Comparison of anatomical and functional outcomes of different surgical techniques in myopic macular hole without retinal detachment.

AIM: To define the anatomic and functional outcomes of pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling, inverted ILM flap and free ILM patch graft technique for the treatment of myopic macular hole (MH) without retinal detachment. METHODS: Sixty-four eyes of 64 patients who underwent PPV for myopic MH were included. Group 1 consists of patients underwent ILM peeling (n=26), and Groups 2 and 3 consists of patient underwent free ILM patch graft (n=20) and inverted ILM flap procedure (n=18) respectively. Outcomes following surgery were MH closure and best corrected visual acuity (BCVA) in logMAR at 6mo. RESULTS: Closure of MH was obtained in 20 eyes (76.9%) of the Group 1, in 16 eyes (80%) of the Group 2 and in 16 eyes (88.9%) of the Group 3. The mean preoperative and postoperative BCVA was 1.60±0.53 logMAR and 1.27±0.58 logMAR, respectively (P<0.05). There was no significant difference in the postoperative BCVA and anatomical closure rates in the three groups. Although the anatomical closure rate did not differ significantly in the groups, closure of MH tended to be better in the inverted ILM flap technique group at 6mo. CONCLUSION: Different surgical techniques may provide favorable visual and anatomical results for myopic MH surgery. ILM flap techniques offer higher closure rates compared to ILM peeling technique. However, in terms of visual outcomes, the study reveals no difference in three surgical techniques.

Effect of ILM Peeling on Anatomical and Visual Outcomes in Diabetic Tractional Retinal Detachment.

Objectives: The objcetive is to compare the anatomic and functional outcomes of vitrectomy between internal limiting membrane (ILM) peeling and non-ILM peeling in diabetic tractional retinal detachment (TRD). Methods: Twenty-three eyes with diabetic TRD with ILM peeling were compared with twenty-four eyes with non-ILM peeling. Best-corrected visual acuity (BCVA) was recorded at baseline and 3, 6, 9, 12 months, and end of follow-up. The mean retinal thickness across nine different regions that defined in the Early Treatment Diabetic Retinopathy Study (ETDRS) were obtained. The ETDRS grid was used to determine the extent of macular involvement. Results: In the 1st month postoperatively, the mean BCVA of eyes with ILM peeling (1.08±0.63 LogMAR) was significantly better than eyes with ILM non-peeling (1.69±0.75 LogMAR, p=0.003). There was also a significant difference at 9 and 12 months between groups in BCVA, in favor of ILM peeling (p=0.012 and p=0.047, respectively). Seven patients (29.2%) developed epiretinal membrane (ERM), and one patient (4.1%) had ERM with the lamellar macular hole in the ILM non-peeling group, while only one patient developed ERM in ILM peeling group during the follow-up. Conclusion: ILM removal may be considered in diabetic TRD surgery, as it can provide rapid visual recovery. Moreover, post-operative ERM formation was less frequent in ILM peeled eyes within 1 year after surgery.

Three year outcomes of intravitreal ranibizumab and aflibercept treatment of patients with diabetic macular edema: A comparative study.

Background: Diabetic macular edema (DME) is the most common cause of visual deterioration in patients with diabetes mellitus. Various treatment options have been used for DME, including intravitreal injection of steroids and anti-vascular endothelial growth factors. Objectives: To evaluate and compare the functional and anatomical outcomes of intravitreal ranibizumab (IVR) and intravitreal aflibercept (IVA) treatments in patients with DME. Design: Retrospective study. Methods: Four hundred three eyes of 235 naïve patients who underwent IVR or IVA treatment for DME followed up to 36 months included in the study. Best corrected visual acuity (BCVA) and central macular thickness (CMT) were measured at baseline, year 1, 2 and 3. Primary endpoint of the study was the change in BCVA and CMT each year from baseline and requirement of additional treatment (laser/steroid injection). Results: There were 198 eyes in IVR group and 205 eyes in IVA group. The changes in mean BCVA were 0.09 ± 0.32 versus 0.17 ± 0.41 Logarithm of the minimum angle of resolution (logMAR) (p = 0.042) at year 1, 0.09 ± 0.37 versus 0.12 ± 0.45 logMAR (p = 0.512) at year 2 and 0.13 ± 0.36 versus 0.15 ± 0.48 logMAR (p = 0.824) at year 3 in IVA and IVR groups, respectively. The baseline mean BCVA were lower (p = 0.004) in IVA group. The mean total number of injections was 7.93 ± 3.38 versus 7.42 ± 3.05 (p = 0.112). Conclusion: At year 1, change in mean BCVA was statistically significantly higher in IVA group; however this difference did not persist at years 2 and 3. Although the mean total number of injections was similar between groups, the requirement for adjuvant steroid treatment was significantly higher in ranibizumab group, which may affect the number of visits and treatment costs. Both ranibizumab and aflibercept treatments achieved a good long-term visual and anatomical response in DME patients.

The Effect of Combining Scleral Buckle Surgery with Pars Plana Vitrectomy for Treatment of Recurrent Retinal Detachment Secondary to Proliferative Vitreoretinopathy.

Objectives: The objectiove of the study is to evaluate and compare the outcomes of pars plana vitrectomy (PPV) and PPV combined with scleral buckle (SB) in vitrectomised cases with recurrent retinal detachment (RD) and to analyze the effects of adding SB to the procedure. Methods: Patients with recurrent RD due to grade C proliferative vitreoretinopathy (PVR) were included in this retrospective comparative case series. Patients who underwent re-PPV with or without SB were included and two groups (re-PPV; re-PPV+SB) were compared in terms of anatomical and functional success. Results: Sixty-five cases were included in the study: 32 underwent re-PPV and 33 underwent re-PPV+SB procedures. Reattachment was achieved in 59.4% of the re-PPV group versus 81.8% of the re-PPV+SB group (p=0.047). Although preoperative BCVA was worse in the re-PPV+SB group (p=0.005), postoperative BCVA at the last visit was similar in both groups (p=0.065). Conclusion: In the treatment of recurrent RD with grade C PVR, combining the SB procedure with PPV contributes to anatomical and functional outcomes.

Based on the Real-Life Data of Türkiye; Comparison of Anatomical and Functional Outcomes of Phakic and Pseudophakic Patients in Wet Type Age-Related Macular Degeneration.

Objectives: The aim of the study was comparison of wet-type age-related macular degeneration in phakic and pseudophakic patients in terms of anatomical and functional success based on the real-life data of Türkiye. Methods: The multicenter retrospective real-life study data of the. retinal study group were used in this study. Among 867 eyes of 867 patients were included in the study. Patients were divided into two groups according to the status of the lens; phakic group and pseudophakic group. The follow-up period of the two groups, the number of injections at the 1st, 2nd, and 3rd years, and changes in the central macular thickness (CMT, µ) and visual acuity (VA, logMAR) of the patients at the beginning, 6th, 12th, 24th, and 36th months were examined. Results: In our study, the number of injections in the 1st, 2nd, and 3rd years, respectively, was 4.2±2.0, 1.8±1.9, and 1.0±1.7 in the phakic group, and 3.9±2.0, 1.7±1.9, and 0.8±1.4 in the pseudophakic group. When the two groups were compared in terms of the number of injections, there was a statistically significant difference in the 1st year, but there was no significant difference in the 2nd and 3rd years (p=0.001, p=0.350, and p=0.288, respectively). There was no statistically significant difference between the groups in terms of CMT in the baseline, 6th, 12th, 24th, and 36th months (p=0.991, p=0.327, p=0.652, p=0.599, and p=0.873, respectively). Although there was no difference in VA between groups at the beginning (p=0.052), the phakic group showed statistically better VA in controls at 3rd, 6th, 12th, 24th, and 36th months (p=0.001, p=0.001, p=0.000, p=0.000, and p=0.003, respectively). Conclusion: Differences in the number of injections and visual results between phakic and pseudophakic patients in wet type AMD may necessitate the creation of different treatment and follow-up protocols.

Results of anti-VEGF treatment for neovascular AMD in eyes with different baseline visual acuity in Turkish population-based on real life data-Bosphorus retina study group.

BACKGROUND: To investigate the anatomical and visual outcomes of the patients with neovascular age-related macular degeneration (nAMD) treated with anti-vascular endothelial growth factor (anti-VEGF), according to the baseline best-corrected visual acuity (BCVA) based on the multicenter real-life data. METHODS: Five-hundred-ninety patients who had taken the Pro Re Nata (PRN) treatment regimen with three loading doses and at least one year of follow-up were included. The patients were divided into three groups according to the baseline BCVA: Group 1 (BCVA ≥ 1.3 Logmar), Group 2 (1.3 Logmar > BCVA ≥ 0.3 Logmar), and Group 3 (BCVA ≤ 0.2 Logmar). BCVA, central macular thickness (CMT), and the number of injections and visits were evaluated. RESULTS: There were 175, 322, and 93 patients in Group 1, Group 2, and Group 3, respectively. The number of visits and injections in the 1st year was not different between the groups (p = 0.58 and p = 0.08) and was 7.09 and 4.41 (Group 1), 6.59 and 5.58 (Group 2), 6.77 and 4.08 (Group 3). There was a significant difference in CMT between the baseline and 12th month in Group 1 and Group 2 (p < 0.001, p < 0.001, respectively) but not in Group 3 (p = 0.84). BCVA was significantly better in the 12th month in Group 1 (p < 0.001), slightly worse in Group 2 (p = 0.79), and significantly worse in Group 3 (p < 0.001). CONCLUSION: This study provides evidence that an inadequate number of injections cannot protect vision. Moreover, it can cause vision loss, especially in the eyes with good vision.

Single Layered Free ILM Graft Technique in Large Macular Holes with Associated ERM.

PURPOSE: We aimed to describe single layered free ILM graft technique (FIGT) and present results of this technique in the primary surgery of large macular holes (MHs). METHODS: In this retrospective study, we identified MHs with a minimum hole diameter >400 µm that underwent FIGT by a single surgeon. Nineteen eyes were found to have an associated epiretinal membrane (ERM) and four eyes demonstrated a patchy ILM staining intraoperatively. A single layered FIGT was performed first by peeling the ILM around the hole and then creating a free ILM flap and transplanting it to cover the hole. All cases were evaluated for anatomical closure and visual improvement. RESULTS: Twenty-three eyes of 22 patients (mean age 68.7 ± 7.4 years) were included in the study. The mean follow-up was 9.6 ± 4.9 months. Flap closure was observed in two eyes (8.6%) at week 1, while all eyes (100%) showed a complete closure at month 1. Mean preoperative visual acuity of 1.42 ± 0.66 LogMAR increased to 1.11 ± 0.51, 0.99 ± 0.34, 0.92 ± 0.38, 0.74 ± 0.37, 0.52 ± 0.28, 0.64 ± 0.39 respectively at week 1, month 1, month 3, month 6, year 1 and final follow-up postoperatively (p < .05 for all). In none of the eyes ERM recurred, nor flap contraction developed. CONCLUSION: The study showed encouraging results using free ILM graft in the primary surgery of large MHs. This technique might be considered in large MHs that are associated with ERM or demonstrate patchy ILM staining. Further studies are needed to prove the effectiveness also in the long-term.

Repeat Surgery following Temporal Inverted ILM Flap Technique: Next Step after Primary Failure.

PURPOSE: We aimed to report our surgical experience with repeat surgery as the next step after an unsuccessful hole closure with the primary single-layered temporal inverted flap technique (IFT). METHODS: We identified cases with persistent macular holes by reviewing the records of eyes that underwent IFT between October 2018 and October 2021. These cases were evaluated for hole features, anatomical closure, and visual improvement before and after the first and second surgeries. In addition, the technique applied in repeat surgery was recorded. Optical coherence tomography (OCT) images at follow-up were used to evaluate the flap position. RESULTS: A persistent hole was identified in 11 (6.4%) of 172 patients who underwent IFT. An inferotemporal displacement was observed in seven eyes, while no flap could be identified in the OCT images of the other four eyes. In the second surgery, the old flap was reinverted in one eye, and a new flap was created from the superior region in five eyes and the nasal region in the other five eyes and was stabilized under perfluorocarbon liquid. A gas tamponade (C3F8/SF6) was used in all patients at the end of surgery. The minimum hole diameter was > 400 µm in all eyes and 100% closure was achieved after the second surgery. Visual acuity gain of ≥ 3 lines was observed in 9 of the 11 eyes (81.8%). The mean visual acuity increase at the last follow-up was significant (p = 0.008). CONCLUSION: With single-layer temporal IFT in the primary surgery of macular holes, unsuccessful results may be observed due to the flap displacement in the early period. In our series, IFT was applied again with the use of the old flap or the creation of a new flap in the second surgery of the persistent holes, and successful results were obtained.

A full thickness macular hole following severe preeclampsia: a case report / Buraco macular de espessura total após pré-eclâmpsia severa

ABSTRACT We report a case of a young woman presenting with decreased vision in the right eye. One month earlier, she developed severe preeclampsia at 22 weeks of gestation and the pregnancy was terminated. Fundus examination revealed cotton wool spots and hard exudates in the macula bilaterally, with a yellow spot at the center of the fovea in the right eye. Optic coherence tomography showed a full thickness macular hole with elevated cystoid edges in the right eye. The patient was diagnosed with macular hole secondary to preeclampsia and followed up for spontaneous closure. One month after the first visit, surgical intervention was suggested due to declining vision. Three months later, the patient agreed to surgery. She underwent pars plana vitrectomy with a temporal inverted internal limiting membrane flap and C3F8 endotamponade, which provided anatomic and visual improvement.

RESUMO Relatamos o caso de uma jovem com diminuição da visão do olho direito. Um mês antes do primeiro atendimento, a paciente desenvolveu pré-eclâmpsia grave com 22 semanas de gestação e interrompeu a gravidez. O exame de fundo revelou manchas algodonosas e exsudatos duros na mácula em ambos os olhos, com uma mancha amarela no centro da fóvea do olho direito. A tomografia de coerência óptica mostrou um buraco macular de espessura total com bordas cistoides elevadas no olho direito. A paciente foi diagnosticada com buraco macular secundário a pré-eclâmpsia e acompanhada para fechamento espontâneo. Um mês após a primeira visita, foi-lhe sugerida a intervenção cirúrgica, devido a um declínio em sua visão. Três meses depois, o paciente aprovou a cirurgia e foi submetida a uma vitrectomia via pars plana com retalho invertido de membrana limitante interna e tampão interno C3F8, o que proporcionou uma melhora anatômica e visual.

A full thickness macular hole following severe preeclampsia: a case report.

We report a case of a young woman presenting with decreased vision in the right eye. One month earlier, she developed severe preeclampsia at 22 weeks of gestation and the pregnancy was terminated. Fundus examination revealed cotton wool spots and hard exudates in the macula bilaterally, with a yellow spot at the center of the fovea in the right eye. Optic coherence tomography showed a full thickness macular hole with elevated cystoid edges in the right eye. The patient was diagnosed with macular hole secondary to preeclampsia and followed up for spontaneous closure. One month after the first visit, surgical intervention was suggested due to declining vision. Three months later, the patient agreed to surgery. She underwent pars plana vitrectomy with a temporal inverted internal limiting membrane flap and C3F8 endotamponade, which provided anatomic and visual improvement.

Macular and peripapillary microvasculature after dexamethasone injection in diabetic macular edema.

PURPOSE: To evaluate the microvascular changes in the macular and peripapillary area after intravitreal dexamethasone implant in diabetic macular edema (DME). MATERIAL AND METHODS: We included 31 eyes of 31 patients treated with a single dose dexamethasone implant for DME. All subjects underwent swept-source optical coherence tomography (OCT) and OCT angiography imaging before (T0), and one month (T1), two months (T2), and four months (T4) after dexamethasone injection. The foveal avascular zone (FAZ) area of superficial and deep capillary plexus (SCP and DCP) was calculated by delineating the FAZ border using the measurement tool of the device. The vessel density (VD) of SCP and DCP and choriocapillaris (CC) in the macular and peripapillary area were automatically calculated. RESULTS: There was an insignificant reduction in FAZ area measurements of SCP after dexamethasone injection in DME patients (p = 0.846). The FAZ area of DCP were significantly smaller compared to T0 measurements at T1, T2, and T4 (p = 0.013, p = 0.031, and p = 0.029, respectively). The mean average parafoveal VD measurements were significantly decreased after dexamethasone injection in SCP and DCP (p = 0.004, p = 0.005). The peripapillary VD in retinal capillary plexuses and choriocapillaris showed no significant difference after dexamethasone injection. CONCLUSION: Intravitreal dexamethasone leads to a significant FAZ area decrease in DCP with a reduction in parafoveal VD measurements. In addition, no significant VD changes were observed in the peripapillary area after dexamethasone. These findings indicate that dexamethasone may improve macular ischemia with no significant effects on peripapillary microvasculature in DME patients.

A Case of Paracentral Acute Middle Maculopathy Occurring After Pars Plana Vitrectomy.

Paracentral acute middle maculopathy (PAMM) is a clinical finding that is thought to be a result of ischemia in the middle and deep capillary plexus of the retina. It has been reported in the literature that PAMM may be associated with systemic and vascular risk factors. This report describes a case of PAMM that occurred following a pars plana vitrectomy.

Comparison of two different treatment regimens' efficacy in neovascular age-related macular degeneration in Turkish population-based on real life data-Bosphorus RWE Study Group.

AIM: To compare two different anti-vascular endothelial growth factor (anti-VEGF) treatment regimens'-a priori pro re nata (PRN) and PRN regimen following the loading phase-anatomical and functional results in neovascular age-related macular degeneration (nAMD) patients. METHODS: Totally 544 nAMD patients followed and treated with aflibercept (n=135) and ranibizumab (n=409) at 9 different centers between 2013 and 2015 were enrolled into this retrospective multicenter study. Patients with initial best corrected visual acuity (BCVA) interval of 1.3-0.3 (logMAR) and a minimum follow-up of 12mo were included. Patients under two different regimens-a priori pro re nata (1+PRN) or 3 consecutive intravitreal injections followed by a PRN regimen (3+PRN)-were compared in BCVA at 3th, 6th and 12th months, and in central macular thickness (CMT) at 6th and 12th months. The total study group, intravitreal ranibizumab (IVR) and intravitreal aflibercept (IVA) groups were evaluated separately. RESULTS: The mean CMT decreased in the 1+PRN (n=101) regimen from 407 to 358 and 340 µm and in the 3+PRN (n=443) group from 398 to 318 and finally to 310 µm at months 6 and 12, respectively. Anatomically, the CMT reduction at 6th month (48.5 vs 76.4; P<0.05) was statistically significant in favor of 3+PRN group. BCVA changed in 1+PRN group from 0.77 to 0.78, 0.75 and 0.75; in 3+PRN group from 0.81 to 0.69, 0.72, and 0.76 at months 3, 6, and 12, respectively. Visual gain was statistically better in 3+PRN group at 3th month (-0.01 vs 0.12; P<0.001). In IVR group, CMT reduction was in greater in 3+PRN at 6th (44 vs 72) and 12th month (61 vs 84), but statistically insignificant. The 3+PRN group revealed statistically better visual results at 3th month (-0.02 vs 0.11, P<0.05). In IVA group, although statistically insignificant, CMT reduction (61 vs 89, 6th month; 85 vs 97, 12th month) and visual gain (0.02 vs 0.16; 0.02 vs 0.14; 0.05 vs 0.11) was found in favor of 3+PRN group at all visits. CONCLUSION: The loading dose of anti-VEGF treatments in nAMD leads to significantly better anatomical and functional results, regardless of the agent, specially in early follow-up interval.

Treatment of intravitreal bevacizumab combined with focal laser photocoagulation in the case of macular telangiectasia type 2 with retinal arterial macroaneurysm.

Macular telangiectasia type 2 (Mac Tel 2) is a bilateral disease of unknown cause with characteristic changes of the retinal vasculature. To the best of our knowledge, we could not find any reported cases of Mac Tel 2 with retinal arterial macroaneurysm (RAM). Our aim is to report a case of Mac Tel 2 with RAM.

Treatment of intravitreal bevacizumab combined with focal laser photocoagulation in the case of macular telangiectasia type 2 with retinal arterial macroaneurysm.

Macular telangiectasia type 2 (Mac Tel 2) is a bilateral disease of unknown cause with characteristic changes of the retinal vasculature. To the best of our knowledge, we could not find any reported cases of Mac Tel 2 with retinal arterial macroaneurysm (RAM). Our aim is to report a case of Mac Tel 2 with RAM.

Real-World Outcomes of Anti-VEGF Treatment for Neovascular Age-Related Macular Degeneration in Turkey: A Multicenter Retrospective Study, Bosphorus Retina Study Group Report No: 1.

OBJECTIVES: To evaluate the real-world outcomes of intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment in neovascular age-related macular degeneration (nAMD) patients. MATERIALS AND METHODS: Multicenter, retrospective, interventional, non-comparative study. The records of nAMD patients treated with an anti-VEGF agent on a pro re nata treatment regimen basis between January 2013 and December 2015 were reviewed. The patients who completed a follow-up period of 12 months were included. Primary outcome measures of this study were the visit and injection numbers during the first year. RESULTS: Eight hundred eighty eyes of 783 patients met the inclusion criteria for the study. Mean number of visits at month 12 was 6.9±2.5 (range: 1-15). Mean number of injections at month 12 was 4.1±1.9 (range: 1-11). Mean visual acuity at baseline and months 3, 6, and 12 was 0.90±0.63 LogMAR (range: 0.0-3.0), 0.79±0.57 LogMAR (range: 0.0-3.0), 0.76±0.57 LogMAR (range: 0.0-3.0), and 0.79±0.59 LogMAR (range: 0.0-3.0), respectively. Mean central retinal thickness at baseline and months 6 and 12 was 395±153 µm (range: 91-1582), 330±115 µm (range: 99-975), and 332±114 µm (range: 106-1191), respectively. CONCLUSION: The numbers of visits and injections were much lower than ideal and were insufficient with the pro re nata treatment regimen.

Efficacy of Intravitreal Bevacizumab in Treatment of Proliferative Type 2 Idiopathic Juxtafoveal Telangiectasia.

OBJECTIVES: To evaluate the effectiveness of intravitreal bevacizumab (IVB) in patients with subretinal neovascularization secondary to type 2 juxtafoveal telangiectasia. MATERIALS AND METHODS: Ten eyes of 10 patients were included in this retrospective study. All cases were treated with IVB (1.25 mg bevacizumab). Visual acuity and slit-lamp anterior and posterior segment examinations were performed at each visit. Central macular thickness (CMT) and intraretinal/subretinal fluid were evaluated via spectral domain optical coherence tomography (OCT). Loss of a line in visual acuity chart and presence of fluid on OCT were defined as criteria for repeated treatment. RESULTS: The mean age of patients was 66.0±7.0 years (56-75). The mean follow-up time was 54.7±16.0 month (24-72). The mean BCVA was 0.62±0.35 (0.00-1.00) logMAR at baseline and 0.54±0.35 (0.00-1.00) logMAR at final exam (p=0.03). The mean CMT was 251±25.4 µm at baseline and 239±39.3 µm at final exam (p=0.01). Patients received an average of 1.7±1.0 IVB injections during follow-up. At baseline, all cases had intraretinal/subretinal fluid. There was no fluid at final examination of all cases. CONCLUSION: IVB treatment may be effective in the treatment of subretinal neovascularization secondary to type 2 juxtafoveal telangiectasia.

Comparison of Accelerated Corneal Collagen Cross-linking Types for Treating Keratoconus.

PURPOSE: To compare the results of different protocols for accelerated corneal collagen cross-linking (CXL) in patients with progressive keratoconus. MATERIALS AND METHOD: This prospective comparative study involved 40 patients treated with intended UV-A radiance of 5.4 J/cm2 in 74 eyes (Group 1) and 42 patients treated with radiance of 7.2 J/cm2 in 72 eyes (Group 2). Visual acuity, subjective manifest refraction and corneal topography were analyzed before and 12 months after surgery in both groups. Postoperative complications were also noted. The results of the two protocols were statistically compared. RESULTS: There were no statistically significant differences between the groups in uncorrected distance visual acuity, corrected distance visual acuity or corneal topography pre- or postoperatively. The differences in keratometric readings (K apex, SimK1 and SimK2) and refractive results were not significant. CONCLUSION: The application of total intended UV-A radiance of 5.4 J/cm2 or 7.2 J/cm2 for accelerated CXL in patients with progressive keratoconus resulted in similar refractive and topographic outcomes.

Comparison of Changes in Corneal Biomechanical Properties after Photorefractive Keratectomy and Small Incision Lenticule Extraction.

OBJECTIVES: To compare the postoperative biomechanical properties of the cornea after photorefractive keratectomy (PRK) and small incision lenticule extraction (SMILE) in eyes with low and moderate myopia. MATERIALS AND METHODS: We retrospectively examined 42 eyes of 23 patients undergoing PRK and 42 eyes of 22 patients undergoing SMILE for the correction of low and moderate myopia. Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured with an Ocular Response Analyzer before and 6 months after surgery. We also investigated the relationship between these biomechanical changes and the amount of myopic correction. RESULTS: In the PRK group, CH was 10.4±1.3 mmHg preoperatively and significantly decreased to 8.5±1.3 mmHg postoperatively. In the SMILE group, CH was 10.9±1.7 mmHg preoperatively and decreased to 8.4±1.5 mmHg postoperatively. CRF was significantly decreased from 10.8±1.1 mmHg to 7.4±1.5 mmHg in the PRK group whereas it was decreased from 11.1±1.5 mmHg to 7.9±1.6 mmHg in the SMILE group postoperatively. There was a significant correlation between the amount of myopic correction and changes in biomechanical properties after PRK (r=-0.29, p=0.045 for CH; r=-0.07, p=0.05 for CRF) and SMILE (r=-0.25, p=0.048 for CH; r=-0.37, p=0.011 for CRF). CONCLUSION: Both PRK and SMILE can affect the biomechanical strength of the cornea. SMILE resulted in larger biomechanical changes than PRK.

Visual and Refractive Outcomes of Photorefractive Keratectomy and Small Incision Lenticule Extraction (SMILE) for Myopia.

PURPOSE: To compare the refractive outcomes of small incision lenticule extraction (SMILE) with photorefractive keratectomy (PRK) using an aberration-free ablation profile. METHODS: One eye of patients diagnosed as having myopia for bilateral refractive correction was randomly allocated to either PRK or SMILE. The primary outcome measures included refractive efficacy, predictability, safety, stability, corneal aberrations, and adverse events. Patients were followed up for 1 year postoperatively; postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, and corneal aberrations were recorded and compared with preoperative data. RESULTS: Thirty-nine patients in the PRK group and 35 patients in the SMILE group completed the study. The mean preoperative spherical equivalent refractions were -3.27 ± 0.62 diopters (D) for the PRK group and -3.56 ± 1.12 D for the SMILE group. The average postoperative spherical equivalent refractions were -0.26 ± 0.29 and -0.43 ± 0.38 D for the PRK and SMILE groups, respectively (P = .06). Total higher order aberrations in the 6-mm central corneal zone were significantly higher in the SMILE group (0.21 ± 0.10 µm) than in the PRK group (0.09 ± 0.03 µm) (P = .01) 12 months postoperatively. However, no statistically significant differences were found among spherical, trefoil, and coma aberrations between the groups. CONCLUSIONS: The refractive results of PRK with aberration-free aspheric ablation are similar to those of SMILE in eyes with low myopia. The induction of coma, spherical, and trefoil aberrations did not statistically differ after both surgeries, but the total higher order aberrations after SMILE were significantly higher than PRK with aberration-free aspheric ablation. [J Refract Surg. 2016;32(9):604-610.].