This prospective study was intended to be carried out for a period of 6 months. Depending on previous experience it was proposed to include 100 patients above 18 years of age and with visually significant cataract requiring cataract surgery during study period after applying exclusion criteria. Further after analysing the results of current study, power of study has come out to be 90% depending on difference between proportions of patients presenting with aqueous flare on day 1. Patients with history of diabetes, hypertension or any other systemic disease, use of ophthalmic analgesics, immunosuppressants, having any other ocular disease like uveitis, glaucoma and corneal disease, any known hypersensitivity to drugs used in study and any operative complications like PCR, nucleus drop, vitreous loss were excluded from study. They were randomly divided into two groups Group A and Group B, each consisting of 50 patients all of which underwent phacoemulsification. Group A patients received 1% Prednisolone acetate ophthalmic suspension and Group B patients received 0.05% Difluprednate ophthalmic emulsion post-operatively. After routine preoperative investigations, Best Corrected Visual Acuity (BCVA), intra-ocular pressure, fundus examination, sac test, viral markers (HIV I and II, HBsAg and HCV), blood pressure and random blood sugar, Standard phaco-emulsification (clear corneal incision) with foldable posterior chamber IOL implantation was carried out in all the patients. Patients in group A were administered 1% Prednisolone acetate ophthalmic suspension drops six times a day and in Group B were administered 0.05% Difluprednate ophthalmic emulsion drops six times a day for 4 weeks.

Post-operative evaluation was done on day 1, 1^st week, 2^nd week, 4^th week with following parameters: Snellen’s visual acquity (uncorrected and BCVA) and IOP was measured using Goldmann Applanation tonometer. Visual Analog Scale (VAS) was used to record ocular pain and Slit lamp biomicroscopy was done to evaluate anterior chamber cells and flare [9]. Efficacy of drug was evaluated in terms of decrease in ocular pain, anterior chamber reaction in the form of aqueous cells and flare and final visual acuity.

Grade 1: Trace—slight sensation of pain or discomfort

Grade 2: Mild—mild, tolerable aching of the eye

Grade 3: Moderate—moderate and prolonged aching sufficient to require the use of analgesics

Grade 4: Moderately severe—prolonged intense aching requiring the use of analgesics

Grade 5: Severe—prolonged sharp ocular or periocular pain

Grade cells in field

0 <1

+ 1-5

+ 1 6-15

+ 2 16-25

+ 3 26-50

> 50

Description grade

Nil 0

Just detectable +1

Moderate(Iris and lens details clear) +2

Marked (iris and lens details hazy) +3

Intense (fibrinous exudates).

Data entered was analysed using SPSS software (version20.0). Proportions have been expressed as percentages and finally chi-square test was applied to show difference between outcomes in two groups. Fisher-exact test and Yates modification was applied wherever required since many frequencies of subcategories were less than 5. The p-value <0.05 was taken as significant at 95% confidence interval.

In our study, 45 patients were >60 years of age, 32 in the age group 51-60 years and 23 <50 years of age. In group A, out of 50 patients 26 (52%) were males and 24 (48%) were females. In group B there were 25 males (50%) and 25 females (50%).

On Day 1, 58% of patients in Group A had Grade 1 aqueous cell and 42% had Grade 2 while in Group B, 54% had Grade 2 cells and 40% had Grade 1 aqueous cells. At the end of the study, 98% of patients in Group A showed Grade 0 and all the patients in Group B showed Grade 0 cells as depicted in [Table/Fig-1].

On Day 1, 68% of patients in Group A had Grade 1 aqueous flare and 14% had Grade 2 while in Group B, 82% had Grade 1 flare and 12% had Grade 2 aqueous flare. At the end of the study, all the patients in both the groups showed Grade 0 as depicted in [Table/Fig-2].

On Day 1, 46% of patients in Group A had Grade 1 ocular pain and 50% had Grade 2 while in Group B, 44% had Grade 1 pain and 54% had Grade 2 pain. At the end of the study, none of the patients complained of any ocular pain in Group A and 4% patients had only mild discomfort as shown in [Table/Fig-3].

In Intra-group trend, the difference between aqueous cell score, aqueous flare and pain score on Day 1 and at the end of 4 weeks was statistically significant with p-value <0.05 in both the groups while on comparing two study groups, difference in Aqueous cell score [Table/Fig-1], aqueous flare [Table/Fig-2] and pain score [Table/Fig-3] was statistically non-significant on Day 1 and all subsequent follow up visits.

There was improvement in visual acuity in all the patients in both the groups at the end of the study with p-value<0.001. All the patients in both the groups had final best corrected visual acuity 6/9-6/6 with statistically non-significant difference between two study groups [Table/Fig-4].

Senile cataract is the most common cause of visual impairment. Removal of cataract and implantation of IOL is the main surgical approach for cataract. The major block in quick visual rehabilitation of the patient is post-operative inflammation. Post-operative inflammation is accepted as natural consequence of the procedure irrespective of type of surgery, surgical technique and instrumentation used. To limit post-operative inflammation corticosteroids drugs are used in routine prophylactically. Post-operative inflammation presents as protein flare and inflammatory cells in anterior chamber, hyperemia, oedema. Corticosteroids have remained the main stay of treatment for Post-operative inflammation after cataract surgery. Corticosteroids suppress the production of inflammatory mediators. It inhibits the release of arachidonic acid from cell membrane phospholipids and prevents the formation of both leukotrienes and prostaglandins. Predinisolone acetate ophthalmic suspension is a glucocorticoid and has 3-5 times anti inflammatory potency of hydrocortisone [7]. Difluprednate 0.05% ophthalmic emulsion (difluoroprednisolone butyrate acetate) is a new synthetic diflourinated prednisolone derivative. Unlike other corticosteroids, difluprednate is preservative free and a prolonged use does not cause irritation or dry eye and hence increases tolerance to drug [10]. It is also associated with enhanced penetration, better bioavailability, and strong efficacy.

This study was done to compare the efficacy of difluprednate ophthalmic emulsion and prednisolone accetate ophthalmic suspension on post-operative inflammation in cataract surgery.

Ocular Pain Assessment: Ocular pain assessment was done using Visual Analogue Scale (VAS) and was compared in both the groups. At the end of study none of the patient in group A and 96% of patients in group B had no ocular pain (grade 1). Difference was statistically non significant in both the groups (p>0.05). Korenfeld MS et al., in his study showed decreased pain as well as inflammation with the use of Difluprednate ophthalmic emulsion 0.05% as compared to control group [10]. Foster CS et al., found in a study pain resolution with difluprednate was slightly faster as compared to prednisolone acetate ophthalmic suspension [11].

IOP Assessment: In the study, maximum number of patients had IOP in range of 14-15mmHg. Mean IOP was normal in both the groups and difference between two groups was found to be statistically insignificant. None of the patient showed clinically significant IOP rise >21 mmHg. This was in accordance with a study conducted by Jamal KN [12] which showed similar observations at the end of the study in IOP measurement while using difluprednate and prednisolone acetate eye drops. In another study with the use of these drugs Foster CS et al., found clinically significant increase in IOP in 11% of patients [11]. Korenfeld M S et al., however, found that with Difluprednate 0.05%, there was 3% increase in intraocular pressure as compared to 1% rise with control group [10]. Similarly, Meehan K observed increase in IOP with topical difluprednate use [13].

Aqueous Cell Assessment: At the end of study in 98% patients there was no cells in group A (AC cell score 0). A 2% patients showed cell score (±) whereas, 100% in group B showed AC cell clearance (AC cell score 0). Foster CS et al., found similar observations, at day 14, mean AC cell grade with difluprednate-treated patients was similar to prednisolone-treated patients (2.1 vs. 1.9 respectively) [11]. Smith S, showed AC cell grade of 0 (≤ 5 cells) and flare grade 0 (complete absence) was achieved in a significantly greater percentage of subjects treated with difluprednate, compared with placebo [14].

Aqueous Flare Score Assesment: No flare was detected in any study group at the end of the study. Foster CS et al., concluded that difluprednate was not inferior to prednisolone acetate in showing improvement in aqueous cells and flare clearing [11].

Visual Acquity: In the present study BCVA was recorded on day 1, week 1, week 2 and week 4. In group A, there were 92% patients who had BCVA 6/6 and 8 % who had best corrected visual acquity 6/9. In group B 90% patients had best corrected visual acquity 6/6 and 10% had BCVA 6/9. A study conducted by Stephen Smith administered difluprednate emulsion 0.05% post-operatively and found it to be highly effective for managing intra-ocular inflammation and pain with BCVA 6/6 in all patients [14]. Erric D Donnenfeld showed that with difluprednate uncorrected and BCVA was significantly better than prednisolone [15]. They concluded that difluprednate reduced inflammation, more rapid return of vision and superior at protecting cornea. Administration of difluprednate provides better vision and less corneal oedema as compared with prednisolone.

Wilson ME in his study in paediatric patients (age group 0-3year) found difluprednate to be equally safe and efficient in controlling post cataract surgery inflammation as prednisolone acetate eye drops [16].

Sheppard JD, in his study concluded that difluprednate 0.05% four times daily is equivalent to prednisolone acetate 1% eight times daily in management of intra ocular inflammation in endogenous anterior uveitis [17].

M Bartin in his study concluded that both difluprednate ophthalmic emulsion 0.05% as well as prednisolone Acetate 1% ophthalmic suspension are equally safe and effective in controlling postoperat ive inflammation after catatract surgery and both the groups achieved best corrected visual acuity of 6/9-6/6 at the end of 4 weeks [18].

In this study, difluprednate was found to have safety profile as prednisolone acetate in all follow-up visits and was well tolerated. Foster CS et al., found that drop concentration of difluprednate emulsion was uniform in patients usage conditions whereas the drop concentration of prednisolone acetate suspension was highly variable [12]. The difluprednate emulsion formulation does not require shaking and delivers constant concentration of active ingredient in each drop. Prednisolone acetate requires shaking before every instillation. Study conducted by Stringer W and Bryant R showed the amount of drug delivered by prednisolone acetate suspension is variable [19].

In our study we evaluated parameters of anterior segment inflammation only. Other factors like Corneal oedema, Posterior segment manifestations of intraocular inflammation like vitritis, macular oedema depicted as increase in macular thickness were not evaluated.

There is no statistically difference in efficacy of difluprednate 0.05% ophthalmic emulsion and prednisolone acetate 1% ophthalmic suspension in treating post cataract surgery intra-ocular inflammation. Though prednisolone acetate has been the gold standard anti- inflammatory agent difluprenate ophthalmic emulsion is equally effective as 1% prednisolone acetate ophthalmic suspension in treatment of post-operative inflammation. Difluprednate have added an advantage of uniform drug dosage and absence of harmful preservative. From the observations seen in this study it is concluded that difluprednate is a new topical corticosteroid with efficient anti-inflammatory properties with ideal formulation for easy usage for patients.