Corneal involvement in uneventful cataract surgery: an in vivo confocal microscopy study

Impact of Topical 0.05% Cyclosporine A Eye Drops on Post-Femtosecond-Assisted Laser In Situ Keratomileusis Ocular Surface Recovery: A Randomized Clinical Trial

OBJECTIVES

To investigate the effect of topical 0.05% cyclosporine A (CsA) eye drops as an adjunct to conventional therapy in maintaining post-femtosecond-assisted laser in situ keratomileusis (FS-LASIK) ocular surface stability.

METHODS

Sixty-six patients (eyes) undergoing FS-LASIK were randomized into 2 groups: 33 patients (eyes) in group I (conventional treatment group) and 33 patients (eyes) in group II (CsA group). Conventional treatments include topical levofloxacin, fluorometholone, and artificial tears. Group II received topical 0.05% CsA eye drops twice daily for three months in addition to conventional treatment. Ocular Surface Disease Index (OSDI), numerical rating scale (NRS), tear break-up time (TBUT), Schirmer I test (SIt), corneal fluorescein staining (CFS), conjunctival lissamine green (LG) staining, corneal sensitivity, and corneal nerve morphology were measured. In addition, tear inflammatory cytokine levels were measured using the Luminex assay. Follow-up was performed preoperatively and 1 and 3 months postoperatively.

RESULTS

In the CsA group, OSDI, TBUT, LG, corneal sensitivity, and corneal nerve fiber total branch density recovered better than in the conventional treatment group. As for tear inflammatory cytokines, interferon (INF) -γ, interleukin (IL)-10, and IL-6 levels were significantly higher in the conventional treatment group as compared with the CsA group. In addition, no significant differences in NRS, SIt, and CFS scores were observed between the two groups.

CONCLUSION

In conclusion, 0.05% CsA eye drops is a useful adjunct to conventional treatment for restoring the ocular surface stability after corneal refractive surgery and is more potent in sustaining anti-inflammatory effects.

Change Patterns in Corneal Intrinsic Aberrations and Nerve Density after Cataract Surgery in Patients with Dry Eye Disease

This study aimed to evaluate the change patterns in corneal intrinsic aberrations and nerve density after cataract surgery in dry eye disease. The preoperative, 1- and 3-month postoperative dry eye-related parameters were obtained by the Oculus keratograph and the ocular surface disease index questionnaire. The corneal intrinsic aberrations were measured using the Pentacam HR system. In vivo confocal microscopy was performed to observe the vortical and peripheral corneal nerves. An artificial intelligence technique run by the deep learning model generated the corneal nerve parameters. Corneal aberrations on the anterior and total corneal surfaces were significantly increased at 1 month compared with the baseline (p < 0.05) but gradually returned to the baseline by 3 months (p > 0.05). However, the change in posterior corneal aberration lasted up to 3 months (p < 0.05). There was a significant decrease in the corneal vortical nerve maximum length and average density after the operation (p < 0.05), and this damage lasted approximately 3 months. The corneal vortical nerve maximum length and average density were negatively correlated with the anterior corneal surface aberrations before and 1 month after the operation (correlation coefficients, CC = −0.26, −0.25, −0.28; all p < 0.05). Corneal vortex provided a unique site to observe long-term corneal nerve injury related to eye dryness. The continuous damage to the corneal vortical nerve may be due to the continuous dry eye state.

Evaluation of Ocular Surface after Cataract Surgery—A Prospective Study

This study evaluated tear film and ocular surface parameters in patients after cataract surgery. Methods: a prospective clinical study included 48 eyes of 48 patients who underwent uncomplicated phacoemulsification performed by one surgeon. Tear break-up time (TBUT), Schirmer’s I test, Cochet–Bonnet esthesiometry and in vivo laser scanning confocal microscopy was carried out and the OSDI questionnaire was filled out. All tests were assessed before and 1 month after the surgery. Results: there were 32 (66.7%) women; 16 (33.3%) men, mean age was 74.08 ± 5.37. Mean TBUT at baseline was 8.6 ± 1.9 s, after the surgery, it was 7.7 ± 2.7 s, p = 0.004. Schirmer’s I test was 8.7 ± 3.9 mm versus 8.1 ± 3.7 mm, p = 0.002. Mean corneal nerve density at baseline was 15.70 ± 2.34 and at the first postoperative month 14.94 ± 1.48 mm/mm², p = 0.02. The OSDI questionnaire score increased from 12.15 ± 10.34 before the surgery to 13.79 ± 10.88 in the first postoperative month, p = 0.001. Conclusions: the ocular surface was affected 1 month after the cataract surgery: TBUT was shorter, Schirmer’s I test and corneal nerve density were decreased while the OSDI score increased.

Neuroimmune crosstalk in the cornea: The role of immune cells in corneal nerve maintenance during homeostasis and inflammation

In the cornea, resident immune cells are in close proximity to sensory nerves, consistent with their important roles in the maintenance of nerves in both homeostasis and inflammation. Using in vivo confocal microscopy in humans, and ex vivo immunostaining and fluorescent reporter mice to visualize corneal sensory nerves and immune cells, remarkable progress has been made to advance our understanding of the physical and functional interactions between corneal nerves and immune cells. In this review, we summarize and discuss recent studies relating to corneal immune cells and sensory nerves, and their interactions in health and disease. In particular, we consider how disrupted corneal nerve axons can induce immune cell activity, including in dendritic cells, macrophages and other infiltrating cells, directly and/or indirectly by releasing neuropeptides such as substance P and calcitonin gene-related peptide. We summarize growing evidence that the role of corneal intraepithelial immune cells is likely different in corneal wound healing versus other inflammatory-dominated conditions. The role of different types of macrophages is also discussed, including how stromal macrophages with anti-inflammatory phenotypes communicate with corneal nerves to provide neuroprotection, while macrophages with pro-inflammatory phenotypes, along with other infiltrating cells including neutrophils and CD4⁺ T cells, can be inhibitory to corneal re-innervation. Finally, this review considers the bidirectional interactions between corneal immune cells and corneal nerves, and how leveraging this interaction could represent a potential therapeutic approach for corneal neuropathy.

Alpha-Glycerylphosphorylcholine and D-Panthenol Eye Drops in Patients Undergoing Cataract Surgery

Cataract surgery is widespread. The surgical procedure is associated with damage to the epithelial barrier and interruption of the corneal innervation. In addition, pathological events sustain signs and symptoms that may persist for a long time. Recently, a fixed combination of alpha-glycerylphosphorylcholine and D-Panthenol (Oftassiale) has been available as eye drops. The present study investigated the effects of an Oftassiale therapy in 20 patients undergoing cataract surgery. A comparison group included 20 patients treated with topical hyaluronic acid. Standard prophylactic and anti-inflammatory treatment was prescribed to all patients. Clinical signs and symptoms were assessed over time. In vivo confocal microscopy (IVCM) was performed accordingly. Oftassiale treatment significantly reduced clinical features and improved IVCM outcomes. In addition, therapy was well-tolerated, and no clinically significant adverse events occurred. In conclusion, this study confirmed that IVCM helps assess the tunnel after cataract surgery due to its ability to provide microscopic details in vivo. Topical therapy with alpha-glycerylphosphorylcholine and D-Panthenol eye drops promoted and stabilized the reepithelialization process. This fixed combination also accelerated and modulated the repair of the corneal innervation. Moreover, this treatment was well-tolerated and safe.

Dry eye and inflammation of the ocular surface after cataract surgery: effectiveness of a tear film substitute based on trehalose/hyaluronic acid vs hyaluronic acid to resolve signs and symptoms

PURPOSE

To compare the effect of trehalose 3%/hyaluronic acid 0.15% vs hyaluronic acid 0.15% eyedrops in reducing ocular surface inflammation after cataract surgery.

SETTING

Perugia, Italy.

DESIGN

Randomized, prospective study.

METHODS

Patients with healthy ocular surface were enrolled. Tear break-up time (TBUT), Schirmer test, corneal fluorescein staining (CFS), ocular surface disease index (OSDI) and in vivo confocal microscopy (IVCM) were performed preoperatively and at 1 months, 4 months, and 8 months postoperatively. Patients were randomly assigned to receive trehalose 3%/hyaluronic acid 0.15% eyedrops (Group A), hyaluronic acid 0.15% eyedrops (Group B), or no treatment (Group C).

RESULTS

98 patients were randomized as follows: 33 in Group A, 33 in Group B, and 32 in Group C. Schirmer test increased at 1-month follow-up in Group A and unchanged in Groups B and C. TBUT and CFS increased at 1-month follow-up in Group A and after 8 months in Groups B and C. OSDI score decreased at 1-month follow-up in Group A and at in Groups B and C. IVCM showed a reduction in the number of nerve fibers of the subbasal nerve plexus at 1 month in all groups and progressively increased to preoperative levels at 4 months in Group A, and at 8 months in Groups B and C. Tortuosity and reflectivity of subbasal plexus progressively decreased to became significant at 4-month follow-up in Group A whereas increased at 1-month follow-up and become normal at 8-month follow-up in Groups B and C. Langerhans cells and activated stromal keratocytes were higher in Groups B and C throughout the follow-up with a significantly lower density of hyperreflective stromal cells in Group A.

CONCLUSIONS

Trehalose 3%/hyaluronic acid 0.15% eyedrops were effective in reducing inflammation and dry-eye symptoms.

Corneal Subbasal Plexus in Eyes with Fuchs' Endothelial Corneal Dystrophy after Two Different Endothelial Surgeries

Purpose

To evaluate the morphological features and density of corneal subbasal plexus (SBP) using in vivo corneal confocal microscopy (IVCCM) in patients affected by Fuchs' endothelial corneal dystrophy (FECD) six months after Descemet membrane endothelial keratoplasty (DMEK) and Descemet-stripping automated endothelial keratoplasty (DSAEK).

Methods

We included patients affected by FECD, requiring corneal endothelial surgery due to corneal oedema occurred from 3 to 6 months. 7 eyes underwent DMEK and 7 eyes DSAEK. All patients performed IVCCM preoperative and in six months postoperative. We analyzed SBP parameters, using CS4 Nerves Tracking Tool, and we studied the differences between the two endothelial keratoplasties.

Results

Comparing the eyes treated with DMEK with those treated with DSAEK, preoperative corneal thickness, corrected distance visual acuity (CDVA), and age were similar in both groups. SBP was not detectable at preoperative IVCCM in any eye. Postoperatively, the nerve fibers length, the nerve fibers density, the tortuosity, and the number of fibers and of branching did not differ in the eyes that underwent DMEK compared to DSAEK. The corneal beadings density was higher after DMEK than DSAEK, and this difference was statistically significant (P = 0.004). The type of endothelial keratoplasty was not associated with the presence or absence of postoperative corneal SBP (Pearson' chi-square, 0.755).

Conclusions

Postoperative corneal reinnervation should be easily and noninvasively studied using IVCCM. Morphological postoperative features of SBP did not differ between two different types of endothelial keratoplasty, DMEK and DSAEK, despite the different sizes of the corneal incision. The lower beading density in the DSAEK group should be the consequence of a different distribution of mitochondria along the nerve fibers, as expression of a supposed higher metabolic distress in the DSAEK group.

Clinical Features, Risk Factors, and Therapy of Epithelial Keratitis after Cataract Surgery

Purpose

The study aimed to assess the clinical characteristics, risk factors, and therapy of epithelial keratitis after cataract surgery.

Methods

Medical data of 89 consecutive patients who developed epithelial keratitis after cataract surgery, including 37 patients with diabetes mellitus (37 eyes) and 52 patients without diabetes mellitus (52 eyes), were retrospectively reviewed. The clinical characteristics, risk factors, and therapy in those patients were evaluated.

Results

The preoperative tear film function determined by the tear breakup time, meibomian gland atrophy score, and low tear meniscus height in diabetic patients was poorer than nondiabetic patients (P < 0.001). Of diabetic patients, 83.78% (31/37) had been diagnosed with meibomian gland dysfunction before cataract surgery and treated with topical nonsteroidal anti-inflammatory drugs after cataract surgery for 44.69 ± 10.51 days, compared to 42.31% (22/52) of nondiabetic patients receiving the topical nonsteroidal anti-inflammatory treatment for 33.35 ± 5.16 days (both P < 0.001). Epithelial lesions progressed within three to four days following cataract surgery in 59.46% (22/37) of diabetic patients, versus 30.77% (16/52) of the nondiabetic patients (P=0.025). Patients with combined meibomian gland dysfunction and epithelial defects accounted for 48.65% (18/37) in the diabetic group and 25.00% (13/52) in the nondiabetic group (P < 0.001). In vivo confocal microscopy showed absence of subbasal never fibers in eyes with epithelial defects, and central corneal sensation was also significantly depressed in those eyes, but there was no significant difference between the two groups (P=0.227). Corneal ulceration and herpes simplex keratitis were found in 2.70% (1/37) and 5.41% (2/37) of diabetic patients, respectively. Amniotic membrane transplantation was required in 32.43% (12/37) of patients in the diabetic group, and the proportion was higher than 1.92% (1/52) in the nondiabetic group (P < 0.001). Average healing time of the corneal epithelium in the diabetic group was 40.62 ± 20.0 days, much longer than 21.74 ± 6.94 days in the nondiabetic group (P=0.002).

Conclusion

Epithelial keratitis after cataract surgery in diabetic patients has the characteristics of rapid development, severe epithelial damage, and slow repair of the corneal epithelium. Amniotic membrane transplantation is a good choice for persistent epithelial defects associated with such epithelial keratitis. Attention should be paid to the tear film function and use of topical nonsteroidal anti-inflammatory drugs in patients undergoing cataract surgery.

Bilateral morphometric analysis of corneal sub-basal nerve plexus in patients undergoing unilateral cataract surgery: a preliminary in vivo confocal microscopy study

AIMS

To evaluate bilateral morphometric changes of corneal sub-basal nerve plexus (CSNP) occurring after unilateral cataract surgery by in vivo confocal microscopy (IVCM) images analysed with automated software.

METHODS

IVCM was performed before (V0) and 1 month after surgery (V1) in both operated eyes (OEs) and unoperated eyes (UEs) of 30 patients. Thirty age and sex-matched subjects acted as controls. Corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD), corneal nerve fibre length (CNFL), corneal nerve total branch density (CTBD), corneal nerve fibre area (CNFA), corneal nerve fibre width, corneal nerve fractal dimension (CNFrD) and dendritic cells density were calculated.

RESULTS

Mean CNFD, CNBD, CNFL, CTBD, CNFA and CNFrD significantly decreased at V1 versus V0 in both eyes (respectively, 15.35±7.00 vs 21.21±6.56 n/mm² in OEs and 20.11±6.69 vs 23.20±7.26 in UEs; 13.57±12.16 vs 26.79±16.91 n/mm² in OEs and 24.28±14.88 vs 29.76±15.25 in UEs; 9.67±3.44 mm/mm² vs 13.49±3.42 in OEs and 12.53±3.60 vs 14.02±3.82 in UEs; 22.81±18.77 vs 42.25±24.64 n/mm² in OEs and 38.06±20.52 vs 43.93±22.27 in UEs; 0.0040±0.0021 vs 0.0058±0.0020 mm²/mm² in OEs and 0.0049±0.0016 vs 0.0057±0.0019 in UEs; 1.418±0.058 vs 1.470±0.037 in OEs and 1.466±0.040 vs 1.477±0.036 in UEs; always p<0.049).

CONCLUSION

Patients undergoing cataract surgery exhibit bilateral alterations of CSNP. This finding could have broad implications in the setting of sequential cataract surgery.

New Therapeutic Strategy and Innovative Lubricating Ophthalmic Solution in Minimizing Dry Eye Disease Associated with Cataract Surgery: A Randomized, Prospective Study

INTRODUCTION

To evaluate the effects of a new lubricating, antioxidant solution (VisuEvo^®) on dry eye disease (DED) in patients undergoing cataract surgery.

METHODS

Patients requiring cataract surgery with either healthy ocular surface or mild DED (tear break-up time, TBUT > 7, Schirmer I test > 15 mm/5 min) were enrolled in this multicenter, open-label, randomized, prospective study. Scheduled visits were 2 weeks before surgery (screening), day of surgery (V0), week 1 (V1), and 2 (V2) after surgery. VisuEvo^® was self-administered three times daily for the whole study duration (group A); the control group (group B) had no tear substitute administration. The primary endpoint was the change in TBUT over time; the secondary endpoints were changes in Ocular Surface Disease Index (OSDI), ocular surface staining, the Schirmer I test, and osmometry.

RESULTS

A total of 45 patients were included (group A, 23; group B, 22; age 74 ± 8 years). At the screening, TBUT was similar between the groups (group A, 8.5 ± 1.8 s; group B, 7.8 ± 0.7, p = 0.11). At the scheduled visits, TBUT increase vs screening visit was significantly higher in group A: +1.2 s at V0, +1.4 s at V1, and +1.9 s at V2 (p < 0.01). Also, OSDI was significantly lower in group A at V0, V1, and V2 (p < 0.027). After surgery, corneal staining was absent in 65-78% of group A compared with 54-59% in group B. The two groups did not show any significant differences of osmometry and the Schirmer I test.

CONCLUSIONS

The ocular surface was more protected and quickly restored from surgery when VisuEvo^® was used from 2 weeks preoperatively to 2 weeks postoperatively.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03833908.

[Phacosurgery effects on the condition of corneal nerve fibers]

The question of potential changes in the nerve fibers of the cornea induced by phacosurgery remains poorly investigated. This is a review of results of many individual studies aimed at assessing the condition of corneal nerve fibers following different techniques of cataract removal. The authors substantiate the necessity for structural analysis of fiber changes based on in vivo confocal microscopy of the cornea. Functional assessment of corneal sensitivity (esthesiometry) does not allow objective conclusions, for several reasons. Further studies on corneal nerve changes after phacosurgery could be directed at improving software products for objective quantitative assessment of corneal nerve fibers and analyzing long-term results of various phacosurgery techniques.

Corneal nerve fiber loss in diabetes with chronic kidney disease

AIMS

Patients with chronic kidney disease (CKD) in type 2 diabetes typically manifest with severe peripheral neuropathy. Corneal confocal microscopy is a novel technique that may serve as a marker of nerve injury in peripheral neuropathy. This study examines the changes that occur in corneal nerve morphology as a result of peripheral neuropathy due to renal dysfunction in people with type 2 diabetes.

METHODS

Sixty-two participants (mean age, 62 ± 12 years) with type 2 diabetes and 25 age-matched healthy controls underwent a comprehensive assessment of neuropathy using the total neuropathy score (TNS). The corneal sub-basal nerve plexus was imaged using corneal confocal microscopy. Corneal nerve fiber length, fiber density, branch density, total branch density, nerve fractal dimension, inferior whorl length and inferior whorl nerve fractal dimension were quantified. Based on the eGFR, participants were classified into those with diabetic CKD (eGFR < 60; n = 22) and those without CKD (eGFR ≥ 60; n = 40).

RESULTS

Participants with diabetic CKD had significantly lower corneal nerve fiber density (P = 0.037), length (P = 0.036) and nerve fractal dimension (P = 0.036) compared to those without CKD. Multiple linear regression analysis revealed that reduced corneal nerve fiber density (ß coefficient = 0.098, P = 0.017), length (ß coefficient = 0.006, P = 0.008) and nerve fractal dimension (ß coefficient = 0.001, P = 0.007) was associated with low eGFR levels when adjusted for age, duration of diabetes and severity of neuropathy.

CONCLUSION

Corneal confocal microscopy detects corneal nerve loss in patients with diabetic CKD and reduction in corneal nerve parameters is associated with the decline of kidney function.

Corneal hypoesthesia, aqueous tear deficiency, and neurotrophic keratopathy following micropulse transscleral cyclophotocoagulation in dogs

OBJECTIVE

To describe ocular surface complications following micropulse transscleral cyclophotocoagulation (MP-TSCPC) in dogs.

ANIMALS STUDIED

Eighteen dogs treated with MP-TSCPC at two institutions for glaucoma management.

PROCEDURES

MP-TSCPC was applied to each eye (avoiding 3 and 9 o'clock positions) with 31.3% duty cycle, 2000-3000 mW energy, and 90-180 seconds duration per hemisphere. Central corneal tactile sensation (CTS) and Schirmer tear test-1 (STT-1) were measured at baseline and ≥2 post-operative visits in each dog.

RESULTS

Corneal sensitivity decreased in 16/18 dogs (89%) by an average of 10%-42% (up to 100% in 4 dogs). CTS decline was rapid (≤1 week) and only fully recovered in 50% of dogs within 8-180 days. Patients' age, glaucoma duration, laser energy, and total energy delivered did not affect CTS at any visit. However, brachycephalic dogs had significantly lower CTS and likelihood to recover full sensation compared with nonbrachycephalic dogs. Aqueous tear deficiency (STT-1 < 15 mm/min) occurred in 8/18 dogs (44%) within 7-270 days, and concurrent signs of keratoconjunctivitis sicca were noted in 2/18 dogs (11%). Neurotrophic corneal ulcers developed in 6/18 dogs (33.3%) and required 16-53 days to heal.

CONCLUSIONS

Corneal hypoesthesia is a common complication of MP-TSCPC in dogs, and can lead to serious adverse effects such as aqueous tear deficiency and neurotrophic corneal ulcers. Brachycephalic dogs represent a population at higher risk. Close monitoring of ocular surface health is recommended for months following MP-TSCPC in dogs.

Corneal Subbasal Nerve Density and Sensitivity After Pars Plana Vitrectomy Using Contact or Noncontact Wide-Angle Viewing Systems

PURPOSE

To assess corneal subbasal nerve density (SBND) and corneal sensitivity (CS) after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD) without intraoperative 360-degree laser treatment using contact or noncontact panoramic viewing systems.

METHODS

This is a prospective study of 34 eyes affected by RRD, which underwent PPV using contact (18 eyes) and noncontact (16 eyes) panoramic viewing systems; 12 eyes which underwent scleral buckling, and 17 eyes which underwent cataract surgery. SBND and CS were assessed before surgery and 3 and 6 months postoperatively by in vivo confocal microscopy and Cochet-Bonnet esthesiometry.

RESULTS

Compared with baseline values, at 6 months, SBND and CS decreased in both contact PPV (SBND preoperative value: 19.1 ± 3.7 mm/mm; SBND postoperative value: 3.5 ± 1.3 mm/mm; CS preoperative value: 5.1 ± 0.5 cm; CS postoperative value: 1.5 ± 0.4 cm) and in noncontact PPV groups (SBND preoperative value: 19.5 ± 3.8 mm/mm; SBND postoperative value: 8.7 ± 2.3 mm/mm; CS preoperative value: 5.3 ± 0.5 cm; CS postoperative value: 2.5 ± 0.7 cm) (P < 0.001 for all comparisons). SBND reduction was greater in the contact PPV group than in the noncontact PPV group (P < 0.001). By contrast, the scleral buckling and cataract surgery group values were unchanged (P > 0.1 for all comparisons). In multivariate analysis, no significant effect was found for cataract surgery associated with PPV, pseudophakia, surgical time, intraocular pressure, or for laser in horizontal sectors for PPV groups. SBND was highly correlated with CS (r = 0.93).

CONCLUSIONS

A contact viewing system reduces SBND after PPV more than a noncontact system does.

Confocal scanning laser microscopy in patients with postoperative endophthalmitis

PURPOSE

To investigate alterations of corneal layers in eyes treated for acute postoperative endophthalmitis.

METHODS

In this retrospective, nonrandomized comparative study, eyes treated with 25 gauge pars plana vitrectomy (PPV) for acute post-cataract endophthalmitis (group A) were compared to eyes receiving uneventful cataract surgery (group B) and uneventful 25 gauge PPV for epiretinal membrane (group C). After a minimum follow-up of 8 months from last surgical procedure, laser scanning in vivo confocal microscopy (IVCM) was performed.

RESULTS

Twelve eyes for each group were recruited. Comparing study eyes with control eyes of group B and C, no statistical difference was found in corneal epithelial cell density (p = n.s.), in density of nerve fibers (p = n.s.), mean grade of nerve reflectivity (p = n.s.), mean grade of nerve tortuosity (p = n.s.), mean grade of anterior keratocyte activation (p = n.s.), and corneal endothelium cell density (p = n.s.), whereas a statistically higher mean grade of posterior keratocyte activation was found in group A (p < 0.01). Epithelial and endothelial corneal morphologies were graded as regular in all groups. Langerhans cells and corneal dendritic-shaped hyper-reflective endothelial deposits were found in group A. Both findings were absent in group B and C, and the difference was statistically significant (p < 0.01).

CONCLUSIONS

IVCM was a useful tool in the detection of microscopic chronic corneal abnormalities caused by postoperative endophthalmitis. These findings confirmed the presence of a subclinical chronic corneal inflammation localized to the posterior stroma that should be related to the infectious process. Future studies might clarify pathological processes in the acute phase of postoperative endophthalmitis.

Corneal nerve regeneration after herpes simplex keratitis: A longitudinal in vivo confocal microscopy study

PURPOSE

To evaluate the long-term alterations of corneal nerves in patients with herpes simplex virus (HSV) keratitis using in vivo confocal microscopy (IVCM).

DESIGN

Prospective, longitudinal, cross sectional.

METHODS

This study included 16 patients with a history of HSV keratitis and 15 age-matched normal controls. Slit-scanning IVCM was performed in all subjects at baseline and then after a mean follow-up of 37.3 ± 1.7 months in the patient group. Corneal subbasal nerve density and corneal sensation were compared between groups at baseline and follow-up.

RESULTS

At baseline, the mean subbasal nerve density was significantly lower in both affected eyes (1.4 ± 0.6 mm/mm²) and contralateral unaffected eyes (6.4 ± 0.7 mm/mm²) compared with the controls (14.1 ± 1.6 mm/mm²; all P < .001). At the end of follow-up, the mean nerve density in affected eyes increased to 2.8 ± 0.7 mm/mm² (P = .006), with no significant change in contralateral unaffected eyes (6.5 ± 1.0 mm/mm², P = .72). However, both eyes had lower nerve density than controls (all P < .001). Corneal sensation was significantly lower in affected eyes (2.6 ± 0.6 cm) than in the control group (6.0 ± 0.0, P < .001) and showed no significant change at the end of follow-up (2.5 ± 0.6 cm, P = .80). Corneal sensation in contralateral unaffected eyes was not different in comparison with controls at both baseline and follow up (all p > .05).

CONCLUSIONS

Our results demonstrate that although corneal nerve regeneration occurs in patients with HSV keratitis, this change is not clinically significant and does not results in changes of corneal sensation. Therefore, these patients need to be followed closely for complications of neurotrophic keratopathy and might benefit from neuro-regenerative therapies.

Corneal microstructural changes in nerve fiber, endothelial and epithelial density after cataract surgery in patients with diabetes mellitus

PURPOSE

The aim of this study was to analyze microstructural corneal changes following phacoemulsification of cataract with intraocular lens insertion in diabetes mellitus (DM).

METHODS

Prospective study of consecutive patients undergoing phacoemulsification with intraocular lens insertion, over a period of 6 months. Age, gender, serum glycosylated hemoglobin A1c levels, and effective phacoemulsification time were recorded. Anterior segment optical coherence tomography and corneal in vivo confocal microscopy were performed preoperatively and 1-month postoperatively. Subbasal nerve plexus (SBN) density, basal epithelial cell density, and endothelial cell density (ECD) were quantitatively analyzed.

RESULTS

Twenty-eight patients with type 2 DM (71.2 ± 7.6 years) and 23 healthy controls (mean age, 74.4 ± 7.4 years) were recruited. Mean hemoglobin A1c level was 7.5% in patients with DM and 5.7% in the control group (P < 0.0001). A significant reduction in SBN density was noted postoperatively in both DM (P < 0.0001) and non-DM groups (P < 0.0001). Patients with DM had a lower mean SBN density compared with non-DM group, before (P < 0.0001) and after surgery (P < 0.0001). Longer effective phacoemulsification time correlated with a greater decrease in ECD postoperatively in the whole cohort (P < 0.0001), and in the control (P = 0.002) and DM (P = 0.039) groups independently. There was no significant difference in preoperative ECD between the DM group (2254 +/- 426 cells/mm(2)) and non-DM group (2384 +/- 438 cells/mm(2); P = 0.2). [corrected].

CONCLUSIONS

Subbasal nerve density is reduced after cataract surgery in patients with and without DM. However, lower initial SBN density in patients with DM may predispose them to develop diabetic keratopathy. DM does not predispose to greater endothelial loss following phacoemulsification.

Corneal nerve alterations after Descemet membrane endothelial keratoplasty: an in vivo confocal microscopy study

PURPOSE

Recent studies have identified diminishment of corneal nerves as another hallmark of Fuchs endothelial corneal dystrophy. This study aimed to analyze changes in corneal nerves after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Twenty-five patients were assessed for nerve alterations preoperatively and 1 week, 4 months, and 20 months after DMEK surgery. Morphology of the central subbasal nerve plexus was quantified by in vivo confocal microscopy.

RESULTS

The total nerve length (481.2 ± 81.9 vs. 1536.0 ± 123.8 μm per frame, P < 0.0001), total nerve number (2.2 ± 0.3 vs. 7.2 ± 0.5 per frame, P < 0.0001), number of main nerve trunks (1.8 ± 0.2 vs. 3.5 ± 0.3 per frame, P < 0.0001), and number of nerve branches (0.5 ± 0.2 vs. 3.7 ± 0.4 per frame, P < 0.0001) were significantly decreased 1 week after DMEK compared with preoperative measurements. Ten months postoperatively, corneal nerves recovered to preoperative values. Central corneal sensation significantly reduced postoperatively (5.1 ± 1.0 vs. 6.0 ± 0.0, P = 0.001), but recovered during follow-up (10 months: 6.0 ± 0.0).

CONCLUSIONS

DMEK diminishes the density and the function of subbasal corneal nerves early after transplantation. However, a complete recovery of corneal nerve density and function up to preoperative values occurs within 4 to 10 months.

Age-related changes of the ocular surface: a hospital setting-based retrospective study

Purpose. To investigate the effects of age on the prevalence of ocular surface diseases (OSD), adherence to treatment, and recovery rates. Patients and Methods. Retrospective analysis of 3000 clinical records from a first-level general ophthalmology clinic. Patients with OSD were prospectively submitted a questionnaire to assess compliance and recovery rates. Results. OSD prevalence was 10.3%. Patients with OSD were significantly older than patients without it: 67.5 ± 20.3 versus 57.0 ± 22.0 years (P = 0.036). No significant difference in season distribution was shown. Dry eye disease (DED) represented 58% of OSD; its prevalence increased with age until 80 years old and suddenly decreased thereafter. Asymptomatic DED was 37%. Adherence to treatment in OSD was very high (94%); recovery rates were lower in patients aged 21-40 and 61-80 (resp., 65.5% and 77.8%) and this was associated with higher OSDI scores. Tear substitutes represented 50% of all prescribed medications; their use increased with age. Discussion. In a "real-life" low-tech setting, OSD showed a prevalence of 10.3%. DED was the most prevalent disease, and it was asymptomatic in more than 1/3 of cases.