In Vivo Confocal Microscopy Findings After Anterior Stromal Puncture in the Treatment of Recurrent Corneal Erosion Syndrome.

Objectives: The objectives of the study are to show up the healing processes after anterior stromal puncture (ASP) in the cornea using in vivo confocal microscopy (IVCM) and to investigate the efficacy of ASP in the treatment of recurrent corneal erosion (RCE). Methods: This is a prospective, non-randomized, consecutive series. Twenty-three eyes of 19 patients diagnosed with RCE were evaluated between March 2020 and January 2022. Outcome measures included age, sex, laterality, etiology of RCE, duration and recurrence of symptoms, additional treatments required, and complications. IVCM was performed on the same day, at 1st week, 1st, and 6th month. Results: Mean age was 41.5±11.3 years, 63.2% of patients were female and 65.2% of eyes had unilateral involvement. Corneal trauma (56.5%) was the most common cause. Mean follow-up was 21.1 months (range 8-33). At the final follow-up, 69.5% of eyes were symptom free, 17.4% required a second ASP, and 13% needed a third ASP. At the 1st week, the epithelium became intact. An increase in activated keratocytes and dendritic cells (DCs) with beading of nerve fibers was observed. At 1st month, DCs and activated keratocytes were still present. At the 6th month, a scar was left. The superficial and basal epithelial cell formation and subbasal corneal nerve plexus returned to normal. Conclusion: IVCM has a superiority in visualizing cornea at cellular level. After ASP which is a safe, practical, and cost-effective treatment option in paracentral or peripherally located RCE, IVCM may help the surgeon to better observe and understand the post-healing processes and explain the recurrences.

Comparison of surgically induced astigmatic changes after cataract surgery in post-Laser in situ keratomileusis corneas versus virgin eyes.

PURPOSE: Postoperative refraction in modern mi-croincision cataract surgery gained extra importance in patients with the previous laser-assisted in situ keratomileusis (LASIK) surgery. The surgically induced astigmatic changes in those eyes may differ not only in magnitude but also in direction compared to virgin corneas. This study aimed to compare the surgically induced astigmatic changes after microscopic cataract surgery between post-LASIK corneas and virgin eyes. METHODS: Cases that underwent microincision cataract surgery in eyes with and without previous LASIK surgery were reviewed. The demographics, the axial length at cataract surgery, the central corneal thickness, spheric and cylindric values, keratometry readings, and postoperative posterior corneal astigmatism were retrospectively evaluated. A modified Alpins method was used for astigmatic vector analysis, and baseline astigmatism, surgically induced astigmatism, difference vector, flattening effect, and torque were assessed. RESULTS: A total of 42 eyes from 24 subjects was evaluated. Group I consisted of 14 eyes with the previous LASIK, and Group II included 28 eyes without any refractive surgery. Preoperative mean central corneal thickness in Group I was significantly thinner (p=0.012). There was no significant difference in baseline astigmatism between the groups regarding magnitude and power vectors. After microincision cataract surgery, there were no significant differences in mean spheric and cylindric values and mean keratometry readings (all p>0.05). However, surgically induced astigmatism and difference vector were significantly higher on J45 vector component in post-LASIK eyes and microincision cataract surgery steepening effect on post-LASIK corneas was significantly higher than those in virgin eyes (p=0.001, p=0.002 and p=0.018, respectively). CONCLUSIONS: Cataract surgery has steepened the corneas in both groups with a significantly higher steepening effect in post-LASIK eyes. Certainly, corneal topography cataract surgery is particularly helpful to provide more precise surgically induced astigmatism interpretations.

Comparison of surgically induced astigmatic changes after cataract surgery in post-Laser in situ keratomileusis corneas versus virgin eyes / Comparação de alterações astigmáticas induzidas cirurgicamente após cirurgia de catarata em córneas ceratomileusis in situ pós-Laser versus olhos virgens

ABSTRACT Purpose: Postoperative refraction in modern mi­croincision cataract surgery gained extra importance in patients with the previous laser-assisted in situ keratomileusis (LASIK) surgery. The surgically induced astigmatic changes in those eyes may differ not only in magnitude but also in direction compared to virgin corneas. This study aimed to compare the surgically induced astigmatic changes after microscopic cataract surgery between post-LASIK corneas and virgin eyes. Methods: Cases that underwent microincision cataract surgery in eyes with and without previous LASIK surgery were reviewed. The demographics, the axial length at cataract surgery, the central corneal thickness, spheric and cylindric values, keratometry readings, and postoperative posterior corneal astigmatism were retrospectively evaluated. A modified Alpins method was used for astigmatic vector analysis, and baseline astigmatism, surgically induced astigmatism, difference vector, flattening effect, and torque were assessed. Results: A total of 42 eyes from 24 subjects was evaluated. Group I consisted of 14 eyes with the previous LASIK, and Group II included 28 eyes without any refractive surgery. Preoperative mean central corneal thickness in Group I was significantly thinner (p=0.012). There was no significant difference in baseline astigmatism between the groups regarding magnitude and power vectors. After microincision cataract surgery, there were no significant differences in mean spheric and cylindric values and mean keratometry readings (all p>0.05). However, surgically induced astigmatism and difference vector were significantly higher on J45 vector component in post-LASIK eyes and microincision cataract surgery steepening effect on post-LASIK corneas was significantly higher than those in virgin eyes (p=0.001, p=0.002 and p=0.018, respectively). Conclusions: Cataract surgery has steepened the corneas in both groups with a significantly higher steepening effect in post-LASIK eyes. Certainly, corneal topography cataract surgery is particularly helpful to provide more precise surgically induced astigmatism interpretations.

RESUMO Objetivo: A refração pós-operatória na cirurgia mo­derna de catarata por microincisão ganha ainda mais importância em pacientes com cirurgia prévia de ceratomileuse in situ assistida por laser (LASIK). As alterações astigmáticas induzidas cirurgicamente nesses olhos podem diferir não apenas em magnitude, mas também em direção em comparação com córneas virgens. O objetivo deste estudo foi comparar as alterações astigmáticas induzidas cirurgicamente após cirurgia de catarata por microincisão entre córneas pós-LASIK e olhos virgens. Métodos: Foi revisada uma série de casos de cirurgia de catarata por microincisão em olhos com e sem cirurgia LASIK anterior. Os dados demográficos, o comprimento axial no momento da cirurgia de catarata, a espessura central da córnea, os valores esféricos e cilíndricos, as leituras da ceratometria e o astigmatismo corneano posterior pós-operatório foram avaliados retrospectivamente. O método Alpins modificado foi usado para análise vetorial astigmática e foram avaliados o astigmatismo basal, o astigmatismo induzido cirurgicamente, o vetor de diferença, o efeito de achatamento e o torque. Resultados: Ao todo, 42 olhos de 24 indivíduos foram avaliados. O Grupo I consistiu em 14 olhos com LASIK prévio; o Grupo II incluiu 28 olhos sem qualquer cirurgia refrativa. A média da espessura corneana central pré-operatória no Grupo I foi significativamente mais fina (p=0,012). Não houve diferença significativa no astigmatismo basal entre os grupos em termos de magnitude e vetores de potência. Após a cirurgia de catarata por microincisão, não houve diferenças significativas nos valores médios esféricos, cilíndricos e leituras médias de ceratometria (todos com p>0,05). No entanto, o astigmatismo induzido cirurgicamente e o vetor de diferença foram significativamente maiores no componente do vetor J45 em olhos pós-LASIK, e o efeito de aumento da inclinação pela cirurgia de catarata por microincisão nas córneas pós-LASIK foi significativo em comparação com olhos virgens (p=0,001, p=0,002 e p=0,018, respectivamente). Conclusões: A cirurgia de catarata aumentou a inclinação das córneas em ambos os grupos, sendo esse aumento significativamente maior nos olhos pós-LASIK. Certamente, a topografia da córnea antes da cirurgia de catarata é particularmente útil para fornecer interpretações mais precisas do astigmatismo induzido cirurgicamente.

The Effect of Anterior Segment Depth on the Accuracy of 7 Different Intraocular Lens Calculation Formulas.

Objectives: To evaluate the effect of anterior segment depth (ASD; sum of anterior chamber depth and lens thickness) on the accuracy of 7 intraocular lens formulas calculated in patients with axial length (AL) between 22.5 and 24.5 mm. Materials and Methods: In this retrospective study, patients who underwent cataract surgery were divided into three groups based on their ASD measurements (Group I: ASD <7.30 mm, Group II: ASD between 7.30-7.90 mm, Group III: ASD >7.90 mm). The mean predictive error (MPE), mean absolute error (MAE), and median absolute error (MedAE) values of each group were compared. The effect of ASD on the predictive error (PE) of each lens formula was additionally tested in subgroups based on mean keratometry (K) values (Subgroup I: K <42.0 D, Subgroup II: K between 42.0-44.5 D, Subgroup III: K >44.5 D). Results: The study included 184 eyes of 184 patients. In Group I, all formulas except Olsen OLCR and Barrett II had clinically myopic MPEs. In Group II, the MPEs of all lens formulas except Barrett II were statistically non-different from zero (p>0.05). In Group III, the MPEs of all lens formulas were found to be statistically hyperopic. In Group III, all formulas except Olsen OLCR were significantly shifted to more hyperopic results when compared with Groups I and II (p<0.05). ASD was positively correlated with the PEs of the SRK/T, Holladay I, Hoffer Q, Barrett II, Hill-RBF, and Haigis formulas. In cases with mean K greater than 42.0 D, ASD was similarly correlated with PE for all formulas except Olsen OLCR. Conclusion: In eyes with AL between 22.5 and 24.5 mm, the predictions of lens formulas were significantly hyperopic in cases with greater ASD.

Comparison of Postoperative Corneal Astigmatism Induced by Two Different Corneal Incisions during Microincisional Cataract Surgery.

Objectives: Clear corneal incision (CCI) architecture in modern microincision cataract surgery (MICS) plays an undeniable role in postoperative refraction. The goal of this study was to evaluate the effect of hinge incision prior to two-step CCI on postoperative refractive astigmatism after cataract surgery and to demonstrate the schematic presentation of these postoperative astigmatic changes via double-angle polar plots. Methods: This study involved a consecutive case series of patients who had MICS. The first incision was performed as a two-step CCI, whereas the second was made as a hinge incision prior to 2-step CCI. The preoperative corneal and postoperative refractive astigmatism and surgically induced astigmatism (SIA) were calculated by vectorial analysis. Hotelling's T2 test was performed to compare the centroid values of preoperative and postoperative corneal astigmatism. Results: A total of 63 eyes from 57 subjects were evaluated. Group I consisted of 27 eyes with the two-step CCI, and Group II included 36 eyes with the hinge incision prior to two-step CCI. No significant difference was found between the groups in terms of age, sex, axial length, keratometry readings, implanted intraocular lens power, and postoperative spherical equivalent. The centroids of corneal astigmatism postoperatively increased to 0.21 D at 87.6°±0.61 with no significance in Group I (p=0.525) and to 0.70 D at 90.6°±0.47 with significance in Group II (p=0.032). The difference in postoperative centroids between the two groups was also significantly different (p=0.043). Finally, the centroids of SIA were 0.12 D at 85.5°±0.50 and 0.22 D at 91.1°±0.49 for Group I and Group II, respectively, with no significance. Conclusion: A hinge incision did not have an unfavorable effect on postoperative refractive astigmatism; therefore, it may be preferred for controlled entrance to the anterior chamber.

Computer-Based Tutorial to Enhance the Informed Consent Process for Cataract Surgery in Serbian- or Turkish-Speaking Patients.

INTRODUCTION: This study analyses if a translated version of the CatInfo tool increases the knowledge of Serbian- and Turkish-speaking patients about cataract surgery. METHODS: In total, 61 cataract patients, literate in Serbian or Turkish, were randomly allocated into two groups. Via an interactive computer-based tool ("CatInfo"), patients either saw a detailed audio-visual presentation about cataract surgery (study group) or a "placebo" video (control group). Afterwards, all participants had a face-to-face discussion with an ophthalmologist. Immediately after the interview and on the day of surgery, all patients had to fill out a questionnaire including knowledge and demographic questions. Patients in the study group were further asked about their satisfaction with the CatInfo tool and the usefulness of such a device before other interventions. RESULTS: Patients in the study group answered significantly more questions correctly compared to the control group, and this information gain remained stable over a 1-week period. There was a significant low negative correlation between educational level and the test results, whereas age and computer habits of the participants did not have an influence on correct answers. Satisfaction with the CatInfo tool was high in the Serbian and the Turkish group (96% and 84%, respectively), and 92% of Serbian patients as well as 62% of the Turkish patients rated that they could imagine to use such a device before any other surgery. DISCUSSION/CONCLUSION: The translated version of the CatInfo tool improved patients' knowledge, and this information gain remained stable until the day of the surgery.

Logistic Regression Model Using Scheimpflug-Placido Cornea Topographer Parameters to Diagnose Keratoconus.

PURPOSE: Diagnose keratoconus by establishing an effective logistic regression model from the data obtained with a Scheimpflug-Placido cornea topographer. METHODS: Topographical parameters of 125 eyes of 70 patients diagnosed with keratoconus by clinical or topographical findings were compared with 120 eyes of 63 patients who were defined as keratorefractive surgery candidates. The receiver operating character (ROC) curve analysis was performed to determine the diagnostic ability of the topographic parameters. The data set of parameters with an AUROC (area under the ROC curve) value greater than 0.9 was analyzed with logistic regression analysis (LRA) to determine the most predictive model that could diagnose keratoconus. A logit formula of the model was built, and the logit values of every eye in the study were calculated according to this formula. Then, an ROC analysis of the logit values was done. RESULTS: Baiocchi Calossi Versaci front index (BCVf) had the highest AUROC value (0.976) in the study. The LRA model, which had the highest prediction ability, had 97.5% accuracy, 96.8% sensitivity, and 99.2% specificity. The most significant parameters were found to be BCVf (p=0.001), BCVb (Baiocchi Calossi Versaci back) (p=0.002), posterior rf (apical radius of the flattest meridian of the aspherotoric surface in 4.5 mm diameter of the cornea) (p=0.005), central corneal thickness (p=0.072), and minimum corneal thickness (p=0.494). CONCLUSIONS: The LRA model can distinguish keratoconus corneas from normal ones with high accuracy without the need for complex computer algorithms.

Keratopigmentation: Is it a Miracle or an Adventure?

OBJECTIVES: This study is an analysis of the cosmetic and functional results of patients who underwent keratopigmentation (KTP). METHODS: Sixteen eyes of 16 patients, 7 females (43.75%) and 9 males (56.25%) were included in the study. Intrastromal and superficial manual KTP were performed under general anesthesia. Patients with no light perception or with only light perception but total corneal opacification, prosthetic contact lens intolerance, or unwillingness to use a contact lens were studied. The main outcomes were postoperative patient's satisfaction, cosmetic results, pigment stabilization and surgical complications. A grading system (0-5 points) was used to assess patient satisfaction and the cosmetic results. RESULTS: The mean age of the patients was 30.5±12.06 years (range: 16-53 years). Black pigment was used in 10 patients (62.5%), a brownish color in 5 patients (31.25%) and a greenish, yellow, blue, and black color pigmentation was used for 1 patient (6.25%). The mean follow-up was 29.31±15.45 months (range: 8-52 months). In 2 of 16 patients, mild to moderate pigment loss was seen 12 months after the surgery and superficial KTP was repeated. Minimal pigment loss was seen in 5 patients, but the cosmetic results were satisfactory and no secondary surgical procedure was required. Pigment leakage underneath the conjunctiva was seen in only 1 patient. Otherwise, there were no complications associated with keratopigmentation. The postoperative mean patient satisfaction score was 4.18±0.75 points (range: 3-5 points). CONCLUSION: KTP is a safe surgical procedure that is easy to learn and perform, does not require expensive materials, and avoids more extensive and invasive reconstructive ocular procedures. Corneal KTP may have a great impact on future ophthalmic surgical practice from both therapeutic and cosmetic perspectives.

Results of ethanol-assisted epithelium-on corneal cross-linking with and without intrastromal corneal ring implantation.

PURPOSE: To evaluate the topographic, refractive, and pachymetric changes after ethanol-assisted transepithelial corneal cross-linking (CXL) to stabilize progression of keratoconus (KC). PATIENTS AND METHODS: This study retrospectively evaluated the long-term topographic, refractive, and pachymetric changes in patients diagnosed with KC who underwent corneal cross-linking and/or intrastromal corneal ring segment (ICRS) implantation. The subjects were divided into three groups, corresponding to eyes treated with CXL alone (group 1), CXL and ICRS at the same time (group 2), and CXL after ICRS implantation (group 3). Corrected visual acuity and refraction, steep keratometry (SteepK) values, steepest keratometry reading on sagittal curvature map, and corneal thickness were recorded preoperatively and at each visit. Changes between measurements were assessed during follow-up. RESULTS: Corrected distant visual acuity (CDVA) values improved in all groups compared with baseline, but the differences were not statistically significant except for the first year (p > 0.05). In groups 1 and 3, SteepK values did not change statistically significantly during the entire follow-up (p > 0.05). In group 2, SteepK values statistically significantly decreased at all follow-up examinations compared with baseline, determined as the first month after ICRS implantation (p < 0.05). Complication rates were acceptable without any need for surgical intervention. CONCLUSIONS: Single-session ethanol-assisted transepithelial CXL with or without ICRS implantation was a safe and effective procedure to halt progression of KC.

Comparison of three different diffractive multifocal intraocular lenses with a +2.5, +3.0, and +3.75 diopter addition power.

PURPOSE: To compare the functional outcomes and astigmatic tolerability after implantation of multifocal intraocular lenses (IOLs) with a +2.5, +3.0, and +3.75 diopter (D) addition power. METHODS: This study included 122 eyes of 61 patients who had bilateral cataract extraction and implantation of diffractive aspheric multifocal acrylic IOLs with +2.5 D (+2.5 group), +3.0 D (+3.0 group), and +3.75 D (+3.75 group) addition powers. 1-year after surgery, distance corrected near (DNVA) and intermediate (DIVA) visual acuities at 32, 40, 45, 50, 55, and 60 cm; and contrast sensitivity measurements under photopic, mesopic and mesopic with glare conditions; spherical and astigmatic defocus testing; distance-intermediate-near vision patient satisfaction levels; spectacle dependance; patient-reported outcomes were assessed binocularly. RESULTS: The +2.50 D group had better DIVA than both +3.0 group and +3.75 groups at 45 cm, 50 cm, 55 cm, and 60 cm (p < 0.05). The +3.75 group had better DNVA than both +2.5 and +3.0 IOL groups at 32 cm (p < 0.05). There was no significant difference in mean contrast values at all frequencies between three IOL groups (p > 0.05). The +2.50 D group showed better astigmatic tolerability than +3.00 group (at 2.00 D) and +3.75 group (at 1.50 D, and at 2.00 D) (p < 0.05). CONCLUSION: Multifocal IOLs with +2.5 add power have better intermediate vision, but worse near vision compared to multifocal IOLs with +3.00 D and +3.75 D add power. Multifocal IOLs with +2.50 D add power tend to have better astigmatic defocus tolerability than multifocal IOLs with +3.00 D and +3.75 D add powers.

Capecitabine-Induced Bilateral Ectropion: A Rare Ocular Manifestation Requiring Surgical Intervention.

It has been established that many chemotherapeutic agents are associated with a variety of ocular side effects. As an antineoplastic agent, 5-fluorouracil (5-FU) is the chemotherapeutic agent that is frequently linked with cicatricial ectropion. Capecitabine is a prodrug of 5-FU and has a more favorable side effect profile than 5-FU. Frequent side effects of capecitabine include gastrointestinal events and hand-foot-mouth syndrome; cicatricial ectropion is rather uncommon. Enzyme deficiencies affecting the capecitabine metabolism have been reported to be associated with exaggerated generalized systemic and cutaneous side effects; however, there are no cases in the literature reporting capecitabine-induced isolated bilateral-progressive ectropion. Although cessation of the agent is frequently sufficient for the treatment of ectropion, close follow-up is indicated in such patients as permanent damage may occur if the problem is left untreated. We report a case of capecitabine-induced bilateral cicatricial ectropion refractory to treatment cessation, ultimately requiring surgical treatment.

Persistence of the Cone on the Posterior Corneal Surface Affecting Corneal Aberration Changes After Intracorneal Ring Segment Implantation in Patients With Keratoconus.

PURPOSE: To analyze the changes in anterior and posterior corneal surfaces and aberrations in patients who underwent intracorneal ring segment (ICRS) implantation for the treatment of keratoconus. METHODS: Eighty-nine eyes of 59 patients with keratoconus who underwent ICRS implantation were analyzed. All eyes were evaluated using a tomography system combining a Placido disc and Scheimpflug photography before and at least 6 months after surgery. Total, anterior, and posterior corneal aberrations, anterior and posterior sagittal and tangential anterior and posterior curve analysis, keratometry (K), minimum corneal thickness, and anterior chamber depth were analyzed before and after surgery. RESULTS: Flattening with a decrease in the cone shape on the anterior corneal surface and steepening in the paracentral area with persistence of cone appearance on the posterior corneal surface were noted in all cases after ICRS implantation. The total corneal higher-order aberrations (HOAs) significantly decreased from 1.09 ± 0.43 to 0.71 ± 0.32 µm, and anterior corneal HOAs significantly decreased from 0.98 ± 0.46 to 0.81 ± 0.37 µm, whereas the posterior corneal HOAs increased from 0.53 ± 0.29 to 0.66 ± 0.25 µm after ICRS implantation (P < 0.05). There was a significant decrease in anterior maximum keratometry, but there was a significant increase in posterior maximum keratometry after ICRS implantation (P < 0.05). CONCLUSIONS: The cone shape persists on the posterior corneal surface despite its correction on the anterior corneal surface, leading to a decrease in anterior corneal aberrations and an increase in posterior corneal aberrations after ICRS implantation in eyes with keratoconus.

Corneal flap thickness with the Moria M2 single-use head 90 microkeratome in 72 consecutive LASIK procedures.

PURPOSE: This study aimed to evaluate the accuracy and consistency of corneal flap thickness in laser-assisted in situ keratomileusis (LASIK) with the Moria M2 single-use head 90 microkeratome. METHODS: The central corneal thickness of 72 (37 right, 35 left) eyes of 37 patients was measured by ultrasonic pachymetry preoperatively and intraoperatively after flap cut. The Moria M2 single-use head 90 microkeratome was used to create a superior hinged flap in all eyes. The right eyes were always operated on before the left eyes in each patient, using the same blade in all bilateral cases. All patients underwent LASIK for myopia and/or myopic astigmatism using VISX Star S4 platform. RESULTS: The mean preoperative spherical equivalent refraction was -3.55±2.30 D (range: -0.625 to -11.00 D), preoperative central corneal thickness by ultrasonic pachymetry was 541±26.82 µm (490-600 µm) and steepest K was 44.08±1.49 D (40-46.75 D) in all eyes. The mean flap thickness was 136.97±20.07 µm (106-192 µm), 131.2±19.5 µm (91-192 µm), and 134.16±19.85 µm (91-192 µm) in the right, left, and both eyes, respectively. A positive significant relationship was found between flap thickness and preoperative ultrasonic pachymetry thickness. No significant relationship was found between flap thickness and the age, preoperative spherical equivalent, and preoperative steepest K. The difference between the first and second eyes was not significant. There were no major intraoperative and postoperative complications in all eyes. CONCLUSION: The Moria M2 single-use head 90 microkeratome cut relatively thicker flaps than were intended. The flap thickness range was quite wide. This was a disadvantage for the accuracy and consistency of corneal flap thickness.

In-vivo corneal biomechanical analysis of unilateral keratoconus.

AIM: To evaluate and compare corneal biomechanical findings measured by ocular response analyzer, topographic and pachymetric findings in patients with unilateral keratoconus patients and healthy controls. METHODS: This is an observational, case-control study. Patients with keratoconus in one eye and forme fruste keratoconus in the fellow eye were compared with sex and age matched with controls healthy subjects. All subjects were evaluated with rotating scheimpflug imaging system. The receiver-operating-characteristic curves were analyzed to evaluate the sensitivity and specificity of the parameters. RESULTS: Twenty-seven patients with keratoconus in one eye and forme fruste keratoconus in the fellow eye were compared with 40 eyes of 40 normal subjects. Corneal hysteresis (CH) was 8.0±1.7 mm Hg in keratoconus group, 8.3±1.6 mm Hg in forme fruste keratoconus group, and 9.8±1.6 mm Hg in control groups (P=0.54 between keratoconus and forme fruste keratoconus groups, P<0.01 between control group and other groups). Corneal resistance factor (CRF) was 7.1±2.2 mm Hg in keratoconus group, 7.8±1.2 mm Hg in forme fruste keratoconus group and 9.9±1.5 mm Hg in control group (P<0.001 between control group and other groups). Using receiver-operating-characteristic analysis, the area under curve values of the parameters to distinguish forme fruste keratoconus from control subjects were: CH (0.768), CRF (0.866). Best cut-off points were 9.3 mm Hg and 8.8 mm Hg for CH and CRF respectively. CONCLUSION: Ocular response analyzer parameters (CH and CRF) are found to be significantly lower in forme fruste keratoconus patients compared to normal control subjects.

Comparison of multimetric D index with keratometric, pachymetric, and posterior elevation parameters in diagnosing subclinical keratoconus in fellow eyes of asymmetric keratoconus patients.

PURPOSE: To compare the multimetric D index and other keratoconus-screening parameters in patients with clinical keratoconus in 1 eye and subclinical keratoconus in the fellow eye. SETTING: Medipol University Hospital and Birinci Eye Hospital, Istanbul, Turkey. DESIGN: Retrospective case-control study. METHODS: Patients with clinical keratoconus in 1 eye and subclinical keratoconus in the fellow eye and eyes of normal subjects were evaluated with a rotating Scheimpflug imaging system (Pentacam). Parameters included anterior curve analysis, keratometry (K) values, minimum corneal thickness, pachymetric progression index, Ambrósio relational thickness, posterior elevation, back difference elevation, and D-index values. The receiver operating characteristic (ROC) curves were analyzed to evaluate the area under curve (AUC), sensitivity, and specificity of each parameter. RESULTS: Forty-five patients and 67 normal subjects were evaluated. The pachymetric progression indices, posterior elevation, and the D-index measurements were statistically significantly higher whereas corneal thickness and Ambrósio relational thickness measurements were significantly lower in eyes with keratoconus or subclinical keratoconus than in eyes of normal subjects (P < .05). Using the ROC analysis, the AUC values of the mean steep K, minimum corneal thickness, pachymetric progression index minimum, Ambrósio relational thickness maximum, posterior elevation, back difference elevation, and D index to distinguish between subclinical keratoconus from control subjects were 0.52, 0.64, 0.71, 0.72, 0.71, 0.76, and 0.83, respectively. CONCLUSION: The new multimetric D index seems to be better than other single-metric parameters in diagnosing keratoconus and subclinical keratoconus with good specificity. However, the sensitivity levels of all parameters were relatively limited in the diagnosis of subclinical keratoconus. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Tear osmolarity and tear film parameters in patients with unilateral pterygium.

PURPOSE: The aim of this study was to evaluate the differences in tear osmolarity and tear film parameters between pterygium-affected and healthy fellow eyes. METHODS: The study enrolled 65 patients with unilateral pterygium. Tear osmolarity, tear film break-up time (TBUT), Schirmer I test measurements, fluorescein corneal staining, and conjunctival redness were evaluated. The results were compared between pterygium-affected eyes and healthy fellow eyes of the same patient (controls). The pterygium thickness was measured using optical coherence tomography. We also evaluated the relationship between pterygium thickness and tear osmolarity and between TBUT and Schirmer I test results in eyes with pterygium. RESULTS: The mean tear osmolarity was 307 mOsm/L in pterygium-affected eyes and 294 mOsm/L in control eyes. The mean values of TBUT, Schirmer I test, corneal staining, and conjunctival redness scores were 10.3 ± 3.4 seconds, 14.8 ± 9.2 mm, 1.2 ± 1.1, and 0.9 ± 0.9 in the pterygium group, whereas the mean values were 12.3 ± 4.4 seconds, 16.2 ± 7.2 mm, 0.4 ± 0.8, and 0.4 ± 0.7 in the control group, respectively. Eyes with pterygium had significantly higher tear osmolarity levels, corneal staining, and conjunctival redness scores; and lower tear film TBUT and Schirmer I test values than eyes without pterygium (Wilcoxon signed rank test, P < 0.05). There was no significant correlation between pterygium thickness versus tear osmolarity, TBUT, and Schirmer I test values in eyes with pterygium (r = 0.159, 0.738, 0.321, respectively; P > 0.05). CONCLUSIONS: This study showed that pterygium is associated with tear hyperosmolarity and abnormal tear film function.

Intraoperative and early postoperative flap-related complications of laser in situ keratomileusis using two types of Moria microkeratomes.

The purpose of this study is to describe the incidence, management, and visual outcomes of intraoperative and early postoperative flap-related complications of laser in situ keratomileusis (LASIK) surgery using two types of Moria M2 microkeratomes. This retrospective analysis was performed on 806 primary LASIK cases. The intraoperative and early postoperative flap-related complications were identified and categorized according to type of Moria microkeratome. There were 52 intraoperative and early postoperative complications--one case of partial flap (0.124 %), one case of free flap (0.124 %), one case of small flap (0.124 %), 13 cases of epithelial defect (1.61 %), 12 cases of flap striae (1.49 %), 10 cases of diffuse lamellar keratitis (1.24 %), 10 cases of interface debris (1.24 %), three cases of epithelial ingrowth (0.37 %), and one case of microbial infection (0.124 %). The overall incidence of flap complications was 6.45 %. There were 27 right eye (6.73 %) and 25 left eye (6.17 %) complications. The incidence of complications with the Moria automated metallic head 130 microkeratome was 4.22 % and with the Moria single-use head 90 microkeratome was 2.23 %. We observed one culture-negative interface abscess which was cured with surgical cleaning and intensive medical treatment. The most common complication encountered was epithelial defects, followed by flap striae. Our study showed that LASIK with a microkeratome has a relatively low incidence of intraoperative and early postoperative flap complications. The authors have no financial interest in any of the issues contained in this article and have no proprietary interest in the development of marketing of or materials used in this study.

Comparison of sulfur hexafluoride and air for donor attachment in Descemet stripping endothelial keratoplasty in patients with pseudophakic bullous keratopathy.

PURPOSE: The aim of this study was to evaluate the clinical efficacy and safety of sulfur hexafluoride (SF6) as a tamponading agent after donor placement during Descemet stripping endothelial keratoplasty (DSEK) surgery and to compare the outcomes with those of air. METHODS: Forty-four eyes of 44 consecutive patients who underwent DSEK were included in the study. Air was used in 22 eyes of 22 patients (air group), and SF6 was used in 22 eyes of 22 patients (SF6 group) to attach the donor lenticule. The complications, corrected visual acuity (CVA), and the endothelial cell density (ECD) results were compared between these 2 groups. RESULTS: Six eyes had graft dislocation in the air group that underwent successful rebubbling on postoperative day 1. There was no graft dislocation in the SF6 group. There was no other complication observed in both the groups. The mean increase in the CVA was 1.09 ± 0.36 logarithm of the minimum angle of resolution in the air group, whereas it was 0.80 ± 0.57 logarithm of the minimum angle of resolution in the SF6 group. The mean increase in the CVA was not statistically different between the 2 groups (P = 0.060). Compared with the mean ECD in donor grafts, the mean decrease in the ECD was 222 ± 86 (44%) cells per square millimeter in the air group and 178 ± 52 (39%) cells per square millimeter in the SF6 group at the 1-year follow-up. The mean decrease in the ECD was statistically significantly higher in the air group compared with that in the SF6 group (P = 0.049). CONCLUSIONS: SF6 is comparable to air for attaching the donor graft as a tamponading agent in DSEK surgery.

Corneal densitometry evaluation in archipelago keratitis.

To report a case of archipelago keratitis and its improvement as evaluated by corneal densitometry. A review of the patient's record and relevant literature. A 57-year-old man presented with blurred vision associated with photophobia and halos around lights. Slit-lamp examination revealed multiple confluent, nummular subepithelial infiltrates. The infiltrates were unresponsive to topical nonsteroidal anti-inflammatory drops. The treatment was changed to topical steroids and oral acyclovir and a diagnosis of archipelago keratitis was made. The patient showed quick response to the treatment and the infiltrates disappeared within 5 weeks. However, no clear changes were observed initially by slit-lamp but corneal densitometry allowed us to evaluate improvement as the density value decreased from 96.5 to 38.6. After 10 days of treatment all the symptoms were resolved. Archipelago keratitis responded well to topical steroids and oral acyclovir. We describe the use of corneal densitometry complementary to slit-lamp examination in the clinical observation of archipelago keratitis.

Posterior corneal elevation and back difference corneal elevation in diagnosing forme fruste keratoconus in the fellow eyes of unilateral keratoconus patients.

PURPOSE: To evaluate posterior corneal elevation and back difference corneal elevation in patients with keratoconus in 1 eye and forme fruste keratoconus in the fellow eye. SETTING: Kudret Eye Hospital, Ankara, Turkey. DESIGN: Case-control study. METHODS: This study retrospectively reviewed patients with keratoconus in 1 eye and forme fruste keratoconus in the fellow eye and eyes of normal subjects. All subjects were evaluated with a rotating Scheimpflug imaging system (Pentacam), including sagittal and tangential anterior curve analysis, keratometry, and posterior elevation. The back difference elevation values were extrapolated from the difference maps of the Belin-Ambrosió enhanced ectasia display of the Scheimpflug system. The receiver operating characteristic (ROC) curves were analyzed to evaluate the sensitivity and specificity of the parameters. RESULTS: The corneal power, pachymetric progression index, and posterior corneal elevation (posterior elevation and back difference elevation) measurements were statistically significantly higher in eyes with keratoconus or forme fruste keratoconus than in eyes of normal control subjects (P<.05). Using ROC analysis, the area under the curve values of mean keratometry, steepest point on the tangential curve, minimum corneal thickness, pachymetric progression index, Ambrósio's relational thickness, posterior elevation, and back difference elevation to distinguish forme fruste keratoconus from control subjects were 0.51, 0.84, 0.65, 0.81, 0.72, 0.68, and 0.76, respectively. CONCLUSIONS: Back difference elevation was better than posterior elevation in diagnosing forme fruste keratoconus. However, as sole parameters, both had limited sensitivity and specificity to differentiate between forme fruste keratoconus eyes and normal control eyes.