Assessment of Corneal Densitometry in Rheumatoid Arthritis Patients

Assessment by the Scheimpflug imaging system of corneal clarity and anterior segment properties in rosacea patients

OBJECTIVE

To evaluate the effects of rosacea on ocular surface changes such as alterations in dry eye parameters, corneal densitometry, and aberrations, in comparison with healthy controls.

METHODS

A total of 88 eyes of 44 patients diagnosed with rosacea and 88 eyes of 44 healthy controls were enrolled in this cross-sectional study. All participants underwent a comprehensive dermatologic and ophthalmic examination and Tear Break-Up Time (TBUT) and Schirmer-1 tests were performed. The rosacea subtype and Demodex count and OSDI scores of all participants were recorded. Corneal topographic, densitometric, and aberrometric measurements were obtained using the Scheimpflug imaging system.

RESULTS

The mean age of the 44 patients was 41.2 ± 11.0 years of whom 31 (70.5%) were female. The mean TBUT and Schirmer-1 test values were significantly decreased and OSDI scores were significantly increased in the rosacea group compared to healthy controls (p < 0.01 for all). The most common subtype of rosacea was erythematotelangiectatic rosacea (70.4%). The severity grading of rosacea revealed that 18 (40.9%) patients had moderate erythema. The median (min-max) Demodex count was 14.0 (0-120) and the disease duration was 24.0 (5-360) months. The comparison of the corneal densitometry values revealed that the densitometry measurements in all concentric zones, especially in central and posterior zones were higher in rosacea patients. Corneal aberrometric values in the posterior surface were also lower in the rosacea group compared to healthy controls. The topographic anterior chamber values were significantly lower in the rosacea group.

STUDY LIMITATIONS

Relatively small sample size, variable time interval to hospital admission, and lack of follow-up data are among the limitations of the study. Future studies with larger sample sizes may also enlighten the mechanisms of controversial anterior segment findings by evaluating rosacea patients who have uveitis and those who do not.

CONCLUSION

Given the fact that ocular signs may precede cutaneous disease, rosacea is frequently underrecognized by ophthalmologists. Therefore, a comprehensive examination of the ocular surface and assessment of the anterior segment is essential. The main priority of the ophthalmologist is to treat meibomian gland dysfunction and Demodex infection to prevent undesired ocular outcomes.

Assessment of corneal parameters in patients with rheumatoid arthritis

PURPOSE

To assess the corneal parameters in rheumatoid arthritis (RA) patients.

METHODS

We enrolled 64 patients with RA (32 receiving biologic and 32 receiving conventional drugs) and 32 healthy subjects. Keratometric values (anterior flat [K1], steep [K2], and mean keratometry [Km]), corneal thickness from the pupil center (CCT), apex (ACT), and the thinnest point (TCT), and corneal volume (CV) were measured and compared between the groups.

RESULTS

K1, K2, and Km values were significantly higher in the RA group (P = 0.013, P = 0.048, P = 0.027, respectively). The means of CCT, ACT, TCT, and CV were significantly lower in RA patients (P < 0.001, P < 0.001, P < 0.001, P = 0.011, respectively). When we divided RA patients into two groups according to the treatment and compared them to controls, the differences in K1, CCT, ACT, TCT and CV were significant (P = 0.030, P = 0.005, P = 0.001, P = 0.001, P = 0.034, respectively). K1 and CV values of RA-biologic group were similar to the control group (P = 0.205 and P = 0.127, respectively).

CONCLUSION

Biologic agents contribute to the improvement of K1 and CV values in patients with RA.

Analysis of Corneal and Lens Densitometry Changes in Patients With Type 1 Diabetes Mellitus

PURPOSE

By comparing the densitometry findings of patients with type 1 diabetes mellitus (T1DM) and the healthy group, we aimed to understand the possible changes that may occur in the cornea and lens in those with diabetes mellitus (DM).

DESIGN

Prospective, cross-sectional study.

METHODS

A total of 60 eyes of 60 patients with T1DM and 101 eyes of 101 healthy subjects were included in this study. A complete ophthalmologic evaluation was performed in all participants. Scheimpflug tomography was performed to record the corneal and lens densitometry and other tomographic data. Mean glycosylated hemoglobin (HbA1c) and mean DM duration were recorded.

RESULTS

The mean age of the patients with T1DM and patients in the control group was 29.93 ± 8.56 years and 27.27 ± 1 4.96 years, respectively. The mean HbA1c was 8.43 ± 1.92, and the mean DM duration was 14.10 ± 7.77 years. Corneal densitometry (CD) values were significantly higher in the 0- to 2-mm zone in all layers and in the anterior and central 6- to 10-mm zone in the diabetic group (P = .03, P = .018, P = .001, P = .000, P = .004). The mean crystalline lens densitometry was higher in the T1DM group (P = .129). There were positive correlations between DM duration and CD in the anterior 0- to 2-mm (P = .043), central 6- to 10-mm (P = .016), posterior 6- to 10-mm (P = .022), and posterior 10- to 12-mm zone (P = .043).

CONCLUSIONS

CD values were significantly higher in the diabetic group. Diabetes duration and HbA1c values showed correlations with densitometry especially in the 6- to 10-mm corneal zone. Evaluation of the cornea with optical densitometry will be useful in the early diagnosis and follow-up of clinical structural and functional changes in the cornea.

Analysis of corneal topographic and densitometric properties in patients receiving systemic isotretinoin therapy

PURPOSE

To evaluate dry eye parameters, corneal topographic features, corneal densitometric changes, and anterior segment parameters in patients receiving systemic isotretinoin treatment.

METHODS

This prospective cross-sectional study included 66 eyes of 33 patients who were started on oral isotretinoin therapy for severe acne vulgaris. All patients were evaluated in terms of ocular surface tests such as tear break-up time (TBUT) and Schirmer-1 and were asked to fill in the ocular surface disease index (OSDI) questionnaire. Corneal densitometric and topographic measurements were obtained using the Scheimpflug imaging system.

RESULTS

The mean age of the patients was 19.9 ± 1.6 years, and 21 (63.6%) of the participants were female. The mean OSDI score was significantly higher in the third month than before treatment (20.05 ± 19.38, vs. 26.96 ± 22.94, p = 0.00, respectively). The mean values of the TBUT test were significantly lower in the third month than before treatment (9.06 ± 4.40 sec, vs. 10.71 ± 4.61 sec, p = 0.02, respectively). Mean scores of the Schirmer 1 test showed no statistically significant difference between before treatment and the third month (16.08 ± 8.40 mm, vs. 16.08 ± 8.50 mm, p = 1, respectively). There was no statistically significant difference between before treatment and the third month in the majority of the densitometry measurements in concentric zones. However, the difference tended to be significant between the groups concerning posterior zone 0-2 mm (11.01 ± 0.85 GSU vs. 10.62 ± 0.89 GSU, p = 0.006). The RMS LOAs (front), RMS Total (Total), RMS LOAs Total (Total), RMS HOAs Total (Total), K_max, CCT, and CoV values were significantly higher in the third month than before treatment (p < 0.05 for all).

CONCLUSIONS

The dermatology specialists should be aware of the ocular complications of systemic isotretinoin therapy. Therefore, a complete ophthalmologic examination for the prompt apprehension and management of ocular involvement is essential in patients under isotretinoin therapy to increase ocular comfort and adherence to the therapy.

Evaluating the topographical measurements and tear function status in patients with hemifacial spasm: A comparative fellow eye study

OBJECTIVE

To investigate the effect of eyelid spasm on corneal and tear film characteristics in patients with hemifacial spasm (HFS) and compare these data with those of the contralateral eyes of the same patients.

METHODS

This prospective study is comprised of 64 eyes of 32 HFS patients, 32 eyes on the spasm side (Group 1) and 32 contralateral eyes (Group 2). Corneal tomographic analyses were performed; corneal power of flat axis (K1) and steep axis (K2), astigmatism and thinnest pachymetry; anterior, posterior and total corneal aberrometry [spherical aberration (SA), vertical coma (vcoma), horizontal coma (hcoma), total higher order aberration (THOA) and total RMS], and corneal densitometry values were evaluated and compared between groups. Tear meniscus height and depth (TMH, TMD) were measured using anterior segment optic coherence tomography. Tear function tests including TMH and TMD, the Schirmer I test, and tear break-up time (TBUT) were compared between the groups.

RESULTS

K1, K2, astigmatism and corneal densitometry values were similar between groups (p > 0.05). Thinnest pachymetry values were significantly thinner on the spasm side (p = 0.040). Anterior and total corneal SA and RMS were significantly higher on the spasm side (p = 0.032, p = 0.005; p = 0.015, p = 0.006, respectively). TMH, TMD and TBUT were significantly lower in Group 1 (p = 0.01, p = 0.02 and p = 0.03, respectively). Schirmer I test values were similar between groups (p > 0.05).

CONCLUSION

In HFS patients, there are changes in corneal parameters and tear film in the eye on the spasm side compared to unaffected eye.

Objective assessment of corneal backscattered light in myopic, hyperopic, and emmetropic children

BACKGROUND

To determine the corneal densitometry(CD) values by using Scheimpflug imaging in myopic and hyperopic children and to compare the results with emmetropic children.

METHODS

The CD measurements of the subject were obtained with Scheimpflug tomography. The values were automatically measured in standardized grayscale units over an area 12mm in diameter, which was subdivided into 4 annular concentric zones(0-2mm, 2-6mm, 6-10mm, 10-12mm) and 3 corneal depths(anterior layer: anterior 120µm; central layer: from 120µm to the last 60µm; posterior layer: last 60µm). In addition, we evaluated the correlation between spherical equivalence and anterior corneal morphological parameters and the CD values.

RESULTS

A total of 211 participants were included in this prospective cross-sectional study. The eyes were divided into three groups related to their spherical equivalent(SE) refractive error values as follows: 88(41.7%) hyperopic eyes, 62(29.4%) myopic eyes, and 61(28.9%) emmetropic control eyes. The hyperopic eyes were found to have lower corneal densitometry values in 4 annular zones and the total 0-12 diameter of all layers except the central layer. However, only the 6-10mm annular zone of the central and posterior layers of the myopic eyes had lower corneal densitometry values than emmetropic eyes. There was also a significant correlation between spherical equivalent and corneal densitometry values in the anterior layer(0-2mm, 2-6mm zones), central layer(0-2mm, 10-12mm zones), posterior layer(6-10mm, 10-12mm zones, and the total 0-12mm diameter), and total corneal thickness(0-2mm zone) of the hyperopic eyes.

CONCLUSIONS

Backward scattering of light was lower in hyperopic eyes and this could indicate better visual quality.

Corneal Confocal Analysis after Scleral Lens Wear in Keratoconus Patients: A Pilot Study

SIGNIFICANCE

Scleral lenses rely on the scleroconjunctival region without bearing the cornea, which could improve the symptoms and modify the corneal nerve plexus morphology.

PURPOSE

This study aimed to evaluate symptoms and changes in corneal nerve plexus morphology and density of Langerhans cells in keratoconus patients with and without intrastromal corneal ring before and after scleral lens wear.

METHODS

Sixteen scleral lens wearers with keratoconus were recruited for this short-term experimental pilot study. Subjects were divided into two groups: keratoconus group and intrastromal corneal ring segment group. All subjects were examined in two visits: baseline (before scleral lens wear) and after 6 months of scleral lens wear, after lens removal. The Schirmer I test, the Ocular Surface Disease Index, tear breakup time, and in vivo confocal microscopy were evaluated.

RESULTS

The mean age was 42.33 ± 11.27 years. A significant decrease in tear breakup time was found in the total group ( P = .01, Wilcoxon) compared with baseline. Ocular Surface Disease Index score had decreased after 6 months of scleral lens wear in the keratoconus with intrastromal corneal ring segment subgroup ( P = .03, Wilcoxon) and in the total group ( P = .001, Wilcoxon). No statistical changes in nerve density, tortuosity, and ramification were found for either the total group or the subgroup. However, the mean nerve length was higher in all groups, especially in the keratoconus subgroup ( P = .03, Wilcoxon) after 6 months of scleral lens wear. Regarding optical density, the total group showed a significant increase after 6 months of wearing ( P = .02, Wilcoxon). Finally, Langerhans cell density was not statistically different in any group.

CONCLUSIONS

These results suggest that scleral lens wearing improves the symptoms and increased the mean length nerves after 6 months of wear use in keratoconus patients.

Corneal complications of rheumatoid arthritis

PURPOSE OF REVIEW

Rheumatoid arthritis (RA) is an autoimmune disease that primarily affects the joints. Extra-articular manifestations (EAMs) are common and may affect up to 40.6% of patients. Ocular EAM can occur in 39% of the patients. The cornea is involved by different pathogenic mechanisms and corneal disease varies from mild symptoms to severe corneal ulceration and melting with visual loss. Severe corneal involvement is associated with increased mortality in RA patients. We aimed to review the prevalence, mechanisms, management and overall impact of corneal involvement in RA patients.

RECENT FINDINGS

Corneal involvement is frequent among RA patients. With the wider use of systemic immunosuppression, in particular the disease-modifying antirheumatic drugs (DMARDs), and with improvement of surgical techniques, spontaneous and surgery-related corneal ulceration and melting is becoming less common. However, RA patients are still at risk and should be carefully managed.

SUMMARY

RA-related corneal complications are associated with a decreased quality of life and poor ocular and systemic prognosis. Prompt recognition and a multidisciplinary approach involving topical ophthalmic management and systemic immunosuppression are the key factors to maintain ocular integrity and avoid a lethal outcome.

Corneal Densitometry Assessed With Scheimpflug Camera in Healthy Corneas and Correlation With Specular Microscopy Values and Age

PURPOSE

To investigate correlations between specular microscopy endothelial parameters and age with corneal densitometry values, as they are presented from a Scheimpflug device, in different levels of the cornea.

METHODS

Two hundred eighty-four eyes of 142 healthy subjects were included in this observational, prospective study. Corneal densitometry was evaluated with Scheimpflug imaging system in the central 0- to 2-mm annular zone of the cornea, whereas the endothelial cell properties were assessed with the use of a noncontact specular microscope.

RESULTS

Corneal densitometry values of all corneal layers were statistically significant and positively correlated with age. In univariate linear regression analysis among corneal densitometry values and the endothelial parameters, only endothelial cell density (CD) was statistically significant and inversely correlated with densitometry values in all corneal layers. In stepwise multivariate linear regression analysis, after adjustment for age, hexagonality was statistically significant and inversely correlated with posterior densitometry values, whereas coefficient of variation was positively and significantly correlated with the anterior densitometry values. When repeating stepwise multivariate linear regression analysis without adjusting for age, CD was negatively and significantly correlated with corneal densitometry values of all layers, whereas coefficient of variation was positively and significantly correlated with anterior and total corneal densitometry values.

CONCLUSIONS

Corneal densitometry increases with age. It is also inversely correlated with CD, and this might be used as an indirect way to assess the status of the corneal endothelium.

Analysis of corneal densitometry and endothelial morphometry in patients with psoriasis

BACKGROUND

To evaluate corneal endothelial properties and corneal densitometry values in patients with psoriasis and to compare the results with those of healthy controls.

METHODS

This prospective, comparative, and cross-sectional study included 106 eyes of 53 patients who were diagnosed with psoriasis and 106 eyes of 53 age-gender matched healthy controls. All patients were evaluated in terms of ocular surface tests such as Schirmer-1 and tear break-up time (TBUT). Corneal endothelial measurements were performed using noncontact specular microscopy. Corneal tomographic and densitometric measurements were obtained using the Scheimpflug imaging system. Measurements were also evaluated according to the psoriasis area and severity index (PASI) score.

RESULTS

The mean TBUT and Schirmer 1 test values were significantly lower in the psoriasis group than in the healthy controls (p = 0.02, p < 0.001, respectively). While the mean endothelial cell density was significantly lower in patients with psoriasis than the healthy controls (2389.9±314.9 cells/mm² vs. 2512.4±289.7 cells/mm², p = 0.02), the mean average endothelial cell area, standard deviation of cell area, coefficient of variation of cell area were significantly higher in patients with psoriasis (426.6±62.7 µm² vs. 403.2±46.1 µm², p = 0.01; 206.4±52.3 µm² vs. 183.2±43.8 µm², p = 0.006; and 48.1±6.3% vs. 45.7±6.7%, p = 0.04, respectively). Most of the densitometry measurements in concentric zones were higher in patients with psoriasis than in healthy controls, but none of the differences reached statistical significance.

CONCLUSIONS

A regular eye examination is crucial in patients with psoriasis because corneal structural and functional changes, particularly endothelial alterations, are of utmost importance in planning intraocular surgeries in patients with psoriasis.

Effect of Laser-assisted Subepithelial Keratectomy with Mitomycin C on Corneal Optical Density Measured with Confocal Microscopy

SIGNIFICANCE

The development of confocal microscopy allows one to obtain high-resolution corneal images like its optical density. Some studies have evaluated the optical density with Scheimpflug cameras in the early post-operative period after photorefractive keratectomy, but no studies have evaluated the long-term evolution of optical density after surface ablation when mitomycin C is used.

PURPOSE

This work aimed to study the changes in corneal optical density measured with confocal microscopy in eyes treated with laser-assisted subepithelial keratectomy (LASEK) and intraoperative mitomycin C (MMC) to correct myopia.

METHODS

A study of 24 consecutive myopic eyes that underwent LASEK with 0.02% MMC and a control group of 24 healthy nontreated eyes was performed. Optical density was measured using the images by the confocal microscopy of the Heidelberg Retina Tomograph II with the Rostock Cornea Module. An analysis of confocal microscopy images was performed using the ImageJ software to obtain the optical density, in gray-scale units (GSU). The optical density of the stromal bed was evaluated 3 months, 15 months, and 3 years after surgery and was compared with the optical density at the equivalent depth of the stroma in controls.

RESULTS

The mean values of optical density for the LASEK group were 81.7 ± 9.7, 78.6 ± 11.7, and 73.6 ± 18.7 GSU at 3 months, 15 months, and 3 years, respectively, and it was 61.8 ± 8.2 GSU for the control group. A statistically higher optical density 3 and 15 months after LASEK with MMC was found compared with controls (P < .001). No significant difference was found in optical density at 3 years post-operatively.

CONCLUSIONS

Our study suggests that, after LASEK with MMC, the anterior corneal stroma has a higher optical density at 3 and 15 months post-operatively, which gradually returns to normal values 3 years after surgery.

Evaluation of corneal densitometry changes in patients with lichen planus

PURPOSE

To investigate the corneal topography and densitometry changes in patients with lichen planus (LP).

METHODS

Anterior segment parameters and corneal densitometry of patients with LP and age- and gender-matched individuals with healthy eyes were evaluated using Scheimpflug corneal topography. A 12 mm corneal area was divided into 4 annular zones and 3 regions-in-depth anterior, central and posterior-for densitometry evaluation.

RESULTS

The study included 45 patients with LP and 50 individuals with healthy eyes. The two groups were similar in age and gender, and they showed no significant differences in anterior segment corneal topography parameters. Schirmer's I test results were significantly lower in the patients with LP than in the control group (P ˂ .001). The total corneal densitometry was higher in patients with LP than in the control group (P = .030). The anterior, central and posterior corneal densitometry in the 0-2 mm and 2-6 mm annular zones was higher in the LP group than in the control group. Correlation analysis between disease duration and corneal densitometry values showed a strong positive correlation in the anterior segment and a moderate positive correlation in the central and posterior segments (r = 0.632, P ˂ .001; r = 0.572, P ˂ .001; and r = 0.562, P ˂ .001, respectively).

CONCLUSIONS

Corneal densitometry values were higher in patients with LP than in individuals with healthy eyes, even if the patients had a clinically transparent cornea. More studies are needed to evaluate the changes that may occur in corneal transparency in patients with LP and other autoimmune dermatologic diseases that may affect the eye.

Changes in the Optical Corneal Densitometry, Visual Acuity, and Refractive Error after the Annular Intracorneal Inlay Implantation

Purpose:

To investigate the changes in the optical corneal densitometry as an objective method in assessing the corneal light back-scattering before and 1 year after the annular intracorneal inlay (AICI) implantation into the keratoconic corneas.

Methods:

Changes in the optical corneal densitometry, visual acuity, refractive, and tomographical status were assessed before and 1 year after the AICI implantation into the corneas with different stages of keratoconus. Optical corneal densitometry was evaluated using the Pentacam-HR in 0–2, 2–6, 6–10, and 10–12 mm rings in the anterior 120 μ, central layers, posterior 60 μ and also the total value were measured for cornea in the Grey Scale Unit criterion.

Results:

Totally, 34 patients with keratoconus were studied; the uncorrected and best corrected visual acuity were increased after the surgery (0.98 ± 0.25 to 0.53 ± 0.30 logMAR, P < 0.001 and 0.26 ± 0.18 to 0.19 ± 0.14, P = 0.007 logMAR, respectively); the spherical equivalent was decreased from −4.45 ± 2.25 to − 2.06 ± 2.01 D (P = 0.004). AICI implantation led to an increase in the amount of optical corneal densitometry in 0–2 mm central, 2–6 mm central, 6–10 mm central, total central, 2–6 mm posterior, and 2–6 mm total rings (all, P < 0.05); however, a decrease was observed in 0–2 mm anterior ring (P = 0.049). Results of statistical analysis showed that the total optical corneal densitometry, anterior total, and posterior total back-scattering did not change after the AICI implantation (all, P > 0.05).

Conclusions:

Our results revealed a significant improvement in the visual function, including refractive error and visual acuity following the AICI implantation. Changes in the optical corneal densitometry were different in distinct regions and layers however, the total amount did not change after the AICI implantation.

Influence of peripheral corneal relaxing incisions during cataract surgery for corneal astigmatism up to 2.5 dioptres on corneal densitometry

PURPOSE

To assess the effect of peripheral corneal relaxing incisions (PCRI) for astigmatism between 0.75 and 2.5 dioptres during cataract surgery on corneal densitometry (CD).

METHODS

In this prospective, randomised study, 80 eyes (80 patients), received either tIOL or PCRI. Assessment at pre-operative and 1, 3, 6, 12 months post-operative visit included uncorrected (UCDVA) and best-corrected distance visual acuity (BCDVA), spherical equivalent (SEQ) (only post-operatively), mean anterior and posterior keratometric astigmatism (K_A) and CD with Schiempflug system. CD was analysed in four concentric radial zones from centre to periphery (Zone 1 to 4) and in 3 layers (anterior, mid-stromal and posterior).

RESULTS

Comparing tIOLs vs. PCRIs, there was no significant difference in the UCDVA, BCDVA and SEQ. In PCRI group, anterior K_A decreased at 1 month and remained stable thereafter. For zones 1, 2 and 3, CD significantly reduced after 3 months with tIOLs whereas with PCRIs, it reduced 1 month onwards. For zone 4, CD reduced only at 12 months with tIOLs compared to 3 months onwards with PCRIs. In both groups CD was higher in the zone 4 and anterior layer. Significant reduction in CD was found in all three layers of cornea after 3 months in tIOL and after first month in PCRI groups, respectively.

CONCLUSIONS

Cataract surgery alone reduces the CD. Reducing keratometric astigmatism with PCRIs shows significant differences in CD from early post-operative period for central and anterior corneal layer.

Corneal densitometry in high myopia

Background

To investigate corneal densitometry values obtained using Scheimpflug tomography in normal and highly myopic (HM) eyes and to assess the differences in densitometry values between them.

Methods

Highly myopic and normal corneas were examined using the Pentacam Scheimpflug imaging system. Corneal densitometry was automatically performed over a 12-mm diameter area, which was divided on the basis of annular concentric zones (0–2 mm, 2–6 mm, 6–10 mm, 10–12 mm, total diameter) and depth (anterior layer: inner 120 μm; center layer: from 120 μm to the last 60 μm; posterior layer: last 60 μm; total corneal thickness).

Results

A total of 100 normal and 100 HM eyes were enrolled in this study. Upon total corneal thickness densitometry, the HM group was found to have significantly lower values compared with the normal group in 4 annuli, including the 2 mm central zone, 2-6 mm zone, 6–10 mm zone, and 0–12 mm total diameter. Upon anterior layer densitometry, the HM group demonstrated statistically lower values in the 2-6 mm and 6–10 mm zones. Upon densitometry of the central and posterior layers, the HM group was found to have lower values in all annuli.

Conclusions

The densitometry map reveals that light backscatter was lower in most portions of the HM cornea than in the normal cornea.