Decreased Corneal Sensation and Subbasal Nerve Density, and Thinned Corneal Epithelium as a Result of 360-Degree Laser Retinopexy

Alterations in the Ocular Surface and Corneal Subbasal Nerve Plexus Following Various Retinal Surgical Procedures: A One-Year Confocal Microscopy Prospective Study

Purpose

To evaluate the effects of retinal surgery on the ocular surface and corneal subbasal nerve plexus (SNP).

Methods

Ninety-eight patients undergoing 23-gauge pars plana vitrectomy for various vitreoretinal disorders were prospectively studied. We collected detailed operative and perioperative data, measuring dry eye syndrome (DED) severity and Ocular Surface Disease Index (OSDI) scores before surgery and at postoperative intervals. In vivo confocal microscopy (IVCM) quantified SNP and dendritic cell (DC) densities.

Results

Fifty-three patients were analyzed. Post-surgery, OSDI scores rose from a baseline of 5.5 ± 3.5 to 12.24 ± 6.5 at one month, later reducing to 7.8 ± 4.0 after a year. DED severity increased from 0.6 ± 0.6 initially to 1.6 ± 0.6 at three months, returning to near baseline (0.9 ± 0.6) one year after surgery. DC densities increased notably by the third (58.85 ± 75.6 cells/mm²) and ninth (59.95 ± 86 cells/mm²) postoperative months, especially in patients undergoing combined phacoemulsification, vitrectomy, and C3F8 gas tamponade. SNP parameters, particularly nerve fiber density and length, showed significant declines one month post-surgery, not recovering to baseline levels within a year. Fiber density dropped from 19.06 ± 8.3 fibers/mm² preoperatively to 4.68 ± 4.8 fibers/mm² at one month, partially recovering to 10.64 ± 8.2 fibers/mm² at twelve months. Fiber length decreased from 13.31 ± 3.2 mm/mm² to 6.86 ± 3.4 mm/mm² at one month, later improving to 9.81 ± 4.5 mm/mm² at twelve months, notably in patients with silicone oil (SiO2) tamponade.

Conclusion

Retinal surgery, especially when combined with phacoemulsification and C3F8 or SiO2 tamponade, significantly affects ocular surface integrity and SNP density, with these changes lasting up to a year. Expanded studies with more patients and longer follow-up, using finer 25- and 27-gauge vitrectomy tools, are recommended to confirm and extend these findings.

Long-Term Real-World Outcomes of Corneal Changes in Proliferative Diabetic Retinopathy: Panretinal Photocoagulation vs. Intravitreal Conbercept

PURPOSE

To compare long-term real-world outcomes of corneal thickness (CT) alterations in proliferative diabetic retinopathy (PDR) patients treated with panretinal photocoagulation (PRP) and intravitreal conbercept (IVC).

METHODS

This retrospective study included 69 eyes of 69 patients with PDR (42 PRP and 27 IVC). Full corneal thickness (FCT), corneal epithelial thickness (CET) and corneal stromal thickness (CST) measured by anterior segment optical coherence tomography at baseline were compared between groups. These CT changes at last follow-up from baseline were also compared between groups and within each group.

RESULTS

During a mean follow-up of more than two years, the IVC group demonstrated a significantly increased corneal thickness from baseline compared to the PRP group in some areas (PRP vs. IVC: FCT 0-2 mm: -0.59 ± 9.31 vs. 5.59 ± 9.23 μm, p = 0.009; CST 0-2 mm: -2.05 ± 8.79 vs. 3.48 ± 7.52 μm, p = 0.015; CST 2-5 mm: -1.78 ± 13.27 vs. 5.68 ± 14.53 μm, p = 0.046). In within-group comparisons, a significantly increased FCT from baseline was found in the 0-2 mm area in the IVC group (p = 0.004), but no significant change was observed in the PRP group (p = 0.691). For CET changes, a significantly increased CT was observed in the 0-2 mm, 2-5 mm and 5-7 mm areas in both groups respectively (all p < 0.05). Regarding CST, an increased CT was found in the 0-2 mm area in the IVC group (p = 0.037), while a decreased trend was observed in 0-2 mm and 2-5 mm areas in the PRP group (all p > 0.05).

CONCLUSION

When using PRP or IVC in the long-term management of PDR, CT changes should be considered. This may provide evidence for corneal protection during PDR treatment.

Corneal Epithelial Thickness Mapping in the Diagnosis of Ocular Surface Disorders Involving the Corneal Epithelium: A Comparative Study

PURPOSE

The purpose of this study was to analyze the role of corneal epithelial thickness (ET) mapping provided by spectral domain optical coherence tomography in the diagnosis of ocular surface disorders (OSDs) involving the corneal epithelium.

DESIGN

This was a retrospective comparative study.

METHODS

Institutional settings are as follows. Study population includes 303 eyes with an OSD and 55 normal eyes (controls). Observation procedures include spectral domain optical coherence tomography with epithelial mapping in the central 6 mm. Main outcome measures include ET map classification (normal, doughnut, spoke-wheel, localized/diffuse, and thinning/thickening patterns) and ET data and statistics (minimum, maximum, and SD). A quantitative threshold was determined with receiver operating curves to distinguish pathological from normal corneas. Sensitivity and specificity of classification and quantitative data were calculated using all eyes to assess the ability to distinguish corneas with a given corneal disorder from other conditions.

RESULTS

Classification of full agreement between 3 readers was obtained in 75.4% to 99.4% of cases. Main OSD features were keratoconus (135 eyes), doughnut pattern (sensitivity/specificity = 56/94%), and max-min ET ≥ 13 μm (84/43%); limbal deficiency (56 eyes), spoke-wheel pattern (66/98%), and max-min ET ≥ 14 μm (91/59%); epithelial basement membrane dystrophy (55 eyes), inferior thickening pattern (55/92%), and central ET > 56 μm (53/81%); dry eye (21 eyes), superior thinning pattern (67/88%), and minimal ET ≤ 44 μm (86/48%); pterygium (10 eyes), nasal thickening pattern (100/86%), and nasal ET > 56 μm (80/71%); and in situ carcinoma (11 eyes), max ET > 60 μm (91/60%), and ET SD >5 μm (100/58%).

CONCLUSIONS

The epithelial map pattern recognition combined with quantitative analysis of ET is relevant for the diagnosis of OSDs and for distinguishing various OSDs from each other. Deep learning analysis of big data could lead to the fully automated diagnosis of these disorders.

Complications in Retinal Surgery: A Review of Corneal Changes Following Vitreoretinal Procedures

Purpose:

The purpose of this article is to discuss the early- and late-onset corneal complications that can occur following vitreoretinal surgery.

Methods:

A systematic review of the literature was conducted using PubMed and Google Scholar databases. Articles detailing the clinical findings and the associations between surgical techniques, irrigating solutions, and microsurgical instruments used for vitreoretinal surgery and postoperative corneal complications were included in this review.

Results:

Vitreoretinal surgery can be associated with corneal complications such as persistent corneal epithelial defects, neurotrophic keratopathy, band keratopathy, ocular surface disruption, and endothelial cell damage. Risk factors for the development of cornea complications after posterior segment surgery include history of uncontrolled diabetes mellitus, aphakia or pseudophakia, disrupted anterior lens capsule integrity, use of irrigating solutions without appropriate buffers, use of contact viewing lenses intraoperatively, intraocular gases or silicone oil after vitrectomy, and prolonged duration of surgery.

Conclusions:

Corneal complications secondary to vitreoretinal surgery are multifactorial, but more commonly arise in diabetic patients, those with preexisting ocular comorbidities, and under certain surgical-related conditions. Special pre-, peri-, and postoperative considerations, with a focus on early identification and management of risk factors, are required to help decrease the incidence of corneal complications.

360-Degree laser retinopexy in primary vitrectomy for rhegmatogenous retinal detachment: factors associated with its use and impact on surgical outcomes

BACKGROUND

To determine patient and surgical factors associated with the use of 360-degree laser retinopexy during primary pars plana vitrectomy (PPV) ± scleral buckle (SB) for rhegmatogenous retinal detachment (RRD) and its impact on surgical outcomes.

METHODS

Patients who underwent PPV ± SB for repair of non-complex RRD at a single centre were included in this retrospective study. The primary outcome was single surgery anatomical success (SSAS). Secondary outcomes included visual acuity, epiretinal membrane formation, the presence of cystoid macular oedema, tonic pupil and corneal epithelial defects. Multiple logistic regression and multivariate regression was used.

RESULTS

The study included 192 cases, of which 130 received 360-degree laser. Worse preoperative logMAR visual acuity (P = 0.009), male sex (P = 0.060), higher PVR grades, supplemental SB (P = 0.0468) and silicone oil/C₃F₈ tamponade (P < 0.0001) were associated with 360-degree laser use. No significant associations between 360-degree laser and SSAS (P = 0.079), final logMAR visual acuity (P = 0.0623), ERM development (P = 0.8208), postoperative CMO (P = 0.5946), tonic pupil (P > 0.9999) or corneal epithelial defects (P = N/A) were found.

CONCLUSIONS

360-degree laser retinopexy during primary PPV ± SB for RRD was associated with more complex cases and more extensive operations. Even when accounting for this, there was no difference in surgical outcomes or complication rates.

Factors affecting retinal re-detachment following silicone oil removal for rhegmatogenous retinal detachments

PURPOSE

To report factors affecting retinal re-detachment rate after silicone oil removal (SOR) following rhegmatogenous retinal detachment (RRD) repair.

METHODS

Retrospective cohort study from December 1, 2014 to March 1, 2020 of 205 consecutive patients treated for RRD with SO tamponade and subsequent SOR with at least 6 months follow-up. Primary outcome measure was rate of retinal re-detachment following SOR.

RESULTS

The retinal re-detachment rate following SOR was 18.5%. Preoperative macula and lens status, PVR, previous retinectomy, RD size, concomitant phacoemulsification, previous scleral buckling, and endolaser during SOR did not affect re-detachment rate after SOR. Previous SO exchange was associated with increased re-detachment (OR 2.53, 95% CI (1.11 - 5.80), p = 0.0278). 12 months of SO tamponade had lower re-detachment rates compared to 3 months (OR 0.25, 95% CI [0.04 - 0.09], p = 0.048). Shorter SO tamponade (3 vs. 12 months) had better final visual outcomes after SOR (0.80 ± 0.61 vs 1.41 ± 0.66, p <0.0001).

CONCLUSIONS

No preoperative or intraoperative factors in this analysis influenced the risk of re-detachment following SOR except duration of SO tamponade and previous SO exchange. While longer SO tamponade duration may be associated with lower rates of re-detachment, visual outcomes may be worse.

Protective Role of 360° Laser Retinopexy in Patients with Rhegmatogenous Retinal Detachment: a Systematic Review and Meta-analysis

PURPOSE

Visual impairment from retinal re-detachment could be debilitating. The aim of this review is to evaluate the role of 360° laser retinopexy on success rate of rhegmatogenous retinal detachment (RRD) repair by a meta-analysis study.

METHODS

The PubMed, Scopus, and the Cochrane Library databases were searched comprehensively from the date of database inception to January 2021, evaluating the role of 360° laser retinopexy in visual and anatomical success rate of RRD repair. This review was conducted based on the preferred reporting items for systematic review and meta-analysis (PRISMA) protocols.

RESULTS

Among 202 articles screened for eligibility, six studies were found to be eligible for inclusion in our final analysis. Our meta-analysis demonstrates that prophylactic treatment with circumferential laser photocoagulation has no significant effect on the initial rate of retinal re-detachment or final best-corrected visual acuity following pars plana vitrectomy repair of RRD. Subgroup analysis of studies (n = 3) with 23-gauge pars plana vitrectomy, however, favors attachment rate in patients undergoing 360° prophylactic laser treatment.

CONCLUSIONS

Three hundred and sixty degree laser retinopexy appears to have favorable outcomes in patients undergoing 23-gauge retinal detachment repair. This protective effect, however, is not apparent with inclusion of 20-gauge vitrectomy studies.

Revisiting the Corneal and Blink Reflexes for Primary and Secondary Trigeminal Facial Pain Differentiation

Trigeminal neuralgia is often misdiagnosed at initial presentation due to close connotation with dental pain and is often over diagnosed for the very same reasons leading to numerous unnecessary surgical procedures such as peripheral neurectomy and alcohol injections, while the actual cause may remain elusive for decades. Evaluation of the neurosensory system may disclose the correct anatomical location of the etiology. The neurological examination may be clouded by the sensory deficits subsequent to previous peripheral surgical procedures. The corneal and blink reflexes are integral measures of the trigeminal and facial neurosensory assessment, and their abnormal function may facilitate the identification of intrinsic disease of the brain stem. These reflexes can be employed to discover pathological lesions including intracranial space-occupying trigeminal, lateral medullary, cerebral hemispheric lesions, and degenerative diseases of the central nervous system. Dental surgeons and oral and maxillofacial surgeons should consider corneal reflex in neurological assessment of patient presenting with trigeminal neuralgia-like symptoms. Failure to evaluate corneal sensitivity may lead to delayed or inaccurate diagnosis and unsuitable or redundant treatment interventions. This simple noninvasive reflex can be performed by chair-side and may provide significant information regarding the origin of facial pain and is an invaluable part of clinical methods especially in remote and peripheral healthcare center practitioners where sophisticated radiographic investigations such as computed tomography and magnetic resonance imaging may not be available.

EFFECT OF PANRETINAL PHOTOCOAGULATION ON CORNEAL SENSATION AND TEAR FUNCTION IN PATIENTS WITH DIABETIC RETINOPATHY

PURPOSE

To evaluate the early effects of panretinal photocoagulation (PRP) on corneal sensation and dry eye signs in patients with diabetic retinopathy.

METHODS

Fifty patients with Type 2 diabetes mellitus and very severe nonproliferative or non-high-risk proliferative diabetic retinopathy who required PRP for the treatment of their retinal condition were enrolled. All patients were treated using a pattern PRP device. Esthesiometry, tear breakup time test, Schirmer test, and corneal staining pattern were evaluated at baseline and 2 months after the last session of PRP.

RESULTS

Data from 88 eyes of 50 patients (41 right eyes and 47 left eyes) were analyzed. The mean tear breakup time test (right eyes) was decreased from 9.51 at baseline to 7.66 seconds after PRP (P < 0.001). The post-PRP eyes showed more advanced grades of corneal staining than pre-PRP assessment (P < 0.001). The average value of Schirmer test was 14.39 versus 12.29 mm (without anesthesia; P < 0.001) and 8.17 versus 7.15 mm (with anesthesia, P < 0.001) for baseline versus post-PRP measurements, respectively. The corneal sensation also showed decrease after laser therapy (4.93 versus 4.31 cm; P < 0.001).

CONCLUSION

This study demonstrates that decreased corneal sensation and signs of dry eye are more common immediately after PRP for diabetic retinopathy. These conditions should be discussed with the patient preoperatively and managed postoperatively.

Stickler Syndrome (SS): Laser Prophylaxis for Retinal Detachment (Modified Ora Secunda Cerclage, OSC/SS)

Purpose

To introduce a novel technique of encircling laser prophylaxis (ora secunda cerclage Stickler syndrome, OSC/SS) to prevent rhegmatogenous retinal detachment (RRD) in Stickler syndrome eyes.

Patients and Methods

After first eye RRD at age 50 and at age 18, respectively, a 53-year-old father and his 22-year-old son with type 2 SS (STL2) gave informed consent and underwent OSC/SS prophylaxis, performed in each fellow eye. A 26-year-old STL2 daughter then suffered first eye retinal detachment and similarly chose fellow eye OSC/SS prophylaxis. A second son, 28 years of age with STL2, chose OSC/SS prophylaxis in both eyes.

Results

The three OSC/SS treated fellow eyes have gone 12 years, 11 years, and 8 years without RRD. STL1 and less common STL2 eyes are known to have a similar rate of RRD, and 80% of STL1 fellow eyes develop RRD at a median of 4 years in the absence of prophylaxis. Moreover, five of six (83%) known STL2 family members suffered RRD, only the STL2 son with bilateral OSC/SS remaining bilaterally attached. All five OSC/SS treated eyes (average 8.7 years post-prophylaxis) retained preoperative visual acuity of 20/20 to 20/30, with an average, asymptomatic reduction of meridional field in each eye to 50 degrees. In contrast, in the three eyes having suffered RRD prior to presentation, visual acuity ranged from 20/125 to 8/200 and average meridional field was 29 degrees.

Conclusion

Encircling grid laser (OSC) modified in Stickler eyes to encompass the ora serrata and extend posteriorly to and between the vortex vein ampullae (OSC/SS) is a reasonable RRD prophylaxis option to offer STL1 and STL2 patients as an alternative to no treatment or less effective prophylaxis. Because of rarity and severity, the ultimate proof of safety and efficacy will likely come not from randomized trials, but from a non-randomized, prospective, cohort comparison study of such individual efforts.

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Assessment of corneal epithelial thickness mapping in epithelial basement membrane dystrophy

Purpose

To investigate the corneal epithelial thickness topography with optical coherence tomography (OCT) and its relationship with vision quality in epithelial basement membrane dystrophy (EBMD).

Methods

45 eyes of EBMD patients, 26 eyes of dry eye (DED) patients and 22 eyes of normal subjects were enrolled. All participants were subjected to 9-mm corneal epithelial mapping with OCT and vision quality was assessed with the optical quality analysis system using the objective scatter index (OSI). Central, superior, inferior, minimum, maximum, and standard deviation of epithelium thickness (Irregularity), were analysed and correlations with the OSI were calculated.

Results

The mean (±SD) central, inferior and maximum epithelial thicknesses of the EBMD patients (respectively, 56.4 (±8.1) μm, 58.9 (±6.4) μm, and 67.1 (±8.3) μm) were thicker compared to DED patients (P<0.05) and normal subjects (P<0.05). We found greater irregularity of epithelial thickness in EBMD (5.1±2.5 μm) compared to DED patients (2.6±1.0 μm) (P = 4.4.10⁻⁶) and normal subjects (2.1±0.7 μm) (P = 7.6.10⁻⁷). The mean OSI was worse in EBMD patients than in DED patients (P = 0.01) and compared to normal subjects (P = 0.02). The OSI correlated with the epithelial thickness irregularity (Spearman coefficient = 0.54; P = 2.65.10⁻⁵).

Conclusions

The OCT pachymetry map demonstrated that EBMD patients had thicker corneal epithelium in the central and inferior region. These changes were correlated with objective measurements of vision quality. This OCT characterisation of the EMBD provides a better understanding of the epithelial behaviour in this dystrophy and its role in vision quality.

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.

Long-term evaluation of corneal sub-basal nerve recovery after photorefractive keratectomy and influence of pars plana vitrectomy

The corneal sub-basal nerve (SBN) plexus is destroyed during photorefractive keratectomy (PRK) and its recovery is still a matter of debate. In vivo confocal microscopy (IVCM) was used to evaluate SBN plexus in 23 patients at a distance of 10-25 years (mean 15.6 years) from myopic PRK. Because 8 out of the 23 PRK patients underwent pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment, IVCM was also performed on those patients 6 months after PPV. Thirteen patients matched for age and myopia served as controls (non-PRK). SBN plexus was markedly reduced after PRK compared with non-PRK eyes and showed a slow, continuous but incomplete recovery up to the end of our follow-up (range 10-25 years). PRK and non-PRK eyes showed a marked reduction in SBN density 6 months after PPV, thus demonstrating a detrimental effect exerted by PPV on SBN plexus.

Effects of ambient humidity on the Cochet-Bonnet aesthesiometer

PURPOSE

The Cochet-Bonnet (COBO) aesthesiometer is the current standard in corneal sensitivity assessment. This study investigates the influence of ambient room humidity levels on the stimulus force exerted by the instrument.

METHODS

A COBO instrument (Luneau Opthalmologie) with 0.12 mm nominal nylon filament diameter was placed in an environment chamber (Electro-tech systems Inc. PA, USA) at 25 °C and relative humidity (%RH) set to either 20-80%, in 10% steps. After 12 h in the chamber at a chosen %RH level, the instrument was removed and exerted force measured by pressing the nylon filament onto the plate of an analytical microbalance (Mettler-Toledo AB265; precision ±0.0001 g) at a perpendicular angle, by a predetermined amount. Exerted force onto the microbalance was recorded in grams for a specified filament length. Procedure was repeated for filament lengths 10-60 mm, in 5 mm steps. The instrument was returned to the chamber and procedure repeated 5 times, before repeating at the next %RH setting (random order). Measurements at each filament lengths were compared using one-way ANOVA and post-hoc Tukey's range test. A p-value < 0.05 denoted statistical significance.

RESULTS

Significant differences in exerted force were observed with alteration in %RH levels for each filament length (all p < 0.001). Exerted force decreased significantly with an increase in %RH for all filament lengths, with the average force decreasing by 15% with each 10% rise in %RH.

CONCLUSIONS

This study confirms previous suggestions that the rigidity of the COBO nylon filament is affected by ambient room humidity levels, with implications on the stimulus force delivered by the instrument. A conversion table is provided for converting filament lengths to pressure for a range of relative humidity levels.

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.

The diagnosis of limbal stem cell deficiency

Limbal stem cells (LSCs) maintain the normal homeostasis and wound healing of corneal epithelium. Limbal stem cell deficiency (LSCD) is a pathologic condition that results from the dysfunction and/or an insufficient quantity of LSCs. The diagnosis of LSCD has been made mainly based on medical history and clinical signs, which often are not specific to LSCD. Methods to stage the severity of LSCD have been lacking. With the application of newly developed ocular imaging modalities and molecular methods as diagnostic tools, standardized quantitative criteria for the staging of LSCD can be established. Because of these recent advancements, effective patient-specific therapy for different stages of LSCD may be feasible.

Primary rhegmatogenous retinal detachment with inferior retinal breaks postoperative prone positioning results: 1 day versus 7 days

Background

To compare the primary anatomical outcome of pars plana vitrectomy, 360° peripheral endolaser, and 15% octafluoropropane C₃F₈ gas tamponade in patients with uncomplicated rhegmatogenous detachment and inferior retinal breaks, after 24-h postoperative prone positioning to similar patients with 1 week postoperative prone positioning.

Methods

Records of 5500 patients who underwent pars plana vitrectomy between 2008 and 2015 were retrieved. Collected data included age, gender, number of retinal quadrants with retinal breaks, number of retinal breaks, macula status on presentation (attached or detached), phakic status (phakic, pseudophakic, or aphakic), and primary anatomical outcome (at 1 and 3 months post-operative).

Results

270 patients met the study inclusion criteria (78 females, and 192 males). In the 24-h positioning arm (183 patients), the overall anatomical success rate was 96.2% at 1 month and 83.6% at 3 months. In the 1-week positioning group (87 patients), the overall anatomical success rate was 93% at 1 month and 79% at 3 months. Both positioning groups did not show statistical difference in outcome at 1 month (p-value = 0.7) or at 3 months (p-value = 0.39). Logistic regression analysis found that the number of retinal breaks correlates with the postoperative anatomical success at 3 months (odd ratio 0.8, p-value = 0.016).

Conclusion

This short term retrospective study demonstrated that patients with uncomplicated rhegmatogenous retinal detachment due to inferior retinal breaks, who underwent pars plana vitrectomy, 360° endolaser, 15% C₃F₈ gas, and limited (24-h) prone positioning did not show statistical difference in the anatomical outcome (at 1, and 3 months) when compared with 1 week postoperative positioning. Larger prospective studies are warranted to further elucidate positioning role.

PROPHYLACTIC PREOPERATIVE LASER RETINOPEXY DOES NOT REDUCE THE OCCURRENCE OF RHEGMATOGENOUS RETINAL COMPLICATIONS IN MACULAR SURGERY

PURPOSE

Knowledge on the utility of prophylactic 360° laser retinopexy before pars plana vitrectomy in the absence of peripheral retinal pathology is limited. This study compares the occurrence of rhegmatogenous events in the setting of small-gauge pars plana vitrectomy with and without prophylactic preoperative laser.

METHODS

Our multicenter, retrospective case-control analysis reviewed patients who underwent epiretinal membrane removal or macular hole repair through 23- or 25-gauge pars plana vitrectomy: 205 controls who did not receive prophylactic laser and 176 cases who received preoperative prophylactic laser retinopexy anterior to the equator. Main outcome measures were the rate and characteristics of postoperative retinal tears and detachments. Patients with previous pars plana vitrectomy or significant retinal disease were excluded.

RESULTS

Of those patients with prophylactic laser and those without, there was no significant difference in the number of retinal breaks (1.7% vs. 0.49%, respectively; P = 0.339) or retinal detachments (0% vs. 0.49%, respectively; P = 1.00). Of the lasered group, there was one sclerotomy-related retinal break and two non-sclerotomy-related retinal breaks. Of the nonlasered group, there was one non-sclerotomy-related retinal break and one sclerotomy-related retinal detachment.

CONCLUSION

Preoperative prophylactic peripheral laser retinopexy does not seem to offer an added benefit in the prevention of intraoperative and postoperative rhegmatogenous events.

Navigated Pattern Laser System versus Single-Spot Laser System for Postoperative 360-Degree Laser Retinopexy

Purpose. To compare three 360°-laser retinopexy (LRP) approaches (using navigated pattern laser system, single-spot slit-lamp (SL) laser delivery, and single-spot indirect ophthalmoscope (IO) laser delivery) in regard to procedure duration, procedural pain score, technical difficulties, and the ability to achieve surgical goals. Material and Methods. Eighty-six rhegmatogenous retinal detachment patients (86 eyes) were included in this prospective randomized study. The mean procedural time, procedural pain score (using 4-point Verbal Rating Scale), number of laser burns, and achievement of the surgical goals were compared between three groups (pattern LRP (Navilas® laser system), 36 patients; SL-LRP, 28 patients; and IO-LRP, 22 patients). Results. In the pattern LRP group, the amount of time needed for LRP and pain level were statistically significantly lower, whereas the number of applied laser burns was higher compared to those in the SL-LRP group and in the IO-LRP group. In the pattern LRP, SL-LRP, and IO-LRP groups, surgical goals were fully achieved in 28 (77.8%), 17 (60.7%), and 13 patients (59.1%), respectively (p > 0.05). Conclusion. The navigated pattern approach allows improving the treatment time and pain in postoperative 360° LRP. Moreover, 360° pattern LRP is at least as effective in achieving the surgical goal as the conventional (slit-lamp or indirect ophthalmoscope) approaches with a single-spot laser.

Prophylactic Circumferential Retinal Cryopexy to Prevent Pseudophakic Retinal Detachment after Posterior Capsule Rupture during Phacoemulsification

Purpose. To evaluate whether prophylactic circumferential retinal cryopexy (CRC) can prevent pseudophakic retinal detachment (PRD) development after posterior capsule rupture (PCR) during phacoemulsification. Methods. Retrospective patient chart analysis of eyes experiencing a PCR during phacoemulsification. Comparison of PRD development between eyes receiving CRC (cryo+ group) or not (cryo- group). Results. Overall 106 patients were analyzed, thereof 61 (58%) in the cryo+ and 45 (42%) in the cryo- group. In both clusters a total of 10 PRDs (9.4%) occurred, thereof 3 (30%) in the cryo+ as well as 7 (70%) in the cryo- group (p = 0.087), 79.8 ± 81.58 weeks after PCR. Relative/absolute risk reduction in CRC-treated eyes was calculated to be 68%/11%. Prophylactic CRC reduced PRD development 0.3-fold. Number needed to treat was estimated to be 9.4. Conclusion. Prophylactic CRC might be a useful treatment option in eyes with PCR to hamper PRD development in the further course. Further research is indicated to evaluate this beneficial effect between eyes with and without a rupture of the anterior vitreous cortex and accompanying vitreous loss in an expanding number of eyes.