THE PROPHYLAXIS OF FELLOW-EYE RETINAL DETACHMENT IN STICKLER SYNDROME: A RETROSPECTIVE SERIES.

PURPOSE: To evaluate retrospectively if scleral buckling combined or not to cryopexy reduces fellow-eye retinal detachment (RD) in Stickler syndrome patients who lost their first eye due to RD. METHODS: Retrospective review of 52 Stickler syndrome patients who received a 6-mm wide, 360° encircling scleral buckling. Thirty-nine (75%; Cryo + Group) also received cryo treatment, whereas the reminder 13/52 (25% Cryo - Group) did not. RESULTS: Average follow-up was 15.6 ± 2.41 years. Five patients (5/52; 9.6%) developed a retinal detachment 2.6 ± 0.55 years after prophylactic treatment, respectively, 0/39 patients in the Cryo + Group and 5/13 in the Cryo - Group (P < 0.001). All five RD eyes were successfully reattached through revised episcleral surgery and adjunctive cryo treatment. Postop refraction changed an average -1.9 ± 0.74 diopters and best corrected visual acuity at the end of follow-up was 20/25 (0.1 ± 0.07 logarithm of the minimum angle of resolution), not significantly different from the rest of sample population who did not develop RD in their fellow eye. CONCLUSION: Cryopexy significantly reduced the risk of RD in Stickler syndrome patients undergoing scleral buckling. If RD ensues, the presence of scleral buckling may ease surgical repair and improve final outcome.

RESIDUAL INTRARETINAL EDEMA AFTER 25-GAUGE VITRECTOMY AND MACULAR PUCKER REMOVAL: Is Intraoperative Sustained-release Dexamethasone a Real Treatment Option?

PURPOSE: To investigate the efficacy and safety of intraoperative slow-release dexamethasone implant and 25-gauge (G) vitrectomy plus epiretinal membrane removal in patients affected by idiopathic macular pucker. METHODS: In this randomized, clinical, multicenter study, 60 eyes of 60 pseudophakic eyes having idiopathic macular pucker were enrolled. Thirty eyes underwent 25-G pars plana vitrectomy and internal limiting membrane peeling ("Control group"), whereas 30 eyes underwent 25-G pars plana vitrectomy and internal limiting membrane peeling combined with dexamethasone implant ("DEX group"). Best-corrected visual acuity was investigated using Snellen visual acuity ratio. Anatomical outcomes (foveal thickness and total macular volume) were analyzed with spectral domain optical coherence tomography. RESULTS: After 6-month follow-up, best-corrected visual acuity significantly increased in each group (P < 0.05), but there were no significant differences between groups (P = 0.60). Foveal thickness showed a significant decrease in both groups (P < 0.05), but no differences were seen between groups (P = 0.80). Finally, also total macular volume decreased significantly in both groups at the last follow-up visit (P < 0.05), but both groups a showed similar trend (P = 0.12). CONCLUSIONS: Intraoperative sustained-release dexamethasone implant, a powerful antiinflammatory agent with significant efficacy in vitrectomized eyes, did not result in a significant change in macular thickness and volume compared with the vitrectomy alone without dexamethasone implant at 6-month follow-up. These data support the hypothesis that its etiology does not seem to be mainly related to an inflammatory process.

LONGITUDINAL MICROPERIMETRY EVALUATION AFTER INTRAVITREAL OCRIPLASMIN INJECTION FOR VITREOMACULAR TRACTION.

PURPOSE: To determine whether improvements in microperimetry testing are associated with anatomic resolution after ocriplasmin treatment in patients with symptomatic vitreomacular adhesion (VMA)/vitreomacular traction and relatively preserved baseline best-corrected visual acuity (BCVA). METHODS: Patients with vitreomacular traction received a single 125-µg intravitreal ocriplasmin injection and were followed longitudinally for 6 months with optical coherence tomography, BCVA testing, and microperimetry. Visual function changes were compared between eyes with and without VMA resolution on optical coherence tomography. RESULTS: Eleven of 16 eyes (68.8%) achieved VMA resolution after treatment. Mean baseline BCVA was relatively good (79 ± 3 Early Treatment Diabetic Retinopathy Study letters; 20/52); no patients had a ≥2-line improvement in BCVA over the 6-month follow-up period. In the group with VMA resolution, mean retinal sensitivity significantly increased in the central 4° (15.2 ± 1.9 dB vs. 18.9 ± 0.7 dB, P < 0.001) when comparing baseline and final follow-up microperimetry testing. No change in mean retinal sensitivity was found in the group without VMA resolution. CONCLUSION: Microperimetry demonstrates a significant gain in retinal sensitivity, particularly in the central 4° area, in eyes with anatomic resolution after treatment of vitreomacular traction with intravitreal ocriplasmin injection, even when no significant gain in BCVA is seen.

LASER PROPHYLACTIC TREATMENT OF THE FELLOW EYE IN GIANT RETINAL TEARS: Long-Term Follow-up.

PURPOSE: To report the results of a retrospective study on prophylactic laser treatment versus observation of giant retinal tears (GRTs) fellow eyes. METHODS: One hundred and sixty consecutive charts of patients operated for GRT were included in this retroprospective study. Standard office visit included manifest and corrected refraction, intraocular pressure measurement, slit-lamp examination of the anterior and posterior segment with +90 diopter lens, and indirect ophthalmoscopy were performed at baseline and during follow-up period. RESULTS: Observation group included 62 and prophylactic laser treatment group 98 eyes. The incidence of retinal tears with localized preequatorial retinal detachment, GRTs with macula-ON retinal detachment, and GRTs with Macula-OFF retinal detachment were 3.2, 0, and 14.5%, respectively, during 43.5 ± 19.8 months of follow-up period in observation group and 11.2, 2, and 0%, respectively, in prophylactic laser treatment group during 37.2 ± 16.3 months of follow-up period. CONCLUSION: Prophylactic laser treatment of GRTs fellow eyes decreased the incidence of GRTs and limited the consequences of newly developed tears, lowering the occurrence of a macula-off retinal detachment with a consequent better final visual outcome respect to observation group.

HIGH-RESOLUTION MULTIMODAL IMAGING AFTER IDIOPATHIC EPIRETINAL MEMBRANE SURGERY.

PURPOSE: To investigate the changes of the vitreomacular interface during a 1-year follow-up after idiopathic epiretinal membrane (iERM) surgery. METHODS: Six patients affected by fovea-attached iERM were recruited in this pilot study. Pars plana vitrectomy associated with epiretinal membrane peeling was performed uneventfully in all cases. In four cases, the inner limiting membrane was removed using Brilliant blue G. En face high-resolution adaptive optics and cross-sectional spectral domain optical coherence tomography retinal imaging were performed before and at 1, 3, 6, and 12 months after surgery. The microstructures of vitreomacular interface in high-resolution adaptive optics images were correlated to the cross-sectional spectral domain optical coherence tomography data. RESULTS: Preoperatively, adaptive optics images showed multiple abnormalities of the vitreomacular interface, such as macrofolds, microfolds, and hyperreflective microstructures. We identified two subtypes of iERM according to the distribution of microfolds over the foveal area, which included the radial-type and the grid-type iERM. After surgery, the morphology of the vitreomacular interface changed compared with the preoperative state. The number of both macrofolds and microfolds was reduced in all cases. The hyperreflective structures were still resolvable in all cases, however presenting different shape and morphology than preoperatively. In addition, they showed marked differences between eyes that had internal limiting membrane removal and eyes that did not. CONCLUSION: Adaptive optics imaging gives new insight into the changes of vitreomacular interface after iERM surgery. Enhanced multimodal imaging of the vitreomacular interface and retinal structures can be valuable to monitor treatment outcome of iERM.

ADJUSTABLE MACULAR BUCKLING FOR FULL-THICKNESS MACULAR HOLE WITH FOVEOSCHISIS IN HIGHLY MYOPIC EYES: Long-Term Anatomical and Functional Results.

PURPOSE: To assess functional and structural outcome after adjustable macular buckling for the treatment of foveoschisis (FS), associated with full-thickness macular hole (FTMH) in highly myopic eyes. METHODS: Eighteen consecutive patients who underwent adjustable macular buckling for FS associated with FTMH were included in this prospective study. Three cases were not included in the analysis due to short follow-up period (less than 3 months). Outcome measures included anatomical success rate with FS resolution and FTMH closure, best-corrected visual acuity, mean retinal sensitivity, central retinal thickness, and fixation site and stability. RESULTS: Foveoschisis resolution and FTMH closure were observed in all cases between 1 month to 3 months after surgery. At 24 months of follow-up visit visual acuity improved in 13/15 eyes (86.7%) and remained stable in 2 (13.3%). Mean retinal sensitivity showed significant improvement from baseline 5.69 ± 3.52 dB to final 8.35 ± 3.86 dB; P < 0.001. Fixation stability inside central 4° improved from baseline 58.5 ± 17.8% to final 73.7 ± 23.0%; P = 0.009. Central retinal thickness did not change significantly throughout follow-up. No FTMH or FS recurrence occurred and no surgical complications arose. CONCLUSION: Adjustable macular buckling exoplant may represent an effective surgical option for the treatment of FS associated with FTMH in highly myopic eyes. Adjustable macular buckling showed high closure rate and virtually no tendency to recur. Functional results and safety are also interesting because vision improved and retinal thickness did not reduce significantly at 24 months of follow-up.

Encircling scleral buckling with inferior indentation for recurrent retinal detachment in highly myopic eyes.

PURPOSE: To report on the use of scleral buckling (SB) alone or associated to pars plana vitrectomy (PPV) for the treatment of recurrent retinal detachment in highly myopic eyes with axial length >26.5 mm. METHODS: Single-surgeon, retrospective consecutive operative series consisting of 255 eyes of 237 highly myopic patients suffering recurrent retinal detachment after primary SB (40%), primary PPV (40%), and multiple surgery (20%). Included eyes underwent either a 6-mm encircling band associated to a 6-mm inferior buckle wedge-shaped or 2.5 mm band and 15 mm inferior buckle. RESULTS: Overall 88% of sample population had an attached retina after 1 surgery (90% in the post-SB group, 90% in the post-PPV group, and 85% in the post-multiple surgery group). Visual acuity results were less encouraging with a mean 20/60 visual acuity in the post-SB group and 20/200 in both post-PPV and post-multiple surgery groups. CONCLUSION: Encircling SB explants with extensive inferior indentation can be a valuable adjunct to PPV, membrane peeling, and silicone oil tamponade in the treatment of recurrent retinal detachment in highly myopic eyes. Although anatomical success rate is increasingly high, vision is often disappointing.

Macular pucker: to peel or not to peel the internal limiting membrane? A microperimetric response.

BACKGROUND: To compare functional and anatomical outcomes after idiopathic macular pucker removal between eyes that underwent internal limiting membrane (ILM) peeling and eyes that did not. METHODS: In this multicentric, randomized clinical trial, 60 eyes of 60 patients affected with idiopathic macular pucker were enrolled. Thirty eyes underwent 23-gauge pars plana vitrectomy associated with ILM peeling ("ILM peeling group"), whereas 30 eyes did not undergo ILM peeling ("ILM not peeling group"). Retinal sensitivity, frequency of microscotomas, and all the other microperimetric parameters were tested by MP1 microperimetry. Best-corrected visual acuity was investigated with the Early Treatment Diabetic Retinopathy Study chart. Anatomical outcomes were analyzed with spectral domain optical coherence tomography. RESULTS: After a 12-month follow-up, the mean retinal sensitivity in the 4° central area showed a greater and faster recovery in the ILM not peeling group than in the ILM peeling group (P = 0.041). The number of absolute microscotomas (0 dB) within the 12° central retinal area was significantly higher in the ILM peeling group than in the ILM not peeling group (P = 0.044). CONCLUSION: The ILM not peeling group seems to show better outcomes than the ILM peeling group as measured by mean retinal sensitivity and number of microscotomas after a 12-month follow-up.

Adaptive optics imaging of parafoveal cones in type 1 diabetes.

PURPOSE: To evaluate the parafoveal cone density in patients with Type 1 diabetes mellitus (DM1). METHODS: Adaptive optics retinal images of the photoreceptor mosaic were acquired from 11 DM1 patients (study group) and 11 age-matched healthy subjects (control group). Cone density was analyzed, along the horizontal and vertical meridian, at 230-µm, 350-µm, and 460-µm eccentricity from the fovea. Central retinal thickness was measured using a Spectralis spectral-domain optical coherence tomography. A multiple regression model was performed to determine the relationships between the explanatory variables (age, glycohemoglobin level, presence of diabetic retinopathy, duration of diabetes, and central retinal thickness) and cone density. RESULTS: Patients had a diagnosis of DM1 in the past 9 years to 21 years. Of these, five patients had a diagnosis of no diabetic retinopathy and six had mild nonproliferative diabetic retinopathy. On average, cone density was 10% lower in the study than in the control group at each retinal eccentricity along the horizontal and vertical meridians (analysis of variance, P < 0.001). The central retinal thickness was thicker in DM1 eyes than in the control eyes (278 ± 20 µm and 260 ± 13 µm; P < 0.05). The model explained 61% (P < 0.01) of the variance of cone density in the population, with the variables representing an abnormal glucose metabolism, that is, a higher glycohemoglobin level, the presence of diabetic retinopathy, and a chronic diabetes, having the highest influence on cone density decline. CONCLUSION: A subtle decrease of parafoveal cone density was found in DM1 patients in comparison with age-matched control subjects via high-resolution adaptive optics retinal imaging. The cone density decline was moderately associated with a disturbance in the glucose metabolism.

Analysis of retinal capillaries in patients with type 1 diabetes and nonproliferative diabetic retinopathy using adaptive optics imaging.

PURPOSE: To illustrate a noninvasive method to analyze the retinal capillary lumen caliber in patients with Type 1 diabetes. METHODS: Adaptive optics imaging of the retinal capillaries were acquired in two parafoveal regions of interest in eyes with nonproliferative diabetic retinopathy and unaffected controls. Measures of the retinal capillary lumen caliber were quantified using an algorithm written in Matlab by an independent observer in a masked manner. Comparison of the adaptive optics images with red-free and color wide fundus retinography images was also assessed. RESULTS: Eight eyes with nonproliferative diabetic retinopathy (eight patients, study group), no macular edema, and preserved visual acuity and eight control eyes (eight healthy volunteers; control group) were analyzed. The repeatability of capillary lumen caliber measurements was 0.22 µm (3.5%) with the 95% confidence interval between 0.12 and 0.31 µm in the study group. It was 0.30 µm (4.1%) with the 95% confidence interval between 0.16 and 0.43 µm in the control group. The average capillary lumen caliber was significantly narrower in eyes with nonproliferative diabetic retinopathy (6.27 ± 1.63 µm) than in the control eyes (7.31 ± 1.59 µm, P = 0.002). CONCLUSION: The authors demonstrated a noninvasive method to analyze, with micrometric scale of resolution, the lumen of retinal capillaries. The parafoveal capillaries were narrower in patients with Type 1 diabetes and nonproliferative diabetic retinopathy than in healthy subjects, showing the potential capability of adaptive optics imaging to detect pathologic variations of the retinal microvascular structures in vaso-occlusive diseases.

Interocular symmetry of parafoveal photoreceptor cone density distribution.

PURPOSE: To investigate the variation and symmetry of cone density distribution along the nasal and temporal retina of fellow eyes. METHODS: An adaptive optics retinal camera (rtx1; Imagine Eyes) was used to obtain images of the parafoveal cone mosaic in 20 healthy subjects. Cone density was estimated at 250, 420, 760, and 1,300 µm eccentricity from the fovea along the nasal and temporal retina of both eyes in each subject. The coefficient of variation and the intraclass correlation coefficient were used to calculate the variation and absolute agreement of cone density between the same retinal eccentricity locations of fellow eyes, respectively. RESULTS: A considerable variation of cone density between subjects was found at all eccentricities along the nasal and temporal retina (intersubject coefficient of variation ≥ 11%, P < 0.001). The intrasubject variation of cone density was, however, moderate (coefficient of variation ≤ 13% in 95% of the subjects); a high agreement was, on average, found between the cone density estimates at the same eccentricity along the nasal and temporal retina of fellow eyes (intraclass correlation coefficient ≥ 0.86, P < 0.001). CONCLUSION: Cone density follows a symmetrical distribution between fellow eyes. A systematic distribution of parafoveal cones between fellow eyes may provide an anatomical basis for the involvement of the photoreceptor layer in the first step of binocular spatial sampling.

Macular vitreoretinal interface abnormalities in highly myopic eyes with posterior staphyloma: 5-year follow-up.

PURPOSE: To review prevalence, long-term progression, and prognosis of vitreoretinal interface modifications in pathologic myopia with posterior staphyloma and investigate foveal sensitivity and fixation stability. METHODS: Retrospective single-institution series of 214 eyes (116 patients) with pathologic myopia, axial length >30 mm, and posterior staphyloma. Exclusion criteria included follow-up less than five years, incomplete records, and/or less than three optical coherence tomography or microperimetry. Patients were divided into 5 groups according to optical coherence tomography: 1) epiretinal membrane without schisis (ERM); 2) macular retinal schisis (Schisis); 3) partial thickness macular hole (PTMH); 4) full-thickness macular hole (FTMH); and 5) posterior retinal detachment (PRD) with or without macular hole. Disease progression was defined as a visual acuity decrease of two or more lines associated to objective worsening of the optical coherence tomography and/or microperimetry. RESULTS: Vitreoretinal abnormalities at baseline were present in 116 of 204 patients (56.8%) and 214 of 408 eyes (52.4%); 98 of 116 patients (84.4%) showed bilateral involvement. Baseline visual acuity and foveal sensitivity varied significantly with ERM performing better and PRD worse than others; PTMH and FTMH did not differ. During the 66 months of average follow-up, 33 of 214 eyes (15.4%) required surgery and 13 of 33 eyes (39.3%) needed reintervention. Surgery rate significantly differed among groups: 2% for ERM, 20% to 25% for Schisis, PTMH, and FTMH, and up to 50% for PRD. Progression rate of Schisis and FTMH was the same, regardless of symptoms, while macula-off PRD always required surgery. Decrease of fixation stability and foveal sensitivity correlated to need for surgery, while baseline foveal sensitivity and fixation did not. CONCLUSION: Vitreoretinal interface pathology in pathologic myopia with posterior staphyloma encompasses a spectrum of conditions whose baseline functionality, prognosis, rate, and amount of progression vary significantly. Customized treatment for each different condition should be considered.

Fellow eye findings of highly myopic subjects operated for retinal detachment associated with a macular hole.

PURPOSE: To identity anatomic risk factors involved in the onset of retinal complications causing decrease of visual acuity (VA) in the fellow eyes of highly myopic patients operated for retinal detachment with macular hole (RDMH). DESIGN: Cohort study. PARTICIPANTS: Ninety-eight patients (mean age, 51.5+/-8.0 years) with bilateral high myopia (mean myopia of the fellow eye, 20.4+/-5.5 diopters) affected by RDMH in the other eye at baseline. METHODS: Evaluation of the anatomic features at baseline and during 84+/-2.7 months of follow-up by biomicroscopic examination, indirect binocular ophthalmoscopy, B-scan ultrasonography, and optical coherence tomography. MAIN OUTCOME MEASURES: Detection of anatomic features associated with onset of retinal complications causing decrease of VA during the follow-up period. RESULTS: The fellow eyes were divided into 2 groups according to the clinical features of the RDMH eyes: Group 1, presence of posterior vitreous detachment (PVD); and Group 2, presence of posterior vitreous schisis (PVS). At baseline, the incidence of PVD in group 1 was 31 of 47 eyes (65.9%) and the incidence of PVS in Group 2 was 42 of 51 eyes (82.3%). At the end of follow-up, group 1 eyes had a lower incidence of retinal complications causing visual decrease than group 2 eyes (group 1, 2/47 eyes; group 2, 9/51 eyes). CONCLUSIONS: Fellow eyes of RDMH cases with higher degree of myopia and peculiar vitreoretinal features including PVS, posterior epiretinal membrane, severe posterior staphyloma, and chorioretinal atrophy are more likely to develop retinal complications causing decrease of VA.

Posterior vitreous detachment and retinal detachment after cataract surgery.

OBJECTIVE: To evaluate possible changes of vitreous status in emmetropic eyes after uneventful phacoemulsification surgery, and possible related complications such as the onset of retinal detachment (RD). DESIGN: Retrospective case series. PARTICIPANTS: Four hundred fifty-three emmetropic eyes from 453 patients (mean age, 62.03+/-5.57 years) subjected to uneventful phacoemulsification with intraocular lens implantation in the capsular bag were considered in the study. They had a refractive error within +/-0.5 diopters (mean, -0.21+/-0.08). Eyes with peripheral retinal lattice degeneration were included only if asymptomatic and only if the degeneration involved one retinal quadrant. After cataract surgery, the 453 eyes were evaluated preoperatively at days 1, 15, and 30 and months 3, 6, 12, 18, 24, 36, 48, and 60. The whole period of follow-up was 5 years. METHODS: Evaluation of vitreous status by biomicroscopic examination, indirect binocular ophthalmoscopy, and B-scan ultrasonography. MAIN OUTCOME MEASURES: Postoperative onset of posterior vitreous detachment (PVD) and RD. RESULTS: After cataract surgery, a PVD occurred in 107 of 141 (75.88%) eyes without preoperative PVD or lattice degeneration. Posterior vitreous detachment occurred in 41 of 47 eyes (87.23%) with preoperative lattice degeneration and no PVD. Eyes with preoperative lattice degeneration and postoperative PVD showed a higher incidence of RD after cataract surgery (21.27%) than eyes without preoperative PVD or lattice degeneration (0.70%). In all patients with lattice degeneration, RD originated from horseshoe retinal tears on lattice areas located on the superior quadrants. No correlation was observed between the development of RD and age. CONCLUSIONS: Our results suggest that the onset of postoperative PVD should be considered an important risk factor for the development of RD after cataract surgery, particularly in eyes with lattice areas.

Prevalence of asymptomatic macular holes in highly myopic eyes.

OBJECTIVE: To evaluate the presence of macular holes (MHs) in very highly myopic eyes in the absence of visual symptoms. DESIGN: Retrospective case series. PARTICIPANTS: Three hundred eighty-three eyes from 383 patients (mean age, 51.70+/-12.73 years) affected by very high myopia (between -14 and -32 diopters [D]), with no visual disturbance such as metamorphopsia and with visual acuity (VA) of >0.2 logarithm of the minimum angle of resolution, were considered in the study. They were evaluated at baseline and every 6 months during a mean total period of 30.2+/-0.5 months (range, 28.3-32.1). METHODS: Evaluation of macular morphology by optical coherence tomography (OCT). MAIN OUTCOME MEASURES: Changes in OCT macular morphology ascribed to the presence of an MH. RESULTS: Macular holes were detected by OCT in 24 of 383 (6.26%) myopic eyes. These MHs were defined as asymptomatic (AMHs). The presence of AMHs was more prevalent (although not significantly when compared with the overall study population) in myopic patients younger than 50 years and with concomitant myopia of >-20 D. Posterior vitreous schisis was the most frequent vitreous modification associated with AMH (18/24 eyes [75.0%]). During follow-up, a decrease in VA was observed in 5 of 24 (20.8%) AMH eyes due to the enlargement of the lesion or to posterior retinal detachment, leading to the development of a symptomatic MH. Greater degree of myopia and younger age were associated with the evolution of the macular disease, consisting of an enlargement of the MH and/or the onset of a macular detachment. CONCLUSIONS: A small percentage (6.26%) of highly myopic eyes may develop an MH in the absence of visual symptoms. The absence of symptoms could be related to the localization of the hole in a juxtafoveal area. Its evolution in a symptomatic MH seems to be related to the presence of epiretinal tissue, younger age, and the degree of myopia.

Femtosecond laser photodisruptive effects on the posterior human corneal stroma investigated with atomic force microscopy.

PURPOSE: To analyze the effects of femtosecond laser pulses on the posterior human corneal stroma with atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM). METHODS: A femtosecond laser (IntraLase iFS, Abbott, USA) was programmed to create a full posterior lamellar dissection in 9 human corneal tissues, using 3 different pulse energies (1.00 µJ, 0.75 µJ, and 0.50 µJ). Three corneal tissues were prepared in a similar fashion using a mechanical microkeratome (Moria Evolution 3, Moria, France). Six corneal tissues received an 8.00-mm diameter full cylindrical resection using either the femtosecond laser or the Barron trephine (Katena Products Inc., USA). The posterior corneal lenticules were first examined at AFM (Autoprobe CP, Veeco, USA). Both the posterior lenticules and the trephined corneal samples were scanned by ESEM (FEI Quanta 400, USA). RESULTS: Granules and crater-like features were observed on the stromal interface of all the laser dissected tissues, likely due to a secondary thermal effect of femtosecond laser dissection. Collagen fibers were seen only on samples treated with the 0.50 µJ pulse energy. Images of an even stromal surface were observed on the posterior stroma of mechanically dissected corneal samples. CONCLUSIONS: Mechanical and thermal effects, induced by femtosecond laser pulses on the human corneal stroma, were seen with AFM. Surface regularity of the photodisrupted stroma was inversely and non-linearly related to the pulse energy. The femtosecond laser provided high surface quality for lamellar resection of the posterior stroma comparable to those provided by mechanical devices.