PURPOSE: The purpose of the study was to compare intraocular pressure (IOP) values measured by Goldmann applanation tonometer (GAT) with IOP values measured by Tonopen and non-contact tonometer (NCT) in patients with penetrating keratoplasty (PKP).
METHODS: Eighty-eight eyes of 72 patients who underwent PKP surgery were included in the study. Detailed ophthalmological examination was performed. Central corneal thickness (CCT) was measured with an ultrasonic pachymeter and recorded. IOPs were measured with GAT, Tonopen, and NCT. Data were analyzed statistically.
RESULTS: The mean age of the patients was 56.2±14.7 years; the mean duration of PKP was 62.5±51.6 months. The mean CCT was 561±65µm. Mean IOP values were 15.4±3.0 with GAT, 12.8±4.5 with Tonopen, and 11.7±4.6 mmHg with NCT (p<0.001). There was a difference between IOP values between GAT and Tonopen (p<0.001) and between GAT and NCT (p<0.001), while there was no difference between Tonopen and NCT IOP values (p=0.06). There was no correlation between IOP values measured in all three methods and CCT (p>0.05). Both Tonopen and NCT IOP values were correlated with GAT IOP values (r=0.424, p<0.001; r=0.374, p<0.001).
CONCLUSION: In patients with PKP, IOP values measured with GAT are higher than IOP values measured by Tonopen and NCT. GAT remains the most established method of IOP measurement in clinical practice, yet it has significant limitations in corneas that deviate significantly from normal values, as is the case in PKP. During follow-up, measurements can be taken with the same device suitable for the structure of the eye. Due to structural differences, if the IOP value measured with a device is too high or too low in patients with PKP, the IOP value should be measured with other devices, and the results should be compared.

PURPOSE: To demonstrate the retinal neurodegeneration findings caused by diabetes and diabetic neuropathy in patients without retinopathy, anatomically with spectral domain optical coherence tomography (SD-OCT) and functionally with contrast sensitivity (CS).
METHODS: The presence of diabetic neuropathy was objectively revealed together with neurologists by electromyography (EMG). SD-OCT and CS were evaluated in patients with peripheral neuropathy (diabetic peripheral neuropathy [DPN] + group), without neuropathy (DPN- group), and healthy controls. Average and sectoral retinal nerve fiber layer (RNFL) thickness, average, and 6 sectoral quadrants ganglion cell complex (GCC) were compared between groups. Furthermore, CS measurement values were calculated between groups.
RESULTS: Although there were significant differences between the three groups in the average RNFL, in pairwise comparisons there were no statistical differences in the average RNFL between the DPN (−) and healthy control groups (p=0.679). Average GCC thickness also showed significant differences between the three groups (p<0.001). The post hoc test was performed to determine the group that made the difference, it was seen that the average ganglion cell values of the DPN+ group were lower than the other groups. Furthermore noteworthy, when the diabetic group with “no neuropathy” compared to the healthy control group, GCC values were significantly lower in the diabetic group. When the DPN group was compared with the healthy group, CS values were significantly lower in the diabetic group (p<0.001). Analysis of mesopic CS values and each of the average RNFL and GCC thickness indicated significant positive correlations (r=0.238, 0.326, respectively).
CONCLUSION: Our results suggest that there is evidence of early retinal neuronal damage, particularly on SD-OCT, before DPN occurs in patients with type 2 diabetes mellitus. Although visual acuity is unaffected in diabetic patients, decreased CS and GCC may be an early warning for DPN.

PURPOSE: The purpose of the study was to evaluate thrombophilic/hypofibrinolytic factors in two ocular vascular pathologies; retinal vein occlusion (RVO) and non-arteritic anterior ischemic optic neuropathy (NAION).
METHODS: Prospective study including patients with RVO (n=13), NAION (n=17), and age-sex matched control group (n=14). Clinical history for pre-existing hypertension and diabetes mellitus were recorded. Measured serological thrombophilic markers included Factor V Leiden (FVL) and methyltetrahydrofolate reductase (MTHFR) C677T mutations. Serum Protein C (PC) activity and plasminogen activator inhibitor-1 (PAI-1) levels were also evaluated. P<0.05 was considered statistically significant.
RESULTS: There was no statistically significant difference with demographics between groups. FVL mutation was positive for three patients with RVO (23.1%), two patients with NAION (11.8%), and one subject in the control group (9.1%). MTHFR C677T mutation was found in 12 patients with RVO (92.3%), 15 patients with NAION (88.2%), and three subjects in the control group (27.3%). Even though there was not a statistically significant difference between RVO and NAION groups, this mutation was significantly higher in the patient groups compared to controls (p=0.001). We did not observe a statistically significant difference in PC activity levels between groups (p=0.35). Plasma PAI-1 levels were higher in the patient groups than the control group, however, the difference was not statistically significant (p=0.168) between any of the groups.
CONCLUSION: MTHFR C677T mutation was more common in both patient groups compared to controls, without a statistically significant difference between RVO and NAION groups. PAI-1 levels were also higher in the patient groups; however, the difference was not statistically significant. The findings of this study underscore the potential role of genetic and serological factors in ocular vascular pathologies. Understanding these associations better could lead to more targeted screening and management strategies for patients at risk of ocular vascular disorders. Further studies including larger cohorts are required to elucidate possible associations.

PURPOSE: The purpose of this study was to evaluate the subtypes of diabetic macular edema refractory to vascular endothelial growth factor (anti-VEGF) treated with a single-dose dexamethasone (DEX) implant.
METHODS: In this retrospective study, 81 patients (118 eyes) with diabetic macular edema refractory to anti-VEGF treated with a single injection of DEX implant were evaluated. Diabetic macular edema was classified into four subtypes: Diffuse macular edema (DME) (n=36 eyes), cystoid macular edema (CME) (n=40 eyes), serous retinal detachment (SRD) (n=20 eyes), and cystoid macular degeneration (CMD) (n=22 eyes). Best-corrected visual acuity (BCVA) and central macular thickness (CMT) changes in 2, 4, and 6 months were examined.
RESULTS: The baseline BCVA was significantly lower in CMD eyes compared with the CME eyes (p=0.005). The baseline CMT was significantly lower in CME eyes compared with CMD (n=0.002) and DME eyes (n=0.014). After the intravitreal DEX implant, BCVA increased significantly in the 2nd month in the SRD eyes (p=0.045), in the 4th month in the DME eyes (p=0.038), and in the 6th month in the CME eyes (p=0.014). BCVA changes in CMD eyes were not statistically significant for all months (p>0.05). The mean CMT of all groups decreased significantly in the 2nd month (p<0.001 for all). ΔCMT at 2 months was −231.20±221.12 µm in the SRD group, −112.97±141.02 µm in the CME group, −312.66±175.56 µm in the CMD group, and −190.77±173.04 µm in the DME group (p<0.001). According to post hoc Bonferroni analysis, ΔCMT was statistically significantly higher in CMD eyes than in CME eyes (p<0.001).
CONCLUSION: Different subtypes of diabetic macular edema suggest different etiopathogenesis and drug responses. The eyes with the fastest onset of both morphological and functional improvement of intravitreal DEX implant were eyes with SRD. Although anatomical improvement began early in CME and DME eyes (2nd month), functional recovery begins later (4th and 6th month). The eyes with the least functional recovery were the eyes with CMD.

PURPOSE: We aimed to evaluate the quality of information available on YouTube regarding the basic information, examination, diagnosis, and treatment of pterygium.
METHODS: An online YouTube search was performed on January 10, 2023, for the following three terms: pterygium surgery, pterygium surgery for patients, and pterygium surgery patient education. The first 50 videos were evaluated for each term. Videos were evaluated using three checklists (the modified DISCERN criteria, the Journal of the American Medical Association [JAMA] criteria, and the Global Quality Score [GQS]). Videos were classified into three groups according to the source of the upload: Group 1, doctors; Group 2, profit-oriented clinics; and Group 3, independent users.
RESULTS: After the exclusion of duplicate videos, a total of 133 videos were included for analysis. Sixty-nine (51.9%) videos were uploaded by physicians/doctors, 54 (40.6%) by profit or non-profit-oriented clinics, and 10 (7.5%) by independent users including patients and content creators. The JAMA score was significantly lower in videos uploaded by patients and content creators when compared to videos uploaded by doctors and clinics (p<0.001). All quality scores including the DISCERN score, GQS, and JAMA score were significantly lower in videos describing patient experiences (p<0.001, p<0.001, and p=0.011, respectively), when compared to narrated surgery videos and informative videos. The highest positive correlation was observed between the DISCERN score and the GQS. View rates were significantly correlated with the number of likes. In addition, videos with higher subscriber numbers tended to have a significantly higher number of likes and a higher GQS.
CONCLUSION: Health-related videos on social media platforms, which serve as informational resources, need to be produced by more qualified professionals, and the information they include needs to be objectively provided regarding all available treatment options, potential side effects, and the healing process.

PURPOSE: The study aimed to evaluate the vessel densities (VDs) and ganglion cell inner plexiform layer (GCIPL) thicknesses in macular telangiectasia (MacTel) Type 2.

METHODS: Thirty-six eyes with MacTel Type 2 and 30 controls were included in this prospective study. Based on the presence of ellipsoid zone (EZ) disruption two groups were formed: Group 1, MacTel eyes with intact EZ. Group 2; with EZ disruption.
RESULTS: In all MacTel eyes, a decrease was obtained in VDs and temporal parafoveal thickness in 1st year. (For group 1 p=0.006, p=0.045. For group 2 p=0.002, p=0.02) The average and minimum GCIPL also decreased in Group 2. (For average p=0.005, for minimum p=0.003) The mean VD, temporal and nasal thicknesses, average minimum GCIPL, and retinal nerve fiber layer were lower in Group 2 in the final visit.

CONCLUSION: VDs and GCIPL thickness may be useful parameters in the follow-up of MacTel Type 2 disease in which microvascular changes are observed in parallel with neurodegeneration.

PURPOSE: This study evaluated the posterior segment parameters of the eye in patients using selective serotonin reuptake inhibitors (SSRIs) without systemic disease, using spectral-domain optical coherence tomography (SD-OCT), and compared the effects of different durations of SSRI use on the eye.
METHODS: The study involved 104 participants, divided into three groups: those using SSRIs for less than a year (group 1a), those using SSRIs for 1 year or longer (group 1b), and healthy controls (group 2). The posterior segment parameters of the eye were measured using the SD-OCT, and the data were analyzed using descriptive statistics, analysis of variance, post hoc tests, and correlation analysis.
RESULTS: The results showed that the retinal nerve fiber layer (RNFL) thickness and central foveal thickness (CFT) were significantly lower in Group 1a than in Group 2 (p<0.05), while there was no significant difference between Group 1b and Group 2 (p>0.05). The choroidal thickness was significantly lower in both Group 1a and Group 1b than in Group 2 (p<0.05), but there was no significant difference between the two patient groups (p>0.05). The axial length (AXL) was not significantly different among the groups (p>0.05). There was a weak negative correlation between the duration of SSRI use and the RNFL thickness (r=−0.25, p=0.039), and a moderate negative correlation between the duration of SSRI use and the CFT (r=−0.37, p=0.002). There was no significant correlation between the duration of SSRI use and the choroidal thickness or the AXL (p>0.05).
CONCLUSION: This study suggests that SSRIs may affect the retina and choroid due to various mechanisms. The effects may be time dependent and dose dependent, with longer-term use potentially causing adaptations. Ophthalmologists and psychiatrists should monitor patients for symptoms.

PURPOSE: The study aimed to investigate the effects of blood glycated hemoglobin (HbA1c) and mean platelet volume (MPV) levels in patients with diabetic macular edema who received a dexamethasone implant (DEXI).
METHODS: Twenty-two Type 2 diabetic patients with pre-existing HbA1c and MPV measurements before injection were selected for the study. These patients received an intravitreal DEXI injection. Optical coherence tomography images and medical records before and after the injection were evaluated retrospectively.
RESULTS: The mean visual acuity level before and after the injection was 0.21±0.1 and 0.30±0.09, respectively. The median values for patient age, HbA1c, and MPV were 65 years, 7.4, and 10.6, respectively. There was no statistically significant difference in visual acuity levels and foveal macular thickness changes before and after the injection between groups with MPV levels above and below 10.6 (p>0.05). In addition, there was no statistically significant difference in visual acuity changes before and after the injection between patients under and over 65 years of age (p>0.05). There was also no statistically significant difference in foveal macular thickness changes before the injection between patients under and over 65 years of age (p>0.05). However, a statistically significant decrease in central macular thickness was observed after the injection in patients under 65 years of age compared to those over 65 years of age (p<0.05).
CONCLUSION: MPV and HbA1c values have been shown to be markers of inflammation and poor disease control in diabetic patients. Our study indicates that there is no correlation between the response to DEXI injection and MPV or HbA1c values.

Thelaziasis is generally a zoonotic disease that affects the eyes of domestic and wild animals. It is transmitted by flies belonging to the Drosophilidae family. While rare in humans, there have been occasional reported cases in low-socioeconomic families living in rural areas. An 83-year-old male farmer with a history of trauma and previous loss of vision in one eye presented with complaints of itching in the affected eye. Upon examination, worm-like parasites were observed in the inferior fornix of the affected eye, leading to a referral to our center. Two worms were mechanically extracted from the right eye. The diagnosis was confirmed as Thelazia spp. through parasitological laboratory testing. This case holds significance as it represents Türkiye’s first reported human case of ocular thelaziasis.

Ocular toxoplasmosis is the most common cause of infectious retinochoroiditis in humans. Atypical and unilateral presentations such as papillitis without vitritis are especially challenging for diagnosis. Here, we report a case of a 17-year-old man with unilateral Toxoplasma papillitis without vitritis. Fundus examination revealed unilateral inflammation in the right optic disc and peripapillary area. Toxoplasma immunoglobulin (Ig)M titer was positive and IgG negative. During the follow-up, while the IgM titer decreased, the IgG titer increased. After possible etiologies were excluded, the patient was diagnosed with presumed Toxoplasma papillitis with a complete absence of vitritis at presentation. The patient was treated with appropriate antiparasitic agents and good response was observed without recurrence.

Anti-vascular endothelial growth factor (anti-VEGF) drug is a biological drug that is widely used in the treatment of retinal diseases and imposes a high financial burden on the healthcare system. The introduction of biosimilar drugs has come to the forefront with the expiration of patents on biological drugs. Biosimilar drugs have the same effectiveness and safety, but are more cost-effective. This feature of biosimilar drugs offers an important opportunity to reduce healthcare costs and to ensure patient compliance. This review aims to provide an overview of biosimilar drugs, highlight their advantages, and discuss both approved and investigational anti-VEGF biosimilar drugs. The goal was to provide ophthalmologists with a comprehensive understanding of this rapidly evolving field.