Background: The number of corneal transplants is rising, with the aim to treat a spectrum of diseases ranging from dystrophies to corneal opacities caused by trauma or chemical burns. Refractive outcomes after this procedure are often impossible to predict and associated with high levels of astigmatism. However, there are many techniques that affect the reduction of astigmatism and improve the quality of life of patients. Objectives: The aim was to compare the improvement in postoperative visual acuity (logMAR) and amount of corneal astigmatism (Diopters) after corneal keratoplasty in patients who additionally underwent a surgical procedure, which affects the reduction in postoperative astigmatism, and to determine the most effective method. Search Methods and Selection Criteria: A thorough search was carried out across online electronic databases including PubMed, Embrase, Ovid MEDLINE, Scopus, and Web of Science, using combinations containing the following phrases: postoperative astigmatism, post-keratoplasty astigmatism, anterior lamellar keratoplasty (ALK), deep anterior lamellar keratoplasty (DALK), posterior lamellar keratoplasty, endothelial keratoplasty (EK), penetrating keratoplasty (PK), corneal transplant, keratoplasty, refractive surgery, kerato-refractive surgery, laser in situ keratomileusis (LASIK), and femtosecond LASIK. This was to determine all English-language publications that discuss refractive operations for postoperative or post-keratoplasty astigmatism. These bibliographies were searched for English-language publications published between 2010 and 2023. We proceeded to review each detected record\'s reference list. Data Extraction: Study characteristics such as study design, sample size, participant information, operations performed, and clinical outcomes were all extracted. Data Statistical Analyses: The Comprehensive Meta-Analysis software (version 3.3.070, 2014) was used to perform the analysis. The threshold of 0.05 for p-values was considered statistically significant. All effect sizes are reported as standardized differences (Std diff) in means with a 95% confidence interval (CI) and visualized graphically as forest plots. Publication bias is presented as a funnel plot of standard error by Std diff in means. Four methods were used to evaluate the heterogeneity among the studies: Q-value, I2, chi-square (χ2), and tau-squared. Main Results: We included 21 studies that randomized 1539 eyes that underwent corneal transplantation surgery either by PKP, DALK, or DSEAK techniques. The results showed the most significant improvement in the visual acuity and significant decrease in the corneal astigmatism after laser surgery procedures, like femtosecond-assisted keratotomy after DALK and PKP and LASIK after DSEAK.

OBJECTIVE: To determine the influence of gaps [places where neither the donor\'s nor the recipient\'s Descemet\'s membrane (DM) is present] and overlaps (places where the recipient\'s DM is covered by the donor\'s DM) on the frequency of postoperative detachment of DM endothelial keratoplasty (DMEK) lamellae.
METHODS: Totally 64 eyes of 64 patients with Fuchs\' endothelial dystrophy or bullous keratopathy indicated for DMEK were randomly divided in two groups. The diameter of the implanted DMEK lamella was the same in both groups (8 mm), but we changed the diameter of the removed recipient DM. In the first group (32 eyes), the circular area was approximately 8.5 mm (gaps); in the second group (32 eyes), the diameter was 7.5 mm (overlaps). Postoperatively we noted all cases of detachment visible on the slit lamp and these cases we indicated for rebubbling. We also measured the uncorrected distance visual acuity (UDVA) as well as corrected distance visual acuity (CDVA) in decimal and postoperative endothelial cell density (ECD). The minimum follow-up time was 6mo.
RESULTS: The number of rebubbling procedures in the entire group of patients was 13, i.e., 20.3%, with 6 eyes (18.7%) in the gap group, and 7 eyes (21.9%) in the overlap group. Lamella replacement (re-DMEK) was required in 3 (gap group) and 2 patients (overlap group), respectively. The difference between the groups was statistically insignificant. The UDVA was 0.54±0.21 in the gap group and 0.58±0.24 in the overlap group. The CDVA was 0.74±0.22 and 0.80±0.16, respectively. ECD was 1920±491 and 2149±570 cells/mm2. The small differences between both groups were not statistically significant.
CONCLUSIONS: We do not notice any difference in the group of patients with overlaps or gaps of DM. The presence of small areas of gaps or overlaps does not affect the frequency of detachment of the DMEK lamellae.

OBJECTIVE: To evaluate the results of posterior lamellar keratoplasties (DMEK and PDEK) in phakic eyes.
METHODS: Retrospective analysis of surgeries performed in our department between June 2016 and December 2019. The main focus was put on postoperative visual acuity, corneal endothelial cell density and possible peroperative and postoperative complications including cataract formation.
RESULTS: We performed 12 surgeries on 11 eyes of 7 patients. The most prevalent primary diagnosis was Fuchs endothelial dystrophy (7 eyes), followed by bullous keratopathy after phakic anterior chamber IOL implantation (2 eyes) and ICE syndrome (2 eyes). The average length of follow-up was 12.5 months. Clinically significant complicated cataract had developed and was removed in 3 eyes, one eye required rebubbling due to graft detachment and one eye required rePDEK due to graft failure. At the end of follow-up, the average visual acuity was 0.87, while 82% of eyes achieved VA 0.8 or better, and the average endothelial cell density was 1589 cells/mm2.
CONCLUSIONS: Posterior lamellar keratoplasties (DMEK and PDEK) can be performed on phakic eyes. When performed by an experienced surgeon, these are safe procedures with good postoperative results and significant advantage in preserving younger patients accommodation.

OBJECTIVE: To describe a new technique for management of recalcitrant deep stromal keratitis using posterior lamellar keratectomy.
METHODS: A 66-year-old pseudophakic male presented with deep stromal corneal infiltrates, extending from 2 to 4 o\'clock in the vicinity of the limbus of the left eye, 3 months after phacoemulsification. The infiltrates failed to respond to empirical topical medications, anterior chamber wash and intrastromal injection. Posterior lamellar keratectomy was done to debulk the infectious load. In this technique the diseased posterior lamella was excised through a sclerocorneal lamellar pocket without a donor graft.
RESULTS: The infection subsided within 2 weeks after posterior lamellar keratectomy. Patient achieved best corrected visual acuity (BCVA) of 20/60 with complete resolution of symptoms at 2 weeks follow up. Till the last follow-up at 6 months, the patient maintained BCVA of 20/60 with no sign of recurrence or corneal decompensation at the keratectomy site.
CONCLUSIONS: Posterior lamellar keratectomy is a simple, effective and inexpensive technique for management of small, peripheral, deep-seated recalcitrant keratitis. It leads to radical treatment of the disease like therapeutic penetrating keratoplasty but in a less invasive manner and without a donor graft.

UNASSIGNED: Single Observational Case Report.
UNASSIGNED: A 67-year-old male of Persian descent had a complex systemic and ocular history prior to a right penetrating keratoplasty (PK) reported here. The clinical diagnoses leading to the PK included Cogan\'s syndrome, chronic uveitis, secondary glaucoma, and corneal stromal scarring, presumed secondary to a corneal ulcer diagnosed on the second visit to our clinic. The specimen described here had been in place for 11 months and 17 days after the third failed Descemet stripping endothelial keratoplasty (DSEK). Visual acuities had ranged from 20/100 to 20/400 in both eyes. Visual acuity in the right eye just before surgery was 20/400. Intraocular pressures were 22 mmHg in both eyes with functioning Ahmed glaucoma shunts. The stromal cyst was not suspected preoperatively and no clinical imaging was performed.
UNASSIGNED: Histopathology including serial sections and immunohistochemistry.
UNASSIGNED: Histologic study demonstrated a trans-stromal corneal epithelial cyst without goblet cells that extended through a 500 μm gap in the donor tissue surface and edge.
UNASSIGNED: This large stromal cyst was an unusual complication of serial posterior lamellar keratoplasties and we postulate that multiple prior posterior lamellar grafts may have been a risk factor for this complication. Anterior segment imaging with either anterior segment optical coherence tomography or high-resolution ultrasound would likely have detected this stromal cyst.

In 2020 Descemet membrane endothelial keratoplasty (DMEK) has become the gold standard in Germany for the treatment of corneal endothelial diseases; however, the widespread use of DMEK was initially limited due to problems with donor preparation and the difficulty of correctly and gently unfolding the endothelial Descemet membrane (EDM) in the anterior chamber. Following the situational donor selection, the safe single-handed donor preparation of the cornea without tearing or even rupturing the EDM, including the indispensable peripheral semicircular orientation marking. Also presented is a step by step atraumatic loading of the glass cartridge, the introduction of the EDM roll into the anterior chamber, and its safe step by step unfolding based on (1) the sequential use of jets of fluid, (2) repeated tapping on the peripheral/central cornea, (3) controlled flattening of the anterior chamber, (4) use of air bubbles of defined size and finally, the fixation of the EDM in correct orientation to the back of the host cornea with a gas bubble. Since every wrong step with DMEK can have far-reaching consequences for patient and surgeon, this step by step pragmatic approach should minimize the incidence of donor tissue damage and failure in patient maneuvers.

OBJECTIVE: To evaluate clinical results of posterior lamellar keratoplasty performed with Russian femtosecond laser «Vizum» for treating patients with primary and secondary corneal endothelial dystrophies.
METHODS: The study included 30 operated eyes: 10 with Fuch\'s primary endothelial dystrophy of the cornea and 20 with secondary endothelial dystrophy. Patients were examined on the 7th day, as well as at 3, 6, 12 and 24 months after the surgery. All 28 patients (30 eyes) were followed-up for 12 months, 12 patients (14 eyes) were followed-up for 24 months.
RESULTS: In 3 months after the surgery, transparent engraftment was observed in most cases. In 1 case, its primary failure was diagnosed and repeated keratoplasty was performed. Postoperative haze in host-donor interface was observed in 1 case. Central corneal thickness (CCT) was 554±43 µm. Transplant thickness in the central zone was 80±13 µm. The amount of eyes with Best Spectacle-Corrected Visual Acuity (BSCVA) of 0.3 was 43%. Endothelial cells density (ECD) was 1538±500 cells/mm2. Endothelial cells loss amounted to 30.4%. By the 12th month, recipient\'s cornea and the transplant remained transparent in all cases. Haze in the host-donor interface was still observed in 1 case. CCT was 581±47 µm, transplant thickness was 80±16 µm. The amount of eyes with BSCVA of 0.3 was 53%. Keratometry astigmatism was 2.08±1.47 D, refractive astigmatism - 1.72±0.83 D. ECD was 1324±383 cells/mm2. Endothelial cells loss amounted to 40.1%. At 24th months after the surgery (12 patients, 14 eyes) the recipient\'s cornea and the transplant remained clear in all cases. CCT was 591±48 µm, transplant thickness was 81±15 µm. Amount of eyes with BSCVA of 0.3 was 71.4%. ECD was 1426±422 cells/mm2. Endothelial cells loss - 35.1%.
CONCLUSIONS: The predictability of applanation and high quality of cutting of the «Vizum» femtosecond laser assure the predictability of the process of preparing an ultrathin cornel graft from the endothelial side. Clinical results have demonstrated its effectiveness for rehabilitation of visual functions (up to BSCVA 1.0).
UNASSIGNED: Оценить клинические результаты задней послойной кератопластики с применением российского фемтосекундного лазера «Визум» для лечения пациентов с первичной и вторичной эндотелиальной дистрофией роговицы.
UNASSIGNED: Прооперировано 30 глаз: 10 — с первичной эндотелиальной дистрофией роговицы Фукса и 20 — со вторичной. Проведено обследование на сроках 7 дней, 3, 6, 12 и 24 мес после операции. Все 28 пациентов (30 глаз) имеют срок наблюдения 12 мес, 12 больных (14 глаз) — 24 мес.
UNASSIGNED: Через 3 мес после операции в большинстве случаев наблюдали прозрачное приживление. В одном случае диагностировали первичную его недостаточность, выполнена ре-кератопластика, в одном случае визуализировали хейз. Центральная толщина роговицы (ЦТР) — 554±43 мкм. Толщина трансплантата в центральной зоне — 80±13 мкм. Доля глаз с корригированной остротой зрения (КОЗ), равной 0,3, составляла 43%. Плотность эндотелиальных клеток (ПЭК) — 1538±500 кл/мм2. Потеря эндотелиальных клеток (ЭК) — 30,4%. К 1 году роговица реципиента и трансплантат сохраняли прозрачность во всех случаях. Хейз в зоне интерфейса наблюдали в одном случае. ЦТР — 581±47 мкм, толщина трансплантата — 80±16 мкм. Доля глаз с КОЗ ³0,3 составляла 53%. Астигматизм по данным кератометрии составил 2,08±1,47 дптр, рефрактометрии — 1,72±0,83 дптр. ПЭК — 1324±383 кл/мм2, потеря ЭК — 40,1%. На сроке наблюдения 2 года роговица реципиента и трансплантат были прозрачны во всех случаях. ЦТР — 591±48 мкм, толщина трансплантата — 81±15 мкм. Доля глаз с КОЗ, равная 0,3 и выше, составляла 71,4%. ПЭК — 1426±422кл/мм2, потеря ЭК — 35,1%.
UNASSIGNED: Предсказуемость аппланации и высокое качество реза фемтосекундного лазера «Визум» обеспечивают прогнозируемый процесс заготовки ультратонкого трансплантата с задней поверхности донорской роговицы. Клинические результаты свидетельствуют о возможности достижения высоких зрительных функций (вплоть до КОЗ 1,0).

Glaucoma is a well-known complication after corneal transplantation surgery. Traditional corneal transplantation surgery, specifically penetrating keratoplasty, has been slowly replaced by the advent of new corneal transplantation procedures: primarily lamellar keratoplasties. There has also been an emergence of keratoprosthesis implants for eyes that are high risk of failure with penetrating keratoplasty. Consequently, there are different rates of glaucoma, pathogenesis, and potential treatment in the form of medical, laser, or surgical therapy.

BACKGROUND: Laboratory analysis and optical quality assessment of explanted hydrophilic intraocular lenses (IOLs) with clinically significant opacification after posterior lamellar keratoplasty (DMEK and DSAEK).
METHODS: Thirteen opacified IOLs after posterior lamellar keratoplasty, 8 after descemet stripping automated endothelial keratoplasty (DSAEK), 3 after descemet membrane endothelial keratoplasty (DMEK) and 2 after both DSAEK and DMEK were analysed in our laboratory. Analyses included optical bench assessment for optical quality, light microscopy, scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDS).
RESULTS: In all IOLs the opacification was caused by a thin layer of calciumphosphate that had accumulated underneath the anterior optical surface of the IOLs in the area spared by the pupil/anterior capsulorhexis. The calcifications lead to a significant deterioration of the modulation transfer function across all spatial frequencies of the affected IOLs.
CONCLUSIONS: The instillation of exogenous material such as air or gas into the anterior chamber increases the risk for opacification of hydrophilic IOLs irrespective of the manufacturer or the exact composition of the hydrophilic lens material. It is recommended to avoid the use of hydrophilic acrylic IOLs in patients with endothelial dystrophy that will likely require procedures involving the intracameral instillation of air or gas, such as DMEK or DS(A)EK.

OBJECTIVE: To assess the added value of intraoperative optical coherence tomography (iOCT) in evaluating graft adhesion and graft interface in patients undergoing descemet\'s stripping automated endothelial keratoplasty (DSAEK).
METHODS: This is a prospective single-center case series comprising 8 eyes of 8 patients consecutively scheduled for DSAEK surgery. iOCT imaging was performed after insertion of the graft, after pressurizing the eye, and at the end of surgery (three images per surgery). At each stage of surgery, corneal thickness and the widest gap between the recipient and the graft (i.e., maximal interface width) were measured using an image processing tool. Follow-up measurements were taken at 1 day, 3 and 6 months, post-operatively.
RESULTS: Imaging was performed in 21 of 24 scheduled imaging intervals, and required little to no additional surgical time. At the end of surgery, iOCT showed persisting interfaces in six cases. One case showed a full graft detachment necessitating surgical intervention.
CONCLUSIONS: Real-time iOCT is a safe, efficient, and useful tool in assessing graft adherence in DSAEK surgery. With adequate analysis software, iOCT has the potential to be a paradigm-shifting development in posterior lamellar surgery and could aid the clinician in further lowering the rates of graft dislocation after DSAEK.