Role of Anterior Segment Optical Coherence Tomography in Staging and Evaluation of Treatment Response in Infectious Keratitis

PURPOSE

The aim of this study was to evaluate the role of anterior segment optical coherence tomography during follow-up of infectious keratitis and to assess response to treatment.

METHODS

This was a prospective, consecutive, observational clinical series of cases. Twenty-three eyes of 23 patients with clinically proven fungal keratitis were included in the study. The patients received medical treatment according to clinical diagnosis, and follow-up was performed weekly. Slit-lamp examination and photography, and anterior segment optical coherence tomography were performed at initial and follow-up visits until corneal healing occurred. The main outcome measures included infiltrate depth, width, and density; central corneal thickness; minimal corneal thickness; corneal thickness at the site of the lesion; and stromal thickness at the center of the lesion.

RESULTS

Twenty-three eyes of 23 patients (17 men and 6 women), mean age 42.5 ± 19 (8-66) years, were clinically diagnosed with fungal keratitis. Localization was central in 14 cases and paracentral/peripheral in 9 cases. Healing time was 6 to 12 weeks. Minimal corneal thickness, corneal thickness at the site of lesion, and stromal thickness at the center of lesion, and also infiltrate width and depth changed significantly from the first visit to the healing stage at the last follow-up (0.009, 0.001, 0.007, 0.001, and <0.001, respectively).

CONCLUSIONS

In cases of fungal keratitis, anterior segment optical coherence tomography can provide the clinician with a quantitative assessment of a number of corneal parameters that can be used to determine effectiveness of therapy and confirm complete healing of the lesions that cannot be achieved by clinical evaluation.

CLINICAL TRIAL REGISTRATION

The study was registered in Clinical Trials.gov with NCT04969640.

Outcomes of two different treatment modalities in mild to moderate keratoconus

PURPOSE

To describe visual and refractive outcomes of intrastromal corneal ring segments (ICRS) and toric implantable collamer lenses (TICL) implantation in cases of mild and moderate keratoconus.

METHODS

A prospective descriptive interventional case series. 40 eyes were allocated into two groups. First group (20 eyes) was treated with corneal collagen crosslinking (CXL) 1 month after ICRS implantation and the second group was treated using TICL after 1 year of CXL.

RESULTS

Both groups showed statistically significant improvement in spherical equivalent, cylindrical refraction, uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) over the follow-up period.

CONCLUSION

Both ICRS and TICL are effective in treatment of mid and moderate keratoconus with more predictable visual results with TICL.

Type 2 diabetes and thyroid cancer: Synergized risk with rising air pollution

Diabetes is a complex condition, and the causes are still not fully understood. However, a growing body of evidence suggests that exposure to air pollution could be linked to an increased risk of diabetes. Specifically, exposure to certain pollutants, such as particulate Matter and Ozone, has been associated with higher rates of diabetes. At the same time, air pollution has also been linked to an increased risk of thyroid cancer. While there is less evidence linking air pollution to thyroid cancer than to diabetes, it is clear that air pollution could have severe implications for thyroid health. Air pollution could increase the risk of diabetes and thyroid cancer through several mechanisms. For example, air pollution could increase inflammation in the body, which is linked to an increased risk of diabetes and thyroid cancer. Air pollution could also increase oxidative stress, which is linked to an increased risk of diabetes and thyroid cancer. Additionally, air pollution could increase the risk of diabetes and thyroid cancer by affecting the endocrine system. This review explores the link between diabetes and air pollution on thyroid cancer. We will discuss the evidence for an association between air pollution exposure and diabetes and thyroid cancer, as well as the potential implications of air pollution for thyroid health. Given the connections between diabetes, air pollution, and thyroid cancer, it is essential to take preventive measures to reduce the risk of developing the condition.

Validation of the Diagnostic and Prognostic Values of ADAMTS5 and FSTL1 in Osteoarthritis Rat Model

OBJECTIVE

Osteoarthritis (OA) is a global public health problem and a leading cause of morbidity and disability. Due to lack of sensitive and specific tools for early OA diagnosis and predicting prognosis, the availability of new reliable and sensitive biomarkers is a widely appreciated need to identify patients at risk for incident disease or disease progression. Accordingly, our study was conducted to validate the usefulness of disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) and follistatin-like protein 1 (FSTL1) to achieve this goal.

DESIGN

Fifty-four male Wistar rats were randomized into 3 groups; 24 rats were subjected to medial meniscal tear (MMT) surgery on the right knee joint (OA group), 24 rats were subjected to sham surgery (sham group), and 6 healthy rats (negative control group). Six animals from each group were sacrificed every 2 weeks. At each time point, the right knee joint of each animal was visualized radiologically, a blood sample was collected, and cartilage tissues were isolated for histopathological and western blot analysis.

RESULTS

We found that the expression levels of ADAMTS5 and FSTL1 significantly increased with OA progression, especially at weeks 4, 6, and 8 after surgery. Notably, the serum levels of ADAMTS5 and FSTL1 showed significant positive correlations with each other and with the studied inflammatory markers.

CONCLUSIONS

Our findings suggest that ADAMTS5 and FSTL1 can serve as important and informative serological markers of disease activity in OA. However, further research is needed to validate their use for improving the diagnosis and prognosis of OA in humans.

Epidemiology, clinical profile and treatment outcomes of bacterial and fungal keratitis

PURPOSE

The purpose of the study is to determine the microbiological etiology, epidemiological factors, and clinical profile and treatment outcomes of infective keratitis in Ophthalmology department, Minia University, Egypt.

METHODS

Prospective, nonrandomized, observational clinical series of cases, including 150 patients with mean age 30 (range 12 to 85 years), 90 patients (60%) were males and 60 (40%) were females, clinically diagnosed as infective corneal ulcer, attending the Ophthalmology Department-Faculty of Medicine. Minia University, Minia, Egypt. From December 2018 to December 2020. Detailed history taking and all clinical findings were collected. Corneal scrapings were obtained from patients and subjected to staining and culture for bacterial and fungal pathogens; Bacterial and fungal growth were identified by standard laboratory procedures.

RESULTS

Corneal trauma by a vegetative matter was the commonest risk factor associated with infective keratitis in 92 cases (61.3%). Smear and culture was positive in 83 cases (58.4%) of 142 corneal scrapings obtained, of which 60 cases were fungal (72.3%), 21 cases were bacterial (25.3%) and two cases were mixed bacterial and fungal (2.4%), Aspergillus species was the commonest fungal species isolated in fungal keratitis. One hundred forty-two cases (94.67%) healed completely with scar. Only six cases (4%) required evisceration due to aggressive presentation from the start and keratoplasty was performed for two cases (1.33%).

CONCLUSIONS

Fungal keratitis was the commonest type in cases attending to our department. Adequate diagnosis, management and follow-up helped in achieving high successful curative outcomes.

CLINICAL TRIAL NUMBER

Clinical Trials.gov ID: NCT04894630. Time of registration 1 December 2018.

Combined Platelet Rich Plasma and Amniotic membrane in the treatment of Perforated Corneal Ulcers

PURPOSE

To report the outcomes of using synthetic amniotic membrane with platelet rich plasma for the primary management of corneal perforations.

SETTING

Ophthalmology department. Faculty of Medicine, Minia University, Minia, Egypt.

METHODS

A case series of 10 patients diagnosed with corneal perforation underwent emergency surgical procedure for repair of the perforation through the implantation of synthetic amniotic membrane with platelet-rich plasma clot under it and the application of platelet-rich plasma eye drops, with a follow up period of up to 4 weeks.

RESULTS

All cases demonstrated formation of adequate intraocular pressure digitally, within the first 7 days, and all cases showed complete sealing of the corneal perforation within the 4 weeks follow up period, mild symptoms were reported only in the 1^st postoperative week like foreign body sensation and lacrimation. 3 of the treated patients underwent penetrating keratoplasty after 6 months with satisfactory visual outcomes.

CONCLUSION

The combination of amniotic membrane implant and platelet rich plasma in both the clot and eye drop forms is an effective and easy accessible method for the primary management of corneal perforations.

Long Non-Coding RNAs Gene Variants as Molecular Markers for Diabetic Retinopathy Risk and Response to Anti-VEGF Therapy

Background

Long non-coding RNAs (lncRNAs) play essential roles in molecular diagnosis and therapeutic response in several diseases.

Purpose

For the first time, we aimed to evaluate the association of four lncRNAs TUG1 (rs7284767G/A), MIAT (rs1061540T/C), MALAT1 (rs3200401C/T), and SENCR (rs12420823C/T) variants with susceptibility to diabetic retinopathy (DR), disease severity, and early therapeutic response to intravitreous anti-vascular endothelial growth factor aflibercept therapy.

Patients and Methods

This case-control study enrolled 126 adult patients with type 2 diabetes. TaqMan assays using Real-Time PCR were run for genotyping. Multivariable regression analyses were applied to assess the role of each polymorphism after the adjustment of covariates.

Results

Carriers of TUG1 A/G and MIAT T/C and C/C genotypes were more likely to develop DR [OR=3.15 (95% CI=1.15–8.64), and OR=4.31 (95% CI=1.78–10.47)], while MALAT1 T/C conferred protection (OR=0.40, 95% CI=0.16–0.99). For TUG1, MALAT1, MIAT, and SENCR genotype combinations, GTCT and GCCC had a higher disease risk (P=0.012). For disease severity, MIAT T/T homozygosity was associated with higher DR grade [33.3% (T/T) vs 10% (C/C) and 4.2% (C/T) carriers, P=0.012]. Otherwise, patients with the SENCR T variant exhibited better pre-treatment best-corrected visual acuity level (p=0.021). Following aflibercept administration, carrying the TUG1 A or MIAT T/C was associated with a poor therapeutic response (OR=5.02, 95% CI=1.60–15.76, and OR=10.23, 95% CI=1.51–69.15, respectively).

Conclusion

The lncRNAs TUG1 (rs7284767G/A) and MIAT (rs1061540T/C) were associated with increased DR susceptibility and poor response to aflibercept treatment, while MALAT1 (rs3200401C/T) conferred protection to DR. These genetic determinants could be useful in DR risk stratification and pharmacogenetics after validation in large-scale studies.

The Value of Anterior Segment Optical Coherence Tomography in Different Types of Corneal Infections: An Update

Anterior segment optical coherence tomography (AS-OCT) is a modality that uses low-coherence interferometry to visualize and assess anterior segment ocular features, offering several advantages of being a sterile and noncontact modality that generates high-resolution cross-sectional images of the tissues. The qualitative and quantitative information provided by AS-OCT may be extremely useful for the clinician in the assessment of a wide spectrum of corneal infections, guiding in the management and follow-up of these patients. In clinical practice, infections are routinely evaluated with slit-lamp biomicroscopy, an examination and imaging modality that is limited by the physical characteristics of light. As a consequence, the depth of pathology and the eventually associated corneal edema cannot be accurately measured with the slit-lamp. Therefore, it represents a limit for the clinician, as in vivo information about corneal diseases and the response to treatment is limited. Resolution of corneal infection is characterized by an early reduction in corneal edema, followed by a later reduction in infiltration: both parameters can be routinely measured with standardized serial images by AS-OCT.

Incidence and Reasons for Intrastromal Corneal Ring Segment Explantation

PURPOSE

To determine the main causes of intrastromal corneal ring segment (ICRS) explantation and define the incidence rate.

DESIGN

Multicenter, observational consecutive case series.

METHODS

Consecutive cases of ICRSs explanted in the last 10 years were reviewed. Clinical data included age of the patients at explantation, reasons for implantation and explantation, date of implantation and explantation, tunnel creation technique, and ICRS type. Main outcomes measures were the reasons for ICRS removal and the incidence rate.

RESULTS

During the study period, 121 ICRSs (119 patients) were explanted, with an explantation rate of 5.60%. Functional failure (74 eyes, 61.16%) represents the main cause for ICRS removal: of them, 48 (39.67%) ICRSs were removed for refractive failure and 26 (21.49%) in the setting of a keratoplasty related to poor visual performance of the implanted eye. In addition, 47 eyes (38.84%) had ICRS removal for anatomic failure: among them, 36 (29.75%) were explanted for spontaneous extrusion (overall extrusion rate: 1.58%), 7 (5.79%) for suspected infectious keratitis, 3 (2.48%) for corneal melting, and 1 (0.83%) for corneal perforation. Mild cases of keratoconus were more prone to be explanted because of a loss of the initial improved visual acuity, whereas spontaneous extrusion happened often in advanced cases of keratoconus.

CONCLUSIONS

We report the largest series of ICRS explantation as of this writing. The main cause of explantation was functional refractive failure followed by spontaneous extrusion of the ICRS, that is, correlated to an anatomic failure at the site of implantation in an advanced disease.

Association of VEGF Gene Family Variants with Central Macular Thickness and Visual Acuity after Aflibercept Short-Term Treatment in Diabetic Patients: A Pilot Study

INTRODUCTION

Diabetic retinopathy (DR) is one of the major vision-threatening causes worldwide. Searching for an individualized therapeutic strategy to prevent its progress is challenging.

OBJECTIVE

This work aimed to investigate the association of angiogenesis-inducer vascular endothelial growth factor (VEGF) gene family and related receptor variants (rs833069, rs12366035, rs7664413, rs7993418, and rs2305948) with susceptibility of DR and the response to 1 dose of aflibercept treatment in type 2 diabetes mellitus (T2DM).

METHODS

Consecutive eligible patients with T2DM (n = 125) and 110 unrelated controls were enrolled in this preliminary prospective case-controlled study. Genotyping was identified using TaqMan real-time PCR. Adjusted odds ratio (OR) with 95% confidence interval (CI) was applied to assess the strength of the association with the clinical/ophthalmological characteristics and early response to intravitreal aflibercept treatment in terms of improved visual acuity (BCVA) and central macular thickness (CMT).

RESULTS

We found that both VEGFB rs12366035 and VEGFC rs7664413 conferred higher risk for DR progression under allelic (OR [95% CI]: 1.71 [1.07-2.74]), homozygote comparison (3.55 [1.32-9.57]), and recessive (3.77 [1.43-9.93]) models for the former and under allelic (2.09 [1.25-3.490, homozygote comparison (2.76 [1.02-7.45]), and recessive (2.62 [0.98-6.98] models for the latter. In contrast, VEGFR1 rs7993418 conferred protection against DR under heterozygote comparison and dominant models. The rs12366035*T/T genotype showed the worst pretreatment BCVA score (0.35 ± 0.24) compared to other corresponding genotypes (0.66 ± 0.26 in C/T and 0.54 ± 0.25 in C/C carriers) (p = 0.008). Meanwhile, patients with rs7993418*G/G of VEGFR1 exhibited a significant reduction in CMT after aflibercept injection (12.26 ± 35.43 µ in G/G vs. 3.57 ± 8.74 µ in A/A) (p = 0.037).

CONCLUSIONS

Polymorphisms of the studied VEGF/receptors could be considered as genetic risk factors of DM/DR development and could play an important role in aflibercept early response for DR patients in the study population.

Surgery for glaucoma in modern corneal graft procedures

Glaucoma is a common cause of vision loss after corneal transplantion and is considered a major risk factor for graft failure. Glaucoma may be present before corneal transplant surgery, or increased intraocular pressure may develop after keratoplasty in up to one-third of patients. Pre-existing glaucoma should be controlled before keratoplasty, either medically or surgically. For postkeratoplasty increase in intraocular pressure; identifying the risk factors allows appropiate follow-up and management. Patients undergoing anterior lamellar keratoplasty may take advantage of reduced rates of postkeratoplasty glaucoma. Glaucoma also complicates eyes with endothelial keratoplasties, mostly related to management of intraocular pressure spikes derived from anterior chamber air bubbles. Nevertheless, the severity is less, and the intraocular pressure is more easily controlled when compared with penetrating keratoplasty. Adequate management of glaucoma that develops before or after keratoplasty may save eyes from irreversible damage to the optic nerve and increase graft survival.

Circulating long noncoding RNAs H19 and GAS5 are associated with type 2 diabetes but not with diabetic retinopathy: A preliminary study

Recently, a wide range of biological and pathological roles of long noncoding RNAs (lncRNAs) have been discovered. However, the potential role of circulating lncRNAs H19 and GAS5 in type 2 diabetes mellitus (T2DM) and diabetic retinopathy (DR) is not clear. Here, we assessed the plasma levels of H19 and GAS5 lncRNAs in T2DM patients with/without DR and evaluated if H19 and GAS5 pre-treatment plasma levels are a predictor of early response to a single aflibercept dose in DR subgroup. Plasma lncRNA expression profiles of 119 T2DM patients (66 with DR and 53 without DR) and 110 healthy controls were determined by quantitative reverse transcription PCR. The association of lncRNA expression profiles with clinical features and aflibercept early response in DR patients was investigated. Relative H19 expression levels were significantly increased in T2DM group (including DR and non-DR subgroups) vs. controls, while GAS5 levels were decreased in T2DM group (p < 0.001). There was no significant difference in H19 and GAS5 expression levels between DR and non-DR subgroups. H19 and GAS5 expression profiles were not significantly correlated with clinical parameters or response to aflibercept therapy in DR subgroup. Our findings indicate that the circulating lncRNAs H19 and GAS5 may be associated with T2DM prevalence but may not have an important diagnostic/prognostic role in DR or early response to aflibercept intravitreal injection in DR patients. Large-scale transcriptomic studies are warranted to validate our results and investigate other lncRNA candidates in T2DM.

Three-snip punctoplasty versus perforated plugs for management of lacrimal punctal stenosis

PURPOSE

To compare rectangular three-snip punctoplasty and polyvinylpyrrolidone-coated perforated punctal plugs for treatment of acquired lacrimal punctal stenosis.

PATIENTS AND METHODS

In a prospective comparative non-randomized interventional study, 80 eyes with acquired lacrimal punctal stenosis were classified into two groups. Group A was treated by insertion of polyvinylpyrrolidone-coated perforated punctal plugs (FCI ophthalmics)™ and Group B was treated by rectangular three-snip punctoplasty. The study was done in Minia University Hospital between January 2018 and April 2019. Exclusion criteria included allergic punctal stenosis, lid malposition, and lacrimal obstruction distal to the punctum. All patients were subjected to complete history taking, slit lamp examination of tear meniscus height, fluorescein dye disappearance test, punctal position, shape, size, grading of stenosis, and grading of epiphora.

RESULTS

The mean age of the patients was 43.85 ± 14.93 years. They were 30 females and 10 males. Eepiphora Grade 3 or 4, improved postoperatively to Grade 0 or 1 in 97.5% of eyes in Group A versus 55% of eyes in Group B. All eyes (100%) in Group A versus 21 eyes (52.5%) in Group B improved regarding fluorescein dye disappearance test grade (p < 0.001). Restenosis did not occur after plug removal, while it occurred in 10% of eyes subjected to three-snip punctoplasty.

CONCLUSION

Perforated punctal plugs and three-snip punctoplasty are safe and effective in treatment of punctal stenosis. However, perforated plugs are less invasive, better tolerated, and have more stable results compared to three-snip punctoplasty.

Evaluation of acquired punctal stenosis using anterior segment optical coherence tomography

BACKGROUND/OBJECTIVES

The aim of this article was to study the lower punctum parameters in patients with acquired punctal stenosis using spectral-domain anterior segment optical coherence tomography.

SUBJECTS/METHODS

This was a prospective nonrandomized study that included two groups. Group 1 was composed of 32 puncta from 32 subjects (11 males and 21 females, aged 40-62 years) with epiphora and clinically diagnosed punctal stenosis. Group 2 (control group) included 30 puncta from 30 normal subjects (10 males and 20 females, aged 43-63 years). Anterior segment optical coherence tomography was employed to evaluate lower punctum parameters in all subjects; the inner and outer punctal diameters as well as punctal depth were measured.

RESULTS

External punctal diameter (mean: 466.1 ± 120.3 μm), internal punctal diameter (mean: 173.4 ± 55.6 μm) and punctal depth (mean: 188.4 ± 67 μm) values in Group 1 were statistically significantly lower than those in Group 2 (mean: 745.7 ± 156.9 μm, mean: 384 ± 119.1 μm, and mean: 284.9 ± 57.7 μm, respectively).

CONCLUSION

Anterior segment optical coherence tomography could possibly be used as a noncontact and noninvasive diagnostic modality for evaluating and measuring the lower punctum in patients with punctal stenosis. Further research is required to develop a normative database and grading system for stenosed puncta and to correlate the degree of stenosis with the severity of epiphora.

Duloxetine protects against experimental diabetic retinopathy in mice through retinal GFAP downregulation and modulation of neurotrophic factors

Diabetic retinopathy (DR) is recognized as one of the leading causes of blindness worldwide. Searching and validation for a novel therapeutic strategy to prevent its progress are promising. This work aimed to assess the retinal protective effects of duloxetine (DLX) in Alloxan-induced diabetic mice model. Animals were equally and randomly divided to four groups (eight mice per group); group 1: is the control group, 2: diabetic group, 3&4: diabetic and after 9 weeks received DLX for 4 weeks (15 mg/kg and 30 mg/kg), respectively. Quantitative real-time PCR (qPCR) analysis revealed nerve growth factor (NGF), inducible nitric oxide synthase (iNOS) and transforming growth factor beta (TGF-β) genes upregulation in the diabetic group compared to controls. Also, increased retinal malondialdehyde (MDA) and the decline of reduced glutathione (GSH) levels were observed. The morphometric analysis of diabetic retina revealed a significant reduction in total retinal thickness compared to control. Diabetic retinal immunostaining and Western blot analyses displayed glial fibrillary acidic protein (GFAP) and vascular endothelial cell growth factor (VEGF) proteins expression upregulation as well as glucose transporter-1 (GLUT-1) downregulation comparing to controls. However, DLX-treated groups showed downregulated NGF, iNOS, and TGF-β that was more obviously seen in the DLX-30 mg/kg group than DLX-15 mg/kg group. Furthermore, these groups showed amelioration of the oxidative markers; MDA and GSH, retaining the total retinal thickness nearly to control, GFAP and VEGF downregulation, and GLUT-1 upregulation compared to diabetic group. Taken together, it could be summarized that duloxetine can attenuate DR via the anti-inflammatory and the anti-oxidative properties as well as modulating the angiogenic and the neurotrophic factors expressions. This could hopefully pave the road to be included in the novel list of the therapeutic regimen for DR after validation in the clinic.

Treatment with platelet-rich plasma of surgically related dormant corneal ulcers

PURPOSE

To assess the effectiveness of autologous platelet-rich plasma for the treatment of dormant corneal ulcers secondary to corneal surgery and unresponsive to conventional treatment.

SETTING

VISSUM, Ophthalmology Institute of Alicante, Alicante, Spain.

DESIGN

Prospective nonrandomized, observational consecutive study.

METHODS

A total of 44 eyes of 28 patients with dormant corneal ulcers secondary to corneal surgery were included in a prospective study and treated with autologous platelet-rich plasma during 6 weeks. Wilcoxon signed-rank test was used to compare the effect of the treatment.

RESULTS

In all, 28 patients (65.1%) improved their visual acuity at least one line in Snellen chart, 26 (59.09%) had a decrease in the size of the ulcer or even a total closure, and 40 (90.9%) experienced an improvement in their symptoms. The results are also provided for the four groups of patients (keratoplasty, refractive surgery, cross-linking, and chronic postsurgical corneal edema).

CONCLUSION

Platelet-rich plasma eye drops shows to be a good option for the treatment of dormant corneal ulcers secondary to corneal surgery.

Topical Eugenol Successfully Treats Experimental Candida albicans-Induced Keratitis

PURPOSE

To determine the efficacy of eugenol for the treatment of Candida keratitis in an experimental model.

METHODS

The in vitro antifungal activity of eugenol and fluconazole was tested against C. albicans strains via the microbroth dilution method. An experimental model of Candida albicans keratitis was used. Rabbits were classified into those that received no treatment (control; group 1) and those that started eugenol treatment immediately (group 2) or after 4 days (group 3) of keratitis induction (n = 12-16 rabbits/group). The 2 treatment groups were assigned to 50 μL of 4 mg/mL eugenol drops hourly for 15 days, while the control group received saline. Corneal penetration of eugenol was measured using HPLC, and corneal toxicity was evaluated clinically and histopathologically.

RESULTS

The in vitro minimum inhibitory concentrations of eugenol and fluconazole against C. albicans were 2 and > 0.4 mg/mL, respectively. A 4-mg/mL preparation of eugenol in propylene glycol was the maximum nontoxic dose on rabbit corneas as suggested by clinical and histopathologic findings. At least 75% of all eugenol-treated eyes recovered from keratitis, with improvement in the remaining 25% of the eyes compared to controls.

CONCLUSIONS

Eugenol can act as a natural, safe, and effective treatment for fungal keratitis, regardless of whether treatment is started immediately or after 4 days of keratitis induction.

Cataract surgery on the previous corneal refractive surgery patient

Cataract surgery in cases with previous corneal refractive surgery may be a major challenge for the ophthalmologist. The refractive outcome of the case deserves special attention in the preoperative planning process, which should be tailored for the type of prior refractive procedure: incisional, ablative under a flap, or on the corneal surface. Avoiding refractive surprise after cataract surgery in these cases is principally dependent on the accuracy of the intraocular lens calculation, together with the selection of the appropriate biometric formula for each case. Modern techniques for cataract surgery help surgeons to move toward the goal of cataract surgery as a refractive procedure free from refractive error. We give practical guidelines for the cataract surgeon in the management of these challenging cases.

A new epidescemetic keratoprosthesis: pilot investigation and proof of concept of a new alternative solution for corneal blindness

PURPOSE

To report the outcomes of a new model of epidescemetic keratoprosthesis (Kpro) implanted without total corneal trephination.

METHODS

Patients were considered for implantation with the new Kpro model (KeraKlear) if they were at high risk of failure with standard penetrating keratoplasty (PK) or showed conditions with a poor prognosis following PK such as severe chemical injury. We used femtosecond laser to create the surgical planes adequate for the purpose of the Kpro implantation, and the Kpro was implanted intralamellar in 11 eyes and epidescemetical in 4 eyes. Follow-up was between 7 and 21 months and mainly for anatomical outcomes and complications.

RESULTS

For the intralamellar technique, the anatomical outcome was excellent in five eyes with no complications. The other six eyes developed complications such as deep corneal inflammatory membrane, totally vascularised cornea, extrusion of the Kpro and corneal melting, all of which were managed successfully. No eye was lost. For the epidescemetical technique, the anatomical outcome was excellent in all four eyes.

CONCLUSIONS

The new KeraKlear Kpro has proved to be a viable alternative to corneal transplantation with potential advantages like decreased risk of endophthalmitis, expulsive haemorrhage and worsening glaucoma. KeraKlear Kpro is better tolerated and less prone to complications when implanted epidescemetically; cases with poor corneal quality are better associated to a lamellar fenestrated donor corneal graft, leaving the posterior corneal surface intact and implanting the Kpro between.

Surgical options for correction of refractive error following cataract surgery

Refractive errors are frequently found following cataract surgery and refractive lens exchange. Accurate biometric analysis, selection and calculation of the adequate intraocular lens (IOL) and modern techniques for cataract surgery all contribute to achieving the goal of cataract surgery as a refractive procedure with no refractive error. However, in spite of all these advances, residual refractive error still occasionally occurs after cataract surgery and laser in situ keratomileusis (LASIK) can be considered the most accurate method for its correction. Lens-based procedures, such as IOL exchange or piggyback lens implantation are also possible alternatives especially in cases with extreme ametropia, corneal abnormalities, or in situations where excimer laser is unavailable. In our review, we have found that piggyback IOL is safer and more accurate than IOL exchange. Our aim is to provide a review of the recent literature regarding target refraction and residual refractive error in cataract surgery.