Predicting Long-Term Endothelial Cell Loss after Preloaded Descemet Membrane Endothelial Keratoplasty in Fuchs' Endothelial Corneal Dystrophy: A Mathematical Model

(1) Background: This study offers a biexponential model to estimate corneal endothelial cell decay (ECD) following preloaded "endothelium-in" Descemet membrane endothelial keratoplasty (DMEK) in Fuchs' endothelial corneal dystrophy (FECD) patients; (2) Methods: A total of 65 eyes undergoing DMEK alone or combined with cataract surgery were evaluated. The follow-up period was divided into an early phase (first 6 months) and a late phase (up to 36 months). Endothelial cell count (ECC) and endothelial cell loss (ECL) were analyzed; (3) Results: The half time of the ECD was 3.03 months for the early phase and 131.50 months for the late phase. The predicted time-lapse interval to reach 500 cells/mm2 was 218 months (18.17 years), while the time-lapse interval to reach 250 cells/mm2 was 349 months (29.08 years). There was no statistically significant difference between the ECL in DMEK combined with cataract extraction and DMEK alone at 24 months (p ≥ 0.20). At the late phase, long-term ECL prediction revealed a lower ECC half time in patients undergoing DMEK combined with cataract surgery (98.05 months) than DMEK alone (250.32 months); (4) Conclusions: Based on the mathematical modeling, a predicted average half-life of a DMEK graft could reach 18 years in FECD. Moreover, combining cataract extraction with DMEK could result in excessive ECL in the long term.

Retropupillary Iris-fixated versus Sutured Scleral-fixated Intraocular Lenses

Aim: To compare the anatomical and functional results and patient satisfaction following retropupillary implantation of Artisan Aphakia iris-fixated intraocular lens (rAAIF) and sutured scleral fixated intraocular lens (SFIOL). Subjects and methods: We presented a prospective double-arm non-blinded study. Forty-one eyes with acquired aphakia, no age-related macular degeneration, no previous keratoplasty, no combined procedures, no AC reaction (cells, fibrin), normal intraocular pressure, no history of endothelial corneal dystrophy in relatives or fellow eye were included. Indications, complications, corrected distance visual acuity (CDVA), endothelial cell density (ECD), and patient satisfaction score were assessed. Results: Retropupillary AAIF was implanted in 21 (51.22%) eyes and SFIOL in 20 (48.78%) eyes. The most common indication was complicated cataract surgery in 18 cases (43.90%), followed by trauma in 16 (39.02%), and spontaneous dislocation in 7 (17.07%). No difference between rAAIF and SFIOL in terms of sex, laterality (χ=0.13, p=0.72), indications (χ=0.78, p=0.68), previous ocular history, and comorbidities was observed. The complications and the visual outcomes at 6 months postoperatively were similar between the two groups (p=0.95 and p=0.321, respectively). The ECD loss in the two groups was also similar (p=0.89). The patient satisfaction score was 58.67±8.80 in the rAAIF and 56.69±11.50 in the SFIOL group, which was statistically similar (p=0.764). Conclusion: Retropupillary AAIF and SFIOL showed similar results concerning visual acuity, endothelial cell loss, and patient satisfaction. Careful preoperative individual assessment is required to have optimal results with either technique. Abbreviations: AAIF = Artisan Aphakia iris-fixated intraocular lens, rAAIF = retropupillary Artisan Aphakia iris-fixated intraocular lens, CDVA = corrected distance visual acuity, ECD = endothelial cell density, IOL = intraocular lens, SD = standard deviation, SFIOL = scleral fixated intraocular lens.

Diagnostic Techniques to Increase the Safety of Phakic Intraocular Lenses

Preoperative and postoperative diagnostics play an important role in ensuring the safety of patients with phakic intraocular lenses (pIOLs). The risk of endothelial cell loss can be addressed by regularly measuring the endothelial cell density using specular microscopy and considering the endothelial cell loss rate and the endothelial reserve in accordance with the patient's age when deciding whether to explant a pIOL. The anterior chamber morphometrics, including the anterior chamber depth and the distance between the pIOL and the endothelium, measured using Scheimpflug tomography and anterior segment optical coherence tomography (AS-OCT), can help to assess the risk of the endothelial cell loss. In patients undergoing posterior chamber pIOL implantation, accurate prediction of the vault and its postoperative measurements using AS-OCT or Scheimpflug tomography are important when assessing the risk of anterior subcapsular cataract and secondary glaucoma. Novel approaches based on ultrasound biomicroscopy and AS-OCT have been proposed to increase the vault prediction accuracy and to identify eyes in which prediction errors are more likely. Careful patient selection and regular postoperative follow-up visits can reduce the complication risk and enable early intervention if a complication occurs.

Evaluation of striate keratopathy after manual small-incision cataract surgery and its final outcomes in a tertiary hospital

Purpose

To study the demographic profile, contributing and precipitating factors, the severity of striate keratopathy and its relation with endothelial cell count, and evaluate the final treatment outcome of striate keratopathy.

Methods: This observational

analytical cohort study was conducted on 75 patients developing striate keratopathy after MSICS in the immediate postoperative period. Demographic profile, preoperative risk factors, and intraoperative complications were evaluated retrospectively. Postoperatively, slit-lamp grading of striate keratopathy was done, and specular microscopy of both eyes was taken. Treatment of striate keratopathy was initiated, and patients were followed up for 6 to 10 weeks for improvement.

Results

Striate keratopathy was most commonly associated with surgeries performed by resident surgeons (92%), longer duration of surgery, associated predisposing factors, and intraoperative or postoperative complications. On postoperative day 1, the majority of patients had moderate and severe striate keratopathy (66% and 32%, respectively). It was associated with significant endothelial cell loss (ECL) at the final follow-up (P = 0.0016). Striate keratopathy resolved in 97.3% of patients, irrespective of the treatment with hypertonic saline. At 6 to 10 weeks, 92% of patients achieved a BCVA of ≥6/9.

Conclusion

A careful preoperative evaluation, adequate training of resident surgeons, meticulous surgical technique, and prompt management of postoperative complications can lead to a decrease in the incidence of striate keratopathy in the majority of cases. The use of hypertonic saline eye drops does not change the final outcome, and most cases resolve spontaneously during follow-up.

Corneal Endothelial Cell Loss in Patients After Minimally Invasive Glaucoma Surgery: Current Perspectives

Minimally invasive glaucoma surgery (MIGS) is a rapidly expanding category of surgical glaucoma treatment options that offer a superior safety profile compared with traditional approaches for reducing intraocular pressure. However, MIGS may cause corneal endothelial cell loss; therefore, it has been receiving increasing attention. This systematic review aimed to evaluate and compare the rate and degree of corneal endothelial loss after MIGS. First, this paper presents an overview of the theoretical effectiveness of MIGS, the fundamental aspects regarding the roles of endothelial cells, and the effect of cataract surgery on the quality and count of endothelial cells. Further, we detail the various surgical techniques involved in MIGS, the development of these techniques over the time, and clinical aspects to consider with respect to the endothelial cell count. We discuss in detail the COMPASS-XT study, which was based on data collected over 5 years, reported that withdrawal of the CyPass Micro-Stent (Alcon Laboratories) yielded increased corneal endothelial cell loss. Generally, MIGS procedures are considered safe, with the incidence of complications ranging from 1% to 20% depending on the surgery type; however, there is still need for studies with longer follow-up. Thus, an adequate count of endothelial cells in the central cornea portion is recommended as necessary for candidate patients for MIGS.

Severe Corneal Edema Increases ECL From Grafts After DSAEK-Corneal Edema and ECL After DSAEK

OBJECTIVES

To determine the relationship between the preoperative degree of corneal edema in the recipient and the endothelial cell density in grafts after Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

This retrospective case series enrolled 111 eyes of 107 patients who underwent DSAEK. The preoperative and postoperative central corneal thickness (CCT) was measured by anterior-segment optical coherence tomography. Eyes were divided into three groups according to the preoperative recipient CCT: group A (mild edema): 550 μm

RESULTS

The recipient CCT (all groups combined) was 805.99±132.70 μm preoperatively and decreased to 656.31±105.02 μm at 1 month, decreased to 626.08±81.40 μm at 6 months, and remained stable between 12 (P=0.144) and 24 months (P=0.485) postoperatively. The mean ECL was 27.34±15.43%, 33.56±17.13%, 39.18±16.71%, and 45.87±14.27% at 1, 6, 12, and 24 months, respectively. The percentage of ECL in group C was higher than that in the other 2 groups through the 24-month follow-up. The difference in ECL between groups A and C was significant at 24 months (group A: 42.45±14.47%; group C: 52.49±10.65%; P=0.019).

CONCLUSIONS

The degree of corneal edema in the recipient was associated with implant ECL. Compared with mild and moderate corneal edema, the severe corneal edema may cause greater ECL after DSAEK.

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Key Words

• dsaek
• endothelial cell loss
• degree of corneal edema

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MESH Headings

• Corneal Diseases/etiology
• Corneal Diseases/surgery
• Corneal Edema/etiology
• Corneal Edema/surgery
• Descemet Stripping Endothelial Keratoplasty/adverse effects
• Descemet Stripping Endothelial Keratoplasty/methods
• Endothelial Cells
• Endothelium, Corneal/transplantation
• Humans
• Retrospective Studies

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Affiliation(s)

Shaofeng Gu Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.
Rongmei Peng Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.
Gege Xiao Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.
Jing Hong Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.

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Qualitative Alterations on Corneal Endothelial Cell Morphometry and Hexagonality After Cataract Surgery

Aim

To deeply analyze quantitative and qualitative changes of corneal endothelium after longitudinal phacoemulsification.

Methods

In this prospective interventional case series study, 50 eyes with age-related cataract have been evaluated preoperatively, intraoperatively and postoperatively. The measured parameters were surgically induced endothelial cell loss (ECL), average endothelial cell area (AVG) and hexagonality (HEX).

Results

The relationship among the measured parameters and the energy dissipated during the two phases of phacoemulsification, sculpting and quadrant removal, has been analyzed with regard to the 5-score harm scale, a new method suggested to categorize cataracts. Two phases of phacoemulsification are linearly related (r = 1.5, P < 0.001, r² = 79%). Plus, a quadratic model described the correlation between the percentages of ECL and AVG (P < 0.0001), while there was no specific model for the correlation between ECL and HEX.

Conclusion

The 5-score harm scale allows to predict the mean changes in percentages of ECL, AVG and HEX of endothelial cells after longitudinal phacoemulsification. Also, this study confirms that the main damage on corneal endothelium is due to the energy delivered in the second phase of phacoemulsification.

Comparison of Femtosecond Laser-Assisted Cataract Surgery and Conventional Phacoemulsification on Endothelial Cell Density When Using Torsional Modality

Purpose

To compare the effects of femtosecond laser assisted cataract surgery (FLACS) and manual phacoemulsification on cumulative dissipated energy (CDE), torsional amplitude, and endothelial cell density (ECD).

Patients and Methods

This prospective, randomized study was conducted at Oka Eye Clinic (Fukuoka, Japan). Surgeries were performed using FLACS (with LenSx) or conventional technique in adults ≥20 years with grade 2–4 cataracts. Visits included preoperative, surgery day, and 5 postoperative visits (days 1, 4–10, 20–40, 60–120, and 150–210). Primary endpoint was CDE. Secondary endpoints included ECD percent change at day 150–210 versus preoperative visit and average torsional amplitude on surgery day. Exploratory endpoints included central corneal thickness and corrected distance visual acuity (CDVA). Superiority of FLACS to conventional technique was evaluated using t-tests based on a mixed model for repeated measures.

Results

Full analysis set included 53 eyes per group. Mean cataract grade was 2.92±0.58 in FLACS and 2.94±0.57 in conventional group. FLACS versus conventional method had significantly lower mean CDE (0.213±0.334 versus 1.718±0.898%-seconds, respectively; P<0.0001), demonstrating superiority of FLACS. Low endothelial cell loss (ECL) was achieved with both FLACS and conventional methods (1.5±5.6% and 2.7±5.2%; P=0.260). Torsional amplitude was significantly lower for FLACS versus conventional method (19.6±16.0% versus 31.1±6.6%; P<0.0001). Central corneal thickness was comparable for both methods at all visits except day 1; CDVA was comparable for both methods at all postoperative visits.

Conclusion

FLACS achieved significantly lower CDE compared with the conventional surgical method (P<0.0001). Low ECL was achieved with both FLACS (1.5%) and conventional (2.7%) methods.

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Endothelial cell loss rate after penetrating keratoplasty: optical versus therapeutic grafts

Background

This study aimed to compare the rate of endothelial cell loss (ECL) after penetrating keratoplasty (PKP) for optical versus therapeutic grafts at 3-, 6-, and 12-month postoperatively. Furthermore, the study aimed to investigate postoperative graft viability and the rate of graft rejection during the first year of follow-up for both indications.

Methods

This was a prospective, observational, comparative study that included patients who sought medical advice at the cornea outpatient clinic of Ain Shams University Hospitals, Cairo, Egypt. The study recruited 60 patients: group 1 included 30 transplanted corneas of 30 patients who underwent optical PKP for various indications, while group 2 included 30 transplanted corneas of 30 patients who underwent therapeutic PKP for unhealed, resistant infectious keratitis. Specular microscopy was performed for all patients at the 3-, 6-, and 12-month follow-up visits using Nidek CEM-530 specular microscopy. Postoperative clinical examinations were performed at the same follow-up visits to detect graft rejection.

Results

There were no statistically significant differences between the groups concerning the postoperative timing of graft clarity or the rate of ECL at 3- and 6-months postoperatively; however, the rate of ECL was significantly greater in group 2 than in group 1 at 12-months postoperatively (P = 0.03), although the difference was small from a clinical point of view. Moreover, there was no statistically significant difference between the groups in terms of the graft rejection rate.

Conclusions

Therapeutic PKP results were comparable to optical PKP with respect to graft viability, the rate of ECL, and the rate of graft rejection 1 year after grafting.

Overall clinical outcomes of Descemet membrane endothelial keratoplasty in 600 consecutive eyes: A large retrospective case series

Purpose:

To analyze the overall clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) in 600 consecutive cases.

Methods:

Retrospective, consecutive interventional case series operated by a single surgeon. Six hundred consecutive eyes of 524 patients with endothelial dysfunctions of different etiologies scheduled for DMEK were included in this study. All donor tissues were prepared by the operating surgeon during the procedure, using McCarey Kaufman medium or Cornisol-preserved cornea with endothelial cell density (ECD) of ≥2500 cells/mm². Indications, postoperative best spectacle-corrected visual acuity (BSCVA), ECD, endothelial cell loss (ECL), and complications were analyzed postoperatively between 3 months and 2 years.

Results:

The commonest indication was post-cataract corneal edema/bullous keratopathy in 262 (43.7%) eyes followed by Fuchs′ endothelial corneal dystrophy 218 (36.3%). Vision affected comorbidities were present in 91 (15.2%) eyes. In phakic eyes with cataract (222; 37%), DMEK was combined with cataract surgery (Triple-DMEK). BSCVA of ≥20/25 was achieved in 41.0%, 46.4%, 49.2%, and 48.7% of eyes at 3, 6, 12, and 24 months, respectively and stabilized at 6 months (P = 0.54). Mean ECD decreased from 2884 ± 178 cells/mm² (n = 600) before surgery to 2223 ± 321 (n = 597), 2099 ± 354 (n = 524), 1918 ± 373 (n = 374), and 1772 ± 439 cells/mm² (n = 158) at 3, 6, 12, and 24 months respectively. The corresponding mean ECL was 22.9 ± 11.4%, 27.2 ± 12.4%, 33.5 ± 13.0%, and 38.6 ± 14.3%, respectively (P < 0.05 for all-time points). The commonest complication was DM detachment in 59 (9.8%) eyes of which 23 (3.8%) eyes required rebubbling. Three (0.5%) eyes had primary graft failure. Endothelial rejection occurred in 7 (1.2%) eyes until the last follow-up.

Conclusion:

DMEK is a safe and effective procedure in different types of endothelial diseases with encouraging surgical and clinical outcomes. Complications are less and ECL percentage up to 2 years is acceptable.

Corneal Endothelial Cell Changes After Phacoemulsification Combined with Excisional Goniotomy with the Kahook Dual Blade or iStent: A Prospective Fellow-Eye Comparison

Purpose

To characterize changes in endothelial cell density and morphology following phacoemulsification combined with either excisional goniotomy with the Kahook Dual Blade (KDB-phaco) or first-generation iStent trabecular microbypass implantation (iStent-phaco).

Setting

A single clinical practice.

Methods

Twenty-one adult subjects from one center with visually significant cataract and mild-moderate open-angle glaucoma underwent KDB-phaco or iStent-phaco in one eye and the alternate procedure in the fellow eye as part of a prospective, multicenter, randomized trial. Specular microscopy and pachymetry were performed before and 6–29 months after surgery. Parameters analyzed included change from baseline of endothelial cell density (ECD), the coefficient of variation (CV), the percent of hexagonal cells (%HEX), and central corneal thickness (CCT).

Results

Baseline ECD, CV, %HEX, and CCT were similar between groups. A mean (standard deviation) of 18.2 (5.8) months postoperatively (range 12.5–28.7 months), the change from baseline in ECD was −90 ± 226 cells/mm² (−3.4%) in KDB-phaco eyes (p=0.083) and −239 ± 247 cells/mm² (−9.0%) in iStent-phaco eyes (p<0.001); the change in iStent-phaco eyes was significantly greater than in KDB-phaco eyes (p=0.013). The magnitude of Endothelial Cell Loss (ECL) was not correlated with length of postoperative follow-up time in either group. No significant differences in change from baseline in CV, %HEX, or CCT were noted with the exception of a decrease in %HEX in iStent-phaco eyes (p=0.017). No eyes manifested corneal edema, decompensation, or other cornea-related complications.

Conclusion

Both KDB-phaco and iStent-phaco are associated with postoperative ECL, with iStent-phaco producing significantly greater ECL than KDB-phaco. The clinical significance of these findings is unclear, and future studies are warranted to more robustly characterize long-term effects of glaucoma surgical procedures—with and without permanent implants—on ECD and corneal health and to develop evidence-based guidelines for the pre- and post-operative evaluation of corneal health in eyes undergoing glaucoma surgery.

Graft survival and endothelial outcomes after penetrating keratoplasty and Descemet stripping automated endothelial keratoplasty: A systematic review and meta-analysis

The present study aimed to compare the outcomes of graft survival, endothelial cell loss and vision improvement between penetrating keratoplasty (PK) and Descemet stripping automated endothelial keratoplasty (DSAEK) for treating corneal endothelium diseases. The PubMed, CENTRAL (Cochrane) and Embase databases were searched for records added until September 20, 2019. The studies considered were two-arm prospective and retrospective studies comparing outcomes of interest between PK and DSAEK. Ultimately, 10 studies were included with a total of 2,634 patients (910 eyes treated with DSAEK; 1,804 eyes treated with PK). Assessment of the summary effect by meta-analysis suggested that, compared with PK treatment, DSAEK was associated with a greater improvement from baseline in best spectacle-corrected visual acuity [difference (diff.) in means of change from baseline=-0.225, 95% CI=-0.341 to -0.109, P<0.001] and a reduced loss of endothelial cell density (diff. in means=-292.05 cells/mm², 95% CI=-419.53 to -146.57 cells/mm², P<0.001). Graft survival rates were similar using either PK or DSAEK (odds ratio=1.005, 95% CI=0.329-3.071, P=0.993). The overall results suggested that DSAEK may have an advantage over PK for corneal endothelial dysfunction in terms of the visual acuity outcome. The absence of definite time frames in the comparisons limits the conclusions on endothelial cell loss and graft survival.

Active-fluidics-based torsional phacoemulsification in diabetic eyes: A prospective interventional study

Purpose:

To compare the outcomes of active-fluidics based torsional phacoemulsification in diabetics and nondiabetics using a balanced tip.

Methods:

Two hundred and forty-eight patients undergoing senile cataract surgery using torsional phacoemulsification on an active-fluidics-based platform from December 2016 to August 2017 were included in this prospective, nonrandomized, interventional cohort study; of the 248 patients, 54 were controlled diabetics and 194 were nondiabetics. Intraoperative parameters such as cumulative dissipated energy (CDE), total ultrasound time, torsion usage time, torsion amplitude, aspiration time, and fluid usage were documented and compared. Endothelial cell loss (ECL) and central corneal thickness (CCT) were evaluated at 1 month postoperatively.

Results:

Diabetics and nondiabetics did not differ in CDE, total ultrasound time, torsion amplitude, aspiration time, fluid usage, endothelial cell count, and CCT. ECL on Day 1 (10.2 ± 8.0%) and Day 30 (11.05 ± 8.3%) were significantly higher in diabetics (P = 0.025 and P = 0.045, respectively). There was an increase in CCT on Day 1 (P = 0.018), which settled by Day 30. Grade 4 cataracts in diabetics had significantly higher CCT at Day 1 (P = 0.032) and Day 30 (P = 0.007). In the diabetic subgroup, Grades 3 and 4 cataracts required lower CDE (P < 0.001) and Grade 4 cataracts showed higher ECL than others till 1 month of follow-up (P < 0.05).

Conclusion:

Intraoperative and postoperative parameters after torsional phacoemulsification are comparable in diabetics and nondiabetics. Endothelial changes and pachymetry may be related to the grade of cataract in diabetics.

Endothelial keratoplasty: The relationship between recipient anterior chamber depth and endothelial cell loss

PURPOSE

To determine the relationship between anterior chamber depth (ACD) and percent endothelial cell loss (ECL) after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK).

METHOD

In 78 eyes receiving triple procedure (DSAEK combined with cataract extraction and posterior chamber intraocular lens (PCIOL) implantation), ACD was measured preoperatively with an intraocular lens (IOL) Master and ECL was calculated with specular microscopy at 6 months, 1, 2, 3, and 4 years postoperatively. ACD and ECL from all 78 eyes were compared using correlation analysis and students t test. Eyes were then separated into 2 groups based on ACD, group 1 with ACD < 3mm and group 2 with ACD ≥ 3mm. Students t test was then performed to compare group 1 and group 2 ECL at 6 months, 1, 2, 3, and 4 years postoperative.

RESULTS

Mean ACD for all 78 eyes was 2.93 ± 0.43 mm. Mean ECL was 32.7%, 27.6%, 29.6%, 32.5%, and 37.2% at 6 months, 1, 2, 3, and 4 years. No significant correlation between ACD and ECL was observed at any time point for the combined analysis of 78 eyes (P > .05). At 2 and 4 years postoperative, mean ECL was 32.6% ± 16.1% and 43.0% ± 23.2% in eyes with ACD < 3mm and 25.3% ± 13.0% and 29.6% ± 18.2% in eyes with ACD ≥ 3 mm (P = .041 at 2 years and .008 at 4 years).

CONCLUSION

ACD and ECL were not directly correlated; however, there may be a threshold ACD in which shallower anterior chambers preoperatively result in greater donor ECL over time.

Central corneal thickness changes following manual small incision cataract surgery versus phacoemulsification for white cataract

Aim: To assess the central corneal thickness (CCT) and endothelial cell loss after manual small-incision cataract surgery and phacoemulsification in patients with white cataract. Material and methods: This is a comparative, prospective, non-randomized study on 42 patients with white cataract, who underwent cataract surgery. The patients were divided into manual small-incision cataract surgery (21 eyes, MSICS group) and phacoemulsification cataract surgery group (21 eyes, phaco group). The endothelial cell density (ECD), central cornea thickness (CCT), and corrected distance visual acuity (CDVA) were evaluated at 1 day, 1 week, 4 weeks, and 3 months postoperatively. The results of 20 cases of nuclear sclerosis grade II-III (LOCS III) who underwent phacoemulsification by the same surgeon were also compared. Propensity scoring was used to adjust for confounding by selection bias. Results: The CCT increased after surgery in both groups. The thickness was greater in the phaco group on first day postoperatively (73 µ increase in MSICS group and 138 µ in phaco group, p=0.008) and it returned to preoperative levels 1 month postoperatively. The endothelial cell loss was lower in the MSICS group at 3 months postoperatively (11.8% in MSICS group and 15.8% in phaco group, p=0.111). The CDVA was not different in both groups at 1 week and 4 weeks postoperatively (p>0.05). Conclusions: Manual small-incision cataract surgery for white cataract provided less central corneal thickness changes compared to conventional phacoemulsification. Abbreviations: CCT = central corneal thickness; ECD = endothelial cell density; CDVA = corrected distance visual acuity; APT = absolute phacoemulsification time; EPT = effective phacoemulsification time; MSICS = Manual small-incision cataract surgery in white cataract; Phaco II = Phacoemulsification in white cataract; Phaco I = phacoemulsification in NS 2 + Cataract; Phaco = Phacoemulsification in white cataract; APACRS = Asia-Pacific Association of Cataract and Refractive Surgeons.

Seven-day storage of pneumatically dissected Descemet's endothelial grafts with and without Dua's layer

PURPOSE

To evaluate the efficacy of big-bubble (BB) technique in separating Dua's layer together with the Descemet's membrane endothelial (DE) graft and the effect of 7-day storage of the prepared tissues on the endothelial cells.

METHOD

This is an experimental study in which 21 human corneo-scleral tissues unsuitable for transplantation were used. Grafts were mounted on artificial chamber; epithelial side-up with BB technique was used to detach the DE graft. The resultant tissues were stored in tissue culture medium for 7 days. Dua's layer presence, endothelial cell density (ECD), endothelial cell loss and viability were assessed after the dissection and at 7 days after storage.

RESULTS

Complete detachment of DE grafts was achieved in 20 cases (95.24%). Histological analysis revealed Dua's layer presence in 14 cases (70%). The mean ECD for the corneas before dissection was 2375 ± 338 cells/mm(2) with significant reduction to 2200 ± 319 cells/mm(2) (p < 0.00001) with endothelial cell loss of 7.3 ± 3.5% and non-viable cells of 6.5 ± 2.5% at the end of the 7-day storage. On comparing the dissected DE grafts with Dua's layer versus those without at 1 day after dissection and at 7 days after storage, we found no statistically significant changes in endothelial cell loss (p = 0.387; p = 0.836 respectively) and non-viable cells percentage (p = 0.180; p = 0.260, respectively).

CONCLUSION

Big-bubble technique is reproducible in dissecting DE grafts with minimal damage to the endothelial cells. The percentage of endothelial cell loss and non-viable cells is similar in the DE grafts with/without Dua's layer after 7-day storage.

Suture pull-through insertion of graft donor in Descemet stripping automated endothelial keratoplasty: Results of 4-year follow-up

Purpose:

To report our clinical experience and 4-year follow-up results of Descemet stripping automated endothelial keratoplasty (DSAEK) with the suture pull-through insertion technique.

Methods:

This is a retrospective study of 195 eyes in which a posterior lamellar keratoplasty was performed between 2007 and 2011. The insertion of a folded donor lenticule was performed with a double-armed 10-0 suture using a straight transchamber needle and half-circle needle. Endothelial cell density was measured annually up to 4 years after the surgery, and cell loss was calculated based on the median preoperative donor endothelial cell density. Postoperative complications, primary graft failure, pupillary block, and dislocation of the donor tissue were assessed.

Results:

All patients underwent uncomplicated DSAEK. Data were available for 195 eyes (100%) at 1 year, 186 eyes (95.3%) at 2 years, 176 eyes (90.2%) at 3 years, and 160 eyes (82%) at 4 years. Median preop-erative donor endothelial cell density was 2688 cells/mm² [interquartile range (IQR) 207.5 cells/mm²], which decreased by 27% at 1 year (1956 cells/mm², IQR 264.8 cells/mm²), 31% at 2 years (1855 cells/mm², IQR 320.5 cells/mm²), 35% at 3 years (1756.5 cells/mm², IQR 306.5 cells/mm²), and 36% at 4 years (1709.5 cells/mm², IQR 288,0 cells/mm²). Nine patients (4.6%) had a dislocation of donor tissue; all were successfully reattached with a second air injection. Only three eyes (1.5%) developed graft failure. Pupillary block was present in 15 eyes (7.7%).

Conclusion:

DSAEK with suture pull-through insertion of donor graft represents a simplified and safe technique that has endothelial cell loss comparable with other techniques and low rates of intraoperative and postoperative complications.

Impact of low versus high fluidic settings on the efficacy and safety of phacoemulsification

PURPOSE

  To compare intraoperative efficiency and postoperative outcomes of cataract surgery with low and high fluidic settings.

METHODS

  In this prospective, randomized, single-blinded study, 114 eyes of 57 patients were operated with low fluidic settings for one eye (group I) and high fluidic settings for the other eye (group II). Efficiency was judged as metred surgery time, effective phacoemulsification time (EPT) and the amount of balanced salt solution used. Visual outcome and endothelial cell count were determined 1 week and 18 months postoperatively.

RESULTS

  The overall effective phacoemulsification energy was statistically significantly lower (p = 0.003) in group II than in group I. Conquest of the nuclei was achieved with about two-thirds of the energy needed in group I, with 6.59 ± 4.79 effective ultrasound energy compared with 3.99 ± 3.18 (p = 0.001). Overall, about 12% more solution was used in group II than in group I. Median visual acuity was 1.0 for both groups 18 months after surgery. The mean endothelial cell loss was 5.0% in eyes in group I compared with 6.3% in eyes in group II (p > 0.5).

CONCLUSION

  Switching from low fluidic settings with a conventional coaxial 20G phacoemulsification tip to higher fluidic settings with a microcoaxial phaco tip statistically significantly decreases EPT. As only marginally more solution was used with the higher aspiration flow, occlusion must be accomplished more often with high than with low fluidics. Aspiration of the quadrants was therefore more efficient with high fluidic settings. The enhanced pump speed did not result in more tissue damage.

Effect of incision width on graft survival and endothelial cell loss after Descemet stripping automated endothelial keratoplasty

PURPOSE

To assess the effect of incision width (5.0 and 3.2 mm) on graft survival and endothelial cell loss 6 months and 1 year after Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

One hundred sixty-seven subjects with endothelial decompensation from a moderate-risk condition (principally Fuchs dystrophy or pseudophakic corneal edema) underwent DSAEK by 2 experienced surgeons. The donor was folded over and inserted with single-point fixation forceps. This retrospective analysis assessed graft survival, complications, and endothelial cell loss, which was calculated from baseline donor and 6-month and 1-year postoperative central endothelial images evaluated by an independent specular microscopy reading center.

RESULTS

No primary graft failures occurred in either group. One-year graft survival rates were comparable (98% vs 97%) in the 5.0- and 3.2-mm groups, respectively (P = 1.0). Complications included graft dislocation, graft rejection episodes, and elevated intraocular pressure and occurred at similar rates in both groups (P > or = 0.28). Pupillary block glaucoma did not occur in either group. Mean baseline donor endothelial cell density did not differ: 2782 cells per square millimeter in the 5.0-mm (n = 64) and 2784 cells per square millimeter in the 3.2-mm (n = 103) groups. Percent endothelial cell loss was 27% +/- 20% (n = 55) versus 40% +/- 22% (n = 71; 6 months) and 31% +/- 19% (n = 45) versus 44% +/- 22% (n = 62; 12 months) in the 5.0- and 3.2-mm incision groups, respectively (both P < 0.001).

CONCLUSIONS

One year after DSAEK, overall graft success was comparable for the 2 groups; however, the 5.0-mm incision width resulted in substantially lower endothelial cell loss at 6 and 12 months.

Influencing factors on chronic endothelial cell loss characterised in a homogeneous group of patients

BACKGROUND/AIM

Advanced donor age, long death to excision time interval, and factors related to organ culture can trigger unfavourable intracellular processes in the graft endothelium and contribute to chronic endothelial cell loss after penetrating keratoplasty. The aim of this study was to investigate factors influencing chronic endothelial cell loss in a homogeneous group of patients.

METHODS

177 patients after first normal risk keratoplasties for keratoconus were retrospectively selected from the quality control database of our clinic. For 71 of them at least four central endothelial cell density values were documented in follow up. From these patients, only those 53 without any further intraocular procedures, without glaucoma, and without graft rejection were considered. A scatter plot of logarithmised endothelial cell density values against postoperative time was drawn for each patient. The slope of the regression line then equals the constant of decay in central endothelial cell density. The influence of donor age and storage time in organ culture on this index value of cell loss was investigated by means of linear regression analysis.

RESULTS

Mean loss of central endothelial cell density was 16.7% per year. Regression analysis revealed a statistically significant negative linear effect of both postmortem time (beta = -0.324; p = 0.014) and donor age (beta = -0.282; p = 0.036) and a trend for storage time in organ culture (beta = -0.195; p = 0.142) in a combined linear regression model.

CONCLUSION

Increased postmortem time and advanced donor age exert a significant negative effect on chronic endothelial cell loss. Storage time in organ culture seems to be third influencing factor. These negative influences may be reduced by compensating advanced donor age with minimised postmortem and storage time.