Comparison between Tear Film Osmolar Cocentration and Other Tear Film Function Parameters in Patients with Diabetes Mellitus

PURPOSE: To evaluate tear film function in patients with diabetes mellitus (DM) using tear film osmolarity (TFO) measurements compared to other tear film function tests. METHODS: DM patients without any history of ocular surface disorder but with potential effects on the tear film were enrolled in this cross-sectional study. Data including dry eye symptoms, duration of DM, stage of diabetic retinopathy and blood hemoglobin A1c levels were recorded. Tear film break-up time (TBUT) and basic tear secretion (Schirmer test) were assessed. TFO was determined using the Tearlab Osmolarity System. The outcome measures were the difference between the mean values of TBUT, basic tear secretion and TFO in both the study and control groups. RESULTS: We recruited 51 DM patients and 20 control subjects with a mean age of 51.2 (range, 21 to 70) and 48.5 (range, 24 to 70) years, respectively. A total of 27 patients (53%) and 11 controls (55%) reported dry eye symptoms (p = 0.668). The mean TBUT was 10.2 ± 4.8 seconds in the study group versus 10.5 ± 2.8 seconds in controls, which was not significantly different (p = 0.747). The mean Schirmer test score was 8.1 ± 4.3 mm in the patients versus 10.1 ± 3.0 mm in the controls (p = 0.069). The mean TFO was 294.1 ± 12.9 mosmol/L in the patients versus 291.4 ± 14.5 mosmol/L in the controls (p = 0.456). It was significantly higher in patients with poor glycemic control determined by hemoglobin A1c > 8% (p = 0.003). TFO had a positive correlation with the duration of DM (p = 0.030) but not with the stage of diabetic retinopathy (p = 0.944). However, TFO showed a significant relationship with dry eye symptoms (p = 0.001). CONCLUSIONS: TFO is impaired in patients with uncontrolled DM and is better correlated with glycemic control and dry eye symptoms than the TBUT and Schirmer tests.

Nicotinic acid treatment for retinal vein occlusion

To evaluate the effect of nicotinic acid in management of retinal vein occlusions [CRVO or BRVO]. This prospective nonrandomized pilot study included 20 patients [21 eyes] with CRVO or BRVO that received nicotinic acid [3 g/day] for 3 months. A complete ophthalmologic examination uncorrected visual acuity [UCVA], best spectacle-corrected visual acuity [BSCVA], testing for a relative afferent pupillary defect [RAPD], slit-lamp examination, gonioscopy, intraocular pressure [IOP] measurement, fundoscopy and fundus photography was performed. Four patients did not appear for follow-up and hypersensitivity reaction to nicotinic acid and severe hyperglycemia happened in two patients. Therefore, the results of treatment in 16 eyes of 15 are reported. These patients had a mean age of 59.56 +/- 11.12 years. The average length of follow-up was 8.6 +/- 2.7 months. The mean BSCVA was 1.56 +/- 0.66 before treatment, 1.38 +/- 0.72 [p>0.05] at one month and 0.88 +/- 0.69 [p<0.01] at three months. The last BSCVA of all 16 eyes averaged 0.97 +/- 0.73 [p<0.01]. All patients had reduction of hemorrhagic events, cotton wool spots, edema in macula and disc, venous tortuosity, and dilation on basis of fundus photographs 3 months after treatment. Nicotinic acid usage provides enough time for development of collateral vessels, by induction of vasodilatation. Nicotinic acid use is tolerable and is related with mild systemic side effects.

Bilateral Macular Hole Following Myopic Photorefractive Keratectomy

A 42-year-old man was admitted to our clinic complaining of visual distortion in his left eye two months after bilateral myopic photorefractive keratectomy (PRK). Macular optical coherence tomography (OCT) showed a stage II macular hole in the left eye. Simultaneous OCT in the right eye showed vitreous traction and distortion of the outer retina. One month later, the patient underwent vitrectomy for the left eye, and the macular hole was closed. Two months after that, the patient complained of visual distortion in the right eye, and OCT revealed increased traction and accentuated outer retinal distortion indicating a stage IB macular hole. Traction attenuated later without any intervention. The short interval between PRK and hole formation, bilateral involvement, and the moderate refractive error in this case highlight the possible role of PRK in aggravating vitreoretinal interface abnormalities. We recommend the addition of PRK to the list of procedures that may be associated with the formation of a macular hole.

[Rhegmatogenous retinal detachment Eye research Center-Mashhad University of Medical Sciences]

Evaluation of epidemiology and seasonal variation of Rhegmatogenous Retinal Detachment [RRD], in patients undergoing retinal detachment surgery. Medical records of 416 patients admitted in KHATAM eye hospital [Mashhad, IRAN] were reviewed between years 2000 to 2008. Information about sex, age, season and month of incidence and operation and concomitant risk factors of patients, were gathered and analyzed. Average age of patients was 41 years old. Most of the cases of the disease were observed in the age group of above 6- y/o [35%]. The frequency of the RRD was higher in male patients than in females. [Ratio: 1.7 to 1]. Distribution of our cases in different seasons showed no significant difference between them [P value = 0.142]. The highest and lowest rate of RRD was observed in October and September respectively with October having 51 patients [12.3%] and September having 23 patients [5.5%]. Myoia and pseudophakia were most common risk factors. There was no statistically significant relationship between age and month [and season] of incidence [or diagnosis and surgical procedure] of the RRD, likewise for gender. This study showed more RRD in male patients. Patients above than 60 years old have greater risks of incidence of RRD. No seasonal incidence pattern for RRD was founded; however, most of cases occurred in October, and at least in September

Alteration of tear film after vitrectomy and its influencing factors

To detect the prevalence of dry eye after vitrectomy and its influencing factors. Schirmer I, Tear Basic Secretion Test and Tear Breakup Time was done preoperatively and 3 months postoperatively on consecutive patients undergoing vitrectomy in Khatam Hospital from 2005 to 2006. Eyes with previous peritomies of more than 120° and symptoms of dry eye or tear tests compatible with a diagnosis of dry eye were excluded. Intraoperative factors including the extent of peritomy, extent of inadvertent conjunctival lacerations, extent of scleral depression and the instrument used for scleral depression were recorded. Scleral depression was graded extensive if it was done for more than 180° of globe circumference. Seventy five eyes of 75 patients were studied. Forty six [61.3%] of patients were male. The mean age of the patients was 47.13 +/- 18.85 years. Peritomy size was on average 179.33 +/- 124.75 and the mean size of conjunctival ruptures was 2.18 +/- 4.33 mm. Based on the type of instrument used for scleral depression, patients were divided into 4 groups: 1] metallic instrument, 6 cases [8%] 2] cotton applicator 32 cases [42.7%] 3] both, 14 cases [18.8%] 4] none [no scieral depression], 23 cases [30.7%]. Of 52 cases with scleral depression, the depression was extensive in 35 cases [46.7% of all eyes]. Thirteen eyes [17.3%] developed tear film parameters or symptoms consistent with dry eye. All of these eyes had undergone extensive scleral depression. Cotton applicator had been used significantly more in cases which developed dry eye. There was a direct relation between extent of peritomy and inadvertent conjunctival laceration and development of dry eye. Due to damage to the conjunctiva during operation, vitrectomy is apt to cause dry eye. To lower the risk of this complication, scleral depression, peritomy and possibility of inadvertent conjunctival lacerations should be minimized. It is also better to use metallic instruments for scleral depression rather than cotton applicator

Visual function following treatment of optic neuritis

To evaluate changes in different aspects of visual function including visual acuity, visual field, contrast sensitivity, colour vision and stereopsis in patients with optic neuritis before and after medical intervention. In a noncomparative interventional case series on 31 eyes of 30 patients with optic neuritis, the following aspects of visual function were compared before and after treatment. Medical intervention was conducted following the Optic Neuritis Treatment Trial [ONTT] guidelines. Visual function was assessed by evaluating changes in visual acuity, visual field [Goldmann in all patients and automated in some patients], contrast sensitivity using Cambridge low contrast grating, colour vision using lshihara plates and stereopsis using Titmus stereoacuity test. Visual acuity was significantly lower [3/10] in affected versus unaffected eyes [8/10] [P<0.00l]. Contrast sensitivity was also significantly better in unaffected eyes. Mean stereoacuity was 310 sec/arc. Visual field impairment was also significantly worse than that of the unaffected eye and normal population sample. Weak deutan defects were present in 60% of the patients. After medical treatment, visual acuity, visual field defects, contrast sensitivity, colour vision and stereopsis were significantly improved. Different aspects of visual function including visual acuity, visual field, contrast sensitivity, colour vision, and stereopsis are impaired in optic neuritis. Medical treatment with intravenous methylprednisolone followed by oral steroids is effective in improving these parameters. However, some deficits may persist after therapy. Since spontaneous recovery after optic neuritis is common, clinical trials are needed to determine the true effect of treatment versus follow-up