Long term results of photodynamic therapy in intraocular tumors.

PURPOSE: To report long term results of photodynamic therapy (PDT) as treatment for intraocular tumors METHODS: Retrospective interventional case series of 15 patients. All patients treated with standard-fluence PDT (83 s; 50 J/cm2) using verteporfin. OUTCOME MEASURES: Tumor diameter, tumor thickness, subretinal fluid resolution, best-corrected visual acuity,intraocular pressure and PDT complications. RESULTS: 10 patients (66.7% of total patients) were diagnosed with choroidal hemangioma, 3 patients (20% of total patients) were diagnosed with choroidal melanoma, and 2 patients (13,3% of total patients) were diagnosed with choroidal osteoma.. Mean follow-up time was 33±18 months. The mean visual acuity was determined as 1.29 ± 0.98 logMAR in the examinations just before the PDT application. At the end of the follow-up period, the mean visual acuity was calculated as 1.41 ± 1.07 logMAR. While VA increased in 3 (20%) patients and decreased in 5 (33.3%) patients; It was determined that VA value did not change after treatment in 7 (46.7%) patients. The mean lesion diameter before PDT was 6573 ± 2115 µm (range; 1500-10,000 µm). The mean tumor thickness before PDT was 3624 ± 1404 µm (range; 600-6000 µm). The mean lesion diameter after treatment was 6026 ± 2521 µm (range; 0-9000 µm), and the mean tumor thickness after treatment was 2280 ± 1740 µm (range; 0-6000 µm).After the PDT, tumor size decreased in 8 (53.3%) patients, increased in 3 (20%) patients, and no change in tumor size was observed in 4 (26.7%) patients. Mean IOP values of all patients were 14.06 ± 3.17 mmHg before treatment; after treatment, it was measured as 13.46 ± 1.70 mmHg. After the treatment, geographic atrophy developed in 1 (6.7%) patient, cystoid macular edema developed in 1 (6.7%) patient, Retinal Pigment Epithelium (RPE) and choroidal atrophy developed in 1 (6.7%) patient. CONCLUSION: There are not enough cases of each to clearly distinguish between these 3 types of ocular cancers.However PDT may be a good option in the treatment of intraocular tumors with the chance of selective treatment and successful response.

Effect of FFP2/N95 facemask wear on retinal and choroidal thickness profile in healthy subjects.

AIM: To investigate the influence of non-oil 95 (N95)/filtering facepiece 2 (FFP2) facemask wear on retinal thickness, choroidal thickness (CT), retinal nerve fiber layer thickness (RNFLT), and ganglion cell layer thickness (GCLT) in healthy subjects. METHODS: In this prospective study, 53 healthy participants who used FFP2/N95 facemask were enrolled. Participants underwent optical coherence tomography imaging before and at 1 and 4h following FFP2/N95 facemask wear. The last imaging session was performed 1h after FFP2/N95 removal. Retinal thickness, CT, RNFLT, and GCLT were assessed at each session. Vital parameters were also assessed. RESULTS: The pulse rate of the subjects significantly decreased at 1 and 4h compared to baseline values (P<0.05). No significant changes in retinal thickness, RNFLT, and GCLT were observed in the study. CT profile showed a significant increase at all measured locations except 1-mm temporal, 1-mm inferior and 2-mm inferior points following FFP2/N95 wear which turned to baseline values after FFP2/N95 removal. Pulse rate and CT changes at 4h were significantly correlated (P<0.05). CONCLUSION: Parasympathetic activation during FFP2/N95 facemask wear might have a role on elevated CT measurements in healthy individuals by virtue of increased choroidal blood flow.

Evaluation of long-term outcomes associated with extended heavy-silicone oil use for the treatment of inferior retinal detachment.

To evaluate macular status with optical coherence tomography (OCT) in eyes that underwent pars plana vitrectomy (PPV) and heavy-silicone oil (HSO) endotamponade for the treatment of rhegmatogenous retinal detachment (RRD) with inferior breaks. Twenty eyes of 20 patients who have RRD with inferior breaks included in the study. Oxane HD was used as an intraocular tamponade for all surgeries. Postoperatively, anatomic reattachment, macular status using OCT imaging, and any long-term complications were evaluated. The mean age was 60.4 ± 11.2 years (range, 37-83). The duration of HSO endotamponade was 15.3 ± 11.0 months (range, 6-48) with some postoperative complications such as HSO emulsification, intraocular pressure elevation, and epiretinal membrane (ERM) formation. Mean follow-up time was 19.5 ± 10.5 months (range, 10-59) after HSO removal or ERM surgery. Primary reattachment was achieved in 90% of eyes and the success rate was 100% with further interventions. Ellipsoid zone (EZ) was continuous in 13 of 20 eyes in which OCT imaging performed as well as the fellow eye. PPV and heavy-silicone oil injection for the treatment of eyes with RRD from inferior break(s) have a good long-term EZ continuity. ERM formation and its removal do not affect EZ.

Long term outcome of adjuvant photodynamic therapy after cyberknife radiotherapy for choroidal melanoma.

PURPOSE: To report the outcome of photodynamic therapy (PDT) for choroidal melanoma as adjuvant treatment with CyberKnife radiotherapy. DESIGN: Retrospective interventional case series. METHODS: Standard-fluence PDT using verteporfin. OUTCOME MEASURES: Regression of tumor; resolution of subretinal fluid (SRF); change in best-corrected visual acuity (BCVA), and complications of PDT. RESULTS: The study included 16 choroidal melanomas (3 pigmented, 4 lightly pigmented, 9 amelanotic) treated with adjuvant PDT after CyberKnife radiotherapy. The mean follow up time was 45.5 months after the initial PDT. 13 patients improved completely with PDT sessions and growth was seen in 3 patients. There was seen completely resolution in SRF in 10 eyes, partial resolution in 3 eyes, and stable in 3 eyes. The mean thickness of tumors was 3.9 mm before PDT and 2.3 mm after PDT. Retina pigment epithelium atrophy in 3 patients and subretinal hemorrhage in 1 patient were seen as complication of PDT. Three patients underwent enucleation for recurrence in the tumor. There was not a higher rate of change in BCVA after PDT (37.5% stable; 25% increase; 37.5% decrease. Poor final visual acuity associated with worse initial visual acuity, proximity of the tumor to the foveola and optic disc, and radiation complications. CONCLUSIONS: PDT seems to offer a good option for posterior pole choroidal melanoma as adjuvant therapy in suitable cases. Future prospective studies with larger number of patients and with longer follow-up are needed to further investigation.

Papilledema and idiopathic intracranial hypertension due to the possible potentiation of ATRA by posaconazole in a case of acute promyelocytic leukemia.

INTRODUCTION: Idiopathic intracranial hypertension (IIH) (pseudotumor cerebri) is a rare side effect of all-trans retinoic acid (ATRA). IIH cases have been observed after the concomitant use of ATRA with azole group antimicrobials such as fluconazole and voriconazole. Here, we discuss about the diagnosis and treatment process of the IIH emerging in a young acute promyelocytic leukemia (APL) case with the ATRA impact, which can be increased by posaconazole. CASE: A 19-year-old male patient was diagnosed with APL. Headache and blurred vision were developed on the 12th day of the AIDA (ATRA, 45 mg/m2/day, oral and idarubicin 12 mg/m2, on days 2, 4, 6, 8, intravenous) protocol and posaconazole proflaxis. He was diagnosed IIH along with the existing eye findings and imagings. MANAGEMENT & OUTCOME: ATRA treatment and posaconazole were interrupted. Systemic acetazolamide and dexamethasone treatment were initiated. After significant clinical response was observed, ATRA treatment was resumed without posaconazole and a similar clinical condition did not recur. DISCUSSION: The combined use of ATRA and azole group drugs increases the risk of developing IIH. Patients with APL who developed IIH during the concomitant use of ATRA and fluconazole or voriconazole have been reported. To the best of our knowledge, our case is the first APL case with a IIH who treated with ATRA-based therapy and used posaconazole. In case of development of side effects, drugs should be interrupted and this combination should be avoided if possible after appropriate approach and clinical improvement.

Anterior segment optical coherence tomography findings in leukemic iris infiltration.

Iris involvement by acute lymphoblastic leukemia is a very rare primary leukemic infiltration. Blurred vision, conjunctival injection, anterior chamber reaction, pseudohypopyon, thickening of the iris stroma, change in iris shape and color are common clinical signs in leukemic iris infiltration. There is no optimal treatment. Radiotherapy, systemic chemotherapy (high-dose of methotrexate and/or high-dose cytarabine), topical and systemic corticosteroids have been reported as treatment modalities. Herein we present anterior segment optical coherence tomography findings in a 21-years-old, male, diffuse B-cell Acute Lymphoblastic Leukemia (ALL) patient who has a leukemic iris infiltration in his left eye that was successfully treated with intravitreal methotrexate.

Coexistence of torpedo maculopathy and retinoblastoma: Differentiation the lesions with hand-held optical coherence tomography.

Torpedo maculopathy (TM) is a rare congenital defect of the retina pigment epithelium, which always localizes to the temporal fovea. It is most commonly unilateral and often occurs in patients without any relevant disease. Classic finding is a flat, hypopigmented, oval lesion, resembling a 'torpedo,' with a wedge-shaped tail extending outward and directed toward the foveola. Visual acuity is generally unaffected due to the central fovea is not involved and this lesions remain stable. Therefore, when it accompanied with a posterior segment disease, we should make differential diagnosis to avoid unnecessary treatment. Herein, we present a child with coexistence of TM and retinoblastoma, and how to manage the lesions. We aimed to alert the ophthalmologists to this unusual combination for avoiding unnecessary treatment modalities. To the best of our knowledge, this combination that has never before been described.

Effect of cataract surgery on subfoveal choroidal and ganglion cell complex thicknesses measured by enhanced depth imaging optical coherence tomography.

PURPOSE: We aimed to evaluate the effect of cataract surgery on subfoveal choroidal thickness (CT) and ganglion cell complex (GCC) thickness, as measured by enhanced depth imaging-optical coherence tomography (OCT). METHODS: This prospective study included 30 eyes of 30 patients who had undergone uneventful phacoemulsification surgery for senile cataract but had no previous ocular surgery or other ocular abnormality. Best-corrected visual acuity, slit-lamp biomicroscopy, intraocular pressure, axial length, and central corneal thickness were measured preoperatively. The operative times (OTs) and effective phaco times were also recorded in each case. OCT measurements were performed at the preoperative visit and 1 month after cataract surgery. Study of CT and GCC thickness changes was the primary objective, but central macular thickness (CMT) and peripapillary retinal nerve fiber layer (RNFL) thicknesses were also obtained by OCT. RESULTS: The mean subfoveal CT was 294.4±39.2 µm preoperatively and 301.4±39.9 µm postoperatively (P<0.001). The mean GCC thickness was 85.0±4.4 µm preoperatively and 89.2±5.3 µm postoperatively (P<0.001). The mean CMT was 247.9±17.6 µm preoperatively and 249.0±17.8 µm postoperatively (P=0.029). The mean RNFL thickness was 97.4±5.4 µm preoperatively and 101.7±5.6 µm postoperatively (P<0.001). Regression analysis showed that age, sex, axial length, central corneal thickness, operative time, and effective phaco time were not associated with CT changes (P=0.834, P=0.129, P=0.203, P=0.343, P=0.547, and P=0.147, respectively) and GCC thickness changes (P=0.645, P=0.542, P=0.152, P=0.664, P=0.448, and P=0.268, respectively) after cataract surgery. CONCLUSION: Our results indicate that all subfoveal CT, CMT, as well as RNFL and GCC thicknesses are slightly affected after uneventful phacoemulsification surgery. After cataract surgery, the examiners should consider obtaining new baseline measurements.

Could Topical Minoxidil Cause Non-Arteritic Anterior Ischemic Optic Neuropathy?

Minoxidil hair formulation is commonly used for the treatment of male or female androgenic alopecia. Minoxidil is a Health Canada and US FDA-approved medication for hair loss in men and women. The drug is marketed as 2% and 5% topical solutions. This over-the-counter product is considered safe, but should be used with caution. Furthermore, minoxidil is an orally active vasodilator for treatment of severe hypertension. Typical side effects of minoxidil are faster heart rate, augmented heart function and stroke volume (which can be associated with reduced vascular resistance upon baroflex stimulus), retained sodium and water and abnormal hair growth. The most common adverse reactions of the topical formulation are limited to irritant and allergic contact dermatitis on the scalp. Herein, we report a non-arteritic anterior ischemic optic neuropathy caused by topical 5% minoxidil treatment that was resolved after discontinuation of minoxidil.

A unique case of isolated sebaceous adenoma of the bulbar conjunctiva.

Our patient was a 34 year-old male who presented with a painless conjunctival mass that had developed 3 months before his first visit. On performing slit-lamp biomicroscopy, a lobulated pink-yellowish solid mobile mass was observed on the nasal bulbar conjunctival surface of his left eye. The tumor was excised, and histopathologic examination of the tumor revealed a sebaceous adenoma. Systemic examination was normal. No recurrence was observed during the 24-month follow-up period. Sebaceous adenoma of the bulbar conjunctiva is an extremely rare benign tumor, which may be observed to be isolated in the absence of malignancy.

A unique case of isolated sebaceous adenoma of the bulbar conjunctiva / Um caso único de adenoma sebáceo isolado de conjuntiva bulbar

ABSTRACT Our patient was a 34 year-old male who presented with a painless conjunctival mass that had developed 3 months before his first visit. On performing slit-lamp biomicroscopy, a lobulated pink-yellowish solid mobile mass was observed on the nasal bulbar conjunctival surface of his left eye. The tumor was excised, and histopathologic examination of the tumor revealed a sebaceous adenoma. Systemic examination was normal. No recurrence was observed during the 24-month follow-up period. Sebaceous adenoma of the bulbar conjunctiva is an extremely rare benign tumor, which may be observed to be isolated in the absence of malignancy.

RESUMO Nosso paciente era um homem de 34 anos que apresentou uma massa conjuntival indolor desde há 3 meses antes da primeira consulta. Na biomicroscopia por lâmpada de fenda, observa-se uma massa rosa-amarelada, sólida, móvel e lobulada na superfície conjuntival bulbar nasal, em seu olho esquerdo. O tumor foi retirado e o exame histopatológico demonstrou um adenoma sebáceo. O exame sistêmico era normal. Nenhuma recidiva foi observada durante os 24 meses de acompanhamento. Adenoma sebáceo da conjuntiva bulbar é um tumor benigno extremamente raro e pode ser visto isolado, sem quaisquer doenças malignas associadas.

Thiol/Disulfide Homeostasis in Patients with Central Serous Chorioretinopathy.

PURPOSE: To evaluate dynamic thiol/disulfide homeostasis in patients with chronic central serous chorioretinopathy (cCSC). METHODS: This prospective study included 34 cCSC cases and 37 healthy individuals who were age- and sex-matched. A new colorimetric method for measuring thiol/disulfide homeostasis was used. Native thiol, total thiol/disulfide levels, disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol ratios were measured. RESULTS: The age and gender distributions were similar in both main groups. The mean duration of disease was 47.29 ± 24 months. Native and total thiol levels were significantly lower among the cCSC group relative to the control group (p < 0.001). There was not a statistically significant difference between the cCSC and the control group in terms of disulfide levels (p = 0.492). While disulfide/native thiol and disulfide/total thiol ratios were elevated, the native thiol/total thiol ratio was decreased in the cCSC group (p = 0.017, 0.021, 0.036, respectively). Ratios obtained using plasma native thiol, total thiol, and disulfide levels differed significantly between the both groups. CONCLUSION: Disulfide/thiol ratio was significantly greater in cCSC patients relative to healthy control subjects. Our results suggest that the oxidative process is involved in the pathogenesis of the cCSC.

Serous retinal detachment in patients with macular edema secondary to branch retinal vein occlusion.

PURPOSE: The aim of the present study was to evaluate visual acuity (VA) and central macular thickness (CMT) to assess the influence of serous retinal detachment (SRD) in eyes with macular edema (ME) secondary to branch retinal vein occlusion (BRVO). METHODS: Sixty-one eyes with BRVO from 61 patients with ME were analyzed and divided into two groups according to the spectral domain optical coherence tomography (OCT) findings of SRD and cystoid macular edema (CME). All patients underwent complete ophthalmic examinations and OCT measurements (Cirrus, Carl Zeiss Meditec Inc, Dublin, CA). Patients with marked retinal hemorrhage, diabetic retinopathy, previous laser photocoagulation, and/or intravitreal injection were excluded. RESULTS: The mean age of included patients (37 males, 24 females) was 65.4 ± 11.4 (53-77) years. There were 21 patients with SRD and 40 patients with CME. All of the 21 patients with SRD had CME. VA was significantly worse in the SRD group compared with the CME (non-SRD) group (0.82 ± 0.34 logMAR vs 0.64 ± 0.38 logMAR; P=0.005). Conversely, CMT was significantly greater in the SRD group than in the CME group (465 ± 115 µ vs 387 ± 85 µ; P=0.00004). CONCLUSION: SRD may be associated with decreased VA. The prognosis of patients with BRVO and SRD requires further investigation.

Evaluation of the retinal ganglion cell and choroidal thickness in young Turkish adults with hyperopic anisometropic amblyopia.

The purpose of this study is to compare the choroidal thickness (CT) and ganglion cell complex (GCC) thickness of the normal fellow eyes and the amblyopic eyes using enhanced depth imaging optical coherence tomography (EDI-OCT) in young Turkish adults with hyperopic anisometropic amblyopia. Patients with unilateral hyperopic anisometropic amblyopia were enrolled and underwent a full ophthalmological assessment, including best-corrected visual acuity, cycloplegic refraction, and axial length (AL) measurements. Cirrus EDI-OCT was used to obtain subfoveal CT, GCC thickness, retinal nerve fiber layer (RNFL), and central macular thickness (CMT) measurements. Comparison was performed between the amblyopic eyes and the normal fellow eyes. Forty-three hyperopic anisometropic amblyopic patients were enrolled in this study. Mean age of 23 female and 20 male patients was 24.8 ± 7.4 years. Mean AL was 21.9 ± 1.3 and 22.4 ± 0.9 mm in amblyopic and fellow eyes, respectively (P < 0.05). Mean subfoveal CT measurements were 325.4 ± 44.2 and 317.9 ± 42.7 µ in amblyopic and fellow eyes, respectively. There was no statistically significant difference between the groups (P > 0.05). Mean GCC thickness was 83.8 ± 3.6 µ in amblyopic eyes and 83.5 ± 3.9 µ in the fellow eyes. Statistically significant difference was not seen between the groups (P > 0.05). Mean RNFL and mean CMT measurements were also similar in two groups (P > 0.05). Subfoveal CT, CMT, RNFL, and GCC thickness measurements were not statistically significant between hyperopic anisometropic amblyopic eyes and normal fellow eyes.

The relation of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and mean platelet volume with the presence and severity of Behçet's syndrome.

Behçet's syndrome (BS) is associated with chronic inflammation and endothelial dysfunction. Although there have been extensive investigations on neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV) in many diseases, their roles in BS is unclear. The purpose of the present study was to evaluate NLR, PLR, and MPV levels in BS patients and explore their clinical significance. The study included 254 patients with BS and 173 healthy individuals. Age, sex, age of onset, duration of disease, smoking, Behçet activity score, total white blood counts, neutrophil, platelet, and T lymphocyte counts of the patients were recorded. White blood cell (WBC), neutrophil, platelet, NLR, and PLR were significantly higher in patients with BS when compared with healthy controls (all p < 0.001). Lymphocyte counts and MPVs of the BS group were not statistically different from healthy controls (all p > 0.05). In the BS group, PLR and MPV were significantly different among the three severity groups (p = 0.037 and p = 0.016, respectively). We showed that any laboratory markers were not associated with joint, eye, central nervous system, large vessel, or gastrointestinal involvement in BS. NLR was shown to be an independent factor for BS by multivariate analysis. We suggest that NLR can be considered to be a diagnostic criterion of BS given the support of the findings from larger prospective studies.

Changes in vision related quality of life in patients with diabetic macular edema: ranibizumab or laser treatment?

PURPOSE: To compare the changes in vision related quality of life (VR-QoL) in patients with diabetic macular edema (DME) undergoing intravitreal ranibizumab (IVR) injection or focal/grid laser. MATERIAL AND METHODS: In this prospective study, 70 patients with clinically significant macular edema (CSME) were randomized to undergo IVR injection (n=35) and focal/grid laser (n=35). If necessary, the laser or ranibizumab injections were repeated. Distance and near visual acuities, central retinal thickness (CRT) and The 25-item Visual Function Questionnaire (VFQ-25) were used to measure the effectiveness of treatments and VR-QoL before and after 6 months following IVR or laser treatment. RESULTS: The demographic and clinical findings before the treatments were similar in both main groups. The improvements in distance and near visual acuities were higher in IVR group than the laser group (p<0.01). The reduction in CRT in IVR group was higher than that in laser treatment group (p<0.01). In both groups, the VFQ-25 composite score tended to improve from baseline to 6 months. And at 6th month, the changes in composite score were significantly higher in IVR group than in laser group (p<0.05). The improvements in overall composite scores were 6.3 points for the IVR group compared with 3.0 points in the laser group. Patients treated with IVR and laser had large improvements in composite scores, general vision, near and distance visual acuities in VFQ-25 at 6 months, in comparison with baseline scores, and also mental health subscale in IVR group. CONCLUSION: Our study revealed that IVR improved not only visual acuity or CRT, but also vision related quality of life more than laser treatment in DME. And these patient-reported outcomes may play an important role in the treatment choice in DME for clinicians.

Short-term effect of topical brinzolamide 1%-timolol 0.5% fixed combination on human central corneal thickness.

PURPOSE: To evaluate the short-term effect of fixed combination of brinzolamide 1% and timolol 0.5% (FCBT) application on human central corneal thickness (CCT). METHODS: This prospective clinical study included 97 patients having Nd:YAG laser posterior capsulotomy for posterior capsule opacification. Patients were randomized to receive apraclonidine hydrochloride 0.5% (APRA) (n=48) or FCBT (n=49) at 1 h before laser surgery. The baseline CCT was evaluated by ultrasonographic pachymetry from the central region ∼1 h before the laser procedure. CCT measurements were applied just before the laser application and then the first, second, and third hour, and the first, third, and seventh day after the Nd:YAG laser capsulotomy. RESULTS: There was no statistically significant difference between the baseline intraocular pressures, CCTs, and demographic and clinical data (age, sex, surgery laser interval, total laser energy) of the APRA and the FCBT groups. The mean CCT values of the APRA group at the first, second, and third hour, and the first, third, and seventh day were 553.8±28.0, 551.4±35.3, 556.8±28.7, 552.6±27.5, 548.2±26.2, and 546.2±25.5 µm, respectively. The mean CCT values of the FCBT group at the first, second, and third hour, and the first, third, and seventh day were 544.21±34.4, 549.4±27.6, 555.94±33.1, 550.8±33.4, 547.2±33.6, and 544.9±33.4 µm, respectively. No statistically significant difference was detected between the 2 groups. CONCLUSION: The difference in CCT increase between both groups was not statistically significant at any follow-up visits. FCBT application does not have a short-term effect on CCT.

An uncommon ocular manifestation of Sweet syndrome: peripheral ulcerative keratitis and nodular scleritis.

Sweet syndrome (acute febrile neutrophilic dermatosis) is characterized by fever, neutrophilic leukocytosis, and abrupt appearance of painful erythematous nodules and plaques, particularly on the face, neck, and limbs. In this study, we report a very rare case of Sweet syndrome in which the patient presented nodular scleritis and peripheral ulcerative keratitis during the dermatologically inactive period of the disease.

Iatrogenic retinal breaks caused by infusion fluid during pars plana vitrectomy.

OBJECTIVE: To describe a series of cases of iatrogenic retinal breaks (IRBs) caused by the infusion fluid flow of a 25-gauge pars plana vitrectomy (PPV) system. DESIGN: Retrospective case series. METHODS: During 25-gauge PPV, 4 cases had IRBs caused by infusion fluid flow. The IRBs rapidly progressed to localized retinal detachment. RESULTS: The first 3 cases had IRBs on the nasal quadrant midperiphery of the retina. The IRBs were treated with laser retinopexy and tamponade during surgery. Case 4 had a macular hole and macular detachment during scleral indentation. The IRBs seemed to be caused by intraocular pressure (IOP) control mechanisms of the vitrectomy device. CONCLUSIONS: To prevent IRBs caused by infusion fluid flow, we recommend using an IOP control limit of 4 mL/min for 25-gauge vitrectomy, with valved cannulas. In addition, the surgeon must be cautious during scleral indentation and air-fluid exchange not to cause a rebound hypotonia.