patients with low values of post-DALK astigmatism correctable with spectacles.

Preliminary Results of a Novel Standardized Technique of Femtosecond Laser-Assisted Deep Anterior Lamellar Keratoplasty for Keratoconus.

PURPOSE: To evaluate the feasibility and the initial outcomes of a novel standardized surgical technique of femtosecond laser- (FSL-) assisted big-bubble deep anterior lamellar keratoplasty (BBDALK) for eyes with keratoconus. METHODS: This prospective interventional case series included 11 consecutive FSL-assisted BBDALK procedures performed for the eyes with keratoconus from September 2019 to December 2019. The FSL was used to create (i) an intrastromal channel incision (1.7 mm in length, 4.6 mm in width, 80% depth, and cut energy of 1.70 µJ) and (ii) a 9.0 mm diameter circular lamellar side cut 65 µm above the endothelium (cut energy of 0.90 µJ) intersecting the intrastromal incision. In the operating room, a blunt dissector was used to open the intrastromal channel incision, through which a blunt spatula was inserted, tangentially advanced towards the center of the cornea, and replaced with a blunt cannula for pneumatic dissection. The subsequent surgical steps did not differ from the conventional technique. Main outcome measures were the success rate of pneumatic dissection and the percentage of intraoperative complications. RESULTS: Eleven eyes of 11 patients (6 males and 5 females; mean age: 34.54 ± 13.23 years) underwent FSL-assisted DALK. Using the FSL, both corneal incisions (lamellar side cut and intrastromal channel incision) were successfully created in all cases without the need for repeat docking or additional dissection. Pneumatic dissection with type 1 bubble formation succeeded in all 11 eyes (100%). DALK surgery was completed uneventfully in all cases. Descemet membrane perforation did not occur in any case, and no procedure was converted to penetrating keratoplasty. CONCLUSION: Using standardized FSL parameters for both incision design and cut energy in BBDALK surgery, pneumatic dissection can be achieved in a very high rate of cases with minimal risk of intraoperative complications.

A Preliminary Comparative Study of Visual Performance Between Two Newly Commercially Available Monofocal Intraocular Lenses Implanted During Cataract Surgery.

PURPOSE: To compare visual outcomes of two newly developed monofocal intraocular lenses (IOLs) (I-Stream H and CT Lucia 211P) implanted in patients undergoing surgery for senile cataract. METHODS: This prospective, comparative, single-center, randomized study included 94 eyes of 94 patients undergoing cataract surgery. Patients were randomized to receive the implantation of I-Stream H IOL (Group 1) or CT Lucia 211P IOL (Group 2). Each patient underwent a complete ocular examination before (V0), 1 month (V1), 3 months (V2) and 6 months (V3) after surgery, including visual acuity testing, objective refraction, slit-lamp biomicroscopy, contrast sensitivity testing and visual function index questionnaire (VF-14). RESULTS: After surgery, a significant increase of best-corrected visual acuity (BCVA), CS and VF-14 and a significant decrease of SE were detected in both groups at each time point compared to baseline (always p<0.01). No significant differences in the postoperative increase of BCVA (p=0.12), CS (p=0.21) and VF-14 (p=0.31) and decrease of SE (p=0.08) were detected comparing patients from Group 1 and Group 2 at V3. Mean and median prediction error, as well as absolute prediction error values, did not significantly differ between the two groups (p>0.05). Eyes with an actual refraction within 0.25, 0.50 and 1 D were 53.1%, 85.1% and 100% for Group 1 and 55.3%, 87.2% and 100% for Group 2 (p>0.05). CONCLUSION: I-Stream H and CT Lucia 211P allowed a satisfied recovery of visual function after senile cataract surgery; both IOLs were shown to have similar outcomes of visual performance.

Sterile Corneal Perforation Occurring Several Years After Biliopancreatic Diversion.

BACKGROUND: To report the first two cases of sterile corneal perforation secondary to vitamin A deficiency after biliopancreatic diversion with duodenal switch (BPD/SW). METHODS: Observational case series. RESULTS: Two patients with a history of BPD/SW presented with corneal perforation associated with conjunctival xerosis and keratopathy. In both cases, serum vitamin A level dosage revealed a marked deficit, and the patients admitted poor compliance with vitamin supplementation. Oral therapy with vitamin A was started immediately, and in one case ocular surgery was performed to preserve the integrity of the globe. CONCLUSIONS: Ophthalmologists should carefully examine the ocular surface of patients undergone bariatric surgery in order to promptly recognize the signs of vitamin A deficiency and avoid serious sight-threatening complications.

Comparison of corneal densitometry between big-bubble and visco-bubble deep anterior lamellar keratoplasty.

AIMS: To evaluate deep corneal densitometry and visual outcomes after big-bubble (BB-DALK) and visco-bubble (VB-DALK) deep anterior lamellar keratoplasty performed in patients with keratoconus. METHODS: Prospective comparative study of 50 advanced keratoconic patients who underwent DALK surgery; 25 eyes (group I) were completed with BB-DALK and 25 eyes (group II) with VB-DALK after the failure of pneumatic dissection. Best spectacle-corrected visual acuity (BSCVA), corneal tomographic parameters and endothelial cell count were recorded 1, 3, 6, 12 and 24 months after surgery. Densitometric analysis of the deep corneal interface was obtained using Scheimpflug tomography at each visit; values recorded were compared between the two groups and statistically analysed. RESULTS: BSCVA was significantly better in the BB-DALK group than the VB-DALK group (0.39±0.29 vs 0.65±0.23 logarithm of the minimum angle of resolution, respectively) for the first 3 months; and in the same time period, densitometry was significantly higher in the VB-DALK group than those recorded in the BB-DALK group (23.97±5.34 vs 17.13±4.44 grayscale units). However, densitometric values and visual acuity did not differ significantly in the two groups at 1 year. No statistically significant difference for the other variables analysed at any time frame was found. CONCLUSION: The use of viscoelastic substance in the VB-DALK technique may induce modification of interface stromal reflectivity resulting in reduced visual acuity up to 3 months postoperatively. However, this initial negative effect on the interface quality does not affect the long-term visual outcome, with densitometric values and visual outcomes similar in the two groups from 6 months postoperatively.

Predictors of Bubble Formation and Type Obtained With Pneumatic Dissection During Deep Anterior Lamellar Keratoplasty in Keratoconus.

PURPOSE: To identify predictors of bubble formation and type during big-bubble deep anterior lamellar keratoplasty (BB-DALK) performed in keratoconus at different stages of severity. DESIGN: Retrospective Cohort Study. METHODS: Setting: University Magna Græcia (Catanzaro, Italy); Study Population: Consecutive keratoconus patients undergoing BB-DALK from September 2014 to February 2019. OBSERVATION PROCEDURE: Keratometric astigmatism, mean keratometry value (K-mean), highest keratometry value (K-max), thinnest point, anterior segment optical coherence tomography (AS-OCT)-based stage of ectasia. MAIN OUTCOME MEASURES: Rate of bubble formation and type; number and fate of micro-/macroperforation; conversion to mushroom keratoplasty (MK); comparison of parameters in patients with bubble formation vs failure and in type 1 vs type 2 bubble; areas under the curves (AUC) of preoperative parameters for distinguishing between bubble types. RESULTS: Pneumatic dissection succeeded in 113 of 155 eyes (72.9%), with 100 type 1 bubbles (88.4%), 11 type 2 (9.8%), and 2 mixed-type (1.8%). Microperforations were managed conservatively in type 1 bubbles; macroperforations occurring in both types of bubbles required conversion to MK. Preoperative K-mean and K-max values were significantly higher in eyes in which bubble formation succeeded (respectively, P = .006 and P < .013). Type 1 bubbles formed in eyes with significantly lower age, K-mean, and AS-OCT stages and higher pachymetric values (always P < .029). Age had the highest diagnostic power for discrimination between bubble types, followed by AS-OCT stage, pachymetry, K-mean, and astigmatism (respectively, AUC = 0.861, 0.779, 0.748, 0.700, 0.670). CONCLUSIONS: Older age and advanced stages of keratoconus were predictors of type 2 bubble formation during BB-DALK that was associated with an increased risk of complications.

Results of viscobubble deep anterior lamellar keratoplasty after failure of pneumatic dissection.

AIM: To report the outcomes of bubble formation obtained by means of intrastromal injection of ophthalmic viscoelastic device (OVD) after failure of pneumatic dissection for deep anterior lamellar keratoplasty (DALK). METHODS: DALK was performed in 140 keratoconic eyes of 130 patients by injecting air and OVD only secondarily, after pneumatic dissection had failed; the bubble formation rates after air and OVD injection were recorded; complications, best spectacle-corrected visual acuity (BSCVA) and corneal tomographic parameters were evaluated 3 months, 6 months and 12 months postoperatively, as well as after complete suture removal. RESULTS: Air injection created a big bubble in 106/140 eyes (75.71%); OVD injection was not attempted in 4 eyes (perforation during cannula insertion n=2; air bubble burst n=2) and created a big bubble in 28 of the remaining 30 eyes (93.33%, 20% of the total). Manual dissection was required in 2/30 eyes (6.66%, 1.42% of the total) after failed OVD-assisted dissection.Deep folds, interface opacity and reduced BSCVA were noted in both eyes after failed OVD-assisted dissection. BSCVA was statistically better after pneumatic-assisted than after OVD-assisted dissection (P 0.01) only up to 3 months postoperatively; no statistically significant differences were recorded between the two techniques at later examinations. CONCLUSION: Intrastromal injection of OVD after failed pneumatic dissection increases considerably the success rate of bubble formation (from 75.71% to 95.71% in our series); however, when bubble formation fails, infiltration of OVD into the residual stroma makes manual dissection particularly challenging and causes severe interface haze resulting in poor visual outcomes.